As the title says, I'm adding a VFD to my drill press. For various reasons (with which I won't bore you), I need to replace the pulleys. This leads to the question of what size pulleys I should get. And that leads to the question of how much should I expect the VFD to slow down the motor.
USAGE: Hobbyist use in my garage. 90% for wood, 10% metal. No boring--just standard drilling. I don't see having this press running more than 5-10 minutes at a time, so overheating the motor doesn't seem likely.
Ideally, I'd like speeds from ~150 to ~3,000 RPM. The motor's speed is 1750 RPM, so:
--If I use the same size pulley on the motor and the quill (assuming no idler pulley), then the max speed is 1750. If the VFD can slow the motor down to 10% of its native speed, I can go down to 175 RPM, which should be fine on the low end. But the max speed of 1750 is not ideal.
--If I use a motor pulley that is twice the size of the quill pulley (example, 6" motor and 3" quill), then the max speed is 3500. If the VFD can slow the motor down to 10%, then low speed will be 350 RPM. If the VFD can slow the motor to 5%, then I can go down to 175 RPM.
The second example makes more sense to me, but I don't know how much I should expect the VFD to slow the motor down. Is it safe for the motor to run at 5%? 10%?
Should I run a couple of idler pulleys and switch belts for high and low RPM use? (Would rather not do this for obvious reasons.)
I'll appreciate any thoughts!