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Author Topic: AL54b (lathe) project from New Zealand  (Read 163020 times)

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Offline Tweakie.CNC

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Re: AL54b (lathe) project from New Zealand
« Reply #60 on: November 12, 2010, 02:28:30 AM »
Quote
* I hope the ball screw has the same pitch as the lead-screw you are replacing, because the back-gearing is designed to work with the lead screw to get all the thread combination's. As this is very unlikely to be the case, you may have an interesting time getting the thread cutting going. Good luck.

Not sure why id keep any of that junk, the computer will cut the threads not the bucket of gears and crappy lead screw (only has about 3mm of backlash - I must have got a good one)

I must admit that I don't know much about lathes but I will be extremely interested to see just how this pans out.   ;)

Tweakie.
PEACE

Offline rcaffin

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Re: AL54b (lathe) project from New Zealand
« Reply #61 on: November 12, 2010, 02:49:57 AM »
I must admit that I don't know much about lathes but I will be extremely interested to see just how this pans out.   ;)
Tweakie.

Oh, with a decent servo drive on both the headstock and the ball screw, with the right sort of sync pulses, it should go just fine. (Plus the new bearings on the ball screw of course.) I hadn't thought it through when I made my comment!

Cheers

Offline Hood

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Re: AL54b (lathe) project from New Zealand
« Reply #62 on: November 12, 2010, 02:52:35 AM »
Only if you wish to use the lathe manually for thread cutting would you have to keep gearboxes and leadsrew pitch the same. I think however once you have done  threading  on a CNC lathe you will never do it manually again, its just so easy and quick :)


Hood
« Last Edit: November 12, 2010, 02:55:53 AM by Hood »

Offline Tweakie.CNC

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Re: AL54b (lathe) project from New Zealand
« Reply #63 on: November 12, 2010, 04:43:21 AM »
Sorry, my mistake.  :-[
I thought you were using that blue coloured ac motor with belt drive for your headstock (as shown in the earlier pictures).

Tweakie.
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Offline Hood

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Re: AL54b (lathe) project from New Zealand
« Reply #64 on: November 12, 2010, 04:51:21 AM »
Sorry, my mistake.  :-[
I thought you were using that blue coloured ac motor with belt drive for your headstock (as shown in the earlier pictures).

Tweakie.

I think he is but that is not a problem for threading as Mach only needs to see an index pulse to do threading. Spindle doesnt even have to be under Mach control.

Hood
Re: AL54b (lathe) project from New Zealand
« Reply #65 on: November 12, 2010, 05:22:12 AM »
Only if you wish to use the lathe manually for thread cutting would you have to keep gearboxes and leadsrew pitch the same. I think however once you have done  threading  on a CNC lathe you will never do it manually again, its just so easy and quick :)


Hood

Correct
Re: AL54b (lathe) project from New Zealand
« Reply #66 on: November 12, 2010, 05:24:22 AM »
Sorry, my mistake.  :-[
I thought you were using that blue coloured ac motor with belt drive for your headstock (as shown in the earlier pictures).

Tweakie.

I think he is but that is not a problem for threading as Mach only needs to see an index pulse to do threading. Spindle doesnt even have to be under Mach control.

Hood

Correct, C3 board from CNC4PC.

Although there is JHChoppers mill thread where he has a stepper that is connected to the spindle for indexing the ATC when i read how he'd done this I thought that would be a great why to run a C axis on a lathe, time will tell.
« Last Edit: November 12, 2010, 05:29:13 AM by jrslick22 »

Offline Tweakie.CNC

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Re: AL54b (lathe) project from New Zealand
« Reply #67 on: November 12, 2010, 05:56:35 AM »
Sorry to be a pain, I said I didn't know much about lathes.
Thanks guys.

Tweakie.
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Offline Hood

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Re: AL54b (lathe) project from New Zealand
« Reply #68 on: November 12, 2010, 06:00:06 AM »
Not a pain at all, good to have questions and thoughts on subjects you are not sure of.

Hood

Offline Hood

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Re: AL54b (lathe) project from New Zealand
« Reply #69 on: November 12, 2010, 06:18:43 AM »

Although there is JHChoppers mill thread where he has a stepper that is connected to the spindle for indexing the ATC when i read how he'd done this I thought that would be a great why to run a C axis on a lathe, time will tell.

 Personally as its not a massive lathe I would be looking out for an AC servo and drive on eBay. Not sure how the market for these are in the antipodes? Having a servo instead of the induction motor would mean perfect spindle control and no need for pulley ranges as torque is constant from zero to rated speed and there is usually at least double available for short periods.
Only issue at the moment is the SmoothStepper does not support the SwapAxis feature of Mach and dont know if it will but if it happens then rigid tapping and spindle indexing would be a piece of cake.

Hood