Shopsmith Forums

I have made a few items that required using some larger diameter Forstner bits and have found that the lowest speed on the SS appears to be a little too fast for these size bits--1 3/4" and up. I know Nick used the speed reducer (555428) in one of his sessions on the bandsaw. Before I start saving for a speed reducer I would like to verify that indeed it can be used in the vertical drill press mode.
Regards,
Dwight

It is verified.

Ed

The speed reducer comes with a clamp that holds it to the way tubes. With it clamped in place you can use it in the lathe or drill press mode. If I remember correctly you can reduce the speed to around 100 rpms.

Question: If it is clamped to the way tubes how can you move the quill/spindle to extend it out for drilling or lathe work?
Regards,
Dwight

I have used my speed recuder several times in the drillpress mode. Just leave the clamps slightly loose on the waytubes.

When properly aligned, the speedreducer slips right along the waytubes and stays in-line with the quill.

alB

Thank you for the clarification.
Dwight

A Bit off the planet but - Can anybody tell me if it would be possible to mount 2 speed reducers so as to get really slow speeds say down to 35 RPM? And if so would the extra strain blow fuses?


i am looking at building a Shopsmith version of a "router-lathe/mill" and need a slow turning speed to work with.

Thanks Sandy in NZ

Hi,

Anything can be done but if you want to just hook them up then no it's not going to happen. One of the connection points is to the quill so you would need to find a method for connecting the second speed reducer to the first.

This is really just a 7:1 belt reduction system so you don't use much power spinning it. As far as speed, the shopsmith's low end is around 700 rpm so the output of the speed reducer is about 100 rpm. If you were to add a second it would be in the 15 rpm range at the low end. Top end would be around 370 rpm (not that you would want to do that). (numbers are rounded)

Ed

Thanks for that Ed. - that just saved me a wad of money.
I will re-plan my thought process but still proceeding with the idea.
Regards
Sandy in NZ

Sandy:

I've never tried to mount two speed reducers in tandom, but it appears to be possible. Keep in mind the fact that with the mechanical nature of geared speed reducers, you will multiply torque proportionally as you reduce speed. Other means of obtaining variable speed, such as a DC motor, do not do this, rather they operate at constant torque as speed is reduced.

You will not "blow" fuses or trip circuit breakers in normal operation as the two reducers will only nominally reduce the power train's efficiency due to friction losses. Keep in mind however, that the gears in the speed reducer are designed to transmit the headstock motor's torque in a 7 to 1 speed reduction range. The second speed reducer is not designed to multiply the kind of torque that is developed at the output of the first speed reducer. If your final output torque requirements are too high, you could easily strip the gears in the second speed reducer. Gearmotors that have high reduction ratios are normally very large in size to accomodate the necessary large and beefy gears.

In a nutshell, if one speed reducer, at 100 rpm is "good to go" with a 3" forstner bit, a 6" bit operating, on the output of the second reducer, will likely destroy the unit.