You DON'T install the bearings before O.D. Grinding. Also, your bearing bores should have been machined undersized and ground to finish AFTER heat Treating. They more than likely have changed size and or distorted during heat treatment. After grinding Bearing I.D.'s, a precision mandrel, (Made specifically for your project), should be used in the bearing bores to O.D. grind the wheel. When completed, then install your bearings.
^what he said! You need to make sure the inner diameter bore for the bearing will give the correct fit for the bearings and will give a precise center point datum to then grind the outer surface concentric. TBH the lads who did the heat treat look well set up to sort it for you if you don’t have the precision grinding equipment.
Russ is spot on! Heat treatment causes all kinds of distortions. Fingers crossed the bores for the bearings were undersized, or that the heat treatment has caused them to shrink.
I thought I was fairly ‘engineering savvy’ but was completely stunned by Wilson Engineering and the things they did in the hardening and tempering processes. What a great bunch of people you have shown us in this series. Amazing! Thanks Dom. Les
Well grinding I have done both on large scale printers it mostly depends on the amount of distortion and allowed tolerance of the finished product. So if you’re happy with the limited amount of distortion from heat treatment do anything other than the polishing process which you will be doing anyway. I do however think that you should consider doing a mild steel version case hardened as this is a much more consistent process and good for large volume production. Really enjoy all of your content if a little sad I am no longer involved with any such projects.
You just don't know what goes on inside places like Wilson, thanks to their generosity in allowing you to film I've learnt a hell of a lot in half an hour, brilliant, thanks Dom👍🏻👍🏻👍🏻👍🏻
Grinding the bore true then the OD should give you perfect concentricity and repeatability. Any future issues will always be from easily replaceable bearings, keep the variables to the wear parts. Only heat treated in ovens so that was great to see.
There's something incredibly British about the processes you showed here, high tech CNC machines in clean rooms, immediately next to, what is basically a shed, with two old geezers in boiler suits preforming alcemy (and I don't mean the Dire Straits album)
And long may it continue. Someone once said, the true genius of the British is that they seem in invent and create incredible things in tatty old sheds. Can't argue with that!!!!
Don’t grind the wheel with the bearings in for 2 reasons: 1, the wheel will be ground to those specific bearings and changing them could cause runout. 2, the risk of grinding dust getting in the bearings and causing premature wear is too high. Great video, really enjoyed seeing the heat treat process.
Exactly this, and use high quality bearings. I would also use rubber sealed bearings. They'll last much better than open bearings in a gritty environment
Also, grind the bearing seats because those dimensions have changed too. Grind them first since there's likely very little material to be removed, set up on mandrel, and grind the outside diameter. Look at induction hardening if you still want to use a hardenable steel.
@@Kurbelweller 2nd sealed bearings, I don't use English Wheels but I doubt the added friction would affect it much compared to the benefit of a dust and grit free race.
I'd suggest asking Wilson Engineering how they'd perform the grinding as they clearly have the experience and expertise, and maybe ask what they'd charge to add grinding onto the end of the heat treatment process as it's likely to cost less than paying for each stage separately. Added value here is if they encounter issues during grinding that originated from the heat treatment stage (eg potential distortion of the inside diameter as commented by others) they can either refine their heat treating process or feedback recommendations re initial manufacture to you. Final thought, it's easy for us 'armchair experts' to make our recommendations, albeit with the very best of intentions. Wilson Engineering will be far more likely to give considered, quality advice as they have their professional reputation to maintain. Great video and fantastic reviving history project!
Absolutely addictive seeing you re-engineer these fantastic tools and the processes involved. These should be shown to kids in school , not everyone is cut out for university, and I’m sure some would be inspired by these videos 👍😊
You may have a problem; the hole for the bearing should have been made undersize to allow for grinding first, to make it round. Then a matching mandrel would be pushed in for the outside to be ground. Hopefully, with it being thick, the heat treatment hasn't affected the shape.
Grind WITHOUT the bearings fitted - Always. If you grid with the bearings in place, there will be movement within the bearing casing. Again, thanks for sharing. From New Zealand. 10/10.
A big thanks to that engineering company for showing you (and us) round and for recording the actual process on your wheel. What a task to take the wheel from the salt bath to the oil bath. Plenty of great comments from this forum. I do wonder why it needs to be hardened through, it appears the original one weren't. Good luck from Spain!! It's a fantastic series to be following.
I would grind it without the bearing because that would guarantee it 100% true. Play in the bearing is out of your control since you aren't manufacturing that part. Should there be play you could try different manufacturer's because they vary in quality. You could also switch to a conical bearing which is adjustable. Look forward to the next episode. Cheers!!
Dom...I do metal shaping in the US and I make dies for the power hammers we use here. I make them out of S7 and 2D tool steel and typically harden them to 58-60 HRC. The S7 and D2 tool steels are air quenched and much more easily hardened in a vacuum furnace. To make the upper wheel perfectly symmetric and run perfectly true you will need to grind it on centers. The heat treatment causes the steel to expand; therefore, you will have to grind the bearing bore back to size first. This will be the bases for the center grinding of the surface of the wheel. A mandrel should be made to fit the bearing bore with the wheel then mounted on the mandrel and the mandrel place on the centers of the grinder. That way the wheel will run true when mounted on the wheeling machine.
In the future you should leave a grinding allowance in the bores has the bores will distort in heat treatment , Then the bores can be ground and then the wheel can be located on a precision mandrel to grind the outside diameter . Where you are now you should mount the wheel on the best fitting mandrel you can make and grind the outside diameter between centres but do not install the bearings , Hope this helps Regards David
You have hit the mark. I deleted my reply. Your reply is more complete. That extra hole is probably for their mandril to drive the wheel in the grinding process. The setup will be different depending on shop tooling.
As well as the bore possibly distorting in the hardening process it will also not necessarily be the same size as before. That’s why all the machined faces need a grinding allowance adding on before hardening. Cylindrically grinding the wheel in one set up will make sure inner and outer diameters will be true to each other. Also don’t get the bearings anywhere near the grinder as they’ll be knackered in no time with that dust and suds in them.
Ensure your centre hole is clean and to the size you require, then place it on a mandrel and grind your outer surface. Do not try to do it with bearings installed, as with previous comments bearings are replaceable, and if you grind to a bearing that will become the datum, and not a fixed internal surface! Hope that makes sense!
Grinding it in any way is going to reduce the hardness as even though it was red hot before quenching, it won't harden consistently throughout the thickness of the material. An alternate approach. Create a mildly hard inner wheel but with a super hard tyre, like on a train wheel but in this case where the inner is pre-shrunk in liquid nitrogen and placed in the middle of the tyre, it expands as it warms up and grips hard. That way you can get the hardness probably more than you need on a thinner tyre which when ground is still at least as hard as you need and when the inner is shrunk in, will ensure concentricity. Hope that makes sense, just a thought.
Looking good there, Dom... Thought for you though. Obviously you're not likely to make thousands of these, but it does look like you'll send up making several Ranalah machines... I'd suggest stamping or engraving EACH part of EACH complete Ranalah with it's serial number, so you know which part was made specifically for each frame. It'll also give you a better way to trace any part needing to be repaired or replaced. Tolerances might be fairly tight, so it'll enable you to recreate more accurately if needed...
EN24 (Or 817M40 as we are now meant to call it) responds well to nitride hardening. That does not introduce distortion, and might be a better bet here as it would mean that no post-treatment grinding was needed. If you do decide to grind, then I would grind on a mandrel, and trust the bearings to be concentric. It is, after all, their job. Actually, even though I use EN24 for almost everything, it might not be the best choice here. You might be better off with a (cheaper) dedicated case-harding or nitride-hardening steel. You don't need a _strong_ stee, the wheel is lightly loaded on compression. What you need is a hard surface on the wheel. Oh, and to answer a question you didn't exactly ask... EN24 (all the EN steels) were invented in 1941. The Emergency Numbers were a set of steels aimed at rationalising the many proprietary steels from all the different manufacturers and also economisong on alloying elements as most pre-war steels were over-alloyed for sales reasons.
I love seeing these old workshops with equipment that goes back 50 or 60 years. This Ranalah journey is fascinating. Thanks Dom and the guys at Wilson Tool.
I am the least ‘engineery’ person in the world, but nonetheless I get a warm fuzzy feeling when I see the skill and precision which exists to produce items like that top wheel. Heartwarming 😊
I keep getting Google ads for wheeling machines they look pants at £400. It makes me cry, I daily see lovely bits of British Engineering weighed in for scrap, it's criminal keep up the good work Dom!
Dom, Great video; thank you. As others have commented the bearing recesses should have been machined undersize so they can be ground to size and circular. The outer is then ground relative to the bearing recess. If the bearing recess distorts and you don’t true it up you’ll get premature wear and bearing failure. Had this in the past with a Triumph 2000 rear hub which I had to regrind true before fitting replacement bearing !! Remember that a case hardened softer steel will be more durable and less likely to fracture. Suggest you leave the sides of the top wheel oil black like the unground and unpainted parts of the Myford Super 7 lathe in the barn.
I agree with the comments about grinding the bore first, then using that as a reference for grinding the working surface. Given the expertise at Wilson Eng. I would think they could give you the best advice.
I remember seeing some of those techniques when I was an apprentice 45 years ago, also the birth of CNC tools. Your series has given me a warm feeling please keep it coming. Thanks 👍🥸
No don’t use the installed bearing inner ring as a reference, use the machined bearing outer face as a location reference. You may need to grind the bearing inner mounting face, assuming a grinding allowance was left on, to ensure that when grinding the wheels outer face it is concentric to the inner.
I am in total agreement with many comments that say, do NOT fit the bearing prior to grinding, and grind OD from the bore sitting on a ground precision fit mandrel, another great video Dom !!!
Grind the wheels without the bearings in. That would be the way that I would do it. Another fantastic and education video. Brilliant to see engineering firms with true skill still going strong
I would make the bore for the bearing undersize so it could be ground first to the correct size for the bearing after heat treatment. Then mount the wheel in the grinder using the bore with a mandrel. Then grind the outer diameter to size. It would take very little material to be removed as you would have held the wheel by the outer diameter to grind the bore.
Fascinating. Every day is indeed a school day. I had no idea about immersing in a hot salt bath for hardening. I always assumed it was just an oven. Thanks 👍
Normally, when grinding a workpiece like your wheel, I start with a bit of extra "meat" on both the ID and OD, then chuck the OD on a rotary fixture plate in the grinder and grind the ID to dimension. Second op mount the now clean ID on a mandrel and grind the OD to dimension. Verify the ID then measure the radial dimension difference at multiple points. Job done.
The part will grow slightly after hardening and the bearings need to have the right fit for a long happy life, so I would start by grinding the bearing housings then fitting a mandrel between dead centres on a cylindrical grinder and drive the part on the mandrel via a dog to the tapped hole on the side. Great episode, Thanks !
Makes the bearings on my 3D printer look a bit puny 🙂. Fascinating insight into the heat treatment world. I had no idea. I'm not a machinist but instinct tells me to leave the bearing out of the equation as they are variable and will be replaced at some point. Good luck.
Bores would be precision ground for the bearing pockets first then a precision centering mandrel would be used in the now concentric breaking bores and the outer diameter ground true to the bearing bore. As the whole wheel has been hardened and tempered rather than mild steel wheel being case hardened, your tolerances for the press fit of the bearings into the bore will need to be very accurate as you need the wheel material to "yield" to accommodate the bearing outer race which will be harder than the wheel and not the other way around or you will deform the bearing race and get increased wear and rough bearings. As the wheel is now hard there will be less yield say compared to a mild steel so the difference in size between the bearing outer race and bore inside diameter of the wheel will need to be a reduced interference fit or press fit. Brilliant documenting of the journey and many thanks for keeping a fabulous tradition alive. Andy
I can’t help you Dom, electronics was my thing. That process was amazing! I’d no idea how stuff was hardened and tempered etc. It’s great seeing how it is done, so thank you Dom for sharing and letting us see how it’s done.
I would suggest working with Wilson tooling and their suggestions. Its been many years since I worked as a toolmaker. Depending on the type of material, we would leave 0.2 to 0.5mm per side for heat treatment. Nitriding doesn't require this amount but it can still move. Sometimes Nitriding will move a certain amount per thickness. This can be calculated fairly accurately. With oil quenching the material will loose size when it scales, but it may also increase in size as the grain changes. Each alloy can vary greatly and experience in each alloy is invaluable. Some alloys will require rough machining, stress relieving in an oven, finish machining, heat treatment, then grinding. I'm enjoying the videos and looking forward to your Ranalah revival products.
Grind without bearing, inner, then outer to get it concentric. Hopefully there's enough meat to still achieve the fit of the bearing, or it's SKF catalogue research time 😀
Hi, I am not a trained machinist. I have thought this out. 1. You have at least 4 variables. Bearings, wheel after hardening, axel and the assembly mount. 2. I would using a surface plate measure the dimensions of all the components you can. 3. Vernia caliper all shafts and bores. 4. Match up as near as possible into sets. 5. Take a set and put them together. Ensuring a fit without any alinement problems. Adjust to suit grinding, milling and turning. 6. Mark number them as a set. Sell them as one. There is no guarantee that your new ones will fit an old machine. 7. I know as an Engineer you require as near to perfection as possible. But consider this, you are making a machine that realies upon hand and eye skills honed (No pun intended) over many hours of practice and use. It therefore follows that every " finnished" part will be slightly different from the last. That is why hand built is better than CNC. Tolerances can be relaxed just a bit to suit, perhaps? Great job so far, can't wait to see the next.
Hi Dom, Take the wheel to a grinding shop they will mount it on a mandrel and grind it true, this will accommodate bearing changes in the future. You also need to establish sound processes going forward when you are making these machines available commercially. These companies your are using will then retain these jigs and fixtures so when you drop of the next component, they already have the tooling to complete your job reducing their costs to you the customer. On the matter of the washer that holds the top wheel in place, please give that some serious thought! Although nothing was done to it on the original machine, it does not mean it cannot be done now. This disk, (I think) needs to advertise your business and at least have the relevant contact details for people with existing machines, so they can get in touch for replacement parts, or for others to source the complete machine. Do not lose this opportunity. Another great video, your excitement is contagious. Look forward to the next video as the wheeling machine nears completion. Regards a fan from Aus.
Dominic love your channel. It's great to see companies like Wilson they are a real treasure. While looking at this instalment I was thinking about the approach used by the railways using relatively thin hardend steel rims 'tires' on the wheels. This approach obviously makes the hardening process much easier. I wonder what Wilson would think of this approach.
If you grind with the bearings installed, which will be built to tolerances you then add the bearing errors onto your grinding error. I would be inclined to grind without the bearings and the result should be more repeatable.
I know you said you learnt the hard way Dom but the Ranalah project for you is one big learning curve so everything after is plain sailing g for all future parts. We'll done mate must admire your patience 👍🏻👍🏻👌👌
This really gave me a better appreciation of outsourcing part creations. So much to consider and so much to go wrong. I'm so use to just myself to blame and small jobs to remake or repair, but I've recently started messing with ideas that I can't produce and started considering outsourcing some of the work. Thanks for your story. I wish you all the best and look forward to your Ranalah back in order.
Brilliant coverage of the process, thank you for sharing the journey. Please don’t put the bearing race in to reface, all your tolerances would be thrown out as it wasn’t originally machined with the bearing in and of course you definitely don’t want to contaminate the bearing. Again brilliant stuff. Regards Frank.
As to your question, bearings are precision-ground inside and out so they run concentric with themselves. Thus, as long as you're using quality bearings, you only need to focus on making very sure that the wheel's inner and outer diameters are concentric to one another. As long as you have the wheel running true, when you press the bearings in.... they'll also run true.. and your axle will be concentric to the wheel's outer diameter. Any company that's grinding for a living will know how to make a shaft to hold the wheel while it's being ground. No worries on that front.
I'd add a couple of points: 1. Bearings are available in different tolerance grades (search ABEC). 2. Bearings may feel "loose" right out of the box, but will tighten up on installation, because the outer race is squeezed.
I suspect you might have measured through the hardened surface layer unless you measured Micro Vickers, which normally is used for hardness profiles. 55-60 HRC sounds pretty perfect for this I think. Loved the workshop. Cool to see!!
Dominic. Lovely to see some real engineering. The original design would have had to contend with material availability, and possible pressure to get things made for war production but the old guys might have had a couple of good reasons for using a case hardened wheel. 1 easier to machine and make the blank on a manual machine, 2 adequate for the jobs in hand, 3 faster. One other reason to case harden might be that it will leave the inner bore un-touched, and un-distorted, (or at least easily machinable to finished size) allowing the outer surface to be ground using a mandrel (possibly even the same one used to machine the blank) and making it easier to press the bearing with an interference fit, as the body of the wheel will still be elastic. With a fully hardened wheel, any distortion in the inner bore will be difficult to remove without internally grinding, finishing the outer surface will still need a mandrel, but may need one which has been made to size. Also here is a risk that pressing a hard bearing into a hard bore could create a crack if the interference fit is too great, in this case freezing the bearing to contract it might be preferable. ( in the 1940s i'm not sure the availability of cryo nitrogen would have been as easy as today) Just my thoughts.
Dear Dom, I’m a 30+yr design engineer with experience of designing canning machines. As you know all metals have internal stresses that remain in the billet prior to machining. Any heating process will inevitably result in those stresses being changed (not necessarily relieved) that may result in significant dimensional changes. Before you grind the outer diameter of your wheel you will need to assess the relative concentricity of the bearing bore to the outer diameter and the relative alignment and dimensions of bores to each other. Through hardening EN24 can result in significant dimensional growth (especially if you have a narrow tolerance for the press-fit of your bearings). Do not grind the outer diameter with the bearings installed as the deep groove bearings will have a significant run out or ‘float’. Also, and this may be too late, can I suggest replacing the ball bearings with a pair of opposed tapered roller bearings that can be thrust adjusted to maintain better concentricity in use without the ball bearing float. So, in conclusion, it may be necessary to grind the bearing bores true before using them to grind the outer diameter of the wheel. Good luck, Mike
That 56Rc is the practical maximum for your EN24 steel (AISI 4340 to me), maybe even a little high for a high pressure application as I would imagine a wheeling would apply. If the surface is really hard you might get some spalling if there's a small local stress such as a grain of sand being rolled accidentally. I'm actually impressed that they were able to maintain that high a surface hardness, I make dies from 4140 (a very similar steel) and am happy when I hit 60Rc pre-relief. Definitely manufacture undersized in the bore and gring in the bearing seat, then mount on a precision arbor to grind in the profile on the outside. You'll want to use ABEC 5 or better bearings (about a DIN P4?) for minimum runout, a cheaper bearing will eliminate all the grinding work with low precision
Yeah, that 60 Rockwell out of the salt pot will be brittle as glass, and 56 is an awfully hard temper to take it down to. Even taking it down to 50 or 52 will improve the toughess a lot and it still shouldn't get all scratched up. Hardness isn't everything.
That was SO interesting. Another fascinating and educational excursion into a world I know absolutely nothing about. I could watch this sort of thing all day though! The last thing I was expecting was to see that precious component lowered into the equivalent of an active volcano ...
As a design engineer who also has his own machine shop to play in, I am loving this series! Grind the bore true after hardening and then grind the OD to get perfect concentricity between bearing housing and wheel (the bearing housing should have been turned slightly under sized before heat treatment)
You would not want the bearing in place during grinding. Even the bearing isn't 100% true. Also, because the original wheel was case hardened, you will want to have your friend with the English Wheel test your new main wheel. It will react differently from the original case hardened wheel. Think about how the case hardening only affects the surface and the remainder of the wheel is softer, this would allow for the softer material to act as a cushion during use. This may or may not positively or negatively affect the operation of the new fully hardened wheel.
As far as grinding goes, mount the wheel on a mandrel, and grind between centres for true concentric. Bearing slip will mean the ground surface may mirror any slip.
Really interesting to see the heat treating process with the lava crucible. Maybe use a sacrificial bearing for grinding then replace for the finished top wheel.
Shame you didn't live near a volcano. Thanks for the insight into hardening steel because I really had no idea and was surprised how long it took. Clever stuff.
My opinion Dom.......I would grind the inside diameter where the bearings go.........then I would grind the outside diameter.........worry about the bearings later.
I’m not an engineer but I have been watching this series with interest, especially as I have also been watching the series on TH-cam by Neville Wheeldon which has documented the use of wheeling machines in the restoration to airworthy of the Avro Lancaster at East Kirkby. Also great to see the ICI logo on the furnace. Where would find another piece of industrial kit like this today?
Hi Dom Don't grind the roller with the bearings installed: a) you will introduce grinding dust in to the bearing, severely limiting it's life b) the wheel will only be concentric to that set of bearings, change the bearings and the wheel will run out. Great vids, keep 'em coming! thanks
Thanks Dom, that was very interesting. heat treatment went a bit over my head at college. I can see why that is a restricted area. I have read the comments re the grinding and I hope your bores are ok. All the best, Mart in Solihull.
Just found your channel following links from The Repair Shop. So nice to have more detailed explanations and demo stuff as (by necessity) all the nitty gritty is lost in production.
The wheel should be ground true to itself and its inner bore. The bearings are a wear item that can & may be changed in the future .. and the quality of the replacement bearings is not a given fact. So long as your wheel it true to itself, then it is true to its design and not relying on third party equipment for it's performance. That's how I see it. Thanks for sharing 🇨🇦
go with the thought of creating each part as accurately as posssible because if there is a variation in the bearing it will be changed with each new bearing you install effectively changing the integrity of the wheel every time you change bearings....if its pecisely round without the bearing you have a given set point to work from. and also if the bearing is wonky you know immediately that you need a different bearing because the wheel is manufactured true. Cracking video ..I want one of these so much...I dont think for a minute I could afford it but....... I feel like Scrat trying to get his acorn ;)
Hi Dom, I'm not an engineer, but it would seem more sensible to grind the wheel on some kind of jig, where you, as the builder, decide true centers etc, rather than relying on the Ranalah's bearing/boring for bearing, which may or may not be running true. Also I would guess that the originals were made off the frames, but you have experienced old machines, used by masters. Those guys are the ones to trust. Thank you for sharing, I really love everything you do and The Repair Shop, you folks really give me a solid grounding in these crazy, scary times. Make things not war right. Big Love. P
Normal for through (or carbourised)hardened parts you leave a few thou on critical surfaces for grinding. As you have not done this you may find your bearing bore clearance has changed. You may get away with it. An alternative in the future is nitriding, which means you do not need post grind. Your best bet for this part is to measure the bores for roundness, clean up with an id grinder if required and the od grind to a mandrel. You can reuse this mandrel for future wheels.
I have no experience or knowledge on any of this but wow do i learn a lot. People must think i’m crazy but this IT lady like this a bit to much (and if i was in the uk i would surely go to the scramble) oww I’m jealous!!! Much ❤️ from 🇳🇱
Caveat IM NOT AN ENGINEER, but in my head if you grind it centred on the baring wall rather than the baring, then if the baring ever gets damaged then replacing the baring wouldn't mean re-grinding the wheel... like I said, not an engineer, but just throwing a thought in based on *some logic 😬
Stunning process Dom. Absolutely loving it! I would never install bearings before grinding. If bearing fails, you'd replace it and what then. Also simply reinstalling the same bearing as you had to pull it apart for whatever obscure reason, bearing would have to go back in identically. Just grind based on bearing face, then buy as good a bearing as you can...
I would say reverse the chuck jaws to expand into the bearing housing and then it will be concentric with the bearing housing. That way you are not relying on the bearings being perfect. If you have problems with a bearing, it should be solved by swapping out the faulty bearing. You need to be sure that the bearing housings are perfect first of course!
Install precision buttons into the bearing cavities before grinding outer service. Ideally the bearing cavities would be turned under size and then ground for bearing tolerance. Thoughts for further wheels.
Agree with Russ Uhls below, an adapter that can center the wheel in a lathe, basically like the bearing dust cover piece you showed but thicker to include bearings OD but slightly smaller so it can be removed without a lot of heating and press work is essential to getting a good concentric wheel. Because it was such a thick piece, the OD and ID for bearing should not have changed significantly and may need only polishing surfaces rather than grinding. You don't have to make the wheels OD extremely exact in it's finished diameter, just concentric and true so it maintains a specific tolerance for compressing metal consistently. Get the bearings chilled in liquid nitrogen to get a minimum size for press fitting in the wheel at room temps... I'm presuming the wheel won't be heated again for bearing install due to intensive heat treatment process needing to be maintained. If necessary the bearing's OD can be modified to fit or re-specced to fit accurately. They are intended to be replaceable after all...
Thank you for the video and update Dom. Sorry no suggestions as far as order of operation but I wouldn’t use the bearing to support the wheel while grinding the outside. Just my .02 worth
You DON'T install the bearings before O.D. Grinding. Also, your bearing bores should have been machined undersized and ground to finish AFTER heat Treating. They more than likely have changed size and or distorted during heat treatment. After grinding Bearing I.D.'s, a precision mandrel, (Made specifically for your project), should be used in the bearing bores to O.D. grind the wheel. When completed, then install your bearings.
^what he said! You need to make sure the inner diameter bore for the bearing will give the correct fit for the bearings and will give a precise center point datum to then grind the outer surface concentric.
TBH the lads who did the heat treat look well set up to sort it for you if you don’t have the precision grinding equipment.
@@Jimbotube1980 agreed
You knew it.We knew it.Guess Dom didn't.Whoever turned it or drew it up might have asked the question.
Russ is spot on! Heat treatment causes all kinds of distortions. Fingers crossed the bores for the bearings were undersized, or that the heat treatment has caused them to shrink.
I thought I was fairly ‘engineering savvy’ but was completely stunned by Wilson Engineering and the things they did in the hardening and tempering processes. What a great bunch of people you have shown us in this series. Amazing! Thanks Dom. Les
Well grinding I have done both on large scale printers it mostly depends on the amount of distortion and allowed tolerance of the finished product. So if you’re happy with the limited amount of distortion from heat treatment do anything other than the polishing process which you will be doing anyway. I do however think that you should consider doing a mild steel version case hardened as this is a much more consistent process and good for large volume production. Really enjoy all of your content if a little sad I am no longer involved with any such projects.
You just don't know what goes on inside places like Wilson, thanks to their generosity in allowing you to film I've learnt a hell of a lot in half an hour, brilliant, thanks Dom👍🏻👍🏻👍🏻👍🏻
Even now, as a retired engineer, I’m still in awe of machinists who know their machines inside out and can perform ‘miracles’.
Grinding the bore true then the OD should give you perfect concentricity and repeatability. Any future issues will always be from easily replaceable bearings, keep the variables to the wear parts.
Only heat treated in ovens so that was great to see.
There's something incredibly British about the processes you showed here, high tech CNC machines in clean rooms, immediately next to, what is basically a shed, with two old geezers in boiler suits preforming alcemy (and I don't mean the Dire Straits album)
And long may it continue. Someone once said, the true genius of the British is that they seem in invent and create incredible things in tatty old sheds. Can't argue with that!!!!
Don’t grind the wheel with the bearings in for 2 reasons:
1, the wheel will be ground to those specific bearings and changing them could cause runout.
2, the risk of grinding dust getting in the bearings and causing premature wear is too high.
Great video, really enjoyed seeing the heat treat process.
Exactly this, and use high quality bearings.
I would also use rubber sealed bearings. They'll last much better than open bearings in a gritty environment
Also, grind the bearing seats because those dimensions have changed too. Grind them first since there's likely very little material to be removed, set up on mandrel, and grind the outside diameter. Look at induction hardening if you still want to use a hardenable steel.
@@Kurbelweller 2nd sealed bearings, I don't use English Wheels but I doubt the added friction would affect it much compared to the benefit of a dust and grit free race.
@@Kurbelweller Good Idea (would you chill the bearings before fitting to assist dropping in place)
@@tombier9170 Yeah I was thinking this. Could you hone out the bore and then mandrel grind the running surface and the radius?
I'd suggest asking Wilson Engineering how they'd perform the grinding as they clearly have the experience and expertise, and maybe ask what they'd charge to add grinding onto the end of the heat treatment process as it's likely to cost less than paying for each stage separately. Added value here is if they encounter issues during grinding that originated from the heat treatment stage (eg potential distortion of the inside diameter as commented by others) they can either refine their heat treating process or feedback recommendations re initial manufacture to you. Final thought, it's easy for us 'armchair experts' to make our recommendations, albeit with the very best of intentions. Wilson Engineering will be far more likely to give considered, quality advice as they have their professional reputation to maintain. Great video and fantastic reviving history project!
If Wilson do the grinding then no opportunity for finger pointing between heat-treater and grinder if it goes pear shaped.
Absolutely addictive seeing you re-engineer these fantastic tools and the processes involved. These should be shown to kids in school , not everyone is cut out for university, and I’m sure some would be inspired by these videos 👍😊
You may have a problem; the hole for the bearing should have been made undersize to allow for grinding first, to make it round. Then a matching mandrel would be pushed in for the outside to be ground. Hopefully, with it being thick, the heat treatment hasn't affected the shape.
Grind WITHOUT the bearings fitted - Always. If you grid with the bearings in place, there will be movement within the bearing casing.
Again, thanks for sharing. From New Zealand. 10/10.
A big thanks to that engineering company for showing you (and us) round and for recording the actual process on your wheel. What a task to take the wheel from the salt bath to the oil bath.
Plenty of great comments from this forum. I do wonder why it needs to be hardened through, it appears the original one weren't.
Good luck from Spain!!
It's a fantastic series to be following.
I would grind it without the bearing because that would guarantee it 100% true. Play in the bearing is out of your control since you aren't manufacturing that part. Should there be play you could try different manufacturer's because they vary in quality. You could also switch to a conical bearing which is adjustable. Look forward to the next episode. Cheers!!
Dom...I do metal shaping in the US and I make dies for the power hammers we use here. I make them out of S7 and 2D tool steel and typically harden them to 58-60 HRC. The S7 and D2 tool steels are air quenched and much more easily hardened in a vacuum furnace. To make the upper wheel perfectly symmetric and run perfectly true you will need to grind it on centers. The heat treatment causes the steel to expand; therefore, you will have to grind the bearing bore back to size first. This will be the bases for the center grinding of the surface of the wheel. A mandrel should be made to fit the bearing bore with the wheel then mounted on the mandrel and the mandrel place on the centers of the grinder. That way the wheel will run true when mounted on the wheeling machine.
In the future you should leave a grinding allowance in the bores has the bores will distort in heat treatment , Then the bores can be ground and then the wheel can be located on a precision mandrel to grind the outside diameter . Where you are now you should mount the wheel on the best fitting mandrel you can make and grind the outside diameter between centres but do not install the bearings , Hope this helps Regards David
You have hit the mark. I deleted my reply. Your reply is more complete. That extra hole is probably for their mandril to drive the wheel in the grinding process. The setup will be different depending on shop tooling.
As well as the bore possibly distorting in the hardening process it will also not necessarily be the same size as before. That’s why all the machined faces need a grinding allowance adding on before hardening. Cylindrically grinding the wheel in one set up will make sure inner and outer diameters will be true to each other. Also don’t get the bearings anywhere near the grinder as they’ll be knackered in no time with that dust and suds in them.
Ensure your centre hole is clean and to the size you require, then place it on a mandrel and grind your outer surface. Do not try to do it with bearings installed, as with previous comments bearings are replaceable, and if you grind to a bearing that will become the datum, and not a fixed internal surface! Hope that makes sense!
As a blacksmith I found that segment on hardening and tempering fascinating,
The chemicals ay.. molten lava
Grinding it in any way is going to reduce the hardness as even though it was red hot before quenching, it won't harden consistently throughout the thickness of the material.
An alternate approach. Create a mildly hard inner wheel but with a super hard tyre, like on a train wheel but in this case where the inner is pre-shrunk in liquid nitrogen and placed in the middle of the tyre, it expands as it warms up and grips hard. That way you can get the hardness probably more than you need on a thinner tyre which when ground is still at least as hard as you need and when the inner is shrunk in, will ensure concentricity.
Hope that makes sense, just a thought.
Maybe the original was made with a hard tyre to start with?
@@spamhead there did appear to be a lip on it but that could just be machining. X-ray it or ultrasound would show.
Looking good there, Dom... Thought for you though. Obviously you're not likely to make thousands of these, but it does look like you'll send up making several Ranalah machines... I'd suggest stamping or engraving EACH part of EACH complete Ranalah with it's serial number, so you know which part was made specifically for each frame. It'll also give you a better way to trace any part needing to be repaired or replaced. Tolerances might be fairly tight, so it'll enable you to recreate more accurately if needed...
EN24 (Or 817M40 as we are now meant to call it) responds well to nitride hardening. That does not introduce distortion, and might be a better bet here as it would mean that no post-treatment grinding was needed.
If you do decide to grind, then I would grind on a mandrel, and trust the bearings to be concentric. It is, after all, their job.
Actually, even though I use EN24 for almost everything, it might not be the best choice here. You might be better off with a (cheaper) dedicated case-harding or nitride-hardening steel.
You don't need a _strong_ stee, the wheel is lightly loaded on compression. What you need is a hard surface on the wheel.
Oh, and to answer a question you didn't exactly ask... EN24 (all the EN steels) were invented in 1941. The Emergency Numbers were a set of steels aimed at rationalising the many proprietary steels from all the different manufacturers and also economisong on alloying elements as most pre-war steels were over-alloyed for sales reasons.
That is interesting as Ranelagh were in production BEFORE 1941
@@highpath4776 Yes, but he already mentioned that Ranelagh didn't use EN24.
@@andypughtube Of course if the company had considered it useful by the time it was introduced they may well have swapped to it.
I've always thought the best engineering happens in the least imposing buildings. Great to see such knowledge is kept burning bright at Wilsons.
I love seeing these old workshops with equipment that goes back 50 or 60 years. This Ranalah journey is fascinating. Thanks Dom and the guys at Wilson Tool.
I am the least ‘engineery’ person in the world, but nonetheless I get a warm fuzzy feeling when I see the skill and precision which exists to produce items like that top wheel. Heartwarming 😊
My engineery skills stop at my bicyle but i like this podcast so much
I keep getting Google ads for wheeling machines they look pants at £400. It makes me cry, I daily see lovely bits of British Engineering weighed in for scrap, it's criminal keep up the good work Dom!
Dom,
Great video; thank you.
As others have commented the bearing recesses should have been machined undersize so they can be ground to size and circular. The outer is then ground relative to the bearing recess. If the bearing recess distorts and you don’t true it up you’ll get premature wear and bearing failure. Had this in the past with a Triumph 2000 rear hub which I had to regrind true before fitting replacement bearing !!
Remember that a case hardened softer steel will be more durable and less likely to fracture.
Suggest you leave the sides of the top wheel oil black like the unground and unpainted parts of the Myford Super 7 lathe in the barn.
I agree with the comments about grinding the bore first, then using that as a reference for grinding the working surface. Given the expertise at Wilson Eng. I would think they could give you the best advice.
I remember seeing some of those techniques when I was an apprentice 45 years ago, also the birth of CNC tools. Your series has given me a warm feeling please keep it coming. Thanks 👍🥸
No don’t use the installed bearing inner ring as a reference, use the machined bearing outer face as a location reference.
You may need to grind the bearing inner mounting face, assuming a grinding allowance was left on, to ensure that when grinding the wheels outer face it is concentric to the inner.
I am in total agreement with many comments that say, do NOT fit the bearing prior to grinding, and grind OD from the bore sitting on a ground precision fit mandrel, another great video Dom !!!
Grind the wheels without the bearings in. That would be the way that I would do it.
Another fantastic and education video. Brilliant to see engineering firms with true skill still going strong
I would make the bore for the bearing undersize so it could be ground first to the correct size for the bearing after heat treatment. Then mount the wheel in the grinder using the bore with a mandrel. Then grind the outer diameter to size. It would take very little material to be removed as you would have held the wheel by the outer diameter to grind the bore.
I would grind the bearing seat then grind the OD to that the it should run perfectly true to the bearings.
I think that’s the way I’ll go!
Fascinating. Every day is indeed a school day. I had no idea about immersing in a hot salt bath for hardening. I always assumed it was just an oven. Thanks 👍
Absolutely fascinating. Lava in Essex - who knew.
Normally, when grinding a workpiece like your wheel, I start with a bit of extra "meat" on both the ID and OD, then chuck the OD on a rotary fixture plate in the grinder and grind the ID to dimension. Second op mount the now clean ID on a mandrel and grind the OD to dimension. Verify the ID then measure the radial dimension difference at multiple points. Job done.
The part will grow slightly after hardening and the bearings need to have the right fit for a long happy life, so I would start by grinding the bearing housings then fitting a mandrel between dead centres on a cylindrical grinder and drive the part on the mandrel via a dog to the tapped hole on the side. Great episode, Thanks !
Makes the bearings on my 3D printer look a bit puny 🙂. Fascinating insight into the heat treatment world. I had no idea. I'm not a machinist but instinct tells me to leave the bearing out of the equation as they are variable and will be replaced at some point. Good luck.
Bores would be precision ground for the bearing pockets first then a precision centering mandrel would be used in the now concentric breaking bores and the outer diameter ground true to the bearing bore. As the whole wheel has been hardened and tempered rather than mild steel wheel being case hardened, your tolerances for the press fit of the bearings into the bore will need to be very accurate as you need the wheel material to "yield" to accommodate the bearing outer race which will be harder than the wheel and not the other way around or you will deform the bearing race and get increased wear and rough bearings. As the wheel is now hard there will be less yield say compared to a mild steel so the difference in size between the bearing outer race and bore inside diameter of the wheel will need to be a reduced interference fit or press fit.
Brilliant documenting of the journey and many thanks for keeping a fabulous tradition alive.
Andy
I can’t help you Dom, electronics was my thing. That process was amazing! I’d no idea how stuff was hardened and tempered etc.
It’s great seeing how it is done, so thank you Dom for sharing and letting us see how it’s done.
I would suggest working with Wilson tooling and their suggestions. Its been many years since I worked as a toolmaker. Depending on the type of material, we would leave 0.2 to 0.5mm per side for heat treatment. Nitriding doesn't require this amount but it can still move. Sometimes Nitriding will move a certain amount per thickness. This can be calculated fairly accurately. With oil quenching the material will loose size when it scales, but it may also increase in size as the grain changes. Each alloy can vary greatly and experience in each alloy is invaluable. Some alloys will require rough machining, stress relieving in an oven, finish machining, heat treatment, then grinding.
I'm enjoying the videos and looking forward to your Ranalah revival products.
First comment!! So glad you kept the Witworth Threads! I love me some BSW and lament folks giving it up.
Grind without bearing, inner, then outer to get it concentric. Hopefully there's enough meat to still achieve the fit of the bearing, or it's SKF catalogue research time 😀
Hi, I am not a trained machinist. I have thought this out.
1. You have at least 4 variables. Bearings, wheel after hardening, axel and the assembly mount.
2. I would using a surface plate measure the dimensions of all the components you can.
3. Vernia caliper all shafts and bores.
4. Match up as near as possible into sets.
5. Take a set and put them together. Ensuring a fit without any alinement problems. Adjust to suit grinding, milling and turning.
6. Mark number them as a set. Sell them as one. There is no guarantee that your new ones will fit an old machine.
7. I know as an Engineer you require as near to perfection as possible. But consider this, you are making a machine that realies upon hand and eye skills honed (No pun intended) over many hours of practice and use. It therefore follows that every " finnished" part will be slightly different from the last. That is why hand built is better than CNC. Tolerances can be relaxed just a bit to suit, perhaps?
Great job so far, can't wait to see the next.
Hi Dom, Take the wheel to a grinding shop they will mount it on a mandrel and grind it true, this will accommodate bearing changes in the future. You also need to establish sound processes going forward when you are making these machines available commercially. These companies your are using will then retain these jigs and fixtures so when you drop of the next component, they already have the tooling to complete your job reducing their costs to you the customer. On the matter of the washer that holds the top wheel in place, please give that some serious thought! Although nothing was done to it on the original machine, it does not mean it cannot be done now. This disk, (I think) needs to advertise your business and at least have the relevant contact details for people with existing machines, so they can get in touch for replacement parts, or for others to source the complete machine. Do not lose this opportunity. Another great video, your excitement is contagious. Look forward to the next video as the wheeling machine nears completion. Regards a fan from Aus.
Dominic love your channel. It's great to see companies like Wilson they are a real treasure. While looking at this instalment I was thinking about the approach used by the railways using relatively thin hardend steel rims 'tires' on the wheels. This approach obviously makes the hardening process much easier. I wonder what Wilson would think of this approach.
If you grind with the bearings installed, which will be built to tolerances you then add the bearing errors onto your grinding error. I would be inclined to grind without the bearings and the result should be more repeatable.
I know you said you learnt the hard way Dom but the Ranalah project for you is one big learning curve so everything after is plain sailing g for all future parts. We'll done mate must admire your patience 👍🏻👍🏻👌👌
This really gave me a better appreciation of outsourcing part creations. So much to consider and so much to go wrong. I'm so use to just myself to blame and small jobs to remake or repair, but I've recently started messing with ideas that I can't produce and started considering outsourcing some of the work. Thanks for your story. I wish you all the best and look forward to your Ranalah back in order.
Nice to see equipment from the old ICI Cassel Works still being used.
Dom this is all so exciting to watch, half of what is going on I have no clue about, but love seeing there things are learning at the same time
Brilliant coverage of the process, thank you for sharing the journey. Please don’t put the bearing race in to reface, all your tolerances would be thrown out as it wasn’t originally machined with the bearing in and of course you definitely don’t want to contaminate the bearing. Again brilliant stuff. Regards Frank.
Thank you no I think we will do it without the bearing
As to your question, bearings are precision-ground inside and out so they run concentric with themselves. Thus, as long as you're using quality bearings, you only need to focus on making very sure that the wheel's inner and outer diameters are concentric to one another. As long as you have the wheel running true, when you press the bearings in.... they'll also run true.. and your axle will be concentric to the wheel's outer diameter. Any company that's grinding for a living will know how to make a shaft to hold the wheel while it's being ground. No worries on that front.
I'd add a couple of points:
1. Bearings are available in different tolerance grades (search ABEC).
2. Bearings may feel "loose" right out of the box, but will tighten up on installation, because the outer race is squeezed.
I suspect you might have measured through the hardened surface layer unless you measured Micro Vickers, which normally is used for hardness profiles. 55-60 HRC sounds pretty perfect for this I think. Loved the workshop. Cool to see!!
I would grind the wheel without the bearing, because of the fact of the delicate bearing, YOU WILL GET A BETTER PRODUCT
Agree with below, don't fit the bearings until the roller is finished. Your video's are entertaining and interesting.
Dominic. Lovely to see some real engineering.
The original design would have had to contend with material availability, and possible pressure to get things made for war production but the old guys might have had a couple of good reasons for using a case hardened wheel. 1 easier to machine and make the blank on a manual machine, 2 adequate for the jobs in hand, 3 faster.
One other reason to case harden might be that it will leave the inner bore un-touched, and un-distorted, (or at least easily machinable to finished size) allowing the outer surface to be ground using a mandrel (possibly even the same one used to machine the blank) and making it easier to press the bearing with an interference fit, as the body of the wheel will still be elastic.
With a fully hardened wheel, any distortion in the inner bore will be difficult to remove without internally grinding, finishing the outer surface will still need a mandrel, but may need one which has been made to size.
Also here is a risk that pressing a hard bearing into a hard bore could create a crack if the interference fit is too great, in this case freezing the bearing to contract it might be preferable. ( in the 1940s i'm not sure the availability of cryo nitrogen would have been as easy as today)
Just my thoughts.
Dear Dom, I’m a 30+yr design engineer with experience of designing canning machines. As you know all metals have internal stresses that remain in the billet prior to machining. Any heating process will inevitably result in those stresses being changed (not necessarily relieved) that may result in significant dimensional changes. Before you grind the outer diameter of your wheel you will need to assess the relative concentricity of the bearing bore to the outer diameter and the relative alignment and dimensions of bores to each other. Through hardening EN24 can result in significant dimensional growth (especially if you have a narrow tolerance for the press-fit of your bearings). Do not grind the outer diameter with the bearings installed as the deep groove bearings will have a significant run out or ‘float’. Also, and this may be too late, can I suggest replacing the ball bearings with a pair of opposed tapered roller bearings that can be thrust adjusted to maintain better concentricity in use without the ball bearing float. So, in conclusion, it may be necessary to grind the bearing bores true before using them to grind the outer diameter of the wheel. Good luck, Mike
Thanks Mike I really appreciate it! I will have to check the original wheel with original bearings to see how round it actually is!
That 56Rc is the practical maximum for your EN24 steel (AISI 4340 to me), maybe even a little high for a high pressure application as I would imagine a wheeling would apply. If the surface is really hard you might get some spalling if there's a small local stress such as a grain of sand being rolled accidentally. I'm actually impressed that they were able to maintain that high a surface hardness, I make dies from 4140 (a very similar steel) and am happy when I hit 60Rc pre-relief.
Definitely manufacture undersized in the bore and gring in the bearing seat, then mount on a precision arbor to grind in the profile on the outside. You'll want to use ABEC 5 or better bearings (about a DIN P4?) for minimum runout, a cheaper bearing will eliminate all the grinding work with low precision
Yeah, that 60 Rockwell out of the salt pot will be brittle as glass, and 56 is an awfully hard temper to take it down to. Even taking it down to 50 or 52 will improve the toughess a lot and it still shouldn't get all scratched up. Hardness isn't everything.
Seeing that salt/lava was amazing. Great that they showed you around and let you show us this process.
That was SO interesting. Another fascinating and educational excursion into a world I know absolutely nothing about. I could watch this sort of thing all day though! The last thing I was expecting was to see that precious component lowered into the equivalent of an active volcano ...
As a design engineer who also has his own machine shop to play in, I am loving this series! Grind the bore true after hardening and then grind the OD to get perfect concentricity between bearing housing and wheel (the bearing housing should have been turned slightly under sized before heat treatment)
I think there will be room to grind the id still, let’s see how much it moves I guess! Thank you
brilliant to see these traditional workshops still working
You would not want the bearing in place during grinding. Even the bearing isn't 100% true.
Also, because the original wheel was case hardened, you will want to have your friend with the English Wheel test your new main wheel. It will react differently from the original case hardened wheel. Think about how the case hardening only affects the surface and the remainder of the wheel is softer, this would allow for the softer material to act as a cushion during use. This may or may not positively or negatively affect the operation of the new fully hardened wheel.
As far as grinding goes, mount the wheel on a mandrel, and grind between centres for true concentric. Bearing slip will mean the ground surface may mirror any slip.
When that came out red hot I was in shock. That’s so wild to watch. I love this whole process from getting the name rights and remaking these.
Love the enthusiasm shown by both yourself & the chaps at Wilson tools well done. 👍
WELL ARD!!
That's all I can say really. I am no engineer but I just love what you are doing.
Really interesting to see the heat treating process with the lava crucible. Maybe use a sacrificial bearing for grinding then replace for the finished top wheel.
Shame you didn't live near a volcano. Thanks for the insight into hardening steel because I really had no idea and was surprised how long it took. Clever stuff.
Thank you! Glad you enjoyed it
Love the show and I'm not an engineer but surely it makes sense to grind with the bearing in as that's how it will be running.
My opinion Dom.......I would grind the inside diameter where the bearings go.........then I would grind the outside diameter.........worry about the bearings later.
I’m not an engineer but I have been watching this series with interest, especially as I have also been watching the series on TH-cam by Neville Wheeldon which has documented the use of wheeling machines in the restoration to airworthy of the Avro Lancaster at East Kirkby. Also great to see the ICI logo on the furnace. Where would find another piece of industrial kit like this today?
I thought it said ICI - got to love a bit of Imperial Chemical Industries!
@ Gordon Bridges, Me too! I'm an avid fan of Neville's documentation of Just Jane's restoration!
Hi Dom
Don't grind the roller with the bearings installed:
a) you will introduce grinding dust in to the bearing, severely limiting it's life
b) the wheel will only be concentric to that set of bearings, change the bearings and the wheel will run out.
Great vids, keep 'em coming! thanks
Great series Dom, we used to quench in whale oil, I'm guessing it's banned these days, good luck bud
Wow what a fascinating process ! When the wheel was glowing ...amazing.
Loving the content.
Thanks Dom, that was very interesting. heat treatment went a bit over my head at college. I can see why that is a restricted area. I have read the comments re the grinding and I hope your bores are ok. All the best, Mart in Solihull.
Dom, fantastic episode in the birth of the next generation of Ranallah. Fascinating to go behind the scenes with you. Great content. Thank you.
Just found your channel following links from The Repair Shop.
So nice to have more detailed explanations and demo stuff as (by necessity) all the nitty gritty is lost in production.
The wheel should be ground true to itself and its inner bore. The bearings are a wear item that can & may be changed in the future .. and the quality of the replacement bearings is not a given fact. So long as your wheel it true to itself, then it is true to its design and not relying on third party equipment for it's performance.
That's how I see it.
Thanks for sharing 🇨🇦
go with the thought of creating each part as accurately as posssible because if there is a variation in the bearing it will be changed with each new bearing you install effectively changing the integrity of the wheel every time you change bearings....if its pecisely round without the bearing you have a given set point to work from. and also if the bearing is wonky you know immediately that you need a different bearing because the wheel is manufactured true.
Cracking video ..I want one of these so much...I dont think for a minute I could afford it but....... I feel like Scrat trying to get his acorn ;)
Hi Dom, I'm not an engineer, but it would seem more sensible to grind the wheel on some kind of jig, where you, as the builder, decide true centers etc, rather than relying on the Ranalah's bearing/boring for bearing, which may or may not be running true. Also I would guess that the originals were made off the frames, but you have experienced old machines, used by masters. Those guys are the ones to trust. Thank you for sharing, I really love everything you do and The Repair Shop, you folks really give me a solid grounding in these crazy, scary times. Make things not war right. Big Love. P
Abject panic at spotting the key in the chuck at 10:15, until sanity arrives a moment later: "dude, it's not a lathe..."
Normal for through (or carbourised)hardened parts you leave a few thou on critical surfaces for grinding. As you have not done this you may find your bearing bore clearance has changed. You may get away with it. An alternative in the future is nitriding, which means you do not need post grind.
Your best bet for this part is to measure the bores for roundness, clean up with an id grinder if required and the od grind to a mandrel. You can reuse this mandrel for future wheels.
I can’t help myself I keep watching it over and over. All episodes
I love seeing the process. Blows my mind.
I have no experience or knowledge on any of this but wow do i learn a lot. People must think i’m crazy but this IT lady like this a bit to much (and if i was in the uk i would surely go to the scramble) oww I’m jealous!!! Much ❤️ from
🇳🇱
Bore grind the bore, mount to mandrel and cylindrical grind the OD then install the bearings.
this series it legendary to watch unfold. thanks for the inspiration, Dom. can't wait to have my own Ranalah in the workshop someday
Caveat IM NOT AN ENGINEER, but in my head if you grind it centred on the baring wall rather than the baring, then if the baring ever gets damaged then replacing the baring wouldn't mean re-grinding the wheel... like I said, not an engineer, but just throwing a thought in based on *some logic 😬
Stunning process Dom. Absolutely loving it! I would never install bearings before grinding. If bearing fails, you'd replace it and what then. Also simply reinstalling the same bearing as you had to pull it apart for whatever obscure reason, bearing would have to go back in identically.
Just grind based on bearing face, then buy as good a bearing as you can...
Grind without the bearings. Bearings and grinding dust are not good bedfellows. Great video Dom.
I would say reverse the chuck jaws to expand into the bearing housing and then it will be concentric with the bearing housing. That way you are not relying on the bearings being perfect. If you have problems with a bearing, it should be solved by swapping out the faulty bearing. You need to be sure that the bearing housings are perfect first of course!
Install precision buttons into the bearing cavities before grinding outer service. Ideally the bearing cavities would be turned under size and then ground for bearing tolerance. Thoughts for further wheels.
Your dedication is really appreciated I so wish I had a use for one of your amazing Ranalahs 👏
That was wonderful to see, those lava pots and the knowledge and skill of those guys is awesome.
They really do know there stuff
Hi Dom That was such an interesting set up in Essex so much variation & tooling.
Excellent video to watch. Take care.
Fascinating Dom, please keep up the video's.
Agree with Russ Uhls below, an adapter that can center the wheel in a lathe, basically like the bearing dust cover piece you showed but thicker to include bearings OD but slightly smaller so it can be removed without a lot of heating and press work is essential to getting a good concentric wheel. Because it was such a thick piece, the OD and ID for bearing should not have changed significantly and may need only polishing surfaces rather than grinding. You don't have to make the wheels OD extremely exact in it's finished diameter, just concentric and true so it maintains a specific tolerance for compressing metal consistently. Get the bearings chilled in liquid nitrogen to get a minimum size for press fitting in the wheel at room temps... I'm presuming the wheel won't be heated again for bearing install due to intensive heat treatment process needing to be maintained. If necessary the bearing's OD can be modified to fit or re-specced to fit accurately. They are intended to be replaceable after all...
Thank you! Appreciate the advice
Thank you for the video and update Dom. Sorry no suggestions as far as order of operation but I wouldn’t use the bearing to support the wheel while grinding the outside. Just my .02 worth
I learnt so much with this video, thanks Dom.