Slowing down a drill press

Inno

Well-known Member
I have a 1/2" tabletop drill press made by Jet. It has 5 pulley settings and even on the slowest setting (small pulley on motor, large one on chuck), it is still way too fast for drilling thick steel etc. I always end up smoking the bits. Reading the post about drilling larger holes in steel is what made me think about it. I have some larger drill bits (up to 1" I think) but I never use them because of the speed issue. Maybe it's time to look for a better drill press, the Jet is a pretty light duty tool for some of the things I try to do.
 
Hello Inno,

You do not say at what speed you are drilling?
What thickness material are you drilling?
1/16 or less can be readily drilled at 2070 R.P.M.'s bit speed. drill bit type will also dictate the speed as well. Lubricating the bit while cutting will greatly increase the life of the bit also. Even water is better then dry,

Guido.
 
I really don't have a specific job in mind but when I get around to fixing up an old back blade I will need some fair size holes drilled in probably 1/4" thick material for pins etc. I always use some sort of oil or lubricating spray (whatever is close at hand, often WD40) when drilling thick steel.
 
If you do not require the high speeds for other work you could install a lower rpm motor but it may be pricey as they are not as common.I have 1/2 benchtop, i believe 1150 rpm motor, the used motor just happened to come in a package deal for us.I have installed a reduction jackshaft on an older floor model but this maybe impractical for the benchtop space
 
I had the same problem. I added a second pulley in the middle. It allows me to greatly reduce the speed when I want. I had the pulley laying around so it was also nearly free.

Here is a picture. It doesn't really make up for owning a really cheap drill press, but it does make it better than it was. It sounds like you'll be starting with a better press in the first place so something like this might be even better for you.

mvphoto18271.jpg

[/img]
 
I had to bolt the base of my drill press to long timbers after modifying it for slower speeds. Made a base out of 3/4 plywood to bolt where the motor was originally to offset the motor to the side. The original motor position now has a jackshaft with step pulleys on both ends. The upper pulley drives the drill spindle, as did the motor originally. The motor off to the side now has the step pulley at the bottom, driving another step pulley at the bottom of the jackshaft. Offers lots of speed options. But attempting to drive the spindle at the highest possible speed with this setup requires more power than the motor can produce. It just trips the breaker.
 
I have an old elcheapo Chicago tools floor drill press that has served me well. It has the center pulley for extra speeds on a pivot (the chart says the slowest is 240) and it has a rack and crank pinion to raise and lower the table.
a118441.jpg
 
(quoted from post at 13:22:26 06/12/13) I have a 1/2" tabletop drill press made by Jet. It has 5 pulley settings and even on the slowest setting (small pulley on motor, large one on chuck), it is still way too fast for drilling thick steel etc. I always end up smoking the bits. Reading the post about drilling larger holes in steel is what made me think about it. I have some larger drill bits (up to 1" I think) but I never use them because of the speed issue. Maybe it's time to look for a better drill press, the Jet is a pretty light duty tool for some of the things I try to do.

What [b:a331a73e01]gtractorfan[/b:a331a73e01] said [i:a331a73e01]and[/i:a331a73e01] go look at some in the store with triple pulleys - the only hard part is getting an eccentric (for belt tension) to mount the bearing & shaft for the 3rd pulley - years ago I used an aluminum round turned to fit the drill press column I.D., bored an off-center hole to fit a water-pump shaft and bearing off of some long-forgotten car (used a set-screw to keep the bearing's external housing from rotating) and then bored a hardware store step pulley to match the w'pump shaft's O.D. I sold it to a friend over 30 years ago and he still uses it. Now, if my old Atlas quit and couldn't be fixed (which I doubt) I'd just buy another press - getting lazy I reckon. JET has a good reputation; have you looked at their catalog? Might be you could upgrade from their parts book. :idea:
 
Have you looked into replacing the AC motor with a variable speed DC motor?

The lease cost solution might be to buy a different drill press or to take your heaviest work to a machine shop with the proper equipment.
 
Just thinkin out loud here.

Could you get a variable speed drive to plug your drill press into??

Everyone around here is using them for irrigation pumps.

I know the price of them is dropping fast

Like I said, just a thought...

Ben
 
Check out Roguefabrication.com https://www.roguefab.com/drillpressreduction.php
They have a simple gear reduction kit and the pictures on their site give you a good idea how it works.
Al
 

i made an adapter to mount my 1/2 inch portable drill to the drill press . used a pulley on a 1/2 inch shaft chucked in the drill to drive the drill press . if need be i can use my router speed control to further reduce the speed .
 
D C motor have a delay on start. Very agervating i try it. Try a
variable freq. drive on a 3 ph. Motor u can find a drive u can
single phase in to get 3 phase out., and vary the speed of
the motor.
 
I've read about guys using the variable speed motor off of a treadmill for powering a drill press. I have my eye on a good one, but she's not completely bored with it yet.

Treadmills are sometimes sitting alongside the road, free for the taking.
 
VFD. Variable speed and torque limiting to reduce bit or tap
breakage. Reversing capability too.
Low purchase price too.
 
Your is fast or slow as the river driving the common shaft is flowing that day.I think I saw yours in the Smithsonian.
 
Hey Inno.

You might try using bi-metal hole saws and plenty of lubricant (I use old atf personally.

A 1" twist bit is a lot for a small drill press.

Brad
 
(quoted from post at 21:17:53 06/12/13) I've read about guys using the variable speed motor off of a treadmill for powering a drill press. I have my eye on a good one, but she's not completely bored with it yet.

Treadmills are sometimes sitting alongside the road, free for the taking.

Bingo! I have one that a friend gave me. Never thought of replacing the motor but that is a good idea. I also have a variac (variable AC transformer) but I don't imagine that lowering the voltage would be too good for the AC motor that's on there.
 
I bolted an old Harley motor to a big drill press to make it go real slow....

But it kept vibrating the bits out of the chuck.

Brad
 
(quoted from post at 17:26:38 06/13/13) I bolted an old Harley motor to a big drill press to make it go real slow....

But it kept vibrating the bits out of the chuck.

Brad

That would be more like a hammer drill wouldn't it, good for concrete I'll bet! :lol:
 
(quoted from post at 15:49:55 06/13/13)
(quoted from post at 21:17:53 06/12/13) I've read about guys using the variable speed motor off of a treadmill for powering a drill press. I have my eye on a good one, but she's not completely bored with it yet.

Treadmills are sometimes sitting alongside the road, free for the taking.

Bingo! I have one that a friend gave me. Never thought of replacing the motor but that is a good idea. I also have a variac (variable AC transformer) but I don't imagine that lowering the voltage would be too good for the AC motor that's on there.

That's what a Variac does - without damage :?
 
Well it's worth a try.......and if I fry the motor I'll throw the one from the treadmill on.
 
(quoted from post at 08:51:17 06/13/13) VFD. Variable speed and torque limiting to reduce bit or tap
breakage. Reversing capability too.
Low purchase price too.

Question about Variable Frequency Drive.
The belt changing drill presses work very well because when you want a slow speed because your using a large bit, the torque is greatly increased. When using a high speed for a small bit you loose the large amount of torque, but don't care because it's not needed.
So if you had a drill press with a 1/2 hp. motor which worked fine with the belt changing set-up, and changed it to a 1/2 hp. motor with VFD, would it work as well ?

I get tired of changing belts.

Dusty
 
VFD is not suitable for single phase motors. Those motors have very little torque if slowed much below full RPM. And most VFDs are designed for 3- phase motors only
 
you could buy different pulley's and see if you can squeeze them in -

or buy a gallon of lube to use when you drill.

Any machinist supply company will carry something cheap you can use.

Fill a squirt bottle - or spray bottle - and just keep the drill bit and work piece constantly soaked while you drill.

Gets a little messy if you're doing a lot of drilling, but it's a very light oil, cleans up easily.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top