PDA

View Full Version : Determining flex shaft rpm



Richard Dooling
02-01-2022, 4:19 PM
I also posted this in the carvers forum but no joy.


I just received my Wecheer 1/2 hp tool with the Wecheer tabletop dial speed control.

I'm not sure how to determine what the no-load speed is for any given point on the dial and I'm concerned about over-revving the reciprocating tool handle. From what I've read high rpms are to be avoided.

I can't find much on this handle in particular but I think the Foredom has a maximum limit of 8000 rpm. Even if this is right, how do I know when I'm in this range? Buy a strobe?

Does anyone know if dial controls provide a linear speed progression as in is the dial at full rotation equal to full speed and at half rotation equal to half speed? My motor's max is 30,000 rpm.

The Wecheer website is leaves a lot to be desired.

Ant insight would be appreciated.

Richard Coers
02-01-2022, 9:34 PM
I'd call WeCheer

roger wiegand
02-02-2022, 7:14 AM
A digital laser tachometer is under $20 on Amazon. I only use mine rarely, but it's handy to have when needed. I've been using my Foredom pretty regularly for pushing 40 years now without paying any attention to rpm. Nothing bad has happened so far. I'm actually shocked at how long the shaft has lasted.

Peter Blair
02-02-2022, 8:48 AM
I do a fair bit of power carving and if it was me i would start out very slow and increase the speed until the tool cuts as you want it to. i have a different speed control and it is definitely not progressive. I use a multitude of cutters, burrs and sanders in various flex shafts and each one requires a different speed to work properly.

Zachary Hoyt
02-02-2022, 12:51 PM
I have been a happy Foredom user for 2 or 3 years. Mine is supposed to go up to 18,000 RPM and has a foot pedal for speed control. I judge the speed partly by tool performance and partly by the sound. I think all of my stuff is rated for up to 30,000 RPM so I don't have to worry about overspeeding it.

Richard Dooling
02-02-2022, 3:41 PM
Thanks for the replies!

Roger, I am thinking about a tach but it would see so little use. Still if one can be had for around $20 maybe.

Peter and Zachary, that's about what the seller told me. Different cutters, different woods different speeds. Experimenting is fine by me but I don't want to exceed the high end for the reciprocating handle. So I'll play around on the low end with some basswood and see how it feels.

Jeffrey J Smith
02-03-2022, 6:30 PM
for what its worth, I've been using the smaller wecheer unit with a flex shaft and the reciprocal handpiece for several years without worrying about the speed. Generally use it at the 4 setting on a wheel where 6 is maxed. Both handpiece and shaft are holding up surprisingly well.

John K Jordan
02-03-2022, 7:27 PM
A digital laser tachometer is under $20 on Amazon. I only use mine rarely, but it's handy to have when needed. I've been using my Foredom pretty regularly for pushing 40 years now without paying any attention to rpm. Nothing bad has happened so far. I'm actually shocked at how long the shaft has lasted.

Same here. I bought this inexpensive laser tachometer and it works well.
https://smile.amazon.com/gp/product/B004Q8L894
The few times I've used it it's worked well. It checked out against the tach readout of my PM lathe.
The last time I used it was to calibrate my milling machine - it has variable speed and no readout so I made a scale.

That said, I've never once been concerned about the speed on my three Fordoms. I just turn it on and adjust the speed for the cut I want for the particular bit and wood. Small diameter, generally higher speed. Most of the time the speed I use is well below the maximum.

I know nothing about the Wecheer.

JKJ

Marvin Hasenak
02-05-2022, 11:55 PM
I got rid of the foot pedal and bought a good router speed control unit to control the speed. A little practice on some scrap wood and you will soon learn what speed works for you. The foot controller caused cramping in my foot and leg. The system tends to make you forget to strop often enough. The best part of the router speed controller is you can keep notes to what speed works best fro what woods you are carving.

Richard Dooling
02-09-2022, 2:50 PM
I've thought about getting a digital tach off and on for some time. Thanks for the link John, I just ordered one.