pressbrake1
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Hopefully but all real precision bearings were ridiculous prices.
Maybe give them a call.
- Thread starter Kram
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Maybe give them a call.
pressbrake1
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Gut feeling £2000 wouldn’t cover even knock off bearings.
Perhaps get a job at gamet and learn how they make them!
slim_boy_fat
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Kram
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Diminishing returns for all that cash?
Unrelated but found this guys videos interesting, but needs subtitles turned on. As he is playing with jet engines he needs high speed bearings. Seems the weak point of most is the pressed steel cage that can collapse.
Unrelated but found this guys videos interesting, but needs subtitles turned on. As he is playing with jet engines he needs high speed bearings. Seems the weak point of most is the pressed steel cage that can collapse.
Kram
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Made a couple quick videos. Couldnt get one while cutting as the mag base vibrates out of place and I havent made an adaptor for the big one yet.
www.youtube.com/watch?v=VaDKJMMKTGg
www.youtube.com/watch?v=p6Heolhnqcw
I have only bored the part since it was chucked - OD hasnt been touched since it was flipped around. Given up with it for now as it makes too much chatter.
www.youtube.com/watch?v=VaDKJMMKTGg
www.youtube.com/watch?v=p6Heolhnqcw
I have only bored the part since it was chucked - OD hasnt been touched since it was flipped around. Given up with it for now as it makes too much chatter.
Not actually sure what you are measuring in the first video. Looks like some form of vibration.
To measure the spindle play or run-out (second video) you need to remove chuck and measure on the spindle face in both planes. That should then be the staring point. You can then add the chuck and test piece and look at the cumulative error they introduce.
Your lathe should have come with a Test Record - unless Warco have stopped providing them- which provides diagrams of all the test measurement points, the allowed tolerance and the measured results for your machine.
I have a Warco WM250V which came with test report although the lathe is 15 years old, one of the first imported. They made quite a few improvements to later machines, ah well that's what you get for being an early adopter! To carry out many of the measurements you need a precision test bar with Morse taper to suit your spindle. they are / were readily available but not cheap, especially for something you may never use again.
The only problem with the taper roller bearings is adjusting the pre-load. I did a bit of research on the subject a few years ago and it seems to be a bit of a black art. For the hobbyist its pretty near impossible to measure and that's if you know what its meant to be in the first place. Most of the methods I have seen involve trial and error. That is applying a small amount that feels good with no end float and then running it for say 20 minutes and seeing how hot the headstock gets. You can then adjust from there according to taste. I am sure there are others on here who have far more knowledge on this subject than me.
To measure the spindle play or run-out (second video) you need to remove chuck and measure on the spindle face in both planes. That should then be the staring point. You can then add the chuck and test piece and look at the cumulative error they introduce.
Your lathe should have come with a Test Record - unless Warco have stopped providing them- which provides diagrams of all the test measurement points, the allowed tolerance and the measured results for your machine.
I have a Warco WM250V which came with test report although the lathe is 15 years old, one of the first imported. They made quite a few improvements to later machines, ah well that's what you get for being an early adopter! To carry out many of the measurements you need a precision test bar with Morse taper to suit your spindle. they are / were readily available but not cheap, especially for something you may never use again.
The only problem with the taper roller bearings is adjusting the pre-load. I did a bit of research on the subject a few years ago and it seems to be a bit of a black art. For the hobbyist its pretty near impossible to measure and that's if you know what its meant to be in the first place. Most of the methods I have seen involve trial and error. That is applying a small amount that feels good with no end float and then running it for say 20 minutes and seeing how hot the headstock gets. You can then adjust from there according to taste. I am sure there are others on here who have far more knowledge on this subject than me.
Kram
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Yes first video is vibration, there is a lot and it is much worse when cutting. I can get away with it at higher speeds and smaller cuts - but is no good for parting or EN19t which seems to need deep cuts at slow speed. Cant continue with er40 chuck because of the noise.
Im not sure if you are telling me there is nothing wrong with it? The test report does not measure while cutting or vibration.
Interested to know if the 250 model has the internal bar in the headstock casting, I saw it in a video of a german branded chinese lathe.
Orderd 3" round lump of cast iron for the headstock spacer tube. I will bore it out and turn it to 72mm long but may need to adjust the length after disassembly.
Im thinking I could seal the front face and fill the whole headstock with oil. Id need a lump 120 * 175 * 25mm, and seal the threads for change gear idlers. That should massively improve vibration damping? I will do that later, first bolt a peice of round alu between and see if improves.
Im not sure if you are telling me there is nothing wrong with it? The test report does not measure while cutting or vibration.
Interested to know if the 250 model has the internal bar in the headstock casting, I saw it in a video of a german branded chinese lathe.
Orderd 3" round lump of cast iron for the headstock spacer tube. I will bore it out and turn it to 72mm long but may need to adjust the length after disassembly.
Im thinking I could seal the front face and fill the whole headstock with oil. Id need a lump 120 * 175 * 25mm, and seal the threads for change gear idlers. That should massively improve vibration damping? I will do that later, first bolt a peice of round alu between and see if improves.
Laurie Tedcastle
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Okay an update on Gamet bearings. Had a chat with a representative on the HB Bearings stand today at Race/Retro at Stoneleigh. HB Bearings have closed the Colchester factory and moved the equipment to their Huddersfield site and production is restarting. Gained the impression that the equipment is a lot more sophisticated than they use for other stuff. All Gamet sales are now from HB directly, 600 Group no longer involved. Did not, however, inquire about pricing.
Laurie
Laurie
pressbrake1
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The way to measure run out and ovality is my doing a test piece with the bearings under load and then put test piece on a tallyrond or other roundness tester
You can see the noise from individual bearing rollers such is the sensitivity
The test card that comes with a gamet equipped Colchester is from a tallyrond.
Even a worn bearing can have play but check out on a clock on the mandrel.
Think op has no choice but to do the unpleasant job of a strip down
You can see the noise from individual bearing rollers such is the sensitivity
The test card that comes with a gamet equipped Colchester is from a tallyrond.
Even a worn bearing can have play but check out on a clock on the mandrel.
Think op has no choice but to do the unpleasant job of a strip down
God mode restorations
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I paid a visit to the 600 group and had a very interesting chat with them. Unfortunately there isn't another bearing that will fit . The original gamet bearings are machined down to 5 microns. Gamet will not deal with people directly but will sell you a set via an independent dealer. You will not get much if any change out of £4000
God mode restorations
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No unfortunately not. It's this reason why a lot of em get sent to scrap. Colchester parts are mega expensive because people bump the prices up as they think they have something special. 550 for a second hand colchester mk1 tailstock.....
