Lathe motors…

[tmac1956]

@david pierce wrote:

Tmac,
That looks like a good heavy powerful lathe and should take the abuse that metal spinning will put on it.
david

David:

Thanks!

tmac

[tmac1956]

david:

One of Grobet’s sellers offers lathe motors. What do you think about these?

https://www.ishor.com/polmotor.php

The last two look like they might be pretty good…

Thanks,
tmac

[tmac1956]

@david pierce wrote:

Tom,
The pulley system can be analyzed with a mathematical proportion. The initial fromula can be stated as:
MOTOR RPM * MOTOR PULLEY DIAMETER = LATHE RPM * LATHE PULLEY DIAMETER. If you know three of these components you can solve for the unknown fourth component. For example, if you know the motor rpm, the motor pulley diameter, desired lathe rpm and want to calculate the LATHE PULLEY DIAMETER, you can rearrange the formula to state ((MOTOR RPM * MOTOR PULLEY DIAMETER) / LATHE RPM) = LATHE PULLEY DIAMETER. The homework assignment for today will be to solve for the other three components.
I found SINCERE TOOLS initially by going to Ebay and looking under WATCHMAKER LATHES. If you scroll through this section until you find a picture of their lathe you will find it. Also, they are always listing their cross slides for sale for $245.00 and you can click them on from there as well. I think they also have a page on the general internet and will take a look.
david

David et. al.:

I finally took my lathe motor out of the box (yes – I am something of a procrastinator). I did the calculations from the formula above and if I did it correctly, it appears as though if I need to keep the lather RPM at or below 3,000, the only pully selection combination I can use are the biggest on the lather and the motor as all other combinations exceed the recommended 3,000 RPM for an 8mm cone bearing lathe.

The foot switch that came with the motor is simply an on/off switch and not a rhesostat so should I try to find one the is a rhesostat? Right now it’s wide open which is a little scary when turing brass rod. Merlin has one here…

http://www.ebay.com/itm/Variable-Speed-Foot-Pedal-Switch-Watchmaker-lathe-/120818875411?pt=LH_DefaultDomain_0&hash=item1c215dbc13

Thanks!
Tom

[david pierce]

Tom,
In order to get the different speeds I use an idler pulley between the motor and lathe. This works on the same principal as compound gears on the watch gear train. You can find them on Ebay or other sources and they usually run around $100.00.
david

[tmac1956]

@david pierce wrote:

Tom,
In order to get the different speeds I use an idler pulley between the motor and lathe. This works on the same principal as compound gears on the watch gear train. You can find them on Ebay or other sources and they usually run around $100.00.
david

David:

I’ll search for one. It’ll be on my list behind that Mill/Drill and the Ace timer.

Thanks!
Tom

[tmac1956]

David:

Is an idler pulley the same as a counter shaft?

Thanks!
Tom

[tmac1956]

David:

Is this what you’re talking about?

http://www.ebay.com/itm/SPRING-BELT-RACK-for-Watchmaker-Lathe/280486261952?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D27%26meid%3D9046073893770948043%26pid%3D100033%26prg%3D1011%26rk%3D2%26sd%3D290836551025%26

THanks!
Tom

[david pierce]

Tom,
Check out Ebay items #161053566075 and #121140571482. The first one shows the item and the second one shows how it is used.
david

[tmac1956]

David:

Got it!

Thanks,
Tom

[david pierce]

Tom,
Go to Youtube and type in WATCHMAKER LATHE WITH MILLING. This shows the purpose of the spring loaded belt tensioner. Under actual use the spindle would not be turning but would be locked in with the index pin for gearcutting.
david

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