Slowing Drill Press RPM's

[34_40]

It has power feed and walked right through.
I have the drill head mounted to a massive 1 3/4" thick cast iron table. The first hole I ever drilled was 1 1/16" in the table top. No pilot hole.
I set it at 60 rpm, feed at the lowest .004/rev and let it go.
Couldn't hear any strain on the motor.
Sorry for bragging but yeah, I'm proud of it. My one, really nice machine.

Brag all you want, that is an awesome setup! Thanks for sharing the pics too....

 

[brino]

The first hole I ever drilled was 1 1/16" in the table top. No pilot hole.
I set it at 60 rpm, feed at the lowest .004/rev and let it go.
Couldn't hear any strain on the motor.
Sorry for bragging but yeah, I'm proud of it. My one, really nice machine.

Yup, that deserves some bragging rights!
Brian

 

[Chips O'Toole]

I stuck a 2-HP motor and VFD on my Rockwell 17". No problems.

 

[u50067]

Sorry. Missed this post…

In addition to the jack shaft pulley, I replaced the 1725 RPM motor with an 825 RPM motor. This reduced the spindle RPM to approx 135 RPM. I think the 825 motor was a direct drive fan motor. Am not sure but believe the fan motors on the outdoor AC units are slower speed motors and would likely be 230v motors. So check the RPMs of motors at sales, etc. I picked mine up at a pawn shop and have another approx 820 RPM 230v motor I found at an auction.

 

[Bi11Hudson]

Where the fan is located is a function of the "class" of the motor and has no bearing on the speed. On my equipment, I often use TENV (totally enclosed non ventilated) motors. There is a fan on the inside. A little pricey, but I like than no chips can get inside. There is a TEFC (totally enclosed fan cooled) as well, but I avoid them because of the external fans. There are many classes of motors that, as a rule, are beyond the means of a hobbyist. By no wise does the fan have anything to do with speed.

.

 

[Provincial]

Another way to get a reduction in speed is to use a 1200 rpm motor. These run about 2/3 the speed of a regular 1750 rpm motor. They commonly use a frame one size larger than the normal 1750 rpm model, so you need to have room to mount them. Using them with a VFD is nice because running them at 150% speed is 1750 rpm! Because they have more torque (to put out the same horsepower at the lower rpm) they still have good torque when in an overspeed situation.