Author Topic: Minature lathe - chuck?  (Read 3601 times)

Offline Starhead

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Minature lathe - chuck?
« on: May 25, 2019, 03:15:05 PM »
Hi folks,
 I've got this lovely little lathe gearbox, I imagine a jeweler's lathe - (see pics)

Does anyone recognize how it connects to the chuck? Any ideas how I can adapt it to receive a standard chuck or a faceplate? The shaft is 1/2" diameter and has a drift pin , a groove presumably for a rubber ring washer, and a threaded hole in the end.

Thanks

Offline philf

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Re: Minature lathe - chuck?
« Reply #1 on: May 25, 2019, 05:59:01 PM »
Hi,

It doesn't look like part of a lathe to me.

The output shaft is really too small for even a watchmaking lathe.

The gear ratio from the pulley to the output shaft looks to be about 16:1. That combined with the large pulley would mean that the torque could be very high but the rotational speed very low.

A lathe spindle needs bearings to take thrust as well as radial loads. Does it have that feature?

Cheers.

Phil.
Phil Fern
Location: Marple, Cheshire

Offline seadog

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Re: Minature lathe - chuck?
« Reply #2 on: May 25, 2019, 05:59:57 PM »
More like a hand grinder.

Offline Starhead

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Re: Minature lathe - chuck?
« Reply #3 on: May 26, 2019, 02:35:58 AM »

Philf there are plenty of mini lathes with a 1/2" shaft, yes it will be low speed, and high torque which is what is needed for turning.

Seadog it's not a hand grinder, if you were to turn it by hand the output speed would be about 2rpm.

Maybe if I ask the question differently.... I've got this metal thing with a shaft sticking out, how can I attach another metal thing to the shaft?

Offline seadog

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Re: Minature lathe - chuck?
« Reply #4 on: May 26, 2019, 03:01:00 AM »
"yes it will be low speed, and high torque which is what is needed for turning"

Only if you're turning something of large diameter. For small parts surely you need a high speed spindle to achieve a decent surface finish?

Offline Starhead

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Re: Minature lathe - chuck?
« Reply #5 on: May 26, 2019, 04:22:36 AM »
The shaft... how do I connect something to the shaft?

Offline pycoed

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Re: Minature lathe - chuck?
« Reply #6 on: May 26, 2019, 05:14:00 AM »
1 Polish the shaft,
2 Obtain or make a piece of thick wall tube that is a shake-free fit on the shaft
3 Mill,  or drill & file a slot in the rear end to fit the drive pin
4 Drill & tap a hole to meet the groove & fit a grubscrew
5 Weld, or shrink on a suitable flange to fit a chuck of your choice
6 Mount chuck & place assembly on shelf while you look for a small lathe, 'cos I doubt this will serve as one :D

Offline Starhead

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Re: Minature lathe - chuck?
« Reply #7 on: May 26, 2019, 12:22:57 PM »
Thanks pycoed, I think that's probably the answer I'm looking for. Ive been searching everywhere for a 1/2" flanged coupler but I can't find anything suitable, everything in the UK seems to be metric now and I don't think I can ream out a 12mm one accurately enough without erm.. a lathe.

I'm pretty sure this will be capable of turning wax which is my intention, for lost wax casting of aluminium.

Offline efrench

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Re: Minature lathe - chuck?
« Reply #8 on: June 02, 2019, 05:07:28 PM »
You don't actually need a chuck.  I use a faceplate with a piece of waste wood attached for most of my wood turning.  I think this would work even better for wax. One nice thing about using a faceplate and waste wood is you don't have to be particularly accurate with the faceplate mount.  Once it's attached to the spindle, you true up the waste wood.  Whereas a chuck should have an accurate mount.