Rethinking the Need for Pulley Steps with VFD on Drill Press

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by bill1608 posted 06-28-2017 05:15 PM 535 views 0 times favorited 0 replies Add to Favorites Watch
View bill1608's profile


14 posts in 1779 days

06-28-2017 05:15 PM

I have a couple drill presses that I am going to convert to VFD. I NEVER considered having one belt step acceptable. But I am rethinking that now for my applications. On my 15” drill press, I can get a spindle rpm range of 6-1 using a 2 hp 1750 rpm motor and still have 1/2 hp at the minimum speed. I can accomplish the 6-1 ratio by overspeeding the motor by 50% (90 hz). On that drill press, I would size a single motor pulley running with the largest front pulley to get 333 to 2000 rpm. On my 17” drill press, I can do a similar method and get 9-1 by using a 3 hp motor. Using a single motor pulley with the largest spindle pulley, I can get 222 to 2000 rpm and still have 1/2 hp at the lowest spindle speed. I consider these speed ranges and hp’s acceptable for these drill presses for my applications. I will probably also use an A belt instead of a 4L belt just for the heck of it. That may not be necessary because my motor pulleys will be at least 5 1/2”, so the belt speed should be fine for the load. The load shouldn’t ever exceed about 1/2 hp. The key to doing all this is using an oversize motor, overspeeding the motor (for the higher spindle speeds and speed range) and not using too small a motor pulley that can’t transfer the power at low speed.

0 replies so far

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics