Craftsman drill press slow speed attatchment pulley

[Reversepolarity]

I am wondering if anyone can give me the dimensions of the OEM pulley for the slow speed attatchment.

I have already built the plug for the drill press post.

I would like to match the stock pulley size. That way the speed chart in the owners manual will match what I am building.

What I need is the O.D.'s of each pulley.

Thank you.

 

[Reversepolarity]

I will be using bronze flanged bearings in the pulley.

 

[Reversepolarity]

I don't know the exact step sizes, but I believe they are 2", 3", 4", and 5"... the same as the spindle pulley.



JZiggy makes these slow-speed pulleys and may know.



However, if I were making my own, I think I'd go larger if possible, to slow down the chuck even more.



Here's a speed calculator. You need to perform the calculation twice for a middle pulley.

http://www.woodmagazine.com/woodworking-tips/techniques/drilling-boring/determining-pulley-speeds/

Thank you.
I assumed it was the same as the other pulleys.
Just wanted to make sure.

 

[gungatim]

if you have the speed chart, and the dimensions of the driven pulley, you can calculate the unknown pulley diameter using algebra...

Belt speed is a function of the circumference of the pulley X motor RPM. calculate out your motor pulley first, then solve for desired rpm of each speed to calculate needed secondary pulley diameter (or 3rd, or whatever the setup is).

(Motor rpm)(Motor Pulley Dia.)(Pi) = (Desired Mandrel rpm)(Mandrel Pulley dia.)(Pi)

 

[Reversepolarity]

I will take some pictures after work.

 

[gungatim]

you can make a quick spreadsheet like below (just the circled part, you don't care about trans/rear end ratios or speedometer gearing).

just plug the known (green cells) for each step on the pulley and desired speeds. Ignore belt speed column it is irrelevant for this application.

 

[Reversepolarity]

Cool

 

[Reversepolarity]

FrankLee,
This is what I am going to use.
Shaft is 3/8" off center.
Will secure with a couple of set screws drilled and tapped in the drill press post.