Lathe - Barber Shop Pole Pattern, Loose Carraige?

Maybe the motor is vibrating the lathe, maybe try isolating it?

On another note: I looked at a 15x50 Colchester today. :grin:
 
I isolated it soon after I bought it Jim. No worries there is a metal recycler just a few miles from me, I wonder how much I'd get for a 1,000 lbs of cast iron and steel. :burned up:

I'm going to check the lathe level and pads tomorrow. I used the old hockey pucks for leveling pads. Maybe it settled, that's about the only thing I can think of why the lathe would work fine, then sit for a few months, then do this out of the blue. On the bright side now I feel vindicated for buying that Starrett precision level on ebay months ago!!
 
Do'nt be a defeatist!. No wonky pullets/bearings?. Headstock tight to bed?. You must get to the bottom of this if only for your peace of mind ,and everyone else who is following this thread. P.S. I will give you TWICE scrap value for it if you can pay the delivery to Australia:).
John.
 
After re-reading your thread, I think you need to pull the spindle, chunk the existing bearings, and buy a good name brand set of bearings to replace the Asian junk bearings!!! If there is any gearing in the headstock, which I suspect there is, check the wear pattern on the gear teeth. There could be a gear that is not meshing correctly. IF so, get with the manufacture, and see if you can't get replacement gears to replace any that are suspect.
Then try again.

Edit: One more thing to check while you have the headstock gutted, as turnitupper mentioned, pull the bolts loose that hold the headstock casting to the bed. Run a .001" feeler gage around to seee if it goes under the HS casting. IF so, see what the thickest feeler i you can get under the HS casting. If you can't get a feeler gage under the HS casting that is great. If a feeler goes any at all, that not good! That means the HS casting was twisted when the bolts were tighten. With the HS casting twisted, this would put the spindle in an out of alignment condition with the bearings and gearing. IF this was happening, it could be causing your condition as you have shown us.
Let's hope its something simple as bad spindle bearings!
 
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coolidge said:
I wonder how much I'd get for a 1,000 lbs of cast iron and steel. :burned up:
Click to expand...

About $35, scrap is going for about $70 / ton. Scrap price is way down right now.
 
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4gsr it comes from the factory already upgraded NSK spindle bearings.
 
Well I got the shop crane out, removed the hockey puck leveling pads and lowered the lathe right onto the concrete. Its more firmly planted than before we'll see if that makes any difference. Its not a cast iron stand so its not stable as granite, you can still jiggle the lathe a bit but its an improvement. I shimmed it level with the Starrett precision level before calling it a night. Tomorrow I'll see if this improves the surface finish.
 
Well I turned some brass just now and FAIL I still have the spiral pattern. :cussing:
 
I think it’s machine harmonics. I have seen it before. Could be a vibrating motor? Could be the drive belt(s) flapping or just bad belts? Could be an out of balance pulley in the belt drive assembly? Could be headstock gearing? Could be the lathe is not firmly seated to the floor? Whatever it is, it is telegraphing the harmonics to the cut in progress and is making a recording of it as in the finish you see. Does the lathe run smoother at certain speeds and noisier at other speeds. I would look for a machine harmonic problem. My experience has been as easy as just loosening up the drive belt a bit and the weird pattern went away…Good Luck, Dave.
 
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