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HOME MADE SPEED REDUCER

Posted: Fri Jun 02, 2017 9:52 am
by woodmeister
Need some advice. Planning to fabricate this using shopsmith parts and an electric motor. Will it work?
Mounting and MV extension table on way tubes using the same wing nuts they use to attach the planner. Attach the electric motor onto the extension table. Use a 2 in pulley on motor. Then take a 12 inch sanding disk and mount a hard wood board onto it and turn it to be concentric with disk and put the same groove the 2 in pulley has. Then turn speed control up to high speed and unplug SS. Now put the newly made 12 in pulley onto the accessory side of the head stock(highest hub) attach belt to both pulleys and turn electric motor on. Saw something like this online but never got any feed back on safety or function. Will it work?

Re: HOME MADE SPEED REDUCER

Posted: Fri Jun 02, 2017 10:23 am
by reible
In general simple math says the the center to center dimension of the pulley's has to be half the larger and half the smaller plus something. As a pure guess I'd put that about 9". This pretty much says that mounting a motor to the way tubes above is not going to work. I'll let you figure other options since I'm not really clear on what you intend to do.

I'm not going to address the power loss by driving the headstock parts, even at high speed....

Ed

Re: HOME MADE SPEED REDUCER

Posted: Fri Jun 02, 2017 11:27 am
by JPG
Since speed reduction is the goal. the idler shaft is a 'better' shaft to be driven. It already has a 1.6:1 speed ratio to the quill shaft.

That will reduce the size of the possible 'big pulley' however.

A concern I have is the extra loading of the internal drive parts which are not doing anything useful.

Bill Mayo has previously posted a method that includes removal of the poly-v/gilmer belt and using a small pulley on the idler shaft and a larger pulley of the upper shaft. That allows use of the SS internal motor and the built in speed reduction(3750:700). The downside is the effort needed to remove/add the idler-quill shaft belt.

Re: HOME MADE SPEED REDUCER

Posted: Fri Jun 02, 2017 11:55 am
by woodmeister
well the ss extension table is mounted to tubes leaving the table 90 deg outward from table. the motor is mounted to the extension with the 2 in pulley on it. The 12 inch pulley (sanding disk part) will be attached to the upper hub on the accessory side. The pulleys will not be directly above one another on head stock rather on end of extension table on ac motor. If there is no power on ss head stock and it is on high speed how will this possibly harm the motor? Want is just rotate at rate of ac motor?
Thanks for the reply

Re: HOME MADE SPEED REDUCER

Posted: Sat Jun 03, 2017 12:02 am
by JPG
I guess I do not understand what you are describing, since it does not make sense to me. :confused:

Re: HOME MADE SPEED REDUCER

Posted: Sun Jun 04, 2017 6:35 pm
by peterm
Here is some previous discussion........scroll down to see my setup. It worked fine at the time. http://www.shopsmith.com/ss_forum/viewtopic.php?p=75668