Slowing down a drill press

[nate379]

I was thinking about this the other day.

My drill press has a slow RPM of 500, which is about 2x the speed I'd like it to be at for drilling steel with hole saws or large bits. It's a 12" benchtop Delta and most benchtop models can't gear down slower than that. I know the floor models will, but I end up moving around alot (Air Force) and this one is much more portable.

If I put a router speed switch in the circuit and slowed the motor down, would that work out or kill the motor?

http://www.amazon.com/dp/B001JHQ3G8/?tag=atomicindus08-20

 

[KraftwerkMk1Jetta]

Long hair, sweatshirt hood drawstrings, beards, anything else you can get caught up in the drill bit will slow it down some.

 

[Packard V8]

FWIW, there is no difference between the Delta floor and bench models on the smaller drill presses. Delta made a four-step intermediate pulley on a bearing and spindle to go between the motor and the spindle. It drops in the column and locks in place with a bolt. Two shorter belts connect the three pulleys This gives a possibility of 16 speeds. The highest two speeds are so fast the DP begins to taxi for takeoff. Don't even try to use them. The pulley, spindle and base is big bucks new from Delta, but they show up on eBay occasionally. Since the Chicom DPs are often copies of Delta, it is possible there is something usable from them. Good luck.

thnx, jack vines

 

[caper]

I have seen some people install a jackshaft with an extra set of pulleys to slow down the rpm
.

 

[2004f550]

I was thinking about this the other day.

My drill press has a slow RPM of 500, which is about 2x the speed I'd like it to be at for drilling steel with hole saws or large bits. It's a 12" benchtop Delta and most benchtop models can't gear down slower than that. I know the floor models will, but I end up moving around alot (Air Force) and this one is much more portable.

If I put a router speed switch in the circuit and slowed the motor down, would that work out or kill the motor?

http://www.amazon.com/dp/B001JHQ3G8/?tag=atomicindus08-20

it would slow it down but it might not be powerfull enough for bigger drills ( there rated for 15 amps).....Chris.....

 

[Curmudgeon]

it would slow it down but it might not be powerfull enough for bigger drills ( there rated for 15 amps).....Chris.....

If the motor is still turning at the same speed, but the spindle is turning slower, it will increase the power available at the bit. It's the same as dropping to a lower gear in your car.

If the motor is a DC, speed can be varied with the amount of voltage to the armature. If it is an AC motor, the speed is pretty much determined by the 60 hertz line frequency and the motor windings.

 

[Bolster]

I have seen some people install a jackshaft with an extra set of pulleys to slow down the rpm
.

Yep, the whole procedure is detailed, with photos, in a book called Shop Savvy by Roy Moungovan.

Off topic: By gum, it's Festus who posted above me, one of my all time hee-roes!

 

[nate379]

This drill press only has 2 pulleys and they are spring loaded. To adjust the speed the gap on the front pulley is adjusted with a knob and it causes the pulleys to work like a snowmobile clutch setup.

 

[Uncle Buck]

This will give you an idea of one way to skin the cat.

http://www.docstoc.com/docs/2550001/How-to-Bore-the-Big-Ones

 

[Uncle Buck]

Bumpity bump bump!

 

[Gary S]

You can probably find the extra shafts, pulleys, and belts to convert a 5 speed press to a 12 or 16 speed press, but you might find it cheaper to sell the 5 speed and buy a new 12 or 16 speed one. I find that most 5 speed presses will run only as slow as about 500rpm. Most 12 or 16 speed ones will run around 150-200rpm.
Before spending money on your press, consider selling it and buying a different one. The price might be the same.

 

[nate379]

You guys are completely missing the point of my post.

Will the router control work?

 

[Danglerb]

You guys are completely missing the point of my post.

Will the router control work?

I believe they said no, depending on the type of motor.

Routers use a non synchronous type of motor, most likely your motor speed is tied to the AC line frequency.

 

[MAD]

If the drill has a universal motor then I would expect it to work.

I have an old drill press that is essentially a 1/2" electric hand drill mounted to a frame that I used to use a speed control on. (before I got a real drill press).

 

[lilredex]

You guys are completely missing the point of my post.

Will the router control work?

No..............unless you have a universal type motor (the one with brushes)..........not very likely. Like a vacuum cleaner, chop saw, router, hand held drill, etc,

 

[gorilla]

I converted a old flat belt drill press to a 3/4 hp dc motor with a speed control that I bought from surplus sales. It has full torque at zero rpm and infinite speed selection it's reverseable for power tapping also. I think that I paid about $125. for the motor and speed control. This may be simpler than building counter shafts and buying belts and shiv's.

 

[fordbroncodave]

get a dimmer switch for a ceiling fan or a light for your house. connect it in line with your power cord for the drill press. works every time.

 

[nate379]

I was thinking of doing that as well.

It's not an expensive or fancy drill press, I think I paid $100 for it on clearance about 6 years ago, so I don't want to get too crazy with it.

 

[A_Pmech]

Guys...

You can't adjust the speed of an AC induction motor by varying the input voltage, as speed is independent of voltage. Speed is dependent on input frequency and slip rate.

Using light dimmers and router speed controls is only going to burn something up and reduce the motor power output (which IS dependent on voltage)

 

[Griff93]

If you really want to slow it down without doing some mods to it then look at a Variable Frequency Drive. This is the correct way to slow down AC motors by changing the Hz. Say the min rpm is 500 at 60Hz. If you drop the Hz input to 30 your rpm should be 250. These things are used a lot with milling machines and lathes. Another nice feature is most of them will convert from single phase to three phase.