Wow, you sure are brave. My 13X40 Jet Lathe is now 15 years old. So far it has held up well, it is very accurate and no problems with the bearings. The inside of the head does not look a nice as yours, but no chips or junk. I've changed the oil several times little or no grit in the oil. Can't wait to see how you put it all back together.
Makes me wonder if I should open mine up too. Great video Yuchol. I now see that you aren’t afraid to tackle any job thrown at you. Can’t wait to see the second part.
Great video, Yuchol. When you put the headstock back together, might be a good idea to attach a magnet to the drain plug to catch any filings as the gears wear normally.
more than 1 magnet would work in different locations. they won't dislodge from the case if put in the correct places, and will prevent future damage. Nice work. I probably would have taken the handle gears out.. you are already 99 percent there. So little work, and you are waiting.
Hello Yuchol, your Videos are just great ! As mentioned before, the outer Bearing shoud be a tight slip fit on the Spindle, but it never is on import Lathes. But its easy to correct with a Lapping Ring made from Aluminium and some abrasive compound. You could place some wick in the oil feed holes of the Bearings, this would prevent any particles from getting in. The restriction in the flow is no Problem, tapered roller bearings dont need a huge oil flow. They run cooler if they dont need to displace a lot of oil. Some fine wire mesh, like on an oil burner Nozzle (not the sintered stuff) could also be used. Greetings from Germany !
Wow! I'll even say it backwards woW! That is a shot in the pocket book after buying that lathe. Thanks for showing your method behind the madness on replacing the bearing. Good luck! Looking forward to the next one.
Wow! Great job Yuchol! Can't wait for part 2, maybe 3. That's a lot of work. Guess we'd be better off if they just sent us a box of parts and we could clean up and assemble them our selves. That would cut the cost even more. Keep the great videos coming. Stay safe.
Great video. There's something deeply satisfying about upgrading sub-standard machines. You just know that your lathe is going to feel, sound & cut much better than previously. It'll make you feel good every time you use it. If that's not good enough there's the bonus of having to buy quality tools. The other tab I have open is the Knipex catalogue :-) Looking forward to part two. It was rhetorical your question about the shaper restoration...right?
So it sounds like if you buy one of these machines (assuming mills are made to the same modest standards) either one rebuilds it the day that it arrives, or rebuilds it a year or two later. The major difference being that if you clean it up and deburr all of the internal parts on Day 1, one might ultimately be able to save the cost of replacing expensive bearings and gears. Thank you for this very informative and insightful video. I don't own a lathe and never will, but I think you have made a beautiful investigation into sources of failure. Beginning with the folly of assuming that just because an item has been manufactured to spec dimension it has therefore been made "right." Deburring, cleanliness, seals and lubricants being also and equally crucial for long-term success.
Thanks Josh. I bought this lathe because I’ve had the exact one 16 years ago and that was a good lathe. Unfortunately the first one was made in Taiwan where this one was made in China. The quality just isn’t what it was. There are other brands that I feel comfortable buying today, just not this brand anymore.
@@woodscreekworkshop9939 are these models still sold by anyone other than Jet, but still made in Taiwan? I used one about 22 years ago, but it had been abused in the electric motor shop and needed some work, I wanted to take it home and rebuild it because of the size and I thought it had potential for a home shop.
Nice video. I am so happy to see a person who cares about his equipment. Your initiative and patience are obvious to me. Also takes courage to tear into a repair not knowing how much work it will involve to finish. Cleaning the headstock will bring years of trouble free service. Enjoyed watching you proceed with the repair and wish you success in reassembly. Thanks for sharing.
👍 thanks for sharing. These repair videos are the most valuable in my book. They're the rare ones. I'm in the process of cleaning up a Colchester before I put it in service. Sure hope I never have to go under the hood!
Gday Yuchol, it’s disheartening when you see this issue in machinery, a lack of quality control during in the factory, it’s a cost that could be very easily avoided, I’m really looking forward to seeing the shaper, nice addition to the shop, fun times ahead there mate, take care Matty
I don't think it is avoidable, wherever gear surfaces meet, a break-in procedure might be required. After transport, under load and depending on temperature the dimensions do change quite a bit, which means a break-in at the plant won't cover all of that. How much is acceptable depends, and how much burr those parts had when being assembled. This means with new bearings and freshly assembled a new break-in with oil change might be required - but that's usually done to estimate the preload of the bearings alone anyway.
lee I quite agree although the gears may well have contributed to the swarf in the headstock it's mainly as Yuchol has shown where the headstock openings were bored that has left swarf on the outer edge of the casting. Yuchol clearly shows pieces being broken off of the casting. Failure to deburr during manufacturing by the Chinese factory is the complete cause of this problem
Great video man! When it comes to bearings, I’ll only use Japan or USA made. I was really surprised at what Jet was asking for a Chinese made bearing. I wonder what the markup is on that. I look forward to part two of this rebuild!
The mark up margins are enormous. Many hundreds of percentage profit. Rolling element bearings have always been a lucrative business. I had several years experience with a work colleague who was a main stockist for several well known bearing brands. The recommended prices are ridiculously over the top on some larger bearings.
I've bought bearings in china (popular auto /truck replacement sizes and was shocked how they were stored and handled. They have no sense of storing, packaging away from silica contamination. So now i pay a premium for japanese.
Good hunting for those bearings. I spent hours working to find precision bearings for my Boyar Schultz surface grinder spindle. Prices seem to have no upper limit - LOL. Well shot video. Anxious to see the rest of the series.
actually those are tapered roller bearings they will be pretty cheap and easy to find. boyar schultz and most higher precision spindles uses angular bearings which get pricey fast.
HI ! Just wanted to know, did you check any spindle runout before you changed the bearing or just because of the sound. I am asking becuase my lathe has developed spindle runout, but the noise is not that noticable, I tried to preload the bearings but could not fix the runout issue. Please help
The bearing noise comes before you see runouts. If you’re seeing a runout but the bearings sound good, you need to check the spindle preload and adjust accordingly.
Nice job Yuchol, you are doing what should have been done at build. It is completely beyond me why companies put time into line boring castings for shafting, and then just leave burrs everywhere. The de-burr and clean would be less than one tenth of the machining time..... So sad that everything these days is made to a price point rather than a standard. You are bringing it back to life nicely, well done. Jon
Thanks for showing, I like the way you handling this open heart surgery operation. I know this is waiting for me along the line. Please let us know after you replaced all bearings and assembled , apart from the spindle bearing noise if the noise running at various speeds has noticebly changed. My gearhead lathe is quiet enough at low gears forward(No complain), a bit noisy for same gears in reverse. At higher speeds like 1800 it sounds scary to me, but not as scary as some racecars with straight cut grears. I did not had the oppertunity to hear a similar lathe 1st hand, so would really appreciate your take on the noises afterwards, thank you again.
Hey, great video. Well done on taking it on. On my colchester i added an in line oil filter meant for a tractor. It has a removable can with the filter and a mount with hose tails at the inlet and outlet. Very easy to mount between the oil pump and gearbox. Also, for cheap bearings, if you know anyone living in china, buying them on taobao is really cheap. Most sellers wont ship outside of china. But you can get all the big brands like skf nsk etc and high quality but they're about 10% of the price of in the uk. I have worked out there and stock up when i can. Thanks for the video!
thanks for the video! Really helps since I will have to do the same thing soon to my lathe soon. Could you add to the description some details on what tools you are using? I don't have a pencil and paper anywhere near by and have too many gray hairs to remember all the details you just went thru. I am always worried about getting sub-standard tools for a quality price. Since you seem to know what you are looking for, the less informed of us (ie me) would really appreciated the info!
I've got an American turnmaster 15 (copy of clausing colchester) torn apart right now. I need to know how to preload the spindle bearings correctly. Also, I'm fitting an external inline oil filter to filter out grit. Does anyone ever put a magnet inside of these, like a rear differential on a truck?
Many people place magnets inside and I will do the same. Unfortunately lathe doesn’t have an oil pump, so I can’t add a filter. I guess I can always add an external pump 😏. Search on Practical Machinist forum for “spindle bearing preload” and read up on temperature-based method.
Use felt to help filter the metal shavings out of the oil in the holes for the main bearings this will allow the oil to wick through the felt. search felt wick its quite common
Great content, nice work and very informative. Your lathe will perform like new. The source information of the parts and prices was good also. I have a 12 x 36 Enco gear head lathe that I purchased new in 1987. I am thinking it needs the same service as your lathe did. Thanks alot, Ed M.
Looking forward to Part 2, as I’m curious to the proper fitment of the outboard bearing to the spindle. I always thought it should be a slip-fit to allow proper preload adjustment. I have a cheap 10” Taiwanese lathe that has the same press-fit as yours had coming off, I think I should fix it. Anxiously waiting to learn from your experience!
I wonder if all of the crud/chips/dirt was in it when you bought the lath from when it was manufactured? I've seen other videos of people taking apart brand new lath chucks and indexing heads. They were full of grit from the factory. Maybe it would of been a good idea to cleaned it out when you first bought it.
Yuchol, this video has been a huge help to me. Thank you! After recently purchasing a Victor 13x40 a few issues have been found. One was that after running for a few minutes the chuck end of the spindle was puking oil. Seeing how the headstock is assembled was a huge help. Mine isn't identical but it's close enough that there were no surprises when I opened it up. I have a heat gun identical to yours and it worked great with a little patience. The primary reasons for oil running out of the headstock appear to be overfilling and a bad gasket under the bearing cap. A cloudy sight glass didn't help matters. The rollers and races are no longer shiny but still smooth and runout inside the spindle with a dial test indicator was .0001-.0002 so I saw no point in replacing them immediately.
Greetings, just replaced the countershaft bearings on my lathe, similar to yours and a lot of debris from the failed bearings but luckily the spindle bearings seem ok. Mr Pete is 100% correct, I also had machining chips that had migrated through the chuck end Labrinth Seal, the chips CAN go into the gearbox even without using compressed air. I have placed a large magnet in the gearbox and regularly clean to remove debris, most of which comes from the non hardened gears. Looking forward to see you reassemble,
Hi Yuchol Watched your video again. Use to build big race engines about 25 years ago. In the heads where the oil returns back the the main block we epoxied some of those small rear earth magnets to catch and metal files also give a tell tail sign something was wearing out Just a thought. I would hate to go through this myself I have a couple in my old King machine which is also a Chinese made but I have had very good success with since 2004. I change oil about every 6 months and pull the main cover off to check those magnets for chips or filings. Keep up the good work. Cheers Fred
Very interesting and informative video. I'm a new subscriber (today) and really like the thoroughness and clarity of both you video and your narration. Excellent work! I really admire folks who just press ahead when faced with challenges such as the ones you've faced getting, and keeping, this lathe in good running order. Good job sourcing those bearings, standard replacement parts charges are such a rip-off. Jet should be ashamed both of the quality of the machining cleanup during manufacture and of trying to make their standard item spare parts a profit source. Good on you for proving how that will backfire. You got better bearing for a fraction of their asking price. My only slight disappointment was that you didn't show us the comparison of the worn old bearings with the brand new ones. Guess I'll have to be sure to tune in for Part 2. Wait a minute, was that a subtle cliff hanger?? Well intentional or not, I think it will work.
It's a shame that you have to do this. It sould be a trouble free machine with the way you are going about repairs. Nice choices on the bearings and the tooling that you bought for the job. Great job on the way you presented everything in the video. Looking forward to the next video, hope you show going through some of the sub assemblys. Andy
I think the bearings are all made on the same manufacturing procedure and graded accordingly to run out and the p5 tolerance is stamped on the bearing which you pay an arm and leg for.
The production lines for the lower class bearings are not set up to take the all the measurements needed for the higher precision bearings. Precision bearings are usually made on separate lines since they get much more hand fitting and measurements taken. If the rings or rolling elements do not meet the tolerances, they are reground until it is within them. They cost so much more because the labor to make them is significantly higher.
@@mikeb1520 Damn right you are, I used to sell bearings and had an engineer over for super precision spindle bearings problems with an OEM machining center customer. Long story short; all bearings of the run out quality needed be ABEC 3, 5 and 7 are made in specialised produstion lines or plants. The amount of inspections and measurings make these type of super precision bearings so expensive. The most expensive ones are made in sets that are marked not just with top of run out (etched dot), but are sorted and marked with an etched V mark across the set to avoid mixing the bearing set up Guess what; that OEM customer had some apprentice mixing up a set of 4 angular contact bearings, no wonder they had troubles.
ervie60 I used to work for FAG Bearings in the Barden Bearings building, Barden only made ABEC 7 and 9 bearings, these P5 bearings in the video are scrap to them :). The ABEC 9 bearings had their own temperature controlled room with dedicated grinding, honing and measurement equipment, as well as employees. The people making ABEC 9 bearings only made that class bearing. After seeing the work that goes into making bearings of that quality, the prices don’t seem so outrageous.
Some of the ones I’ve pulled apart have had pipe cleaners shoved down the oil holes. Form into a V, shoved down the hole, then bend flat what’s sticking out to stop it going all the way in. Will definitely stop big chunks of grit.
Hi. One more useful tool would be a bearing separator. This comes in two halves which fit round a bearing and then bot together. It has near kife edges that will prise a bearing away from it's neighbour and it also allows long all thread to be used to pull the errant bearing off a long shaft. They are not expensive and well worth having. Probably still need the heat gun. Stay safe folks. BobUK.
Yes, maybe also some tiny ones along the troughs that channel the oil to the spindle bearings themselves. Can't think of any reason not to as long as they don't impede oil flow. Those are easy to get to by just removing the top cover, so Yuchol can keep an eye on things over the first few hours of operation.With the cleanup and deburring Yuchol did, there should be minimal to no large chips anymore!
Great video. Yuchol. My 25 year old Sharp 1340 is very similar. I've changed oil a couple of times...never looked into it as you have. I need to do that.
I am learning that setting the proper bearing load is more of an art than science and the preferred method is to look for a temperature rise at the bearings rather than using torque measurement
I was repairing my milling machine spindle today, it is 100 years old, It runs smooth now, but the taper has a 16um runout (7 tenths), not very good, I am sad
Yuchal, that's Tuff Stuff... I hope the people from Jet Company are watching. That's terrible quality control you should have never had to go through this. Thanks for sharing!
Ouch. Surprising how little care was taken in putting that together at the factory. If it was 80 years ago I reckon there would have been actual people inspecting it before going to assembly. I guess that's what the paint is for lol. Thanks for the share, Yuchol 😊.
Thank you for the movie. Consider putting some big magnet (for example from old speaker) into headstock close to oil pump drop - naturally wearing stuff will not flow internally, but stick to magnet. It also gives better view about oil quality - small pieces will not be visible without optical zoom (at least 2$ small watchmakers x10 magnifier).
@@woodscreekworkshop9939 Yeah, sure will do. I'm just going to fix do a job or two on the lathe first. I've got plans to redo the bearings in the mill, and I want at least ONE of my two machines to work, in case I have to "fix" something.
I ordered new Timken bearings for my Bolton lathe a few months ago and they are just sitting on my workbench because of the dread of installing them, although I read it makes a world of difference to get rid of the Chinese bearings that's in it now.
Yes, I would feel the same. On the other hand seeing this video and also a whole series from a channel called Swan Valley Machine Shop does provide lots of useful illustrations and tips and tricks for getting the job done. The SVMS videos show complete disassembly of a Taiwanese 12 x 36 lathe (different source, but basically identical to the PM-1236T). That combined with this excellent WCW series will be excellent inspiration for getting these jobs done!
@@woodscreekworkshop9939 Well, my motor burned up on my lathe so I had to do quite a bit of disassembly to dislodge it from where its buried in the back and I took the opportunity to replace the spindle bearings. Wasn't as bad as I thought it would be. Thank you for the motivation!
Very good video how long did it take to get that bad and how much use. Was it run very frequently for several years or less? Also did you have much runout because of the bearings?
I’ve had the late and used it “frequently” for a home hobbyist, the runout was really low. Other than the noise, I had no complaints of the machined parts. I am certain the runout would have gotten worse if I kept using it.
This was quite interesting, as my 12x36 has some similarities to your 14x40. I had thought Jet would have had better cleaning and quality control, they have a decent name for themselves. My lathe is due for an oil change anyway, I think the lid will come off like after I first bought it and cleaned it, I'm wondering how much crap is floating in the transmission now!
It's a shame that alot of the final handwork is skipped. I guess these companies are trying to come in at a price point. I imagine that most customers would be happy to pay for a couple more hours of labor considering the difference it would make.
0:05 What is the correct name for the RODE tool for sound analysis of bearing condition? Подскажите пожалуйста, 0:05 как правильно называется инструмент RODE для звукового анализа состояния подшипника? Где можно купить?
I would like to have a lathe that has the old style v-belt system and instead have precision bearings and other equipment critical to accuracy at a affordable price.
What about putting some course gauze in the drain hole over the spindle holes. You might have to replace the gauze twice a year, but it would keep out the metal pieces.
Small heat gun /hair dryer 😂 - necessity is the mother of invention. Good job , I think all that kind of small machinery would benefit from a strip down and clean when you first get it .
Good work cleaning that up I had the same issue of stupid tight bearings with my mill spindle a while back. I suppose it's better than loose PS at 0:51 it looks like you dropped your lathe dog on the floor :P
Great content. I have a kent kls1340a which is very similar I've also have seen similar defects like yours like leaking all over the floor thought about a drip pan like yours didn't have one so i just put gasket maker around the tray and pedestal now oil drippings just flow into chip pan which i also have to redo some of their welds on pan brackets this machine is only 4 years old and not ad much use as yours but the problem appears to be the fact that they have no pride in their workmanship any more. I thought abou selling my original smaller craftex combo lathe mill but decided to keep it because wont get much for it and I've had to use it to make parts for my other lathe and mills when they break down like when you had to make new detent collar but you can't do it if lathe doesn't work at least it wasn't a critical part that machine won't work while making new one. Word of caution for the lid If you don't use a gasket just sealer that rib on lid needs to have notches cut into to allow oil into the trough for oiling the bearings I reused the gasket but lid was bowed so i notched lid for oil flow a used gasket maker on both sides of the gasket this also cured the major part of my oil leak Good luck with getting it back together and getting it going
Those bearings would have been installed by heating them to a temperature of approximately 250 degrees farenheit so they would slip into the spindle shaft. Don't directly apply heat to the bearings nor hammer them
Hi Yuchol I've a Taiwanese Dar Sin 1230 Geared Head Lathe ( Sold by Frejoth (Acra)). I imported myself 1982. I shall renew the spindle bearings in near future. It might be vise to renew all the bearings and clean thew whole headstock. Did you take any video of disassembling, and assembling the gear shafts, gears and bearings?
Some tips to NOT ruin those fine super precise new bearings and the other ones: -put the cups in the freezer to shrink them. -put the cones in your oven and heat them up, mind the temperature of course. I say max. 110-130 Celcius -check housing diameters; if fit is too loose, a bit of loctite works miracles :) And never ever!!!! hammer in a bearing!! might as mount the most crummy el cheapo bearings but mounted correctly! Turn some nylon rings that fit the rings precisely and use that soft mallet to drive them in; all to avoid shock. Better would be to use a press for the cones on the shafts. Brass rings maybe for the shaft mounted bearings (heat!) last tips: -check for markings on spindle bearings for top of run out; usually a dot is etched. Then make sure both bearings are positioned at same spot to avoid -work as clean as you would work on hydraulics -make sure the shoulders are spotless and square. -proper pre load specs for those tapered roller bearings, make sure to make 10 to 20 revolutions so each rolling element makes a full revolution then measure torque with unster. Good luck with the new quality bearings!
Careful, OEM's often order with a specific tolerance on precision and unless you know what it is you may not be getting what you need. Even from a reputable bearing supplier those prices seem to good to be true.
Dear brother I designed a 12 speed lathe Headstock by watching your both bearing replacement videos but it's not working properly I think lot of points are missed due to the fast videos could you please upload the original full video with normal play back so that I could come out of the problem in which I am badly stuck. Please do give me some solution otherwise my job will be in danger I designed it for a company in which I am working with.
You need to loosen the fit of the outer end spindle bearing on the spindle or you will not be able to set the pre load properly! It should be a tight sliding fit. If it binds up as you adjust the preload the main bearing behind the chuck will still be too loose. Phil UK
I bet it is going to feel great to have new high quality bearings in your lathe. I have a 50 year old Colchester with the Gamet bearings. If it ain't broke, don't fix it, in my case. I think when some lathes need spindle bearings, it's time for the scrap yard. If you had to pay over $2,000 to replace bearings in your lathe would you do it? Or look for a new one? I had a 13" South Bend lathe that was made in 1941. The cast iron bearings were in new condition. Maybe those guys knew a thing or two about quality. Of course the max RPM wasn't 2,000+
Man, I admire your courage and skill for taking that on !!
Thanks, I am learning a lot myself by tackling this task 👍🏼
Wish I could do that. Seems like over kill. I think I could change the oil.
Wow, you sure are brave. My 13X40 Jet Lathe is now 15 years old. So far it has held up well, it is very accurate and no problems with the bearings. The inside of the head does not look a nice as yours, but no chips or junk. I've changed the oil several times little or no grit in the oil. Can't wait to see how you put it all back together.
Thanks Dan!
Makes me wonder if I should open mine up too. Great video Yuchol. I now see that you aren’t afraid to tackle any job thrown at you. Can’t wait to see the second part.
Thanks Dale. My motto is “there are very few things that can’t be reversed if I screw it up” 😁
Great video, Yuchol. When you put the headstock back together, might be a good idea to attach a magnet to the drain plug to catch any filings as the gears wear normally.
Thanks. I have few ideas, will show in the part 2 👍🏻
more than 1 magnet would work in different locations. they won't dislodge from the case if put in the correct places, and will prevent future damage. Nice work. I probably would have taken the handle gears out.. you are already 99 percent there. So little work, and you are waiting.
LOL I don't have that problem all my gears are plastic... sometimes cheap Chinese is better...@@woodscreekworkshop9939
@@woodscreekworkshop9939 I'd even wrap the magnet in ziplock bags for easy clean up.
Hello Yuchol, your Videos are just great !
As mentioned before, the outer Bearing shoud be a tight slip fit on the Spindle, but it never is on import Lathes.
But its easy to correct with a Lapping Ring made from Aluminium and some abrasive compound.
You could place some wick in the oil feed holes of the Bearings, this would prevent any particles from getting in.
The restriction in the flow is no Problem, tapered roller bearings dont need a huge oil flow.
They run cooler if they dont need to displace a lot of oil.
Some fine wire mesh, like on an oil burner Nozzle (not the sintered stuff) could also be used.
Greetings from Germany !
Taunus Mechanics thanks! 🙏🏼
Wonderful video Yuchol. I look forward to your next video showing your lathe running with all new bearings. Nice work!
Thanks Guy!
Wow! I'll even say it backwards woW! That is a shot in the pocket book after buying that lathe. Thanks for showing your method behind the madness on replacing the bearing. Good luck! Looking forward to the next one.
Yeah, definitely wasn’t planning on spending that sort of money anytime soon 😒
Wow! Great job Yuchol! Can't wait for part 2, maybe 3. That's a lot of work. Guess we'd be better off if they just sent us a box of parts and we could clean up and assemble them our selves. That would cut the cost even more. Keep the great videos coming. Stay safe.
Thanks Frank!
Great video. There's something deeply satisfying about upgrading sub-standard machines. You just know that your lathe is going to feel, sound & cut much better than previously. It'll make you feel good every time you use it. If that's not good enough there's the bonus of having to buy quality tools. The other tab I have open is the Knipex catalogue :-) Looking forward to part two. It was rhetorical your question about the shaper restoration...right?
😁. I really hope to work in the shaper this summer. Thanks for your kind words Jeremy 🙏🏼
Immediate like for the rocks grinding ASMR
ThatGuy 😂
So it sounds like if you buy one of these machines (assuming mills are made to the same modest standards) either one rebuilds it the day that it arrives, or rebuilds it a year or two later. The major difference being that if you clean it up and deburr all of the internal parts on Day 1, one might ultimately be able to save the cost of replacing expensive bearings and gears.
Thank you for this very informative and insightful video. I don't own a lathe and never will, but I think you have made a beautiful investigation into sources of failure. Beginning with the folly of assuming that just because an item has been manufactured to spec dimension it has therefore been made "right." Deburring, cleanliness, seals and lubricants being also and equally crucial for long-term success.
Thanks Josh. I bought this lathe because I’ve had the exact one 16 years ago and that was a good lathe. Unfortunately the first one was made in Taiwan where this one was made in China. The quality just isn’t what it was. There are other brands that I feel comfortable buying today, just not this brand anymore.
@@woodscreekworkshop9939 are these models still sold by anyone other than Jet, but still made in Taiwan? I used one about 22 years ago, but it had been abused in the electric motor shop and needed some work, I wanted to take it home and rebuild it because of the size and I thought it had potential for a home shop.
Nice video. I am so happy to see a person who cares about his equipment. Your initiative and patience are obvious to me. Also takes courage to tear into a repair not knowing how much work it will involve to finish. Cleaning the headstock will bring years of trouble free service. Enjoyed watching you proceed with the repair and wish you success in reassembly. Thanks for sharing.
I did the same on mine lathe (Paulimot PM4000) some weeks ago. So I know that this job is ....no fun.
Great video! Greatings from Germany
Holger Lauer sorry to hear that 😭
Great approach to a difficult and intricate job, Yuchol-it will be vastly smoother than it came from the factory by far-Well done✅
Thanks Michael as always 🙏🏼
👍 thanks for sharing. These repair videos are the most valuable in my book. They're the rare ones. I'm in the process of cleaning up a Colchester before I put it in service. Sure hope I never have to go under the hood!
Thanks James. I recommend you taking a good look anyway, maybe prevent a future disaster 😁
I love your shirt, you've earned my subscription.
I only wish my lathe was half as simple as yours, then I'd be much more confident to service mine.
Thanks and welcome!
Thanks for a very informative video. Your machine looks very similar to mine inside, so will be a big help when I have to do the same job.
Gday Yuchol, it’s disheartening when you see this issue in machinery, a lack of quality control during in the factory, it’s a cost that could be very easily avoided, I’m really looking forward to seeing the shaper, nice addition to the shop, fun times ahead there mate, take care Matty
Thanks Matty! It made me mad, but we must all forge ahead I guess 😁
I don't think it is avoidable, wherever gear surfaces meet, a break-in procedure might be required. After transport, under load and depending on temperature the dimensions do change quite a bit, which means a break-in at the plant won't cover all of that. How much is acceptable depends, and how much burr those parts had when being assembled. This means with new bearings and freshly assembled a new break-in with oil change might be required - but that's usually done to estimate the preload of the bearings alone anyway.
@@denny9931 yes but they can take a few minutes to debur the machined edges its just slack on the manufacturers part
lee I quite agree although the gears may well have contributed to the swarf in the headstock it's mainly as Yuchol has shown where the headstock openings were bored that has left swarf on the outer edge of the casting. Yuchol clearly shows pieces being broken off of the casting. Failure to deburr during manufacturing by the Chinese factory is the complete cause of this problem
@@samrodian919 AGREED!
Great video man! When it comes to bearings, I’ll only use Japan or USA made. I was really surprised at what Jet was asking for a Chinese made bearing. I wonder what the markup is on that. I look forward to part two of this rebuild!
Thanks Tim!
The mark up margins are enormous. Many hundreds of percentage profit. Rolling element bearings have always been a lucrative business. I had several years experience with a work colleague who was a main stockist for several well known bearing brands. The recommended prices are ridiculously over the top on some larger bearings.
I've bought bearings in china (popular auto /truck replacement sizes and was shocked how they were stored and handled. They have no sense of storing, packaging away from silica contamination. So now i pay a premium for japanese.
Good hunting for those bearings. I spent hours working to find precision bearings for my Boyar Schultz surface grinder spindle. Prices seem to have no upper limit - LOL.
Well shot video. Anxious to see the rest of the series.
Thanks Dan. The words “surface grinder” and “spindle” automatically inflates the price astronomically 😂
actually those are tapered roller bearings they will be pretty cheap and easy to find. boyar schultz and most higher precision spindles uses angular bearings which get pricey fast.
Nice job on the tear down. I could not believe how expensive the OEM bearing are. It goes to show that OEM is not always the best route.
Cheers Fred
Thanks Fred!
Well done Yuchol, and very informative, just reminds me I haven't removed the cover on my lathe for some time now. Cheers!
Thanks!
HI !
Just wanted to know, did you check any spindle runout before you changed the bearing or just because of the sound.
I am asking becuase my lathe has developed spindle runout, but the noise is not that noticable, I tried to preload the bearings but could not fix the runout issue.
Please help
The bearing noise comes before you see runouts. If you’re seeing a runout but the bearings sound good, you need to check the spindle preload and adjust accordingly.
Nice job Yuchol, you are doing what should have been done at build. It is completely beyond me why companies put time into line boring castings for shafting, and then just leave burrs everywhere. The de-burr and clean would be less than one tenth of the machining time..... So sad that everything these days is made to a price point rather than a standard. You are bringing it back to life nicely, well done. Jon
Thanks Jon, it was definitely avoidable
Thanks for showing, I like the way you handling this open heart surgery operation. I know this is waiting for me along the line. Please let us know after you replaced all bearings and assembled , apart from the spindle bearing noise if the noise running at various speeds has noticebly changed. My gearhead lathe is quiet enough at low gears forward(No complain), a bit noisy for same gears in reverse. At higher speeds like 1800 it sounds scary to me, but not as scary as some racecars with straight cut grears. I did not had the oppertunity to hear a similar lathe 1st hand, so would really appreciate your take on the noises afterwards, thank you again.
Thanks Chris, will do
Hey, great video. Well done on taking it on. On my colchester i added an in line oil filter meant for a tractor. It has a removable can with the filter and a mount with hose tails at the inlet and outlet. Very easy to mount between the oil pump and gearbox.
Also, for cheap bearings, if you know anyone living in china, buying them on taobao is really cheap. Most sellers wont ship outside of china. But you can get all the big brands like skf nsk etc and high quality but they're about 10% of the price of in the uk. I have worked out there and stock up when i can. Thanks for the video!
Lorro Symonds thanks. This lathe doesn’t have a pressurized oiling system.
I just finished replacing the bearings in my Monarch 12ck gear box.
thanks for the video! Really helps since I will have to do the same thing soon to my lathe soon. Could you add to the description some details on what tools you are using? I don't have a pencil and paper anywhere near by and have too many gray hairs to remember all the details you just went thru. I am always worried about getting sub-standard tools for a quality price. Since you seem to know what you are looking for, the less informed of us (ie me) would really appreciated the info!
Thanks for the great step by step tear down and information.
Thanks
I've got an American turnmaster 15 (copy of clausing colchester) torn apart right now. I need to know how to preload the spindle bearings correctly. Also, I'm fitting an external inline oil filter to filter out grit. Does anyone ever put a magnet inside of these, like a rear differential on a truck?
Many people place magnets inside and I will do the same. Unfortunately lathe doesn’t have an oil pump, so I can’t add a filter. I guess I can always add an external pump 😏. Search on Practical Machinist forum for “spindle bearing preload” and read up on temperature-based method.
Use felt to help filter the metal shavings out of the oil in the holes for the main bearings this will allow the oil to wick through the felt. search felt wick its quite common
Great content, nice work and very informative.
Your lathe will perform like new.
The source information of the parts and prices was good also.
I have a 12 x 36 Enco gear head lathe that I purchased new in 1987.
I am thinking it needs the same service as your lathe did.
Thanks alot, Ed M.
Thanks Ed! 👍🏻
Great video! Enjoyed as always.
Thanks Jerry!
Mines got a low speed growl coming on too. I was hoping it was just the Covid. Thanks for the content.
Dave Salzer disinfect it 😁
Great content, i sold mine last year and it was starting to develop some noise, Thanks again for great content.
Thanks Carl!
Looking forward to Part 2, as I’m curious to the proper fitment of the outboard bearing to the spindle. I always thought it should be a slip-fit to allow proper preload adjustment. I have a cheap 10” Taiwanese lathe that has the same press-fit as yours had coming off, I think I should fix it. Anxiously waiting to learn from your experience!
Thanks Larry
This is interesting point.
Love this video, can’t wait to see you put it back together. Thanks a lot, great content.
Thanks Rodney 🙏🏼
I wonder if all of the crud/chips/dirt was in it when you bought the lath from when it was manufactured? I've seen other videos of people taking apart brand new lath chucks and indexing heads. They were full of grit from the factory. Maybe it would of been a good idea to cleaned it out when you first bought it.
I am certain that’s how it left the factory, shameful
Yuchol, this video has been a huge help to me. Thank you! After recently purchasing a Victor 13x40 a few issues have been found. One was that after running for a few minutes the chuck end of the spindle was puking oil. Seeing how the headstock is assembled was a huge help. Mine isn't identical but it's close enough that there were no surprises when I opened it up. I have a heat gun identical to yours and it worked great with a little patience. The primary reasons for oil running out of the headstock appear to be overfilling and a bad gasket under the bearing cap. A cloudy sight glass didn't help matters. The rollers and races are no longer shiny but still smooth and runout inside the spindle with a dial test indicator was .0001-.0002 so I saw no point in replacing them immediately.
Greetings, just replaced the countershaft bearings on my lathe, similar to yours and a lot of debris from the failed bearings but luckily the spindle bearings seem ok.
Mr Pete is 100% correct, I also had machining chips that had migrated through the chuck end Labrinth Seal, the chips CAN go into the gearbox even without using compressed air.
I have placed a large magnet in the gearbox and regularly clean to remove debris, most of which comes from the non hardened gears.
Looking forward to see you reassemble,
I will also place magnets in there 👍🏻
Hi Yuchol
Watched your video again. Use to build big race engines about 25 years ago. In the heads where the oil returns back the the main block we epoxied some of those small rear earth magnets to catch and metal files also give a tell tail sign something was wearing out Just a thought. I would hate to go through this myself I have a couple in my old King machine which is also a Chinese made but I have had very good success with since 2004.
I change oil about every 6 months and pull the main cover off to check those magnets for chips or filings. Keep up the good work.
Cheers Fred
Fred's Machine Werks thanks Fred. I will be installing some magnets when I am done
ROCKET MAN! Love it man, love it!
😁 thanks!
Very interesting and informative video. I'm a new subscriber (today) and really like the thoroughness and clarity of both you video and your narration. Excellent work! I really admire folks who just press ahead when faced with challenges such as the ones you've faced getting, and keeping, this lathe in good running order. Good job sourcing those bearings, standard replacement parts charges are such a rip-off. Jet should be ashamed both of the quality of the machining cleanup during manufacture and of trying to make their standard item spare parts a profit source. Good on you for proving how that will backfire. You got better bearing for a fraction of their asking price. My only slight disappointment was that you didn't show us the comparison of the worn old bearings with the brand new ones. Guess I'll have to be sure to tune in for Part 2. Wait a minute, was that a subtle cliff hanger?? Well intentional or not, I think it will work.
Part 2 😁
I would put a few strong magnets in the headstock where you can anyways and a screen in the two holes to oil the roller bearings
Second the neodymium magnets in the headstock sump, don't know how the oil/screen interaction would go (oil flow amount??).
Best wishes
Nice job Yuchol. Looking better all ready. What was the part number for the wear in paste that they used.
Thanks Randy, I will send you some of their paste. It’s called lapping compound, extra corse 😆
@@woodscreekworkshop9939 Oh I thought it was the fine compound. I see.
Комментарий не несет никакой смысловой нагрузки, он служит для поддержки канала и благодарности Автору.👍👍👍
It's a shame that you have to do this. It sould be a trouble free machine with the way you are going about repairs. Nice choices on the bearings and the tooling that you bought for the job. Great job on the way you presented everything in the video. Looking forward to the next video, hope you show going through some of the sub assemblys. Andy
Thanks Andy!
Use a strong magnet to get fine metal out of the gearbox .
Excellent video Yuchol. I suggest you let the hair grow like Rocket Man's. I love the tee shirt. Good detail on the bearings. thanks.
😂 thanks Terry
I think the bearings are all made on the same manufacturing procedure and graded accordingly to run out and the p5 tolerance is stamped on the bearing which you pay an arm and leg for.
They are definitely made the same, just inspected and sorted like you said
The production lines for the lower class bearings are not set up to take the all the measurements needed for the higher precision bearings. Precision bearings are usually made on separate lines since they get much more hand fitting and measurements taken. If the rings or rolling elements do not meet the tolerances, they are reground until it is within them. They cost so much more because the labor to make them is significantly higher.
@@mikeb1520 Damn right you are, I used to sell bearings and had an engineer over for super precision spindle bearings problems with an OEM machining center customer.
Long story short; all bearings of the run out quality needed be ABEC 3, 5 and 7 are made in specialised produstion lines or plants.
The amount of inspections and measurings make these type of super precision bearings so expensive.
The most expensive ones are made in sets that are marked not just with top of run out (etched dot), but are sorted and marked with an etched V mark across the set to avoid mixing the bearing set up
Guess what; that OEM customer had some apprentice mixing up a set of 4 angular contact bearings, no wonder they had troubles.
ervie60 I used to work for FAG Bearings in the Barden Bearings building, Barden only made ABEC 7 and 9 bearings, these P5 bearings in the video are scrap to them :). The ABEC 9 bearings had their own temperature controlled room with dedicated grinding, honing and measurement equipment, as well as employees. The people making ABEC 9 bearings only made that class bearing. After seeing the work that goes into making bearings of that quality, the prices don’t seem so outrageous.
My 2 working lathes both have plain bearings. I am wondering how expensive it is to re-bearing a modern lathe.
Dan Harold I got lucky finding my bearings. I can’t imagine the cost for a really expensive ultra precision lathes 😢
Some of the ones I’ve pulled apart have had pipe cleaners shoved down the oil holes. Form into a V, shoved down the hole, then bend flat what’s sticking out to stop it going all the way in. Will definitely stop big chunks of grit.
Hi. One more useful tool would be a bearing separator. This comes in two halves which fit round a bearing and then bot together. It has near kife edges that will prise a bearing away from it's neighbour and it also allows long all thread to be used to pull the errant bearing off a long shaft. They are not expensive and well worth having. Probably still need the heat gun. Stay safe folks. BobUK.
Yes, need some of those 👍🏼
I thought they placed magnets in bottom of reservoir to collect the metal chips?
Factory did not put any magnets. I out 2 at the bottoms and some by spindle oiling ports after the rebuild
Nice maintenance and upgrade mate.
Nice to see you didn't let those thieves at Jet rob you for inferior bearings ;)
At least not on the second set of bearings.
Yuchol, is the gear box a ferrous cast? If so, I would be dropping a few neodymium coin magnets in the bottom where they can easily be retrieved...
Yes and I plan to
Yes, maybe also some tiny ones along the troughs that channel the oil to the spindle bearings themselves. Can't think of any reason not to as long as they don't impede oil flow. Those are easy to get to by just removing the top cover, so Yuchol can keep an eye on things over the first few hours of operation.With the cleanup and deburring Yuchol did, there should be minimal to no large chips anymore!
Great video. Yuchol. My 25 year old Sharp 1340 is very similar. I've changed oil a couple of times...never looked into it as you have. I need to do that.
Thanks Joe. I’d say if it’s good after all these years, you’re safe 😀
@@woodscreekworkshop9939 I'm sure you're right, but it won't hurt to check. I suspect the spindle bearings could do with a bit of snugging up, too.
Nice video
Im getting a bit of play on the bearings
So now i know
I can tighten the bearings handy
Thanks again 👍👍👍
I am learning that setting the proper bearing load is more of an art than science and the preferred method is to look for a temperature rise at the bearings rather than using torque measurement
How were cut chips getting into the gearbox?
Left over from the manufacturing process at the factory
Complete details spindle fitting please
I was repairing my milling machine spindle today, it is 100 years old, It runs smooth now, but the taper has a 16um runout (7 tenths), not very good, I am sad
🙏🏻
Yuchal, that's Tuff Stuff... I hope the people from Jet Company are watching. That's terrible quality control you should have never had to go through this. Thanks for sharing!
Thanks Mike, I will rebuild 😂
Ouch. Surprising how little care was taken in putting that together at the factory. If it was 80 years ago I reckon there would have been actual people inspecting it before going to assembly. I guess that's what the paint is for lol. Thanks for the share, Yuchol 😊.
Yes, pretty sad
Thank you for the movie.
Consider putting some big magnet (for example from old speaker) into headstock close to oil pump drop - naturally wearing stuff will not flow internally, but stick to magnet. It also gives better view about oil quality - small pieces will not be visible without optical zoom (at least 2$ small watchmakers x10 magnifier).
Excellent video Yuchol, I can't wait to see the results!
Thanks!
This is VERY interesting, as I think my machine, sold under a UK brand, is from the same factory!
Would be good to take a look inside
@@woodscreekworkshop9939 Yeah, sure will do.
I'm just going to fix do a job or two on the lathe first.
I've got plans to redo the bearings in the mill, and I want at least ONE of my two machines to work, in case I have to "fix" something.
Great approach. What make of lathe is this?
Jet GH-1340W
Great Video!
I ordered new Timken bearings for my Bolton lathe a few months ago and they are just sitting on my workbench because of the dread of installing them, although I read it makes a world of difference to get rid of the Chinese bearings that's in it now.
Do it!
Yes, I would feel the same. On the other hand seeing this video and also a whole series from a channel called Swan Valley Machine Shop does provide lots of useful illustrations and tips and tricks for getting the job done. The SVMS videos show complete disassembly of a Taiwanese 12 x 36 lathe (different source, but basically identical to the PM-1236T). That combined with this excellent WCW series will be excellent inspiration for getting these jobs done!
@@woodscreekworkshop9939 Well, my motor burned up on my lathe so I had to do quite a bit of disassembly to dislodge it from where its buried in the back and I took the opportunity to replace the spindle bearings. Wasn't as bad as I thought it would be. Thank you for the motivation!
JETHO321 glad it worked out well!
Yikes, that went pear shaped fast! Good on you taking on the full rebuild.
Thanks man
Very good video how long did it take to get that bad and how much use. Was it run very frequently for several years or less?
Also did you have much runout because of the bearings?
I’ve had the late and used it “frequently” for a home hobbyist, the runout was really low. Other than the noise, I had no complaints of the machined parts. I am certain the runout would have gotten worse if I kept using it.
@@woodscreekworkshop9939 thank you for your reply. I dont have the noise or the runout but i think i can put this on the cards
This was quite interesting, as my 12x36 has some similarities to your 14x40. I had thought Jet would have had better cleaning and quality control, they have a decent name for themselves. My lathe is due for an oil change anyway, I think the lid will come off like after I first bought it and cleaned it, I'm wondering how much crap is floating in the transmission now!
Cool video! As easy as it is to deburr I never understand why it is so often overlooked.
Brian Moore great question 🤷🏻♂️
It's a shame that alot of the final handwork is skipped. I guess these companies are trying to come in at a price point. I imagine that most customers would be happy to pay for a couple more hours of labor considering the difference it would make.
Thank you for the very informative video keep it up 👍
محمد الكريع thank you 🙏🏼
0:05 What is the correct name for the RODE tool for sound analysis of bearing condition?
Подскажите пожалуйста, 0:05 как правильно называется инструмент RODE для звукового анализа состояния подшипника?
Где можно купить?
Erlan Bagyshbekov that is Rode Wireless Go, just a wireless mic system that has a built in mic.
Great video, great sound and video quality.Hang in there and don"t weaken!
Thanks Gary, staying strong here 😁
I would like to have a lathe that has the old style v-belt system and instead have precision bearings and other equipment critical to accuracy at a affordable price.
Get one or make one if you have the money,skills and time.
iam very happy to find something like you. your videos are very good
What about putting some course gauze in the drain hole over the spindle holes. You might have to replace the gauze twice a year, but it would keep out the metal pieces.
That would block the drain and would cause other issues. I have few ideas and will include in the part 2 video. 👍🏻
My one had the same crud in it as well .
Bastards!
Do the bearings get greased?
No grease, oiled in the headstock
Small heat gun /hair dryer 😂 - necessity is the mother of invention. Good job , I think all that kind of small machinery would benefit from a strip down and clean when you first get it .
Good work cleaning that up
I had the same issue of stupid tight bearings with my mill spindle a while back. I suppose it's better than loose
PS at 0:51 it looks like you dropped your lathe dog on the floor :P
He won’t leave me alone 😁
I love your t-shirts, especially the Rocket Man shirt.
One of my favorite 😁
Thank you for the information. I have a Taiwanese ENCO 13x40 that I may have to do some work on.
Thanks, be sure to share if/when you do the work
Great content. I have a kent kls1340a which is very similar I've also have seen similar defects like yours like leaking all over the floor thought about a drip pan like yours didn't have one so i just put gasket maker around the tray and pedestal now oil drippings just flow into chip pan which i also have to redo some of their welds on pan brackets this machine is only 4 years old and not ad much use as yours but the problem appears to be the fact that they have no pride in their workmanship any more.
I thought abou selling my original smaller craftex combo lathe mill but decided to keep it because wont get much for it and I've had to use it to make parts for my other lathe and mills when they break down like when you had to make new detent collar but you can't do it if lathe doesn't work at least it wasn't a critical part that machine won't work while making new one.
Word of caution for the lid
If you don't use a gasket just sealer that rib on lid needs to have notches cut into to allow oil into the trough for oiling the bearings
I reused the gasket but lid was bowed so i notched lid for oil flow a used gasket maker on both sides of the gasket this also cured the major part of my oil leak
Good luck with getting it back together and getting it going
Thanks for the tip. I also made a drip pan out of 16 gauge sheet metal few years ago and that helps. No pride in workmanship these days 🤷🏻♂️
Those bearings would have been installed by heating them to a temperature of approximately 250 degrees farenheit so they would slip into the spindle shaft. Don't directly apply heat to the bearings nor hammer them
Very instructive video. Nice effort!
Thanks Jan
What about putting rear end oil in there
Too thick, need basically hydraulic oil for the bearings
Hi Yuchol I've a Taiwanese Dar Sin 1230 Geared Head Lathe ( Sold by Frejoth (Acra)). I imported myself 1982. I shall renew the spindle bearings in near future. It might be vise to renew all the bearings and clean thew whole headstock.
Did you take any video of disassembling, and assembling the gear shafts, gears and bearings?
There is part 2 video
Good snap ring pliers are very helpful with this kind work.
A lot of machines incorporate a filter system maybe you could look for an aftermarket system because I assume you want to hang on to the lathe.
Some tips to NOT ruin those fine super precise new bearings and the other ones:
-put the cups in the freezer to shrink them.
-put the cones in your oven and heat them up, mind the temperature of course. I say max. 110-130 Celcius
-check housing diameters; if fit is too loose, a bit of loctite works miracles :)
And never ever!!!! hammer in a bearing!! might as mount the most crummy el cheapo bearings but mounted correctly!
Turn some nylon rings that fit the rings precisely and use that soft mallet to drive them in; all to avoid shock. Better would be to use a press for the cones on the shafts.
Brass rings maybe for the shaft mounted bearings (heat!)
last tips:
-check for markings on spindle bearings for top of run out; usually a dot is etched. Then make sure both bearings are positioned at same spot to avoid
-work as clean as you would work on hydraulics
-make sure the shoulders are spotless and square.
-proper pre load specs for those tapered roller bearings, make sure to make 10 to 20 revolutions so each rolling element makes a full revolution then measure torque with unster.
Good luck with the new quality bearings!
Thanks!
Oh, ouch that had to hurt... More power to you! Spindle bearings are the most important thing, next to the ways IMHO. I feel for you, man.
Peter A. Van Tassell thanks Peter 👍🏼
Leaving a large magnet in the reservoir,... after you get 'er all done ... ??
Kenneth Kustren you’ll have to check out the 2nd video 😁👍🏼
@@woodscreekworkshop9939 You can bet yer leadscrew I will !!
Careful, OEM's often order with a specific tolerance on precision and unless you know what it is you may not be getting what you need.
Even from a reputable bearing supplier those prices seem to good to be true.
Attention to detail is key
Dear brother I designed a 12 speed lathe Headstock by watching your both bearing replacement videos but it's not working properly I think lot of points are missed due to the fast videos could you please upload the original full video with normal play back so that I could come out of the problem in which I am badly stuck. Please do give me some solution otherwise my job will be in danger I designed it for a company in which I am working with.
You need to loosen the fit of the outer end spindle bearing on the spindle or you will not be able to set the pre load properly! It should be a tight sliding fit. If it binds up as you adjust the preload the main bearing behind the chuck will still be too loose.
Phil UK
I bet it is going to feel great to have new high quality bearings in your lathe. I have a 50 year old Colchester with the Gamet bearings. If it ain't broke, don't fix it, in my case. I think when some lathes need spindle bearings, it's time for the scrap yard. If you had to pay over $2,000 to replace bearings in your lathe would you do it? Or look for a new one?
I had a 13" South Bend lathe that was made in 1941. The cast iron bearings were in new condition. Maybe those guys knew a thing or two about quality. Of course the max RPM wasn't 2,000+
Jeff Anderson $2000 would be a tough decision, don’t know