VFD (variable frequency drive) for drill press.

[Paul Moir]

Careful running that motor that fast. It won't like it for long.
240Hz = 7200 RPM.

[Rambozo]

Careful running that motor that fast. It won't like it for long.
240Hz = 7200 RPM.

With the right bearings it should be no problem to run at that speed. BTW your math is a bit off as 240Hz on this motor will be 6960 rpm.

[fyidiy]

There's no need to run it that fast for anything other than a no-load demonstration.

The protective box/hood paint job finally dried and I managed to get it all mounted up and wired into the drill press.

Turning it down to 10Hz in order to test cut a 1.5" hole saw hole in 1/4" plate steel worked perfectly. Being a 1.5HP motor there's no stalling it at such a slow setting. However, the belt system can be made to slip with enough downward force on the quill.

All in all, I'm happy with the resulting functionality of the project.

[LincTex]

With the right bearings it should be no problem to run at that speed. BTW your math is a bit off as 240Hz on this motor will be 6960 rpm.

Not worried about the bearings - - is the rotor balanced to handle those speeds?

Will centrifugal force cause anything to become dislodged, warped, or fly off?

[zoama]

Not worried about the bearings - - is the rotor balanced to handle those speeds?

Will centrifugal force cause anything to become dislodged, warped, or fly off?

The post you're responding to is over 2 1/2 years old. It's no problem but it's good to check the dates before replying. I'm sure the man has no use for the higher speeds. The purpose would be to adjust speed for different size drill bits without having to move the belt between different size pulleys. 50-3000rpm would be plenty of range.

[LincTex]

The post you're responding to is over 2 1/2 years old. It's no problem but it's good to check the dates before replying. I'm sure the man has no use for the higher speeds. The purpose would be to adjust speed for different size drill bits without having to move the belt between different size pulleys. 50-3000rpm would be plenty of range.

Yes, but I come back to old posts after several years all the time on other forums, as long as it is still relevant information, or updates are needed. If there is a concern, it would be nice it it were addressed. Like "how does a cheap fractional horsepower belt handle those speeds"? I think that is relevant.

I may actually try to duplicate this setup.

I like the concept, and the possibilities.

[fyidiy]

I think this statement earlier in the thread answers the question:

"There's no need to run it that fast for anything other than a no-load demonstration."

I have *yet* to need anything faster than 60 Hz. with the VFD-configured drill press. I do, however, utilize reduced speeds all the time since the majority of my press tasks are in metal.

[LincTex]

I have *yet* to need anything faster than 60 Hz. with the VFD-configured drill press. I do, however, utilize reduced speeds all the time since the majority of my press tasks are in metal.

How much was your VFD?

I did a quick google search for "single phase VFD drive" and find a lot of attractive units under $200
I have a 10 HP Baldor 3 phase I can use for no-load testing, but there are literally a TON of cheap 3-phase motors out there to be had in the 1hp & under range.

[fyidiy]

The VFD in this project was just south of $300. I'm sure the prices have dropped since. These things should be around $100 or less in a few years.