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  #111  
Old 09-13-2022, 05:02 PM
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greywynd greywynd is offline
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Nope, those are outside jaws, chances of finding the proper matched set for ‘inners’ are slim. Even if you do find them, unless they are ground/fit to that specific chuck, they won’t run 100% true.

Too bad shipping is stoopid pricey, I likely have a chuck with both sets of jaws. If I don’t at home I know there would be one in the storage trailer in Onterrible.


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  #112  
Old 09-16-2022, 11:41 AM
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You're very kind, but don't worry, the Chinaman will provide.

I must upload a video later but my farmer's toolpost grinder did the business just fine.

I spent 20 minutes cutting it, ran the lathe in bottom gear. Stopped every few minutes and put a wet rag on/into the bearing to keep it cool. Spent a lot more time cooling than cutting. Surface finish was perfect and only gave it a run of a stone for a second to clean up the faintest of burrs. The way it was going in meant it only needed a taper on one edge so I just fitted it like it was.

About 3 hours from the UPS man to having it machined, the box rebuilt and refitted.

I've a mini digger coming in the morning so badly need the tractor running for dumper duties
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  #113  
Old 09-16-2022, 08:15 PM
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milomilo milomilo is offline
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Quote:
Originally Posted by JohnBoy View Post
You're very kind, but don't worry, the Chinaman will provide.

I must upload a video later but my farmer's toolpost grinder did the business just fine.

I spent 20 minutes cutting it, ran the lathe in bottom gear. Stopped every few minutes and put a wet rag on/into the bearing to keep it cool. Spent a lot more time cooling than cutting. Surface finish was perfect and only gave it a run of a stone for a second to clean up the faintest of burrs. The way it was going in meant it only needed a taper on one edge so I just fitted it like it was.

About 3 hours from the UPS man to having it machined, the box rebuilt and refitted.

I've a mini digger coming in the morning so badly need the tractor running for dumper duties
Glad to hear it worked out.
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  #114  
Old 09-17-2022, 12:57 PM
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A lathe is a wonderful tool
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  #115  
Old 01-01-2023, 09:27 AM
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Right, I want to dig into my vibration issues.

I think like many performance problems there is no one cause, they tend to be an accumulation of problems.

Definitely one of my problems is the drive setup. it is introducing a degree of the vibration even when not cutting and it is theoretically very fixable, it's just belts and pulleys.

Spent some time this morning with a DTI and stand looking at the setup. Both stepped pulleys on the lathe and countershaft are running true. the big pulley on the countershaft has a few mm of wobble and the motor pulley has about .5mm wobble. Also the end of the countershaft is rough, looks like it was sized with a grinder and the keyway cut with a chisel (slight exaggeration, but it is rough. I think it's a 3/4 inch pulley on a 19mm shaft)

So for the sake of it I'm gonna buy new pulleys and countershaft, got part of my christmas bonus as a prepaid credit card so may as well buy something for me.

This raises a question about speeds.

My maths says I currently have the following speeds: 50, 75, 100, 300, 420, 600 rpm

I can get the same diameter pulleys again and drive on, but there's relatively little difference in price to go up or down a bit to move the speed ranges around. is there any point?
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  #116  
Old 01-01-2023, 03:58 PM
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Or could I improve on this with some shimming I wonder
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  #117  
Old 01-01-2023, 04:22 PM
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midmosandblasting midmosandblasting is offline
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Did Rod not go to a link belt to solve vibration issues on something ?
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  #118  
Old 01-01-2023, 04:34 PM
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Oh man that shaft is ugly. is it bent? Also have you run the motor with everything off of it to see if the motor itself does not cause any vibrations?

Is it a ball bearing motor or sleeve?

Yes Rod used the link belt on the lathe or something and did help with vibrations.

Scott
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  #119  
Old 01-01-2023, 04:37 PM
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mccutter mccutter is offline
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Quote:
Originally Posted by JohnBoy View Post
Or could I improve on this with some shimming I wonder
Maybe clean that shaft and check for runout? Dress the grind marks with a mill bastard file.
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  #120  
Old 01-04-2023, 09:15 AM
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Couldnt accurately measure shaft runout because the surface was a bit undulating at the end but couldnt detect any with a pointer either.

So the good thing about that shaft is it was so "shaped" that there was good room for shimmage.

played around with a soda can and ended up with one piece wrapping about a third of the way around the shaft. Got the pulley runout down to a quarter of a mm which I reckon for a 200mm pulley spinning around 500rpm isnt too bad.

As part of my tinkering I tightened up the mounting for the arm the countershaft and motor hang off, and I put some cow mat into the apex of the join too. The combination of all of these changes has the lathe running a lot smoother now.

I'm still getting chatter, but it's different now. I know nothing about lathes but I just knew there was something else wrong, as a machine it just wasnt smooth/tight enough and as soon as the tool was hitting the whole thing was getting into a resonant type of shake making itself worse.

In time I may get a new shaft and some pulley blanks to machine but for now it's moved down the priority list.

I splurged a bit online the last few days buying a live centre, some HSS tooling, a 3 jaw chuck, some transfer punches and an mt3 dead centre for accurately setting tool height.

I need to tighten the carriage a little bit, print out a belt -> RPM chart and start playing with some metal and the how to run a lathe book.
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