Slow down my drill press?

[kelpaso1]

I would like to slow my drill press down since I mostly drill metal. Slowest speed right now is 620 RPM. I see the most common way on other drills is the extra idler step pulley between the motor and spindle. But I have no clue as to how to rig an idler pulley to this drill. Any ideas, or pics of this modification already done? It's a Delta 12" bench model.

 

[hh76]

Vfd?

 

[Evilunclegrimace]

I might be mistaken but,the only way that I see that you could slow that press down with out a lot off work would be to find another stepped pulley that has a larger set of diameters on the quill drive.

 

[metalmagpie]

A VFD only works on three phase motors. The easiest solution is to buy another drill press. If you want to rig a 3rd pulley go look at a new one at Sears.

 

[nine4gmc]

It's probably not worth the time to slow mod that one, it's a small 12" and probably not rigid enough for constantly drilling metal, therefore the speeds it comes with. Look for a larger unit on CL, often you can find good old used machines for less than you paid for that one and they are way more capable.

That said, if you really feel like keeping that machine, you can add a jack shaft out to the side and route the belt to it but you will lose the belt guard, space and time.

 

[95riosnake]

Rogue Fab makes a kit that I plan to get for my bench top Walker Turner DDP500, they have kits from 2:1 to 16:1 for most types of drill presses on the market both past and present. I know a guy that has the kit and is extremely happy with it.

Links:

https://www.roguefab.com/category.php?category=DPRKS

https://www.roguefab.com/drillpressreduction.php

 

[95riosnake]

Figured I'd copy/paste the post from another site from the guy I mentioned above:


More tool stuff for now. One reason I'm posting this up is for 95riosnake to see since he told me about this kit and was interested in it for himself. By the way I'm glad you told me about these guys, not only for this but because they have a pretty kick *** tubing bender and notcher that I plan to buy. I counted 256 holes to drill for the cart and it's all 3/16" and 1/4" steel so I figured it would be a good time to pick one of these up. This is the Rogue Fabrication 4:1 drill press reduction kit and is $149 shipped. The factory RPM for this Porter Cable drill press is 300-3100, and with this kit the new range will be from 75-775. I tried to piece together a kit myself through McMaster and Grainger (the pillow block bearings were about half the cost at Grainger) and save some money, and I even already have some plate to make the mounting bracket, but the total was only about $10 cheaper, and that was without shipping.

This is the kit as it arrives.

I dressed it up a bit before installing it. Painted the pillow block bearings red, painted the mounting plate flat black to match the drill press, cleaned up the casting flash on the big wheel, polished the rim, and painted the spokes semi-gloss black, polished the shaft, and polished the original cone pulley from the drill press motor.

Here's the drill press before.

And after. The kit went together well. I had to install the pulley assembly on the front side of the plate vs the back because things just lined up and fit better that way; this is normal depending on your application. It took quite a bit of time to get everything adjusted just right, but I expected that. If the mounting plate weren't so universal with all the different slots, things would go faster, but it's ridiculous to expect him to make a specific plate for every drill press out there.

Little closer view. I used some Greenlee punches to make the holes for the rounded corners in the pulley cover then just 'connected the dots' with a cut off wheel, deburred the edges, and cut some small hose to put over the edge. I also had to remove the factory knobs for the press for clearance, but no biggie as I was going to replace them anyways.

View of the backside with the cover open.

 

[Lassen Forge]

Running a larger quill pulley to a small motor pulley was my first thought, but it would be tough on your press, and you would have to fab a belt guard for the larger pulley / longer belt. If I had to do that I would rig mine that way, short term, and then put it back to normal when I was done.

You can mod yours to run an idler intermediate shaft, but it usually involves a special motor mount to push your motor back 12-14" ) and an intermediate pulley where your motor shaft is. You may not have enough room to center-mount an intermediate pulley between your current quill-motor shaft.

 

[nine4gmc]

Riosnake posted the jack shaft concept I was referring to.

 

[LS6 Tommy]

Figured I'd copy/paste the post from another site from the guy I mentioned above:


More tool stuff for now. One reason I'm posting this up is for 95riosnake to see since he told me about this kit and was interested in it for himself. By the way I'm glad you told me about these guys, not only for this but because they have a pretty kick *** tubing bender and notcher that I plan to buy. I counted 256 holes to drill for the cart and it's all 3/16" and 1/4" steel so I figured it would be a good time to pick one of these up. This is the Rogue Fabrication 4:1 drill press reduction kit and is $149 shipped. The factory RPM for this Porter Cable drill press is 300-3100, and with this kit the new range will be from 75-775. I tried to piece together a kit myself through McMaster and Grainger (the pillow block bearings were about half the cost at Grainger) and save some money, and I even already have some plate to make the mounting bracket, but the total was only about $10 cheaper, and that was without shipping.

This is the kit as it arrives.

I dressed it up a bit before installing it. Painted the pillow block bearings red, painted the mounting plate flat black to match the drill press, cleaned up the casting flash on the big wheel, polished the rim, and painted the spokes semi-gloss black, polished the shaft, and polished the original cone pulley from the drill press motor.

Here's the drill press before.

And after. The kit went together well. I had to install the pulley assembly on the front side of the plate vs the back because things just lined up and fit better that way; this is normal depending on your application. It took quite a bit of time to get everything adjusted just right, but I expected that. If the mounting plate weren't so universal with all the different slots, things would go faster, but it's ridiculous to expect him to make a specific plate for every drill press out there.

Little closer view. I used some Greenlee punches to make the holes for the rounded corners in the pulley cover then just 'connected the dots' with a cut off wheel, deburred the edges, and cut some small hose to put over the edge. I also had to remove the factory knobs for the press for clearance, but no biggie as I was going to replace them anyways.

View of the backside with the cover open.

That came out really nice. Other than the mounting plate, I could probably duplicate everything from Grainger's for about $100, so it's a pretty good deal.

Tommy

 

[kelpaso1]

That came out really nice. Other than the mounting plate, I could probably duplicate everything from Grainger's for about $100, so it's a pretty good deal.

Tommy

Thanks guys. I saw those two systems. Looks like the jackshaft system would be something I could fabricate myself but without the middle idler pulley. Would this give me under 200 rpm without that middle ilder?

 

[nine4gmc]

You would need to google a pulley rpm calculator to see what size would be needed with your current setup.

 

[66354dream]

I have that same exact drill press and love it!!! if I start doing more fab work I might look into getting one of those kits my self.

 

[pepi]

No one has mentioned the plastic grips missing. Would mounting the pillow blocks on the back side as designed have allowed them to be used?

Big difference of the two kits produced that's for sure.

 

[95riosnake]

No one has mentioned the plastic grips missing. Would mounting the pillow blocks on the back side as designed have allowed them to be used?

Big difference of the two kits produced that's for sure.

I believe so, he mentioned the plastic grips missing.

"I had to install the pulley assembly on the front side of the plate vs the back because things just lined up and fit better that way; this is normal depending on your application."

"I also had to remove the factory knobs for the press for clearance, but no biggie as I was going to replace them anyways."

If you look at the original handle grips, they were quite long. Replacing them with ball-style knobs would give the clearance needed.

 

[pepi]

Mounting the pillow on the left side of the motor would be a cleaner install, with less interference to the operator control and belt tension.
I realize the hinged cover is an obstacle, but that could be easily over come with a bit of metal work.

I do like the reduction idea, just not sold on the execution seen.

 

[NUTTSGT]

That Rogue fab kit does look decent for the money. It would be a great addition to a second drill press solely for metal fab.

 

[matt_i]

I think running any drill bit 3/4 to 1" at 350rpm is nuts, even with a pilot hole to take away the thrust from trying to jam the center web thru solid material. Try 80-120rpm. There's no need to burn up your expensive edge tooling unless you have 5000 holes to drill. The drill bit will actually cut up nice curls at that rpm rather than just bouncing around a 6 sided hole.

The entire table posted above, used in mild 1018 steel or hot rolled A36 for that matter is a good way to buy or sharpen a lot more drill bits.

 

[dlcwent]

There is a thread somewhere on using a dc motor from a treadmill. It gives you the variable speed for any usage. I'll try to find it. Or if someone else has a link, please post it.

 

[Falcon67]

FYI, note your drill speed will vary depending on the material being drilled, the material of the drill (HSS / Carbide / etc) and the diameter of the cutter. The above chart 350 RPM is too fast for 1" in steel and way too slow for carbide.

 

[kbs2244]

I did the treadmill motor replacement on a very old Craftsman desk top press.
I am happy with it, but the power is less at very low speeds.

 

[kelpaso1]

After further research on the Rouge website their 4:1 kit will lower my RPM's from 3100-620 to 775-155.