Grinding a Magnetic Chuck Flat for a Surface Grinder
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- เผยแพร่เมื่อ 10 มิ.ย. 2021
- Grinding a Magnetic Chuck
Flat for a Surface Grinder
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I was a little surprised he didn't go to the very ends of the bed.
Keith,
I don't know if you told us the history of this grinder, but it is quite old and has a splash job of paint on it. I suspect that it was gone over by the seller and prettied up for the used market. I also suspect that the seller expected that a sale could be very long pending and that they hoped to protect the exposed table surface from damage. The table was obviously cleaned prior to painting and even the clamps were painted. I suspect that this seller's standard practice is to protect exposed surfaces assuming his buyer is going to properly set up the machine.
When our shop tried to dispose of equipment (grinders) of this vintage, buyers were seemingly impossible to find. Hobbiests like us see the value of this old iron, but are tight on the spendable since grinders have such limited application for general work. Our mills and lathes get much more use, comparitively limiting the amount we will willingly spend on grinders. Any of us who wants a machine like yours drools over the opportunity. Production shops that can afford the spendage are looking for new machines in this class or newer technology. Our shop sold a couple similarly sized machines after paying for years of storage. We essentially gave them away. Some of us employees begged for the opportunity to bring one home, but few of us wanted to pay anything.
My new hobby shop will add 3200 square foot of machining and mechanic space. Trusses are here and wall materials are to be delivered today! This will afford the opportunity to upgrade and expand with new to me machines, but I will upgrade with newer mills and lathes before I purchase a surface grinder. If I purchase a surface grinder that has been protected with primer paint, I will happily clean it off. I might consider chemical paint removal just so I wouldn't unnecessarily load up my grinding wheel.
I used to sell used industrial machinery, and nearly everything got cleaned, sanded, and painted, except for spindle heads and ways and chucks. A coat of paint hides a host of sins.
Always a crucial step for a surface grinder! Can't make parts parallel if the surface they're attached to isn't parallel.
We had a factory rep show us a great way to grind our chucks . He dressed the wheel with a hollow in the center to give us a cool grind and then used Crisco to coat the chuck . Works great .
bottom line is the crisco does nothing nor does it cause harm. chucks must be ground wet is the main thing. course 46 grit and best to use an old smaller wheel so the interface of heat is less. Thats also a good trick for precision grinding parts since people will put on a big new wheel then wonder why the parts burn.
@@jaysilverheals4445 46 G works well with the Crisco on the grinders with out flood cooling , very light feed till we spark out .
stay well
That grinding sure brings out the truth of the history of the unit.
Thanks for sharing Keith,
Cheers
Good demonstration. Thanks for the look.
Thank you Keith.
I appreciate your attention to detail...
Thanks for sharing!
Keith, another great video and a really interesting process.thanks.
Keith, thank you for another informative video. The grinder is a great addition to the shop!
Hello Keith,
Another machine ready to rock and roll...
Take care.
Paul,,
Great video Keith, my Reid grinder was painted also, great job.
There is a 5 block test you can do now that you have the chuck ground. Tom Lipton has a video showing the procedure. Basically make 5 steel blocks approximately 1/2” thick by 1” square. Grind one side till they all clean up. Clean everything. Place one block in each corner of chuck and one block in the middle. Now grind the top of the blocks till they all clean up. Number the blocks. Remove and measure each block thickness with a tenths or electronic millionths micrometer.
its fun but not needed if the chuck is ground properly.
Interesting video Keith. Thank you!
got to check everything on new stuff! thanks for sharing!!!
You did a nice job for sure. I wondered what else was painted that shouldn't of been painted.
Nice job Keith!
Thank you for sharing.
Thanks for another great video.🤗🤗
G'day Keith. I just love that big ol Thompson surface grinder of yours. What a beautiful machine mate. Thanks for sharing and cheers from Downunder 🍻. Aaron.
Great Teacher
Nice work
Anyone else's OCD flare up when he didn't grind the the bed through the ends? I know it isn't necessary, but........
The ends of the bed are actually lower than the center part where the magnetic chuck sits. It's just hard to tell. So yeah, definitely not necessary.
I believe the center of the table is higher than the ends where the T slot clamps set. The wheel was not cutting over this area.
I was thinking the same thing. What if he needs to remove the mag chuck and use the T slot bed to mount a part? It would just look better completely ground IMHO
@@christopherlong2301 It might look better if it was completely ground, but it would look even much more better if it was painted. I think we can all agree on that...
yeah but why clog a wheel with paint
Informative. Thank you.
Good morning Keith
I cleaned up a shaper cut block with mine while trying to get acquainted with the controls and developing my technique ( aka: playing). I found the result to be pretty even, so I decided to leave the chuck alone for now ... not going to open that can until I see a need to.
You have a beautiful old surface grinder there Keith. Unbelievable that someone would paint the chuck holder base, obviously they didn’t understand what they were doing. Thanks.
The head step function - should be able to alter the step size to match the wheel thickness - or even have it step over half the wheel thickness so each part is passed twice !
Wow!!! Your going all the way with this. Very cool. That grinder has an awesome design. Could be better than a B&S Micromaster. Mabey. Lol.
It isn't necessary for simple flat work but I like to have the vertical back side of the chuck ground and indicated parallel to the table travel so I can use it as a reference. I have a stop bolted along the back through slots that I can raise to create a shoulder or lower below the top surface of the chuck. If you side wheel a part or want the grind true to a side, having the back edge indicated is critical. Kieth, I know you have a compound sine table for the grinder and this back edge is also critical to get angles correct.
I remember Keith going through the process of mounting a fence on his other grinder and squaring it true to the chuck, maybe a future video he’ll show us the process again on his new machine.
the rail is always dusted in but that is a big hydraulic machine that rarely have the back rails on them. that is not what that machine is used for. back rails will be in place on finishing grinders such as harig 6-12 for precision grinding of parts. that is not what that machine is for and the rail being on there prevents large flat items to be put on
This is one of those times where you use the machine to fix the machine. Great job.
(Keith We are going to start like you are sposed to) HTF grinds paint, it clogs the wheel and cause's excessive loads. Bang the wheel explodes. I cannot believe he thought is was rust on the bed, when the clamps were the same exact colour and the table had white paint on it, without some staining on the table. It's not hard to spot rust.
he did exactly precisely perfect as he did it. grind off the paint or coating in seconds and dress the wheel and spark out.
I may be speaking too soon, but so many people grind the top of the chuck when there is rust under the chuck expanding as it rusts. Good call taking the chuck off
All Eclipse Chucks i have seen have a oil filling plug on the underside, would recommend to check if there is some inside and eventually change it.
I would have waited with the job untill the flood coolant is working.
Paint can easyliy removed with the Biax Scraper ! Try it :-)
Gotta love that paint under the chuck.
I have seen so much of that kind of ignorant stuff over the years that I came up with an acronym for it.
STBD.
"Stuff" That Bubba Did.
Bubba has been a very busy fellow over the years.
Other than that, it looks like a wonderful machine.
As a New to You I thought that you would do this just to confirm a good flat surface. Now we all know it wasn't... but it is now.
I can imagine the previous Machinist having a "Doh!!!" Moment and current Machinist saying "I gotta do this when I go back to work."
That ZIG-ZAG movement of the Y feed was annoying me. Glad it got fixed!
I agree with Paul. Looks like primer to keep rust from killing the ways. Doesn't look like you are swinging enough on the ends. The stone should be off the work not just the look of the center make the center an inch or so so you have a clean edge not with a hook. I have two surface grinders looking for a home. Now a Ruby red for hard steel. White cuts cool as it chips off as well keeping sharp. I don't see either side/end fences to align metal on the magnet. It also keeps items from being slid off the top with the stone moving on it.
Just wondering? In the last video you leveled the grinder, and used a super accurate level. But the chuck and bed wasn’t truly flat. Now that the bed and chuck are ground together will the machine need to be releveled since the machinist level was sitting on the chuck that wasn’t flat?
I think the paint was there only as a pre-sale touch up.
I've seen in the past 1980-90at auction where they switched older mag chucks to the machines and sold the finer newer ones and sold them separately
A friend of mine was using a surface grinder using a magnetic chuck ,trying to reduce the thickness of a piece of bms . For some unknown reason the magnet stopped being a magnet ! You should have seen the sheet of bms fly across the workshop ? Certainly woke me up !
Glad to see that paint removed. It was nothing more than a thin spring.
That paint could be red lead, depending on how long ago it was applied. At any rate, I would have taken a carbide scraper and removed the paint. Then some acetone to get rid of pretty much the rest. I wouldn’t want to grind it off.
I thought that red was rust. And I thought the paint that he was referring to was the gray paint that was splattered on it.
I still like watching and kibitzing on machining videos. That chuck had been ground dry likely in china if not bangladesh. That is why the ends were higher. actually they werent the middle had expanded up and got ground lower. also you mist system is the best and set up perfect.
It doesn’t look like you’re taking a full stroke to both ends of the base
If you look at around 13:40 you will notice that the area were the clamp is sitting, it is lower than were the chuck is sitting.
Thats why the ends of the base are milled off lower
The ends aren't lower, that's just a line in the paint where the mag chuck was sitting.
@@MorseB I would disagree, watch at 8:40, the bottom centre of the grind wheel when it comes to either end and reverses, it goes to about half way into the clamping ends painted area, and they still have paint on at the end of grinding, therefore they have to be lower
Hi Keith is that Eclipse magnetic Chuck a UK made one? Eclipse is a well known and respected tool manufacturer here in the UK, although I do not know if they are still in business any more. I too couldn't believe that there was paint on the bed of the machine! And this was being used in a professional engineering business? The mind boggles lol love the videos, please keep them coming. And you and your family keep safe, this Indian Covid variant is causing us quite a bit of trouble here in the UK, and our restrictions have been extended by another month. Can't wait till this is all over, but it's not done with us yet unfortunately.
I once had a twenty inch grinding wheel disintegrate on me while grinding an axle. Fortunately the safety hood had just recently been extended a bit so no large pieces made it out of the machine. The axle was a write-off and me and the senior grinder were spitting sand the rest of the day.
dont you mean shitting instead of spitting
The oil film between the chuck and the bed will cause the chuck to bow when the clamps are tightened.
The oil has a film strength (it's what makes it a lubricant) and does not just squeeze out as the clamps are tightened.
The bed should have been free from oil for grinding.
had a blast that I started scrolling down the comments and kept replying not sure if that would be considered hi jacking his post but I went all the way to the end. almost all comments YOU CANNOT GRIND OFF PAINT with the wheel it will EXPLODE THE WHEEL! he did it right time is money had there been .020 thick of dried paint and goo? I would blast it off in 30 seconds as he did and dress the wheel and spark out LIKE HE DID. the funniest comment was "me say so happens me ran a grinder once and it was hardinge and I was screaming at monitor every five seconds how bad he was blowing it"!
but most of them were "I would have taken lotions and potions and a razor blade and worked on that table to get that paint off of there" that is why they wouldnt make it dog eat dog shop
Flat out awesome... :-)
Surprised you didn't remove the paint before grinding the paint could have clogged up the wheel
That is exactly what I thought too. But, I figured that if it was a problem Keith would not be doing it. When the wheel finally came down to the steel the sparks were very consistent ruling out any wheel clogging.
Art
Same thought crossed my mind.
I was like NOOOOOOO
Yeah, that was my first thought too. Grinding through paint??
@@bearbon2 That's one of the reasons you periodically dress the wheel - to remove contaminants from the wheel while presenting a fresh cutting surface to the job.
Need to check the gibs of the head machine.you can see when stone grind work just on a front zone,also can see on the magnetic surface.check it
GREAT JOB, GREAT VIDEO, PAT THE CATS AND DOGS FOR ME...
Saw comments from other viewers about recurring rust forming between base & magnet even with heavier oil.
1. What does the manufacturer of current mags recommend?
2. I’d be thinking about using a graphite material like DriSlide, or maybe a thread anti-corrosion compound like Never-Seeze. They have at least a half dozen different formulations now. I’d call tech support.
DOES NOT MATTER. rust down there means nothing. it could always be dusted off anyway.
They must have used that chuck to grind the cylinder head on my Rambler.
I watched the machine being leveled on top of the magnetic chuck, that had 6 thou low spot in the middle in a past video. How level is the machine now that it has been used and the bed/chuck have been trued to wheel?
Exactly my though. But then Keith often does things "his own way" (and sometimes in a rather "mixed-up" order"), so... ;-)
Seriously though, levelling the grinder BEFORE giving it a thorough inspection, i.e. without making sure that the part you're referring off IS indeed in good shape is one of those Keith's quirks I'm not, unfortunately, very much surprised by. But as he said himself previously, in one of his earlier videos, "I'm not a machinist by profession, it's my hobby" (not verbatim, but something to that tune). And yes, one can see that it's certainly true. Still, I do enjoy watching his endeavours, trials and tribulations - it's a good entertainment regardless of all and any foibles ;-)
PS: I'm not a professional machinist either, but I just got the habit of thinking through, thoroughly, any job before I start it - and establishing a "proper" sequence of all partial things and tasks that have to be done from start to finish.
Great video
I'm surprised that nice of a grinder doesn't have a electro magnet on it.
Coolant is next. I think that will be the first new large machine that didn't need so repair work before using.
Thank you for the tips on getting a good grind. 👍
For those that missed it the bed does indeed have steps at both ends and they appear rather large.
You can see the left end step at 1:00 under the table clamp, slightly clearer at 4:23 once the mag chuck has been removed and finally evidence of both at 12.06 when the table reaches end of travel and transitions from a heavy grind with lots of sparks to free air with nothing.
Keith, given you levelled the machine before grinding the chuck will the machine now not need re-levelling ? Cool way of stripping paint -I'm not sure I would use it for a door thought:)
Seen any Churchill grinders?
I wish more bench grinders had balance weights. Toshiba makes portable ones which have them.
"Just wondering? In the last video you leveled the grinder, and used a super accurate level. But the chuck and bed wasn’t truly flat. Now that the bed and chuck are ground together will the machine need to be releveled since the machinist level was sitting on the chuck that wasn’t flat?"
You are 100% correct. Keith is very good at very specific tasks and pretty damn poor at other ones: Gee, let's use my OMG precision-level to level this machine on the surface of an unknown accuracy!
I suspect the chuck is not the one used daily when it was last in operation. Likely they threw this one on it when they decided to sell it and kept the good one for a better machine.
My thought as well.
That's what I was thinking.
The bed had paint spattered on it and would have warped anything sitting on top of it, regardless of whether it was a chuck bundled with the machine or one of Keith's own.
Eclipse invented magnetic chucks in 1934, they are still in production today, exporting all over the world from their factory in Sheffield, Yorkshire, England.
There is bugger all wrong with them.
@@MartinE63 I'd hate to be the person to tell you your car had failed its mot, had no brakes or had bald/shredded tyres because you did nothing to maintain it.
Everything wears and erodes with time and use, including magnetic chucks.
Machining the bed and chuck surfaces back to flat is the least you can do if you want to have even half a chance of grinding any components flat and parallel.
At the US-ARMY we used "Break Free". An oil to keep the moister out.
Keith shouldnt you put the level on it one more time after grinding the surface it was laying on??
my thoughts exactly
I also thought that. Hopefully Kieth will let us know why he didn’t check the level on the bed.
I might’ve missed it but I’m wondering why you didn’t grind all the way to the end on the first service that you ground the painted surface I watch again to see if you mention it or not otherwise excellent you got to feel good about that the magnetic base as well as the machine
Effectively he did. You can see the step in the table at 1:00, 4:23 and the free air grinding (no sparks) when the table reaches the stops at 12:06
Keith if I may ask, why didn’t you grind the table all away to the edges? Where you grind the magnetic table all the way to the edge compared to the table. The reason is? It does look much better. How’s the planer coming?
The table ends are quite a bit lower then the center.
I was about to write the same you did, but then I realized the wheel did grind a little air before the table changed direction.
You can see the step under the clamp at 1:00 and clearer at 4:23
I can easily understand how the paint is a serious no no on such a setup. But you then put oil all over the bed and installed the magnetic plate on top of the oil. The oil has thickness also. A clean dry oil-free surface is the absolute best surface when looking for grinding flat perfection... I was a little shocked to see you do that. JMHO
I think the oil is to prevent it from rusting, and in terms of flatness i assume te constant pressure of the clamps pushes almost all oil out of the mating surfaces leaving a film with a thickness of a few millionth of an inch which is almost constant and therefore does not affect the flatness.
At least it is far less than the much thicker oil film on which the table is moving back and forth...
Next time you grind cast iron, give a silicon carbide (green) wheel a try.
Regards,
Duck
Hiya Keith
@Keith, I have a spare hub which seems to be the same type as the one your Thompson uses. I’d be happy to donate it to you. If you want me to perform some dimensional checks on it to confirm let me know. The hub has also a ruby stone mounted, also happy to donate that if useful for you. The hub comes from what I believe to be a cylindrical grinder but I’m not quite sure about it
Question, could some paint stripper get rid of the paint first? So the wheel don't get loaded with debris, then you can grind just steel afterwards.
I’ve got a 225# fisher anvil with a really good face but some a$&@ sometime in the last 100 years cut two lines across the face with a wafer wheel, I’ve always wanted it ground, is this something I could hire you to do? I’m in East Tennessee, long time subscriber and I could pay you in cash or even stay for a day or two and help with whatever you need, I’m handy lol. I wanted to get in on that new shop build you did a couple years ago but bad timing. Thanks man
I like the part where he stuck his arm between the wheel and the splash guard to turn on the coolant.
You need a lazer rust removal gun....
Just wondering why you didn't tram in the side/fence of the vice before grinding the top of it?
my guess is it doesn't really matter for this machine
with a surface grinder you're only working in one axis (up & down) so x & y alignment don't factor into the end result. you could put the part at any angle on the chuck as long as the two faces were parallel you'd be gravy
I second this comment
@@roseroserose588 One may want to use a cup of form wheel so the fence needs to be parallel.
Hope he indicated the back edge for the fence.
Just curious, I know the chuck doesn't go all the way to the end of the bed, and noticed that you did not grind all the way to the end. I assume that is because the chuck will likely never be moved off of the area that is ground, but I was thinking that if you at sometime had to bold something to the table instead of using the magnetic chuck, you would want the entire bed to be flat. Is the thinking that you will not likely every use the surface grinder on things that would be bolted to the bed?
Edit: And I should have read some of the other comments. Nevermind. :)
HA HA I was getting ready to jump on it
Excruciating waiting for you to let it start grinding! ( at 10:40)
The Bad News îs , that the owner of the Machine didint know that the the paint under precision stuff is a no no. Imagine the “rebuil”, “restauration” that this machine had
Now that the surface has been made true do you need to level the whole machine again because it was leveled on the non-level surface of the table and mag-chuck? If not, can you explain for me?
I could be wrong, but the chuck is only 18" long and doesn't appear that anything resting on the table could be ground that is much longer. I'm just saying that as long as the chuck has been ground level, then whatever is placed upon it should be level once ground. I admit that I don't know the full travel of the machine, but again, whatever is placed upon the chuck should also be level now.
I don't have a lot of experience with service grinders but Id think a surface grinder that big would have a larger work area.
Could you identify the ASMR music in your intro? Drops my heart rate 20bpm.
Keith, many years ago I bought a magnetic chuck, and it looked to be in good repair. However, the magnets had lost a significant amount of flux and so the chuck was unable to hold anything. I no longer have it, but what is the procedure to remagnetize it?
The chuck can be disassembled and the magnets can be placed on a magnet charger. If you don't have a magnet charger you can wrap copper wire around the dead magnets and run a DC current through the wire. Be sure you get the correct magnetic polarization. I have used a DC welder with great results. On AC the welder can be used to demagnetize.
@@chuckinwyoming8526 we looked very carefully at the possibility of disassembly of the chuck, but didn't find a way to get it apart.
With the magnet on the swarf will cling to the chuck and imbed in the grinding wheel. Will it need dressed more often while grinding the chuck top?
he did it exactly correctly.
@@jaysilverheals4445 Your comment answers no question asked above.
Likely the paint was a preservative measure if not in constant use
Show the results dude , i want to see the surface finish on that mag chuck
surface finish does not matter and should be course satin finish not shiny or parts will sling off more easily
Wouldn’t you want to clean off the paint and rust beforehand to prevent it loading the wheel?
I personally would never touch off on a workpiece that you do not know is flat or not with the table or cross feed not moving. You never know if you you touch off at is the the lowest point or highest point. Just a recommendation to have the table/cross feed moving when first touching off. I’ve had wheels explode and it’s not a fun experience to have happen trust me.
Keith I have what's probably a dumb question. Is there a difference in the result of using a milling machine verses surface grinder or even on a lathe?
It looks like you need another 3" of table stroke to clear the ends fully.
Length wasn't the issue, you can clearly see a step under the clamp at 1:00, 4:23 and watch the sparking of the wheel going from heavy to nothing at 12:06. If the wheel was hitting material it would not have stopped sparking.
@@aetch77 It's bizarre that there are continuing T slots on a surface below that of the main part of the table. I've never seen that before.
Maybe in a couple of hundred years it'll have been polished/ground down to the lower level ;)
@@aetch77 I'd still set up the machine to traverse the full length - just in case (OK, I didn't notice the step and haven't gone back to find it - so I don't know how big it is.
@@millomweb I missed the step first time round as well. It was the comments that made me look again. The step looks to be roughly 1/16" to 1/8", rather large when you're just trying to remove the surface rust and flatten the table while taking no more than a couple of thou.
The slots need to run the length of the table. Magnetic chucks aren't the only type of fixture you can mount to the table. Where I used to work we had a lot of fixtures dedicated to specific components, it helped a lot with setup changes.
@@aetch77 It's certainly a bizarre feature of the table. I wonder if the machine's been modified - and it was normal originally flat ?
We ought to have a couple of mag chucks - the first was pathetic in strength, the second is better - I think it also has an end stop - to stop things sliding off the end !
I personally like the idea of direct mounting to the table. I know a lot of people use vices - and why not. It's basically the equivalent of using the 3 jaw self-centring chuck on the lathe. I see a few youtubers want more accuracy than the three jaw offers - so tend to use the 4-jaw independent. Again, my twist on this is to 'know' that the only true surface in connection with cylinders are the internal surfaces - so they should be turned between centres for best accuracy !
He should have stripped the paint, and then done the grinding, you do not grind paint!
like hell you dont. faster to grind it off and dress the wheel in seconds. also he has wheel dresser.
I suppose the previous owners just put the chuck onto the painted bed, ground it in in place and then never took it off.
"Machine, heal thyself."
You should always balance the Stone with the hub before using it...
That part is correct but not as necessary as you think. An unbalanced wheel when dressed with dress according the unbalance and give good results however it would have been best to dress the wheel especially the sides and balance for sure.
@@jaysilverheals4445 I think grinding the table and chuck is such a critical step that you should do that. Also when not using new stones, you cant know if coolant has dried and built up somewhere. Whenever using coolant, you should run the stone dry when stop using the grinder. It also depends what accuracy you are aiming to. In my opinion its good practise to balance the stone with the hub. Then you just change the whole setup.
I would have taken a angle grinder with a wire cup brush and first remove all the paint, then leveled it all the way from end to end, that was driving me crazy. Grinding on that paint will just load up the wheel with paint, would be hard to clean out the wheel. Yes i would have remove all the old rust and paint first.
As unfortunate as the paint was, at least the previous ding dongs prevented further rust. It could be much much worse.
why didn't you adjust travel to remove all the paint???
The table has steps at either end 1:00, it's a bit clearer at 4:23
I did not know that you could grind the magnet side. Learned something new.
To me it seems weird to have the wheel move so fast across compared to the speed of the table and due to the head being lowered after each pass. Is that normal for surface grinders?
Aaaand just after I wrote it, he found the setting to move the wheel in increments.
Why is it always so hard to keep from posting comments untill after the video is over?
@@sturestensson9187 As the poster of a comment, you can use the dots on the right to edit or delete the comment.
@@sturestensson9187 Your wife asks the same question regarding a different subject, "Mr. Quickie"