Belt Speed?

F

Frank Eaton

Joined
Sep 10, 2004
Messages
362
I jsut got my KMG, was grinding with it last night for the first time. It is a mad man. I ground some at the middle speed as I have my pulleys set, and did some at the fastest. One is a little too slow, and one is too fast, but is could be that I am just not used to it yet. What speeds do you grind bevels at? Any preferences?
 
The faster speeds are used to remove more material with the larger grits. Slower with the smaller grits. For just starting out what ever you feel the most comfortable with. They do make a 3 step pully......
 
I have a 3 step on both the motor and the machine, I may have to turn them around and do some more experimenting.
 
Typically I rough grind with a 36 or 40 grit at around 2000 surface feet per minute (sfpm). 80 - 180 grit at around 1200 sfpm and higher grits at around 800 sfpm. The slower the speed the more control you usually have. On my folders, i start with an 80 grit at 1000 sfpm and then go to a 180 at 800 sfpm. Then I hand sand after that.

If you don't know your speeds, drop Mr. Frink a line and I am sure he will be more than happy to help you out.

Oh yeah, I have a variable frequency drive hooked up to my grinder. Those only work with three phase motors. Not sure what type motor you have, but there are various types of speed controlers for AC and DC motors. They are definitely nice to have.
 
Belts speeds vary quite a bit from one maker to another. Mostly determined by "what they are used to" .... For example, someone that learns with a fast speed....seem to always prefer a fast speed.

The step pullies on your KMG will generate 3 speeds. With a 1725rpm motor the pullies should be opposed such that the big dia on the grinder is inline with the small dia on the motor...and so on. Your belt speeds will be aprox 3600ft/min, 1800ft/min and 800ft/min.

-Rob
 
As stated by Ray, I find initial grinding with couser grits best at higher speed and slower as the grits go down in size. I have, or think I have, learned not to lean into the belt. For me it gives better touch and helps elongate belt life, regardless of belt speed. It seems though course belts like higher RPM and better for belt life (so long as the belt is not heavily leaned into). Especially for final finishing and most especially final finishing the blade tip area I go slow speed with finer grit.

RL
 
I have the three step pulley with my KMG and have become comfortable with the middle speed. When flat grinding, I start with the middle and switch to the slow near the end of grinding. I use the middle speed from start to finish when convex grinding. I feel I have more control this way.
Scott
 
on My wilton ,, regretfully now,, :grumpy: didn't come with virie speed ,,
so it's be full speed ahead for me.
ever since. :)
 
Dan Gray said:
on My wilton ,, regretfully now,, :grumpy: didn't come with virie speed ,,
so it's be full speed ahead for me.
ever since. :)
Click to expand...
Dan, I have an old wilton that used to be my main grinder (way to fast) I bought a smaller diameter drive wheel from koval and it made it a lot nicer to work with, best thing I had done at the time until I bought a variable speed grinder ;)

Don Hanson lll
 
sunfishman said:
Dan, I have an old wilton that used to be my main grinder (way to fast) I bought a smaller diameter drive wheel from koval and it made it a lot nicer to work with, best thing I had done at the time until I bought a variable speed grinder ;)

Don Hanson lll
Click to expand...
(way to fast)
Don you were just to slow for the Grinder :footinmou :p :D :D

I've had this one for a long time and I'm use to it. but if I ever try one out with veri speed it may spoil me :)
 
One of the best things about variable speed, and more to the point, slow speed, was it accelerated my learning curve tremendously. At high belt speeds no matter what I did torque would skew the work and I had no control. But once I learned how to hold onto things at a lower speed I started slowly cranking that baby up. Sparks fly these days.

Like Raymond said, larger grits at high speed and finer grits much slower. When finishing I often run the belt as slow as it'll go, though this also depends on how much real estate I'm grinding. ;)

And speaking of grinding - I'm off to make some steel dust. Y'all have a great day.
 
Like Raymond said, larger grits at high speed and finer grits much slower. When finishing I often run the belt as slow as it'll go, though this also depends on how much real estate I'm grinding. ;)




Ha Ha!!, real estate!, Dave: that's funny!!! :)
 
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