Interesting Gear Reducer On Drill Press

[T. J.]

A couple months ago I bought a Rockwell 17" drill press at an auction. It had a funny looking and obviously non-original motor pulley on it.


I didn't pay much attention to it as I had plans to replace the motor with a treadmill motor to give me easier speed variation - especially very low speeds for drilling large holes. As it was, the lowest speed was about 650 RPM. Well today I was rearranging some things and had the DP away from the wall, so I decided to fiddle with that pulley to see if I could figure out how to get it off. The hole in the side tuned out to not contain a set screw so I got a stool to look at the top and found this:

It says "PULL GEAR, PRECISE GEAR CO, WARREN MICH" and a number: PG7 T01
The key in the center pulls out and turns to disengage the shaft from the pulley.


I played with it a little more and found that if the top portion was held stationary while the motor shaft was turned, the pulley turned at a much lower speed! So now that I knew that this was speed reducing gear rather than just a funny looking pulley, I had to figure out how the upper portion was held stationary while the DP was actually running. That's where the other non-original part on top of the DP comes in:

I turned it on and it works like a charm! Using my speed indicator that I got from forum member "WreckWreck", I determined that this devise gives a speed reduction of about 7:1. So combining with the 3 pulley steps, there are 6 speeds from 94 - 1650 RPM. Has anyone ever seen one of these? I think I'll forego the treadmill motor conversion and use it as is.

 

[rrjohnso2000]

That is pretty slick. I hope you have another use for that treadmill motor

 

[kd4gij]

neat. That will give you much more torque than the treadmill motor.

 

[Chipper5783]

neat. That will give you much more torque than the treadmill motor.

Very cool set up. Nice drill press. Make up some sort of a shifter and couple that with a variable speed drive (such as that treadmill motor) and you would hardly ever need to move the belts (though moving belts is no big deal - I actually use my multi-step pully driven drill press more than the variable speed driven one).

Anyway, how much torque can you put through that single belt? You should have a 1HP motor on that, x7 ends up being a pretty good pull on the belt.

Show us more pictures. We want to see "Before" and "After". Attached are a couple pictures of what I've done with mine 17" Rockwell.

 

[brino]

Hmmmmmm......back gear on a drill-press.
I've never seen that.
Thanks for posting!

-brino

EDIT: Are those two ball oilers on the top there too?

 

[T. J.]

Thanks for the comments guys. This really makes me want to go find something thick to drill a big hole in, but unfortunately it only came with a 3/8" chuck! Time to go shopping...

That is pretty slick. I hope you have another use for that treadmill motor

Well now that you mention it, I have an old Craftsman vertical band saw that would be a lot handier if it turned slow enough to cut metal...

Anyway, how much torque can you put through that single belt? You should have a 1HP motor on that, x7 ends up being a pretty good pull on the belt.

Show us more pictures. We want to see "Before" and "After". Attached are a couple pictures of what I've done with mine 17" Rockwell.

I'll take some more pics tomorrow. Its not very flashy right now but I plan on stripping it down and repainting at some point.

Hmmmmmm......back gear on a drill-press.
I've never seen that.
Thanks for posting!

-brino

EDIT: Are those two ball oilers on the top there too?

Yes they are. I tried to get a little oil in there. BTW is there a 'proper' method for oiling ball oilers other than squirting it in with an oil can?

 

[Terrywerm]

You've got it on the ball oilers. Push the nozzle against the ball to push it in, then slowly squirt some oil in.

I like your line of thinking for a speed reduction for a bandsaw. That would probably work out quite well.

 

[wa5cab]

The nozzle on the oil can must end in a truncated (point cut off) cone where the flat tip is slightly smaller than the diameter of the hole the ball pops up against and the base of the cone is slightly larger. The flat depresses the ball and the cone seals against the hole.

 

[T. J.]

I'll have to make one of those. The tip on my oil cans just come to a point. What brands of oil cans are good and where do you get them? The ones from Harbor Freight leak like a sieve!

As promised, here are some more pics of the drill press. As you can see, there is a hole cut in the top cover to provide clearance for the 'pull gear'. It still rubs though, so I've taken the cover off until I can fix it.

 

[wa5cab]

The best one is probably the Eagle No.66. They are all brass. There are usually half a dozen or so available on eBay at any given time. Search for Eagle 66 Oil Can. Typical prices are $20 to $45. I would probably avoid the $20 ones. The 66 is of the style least prone to leakage. Both the spout and the pump actuator stick out the side. The top is thus just a top and less prone to leakage. Also doesn't drip oil all over the bench when you open it to refill. They came with either a rigid or a flexible spout. If you are just buying one, go for the rigid one. You can use it in a ball oiler with one hand. The flex spout one would require two. They work fine with the spout point straight down. You just need to keep the can more than half full. It is the only can I ever found that would reliably put oil into an Atlas Commercial back gear bearing.