Buffer speed

A

alexmin

Joined
Nov 16, 2005
Messages
513
I just ordered a variable speed motor/controller for my KMG.
I am planning to use my current KMG motor + 3 step pulley on a buffing assembly like this one: http://images.grizzly.com/grizzlycom/manuals/h3559_m.pdf

My only concern is that motor 1.5 HP and might be too dangerous since it'll have power to launch a blade into earth orbit.

Am I safer with regular 3/4HP Buffer?
How important to have different speeds on a buffer?

Thanks,
Alex
 
I've been using a Baldor 3/4HP 1800 RPM buffer (332B, I believe) 25 years or so(it looks similar to the picture in the link). I have had no problems with it.
The 3450 RPM buffers scare the hell out of me.

I used to have an old Sears craftsman 1/4HP grinder in that speed range, that I put 6" buffs on, just before I got the Baldor and twice it grabbed knives and taught me how to move very fast.
It ruined both blades slinging them across the room. I'm just lucky they didn't stick in me.:eek:
Some like 3450 RPM and do well with them, but it's just too fast for my taste.
 
I want a slow buffer too. Mine is only 1/3 hp at 3400 and it grabs everything within 3 feet away.
 
alexmin said:
My only concern is that motor 1.5 HP and might be too dangerous since it'll have power to launch a blade into earth orbit.

Am I safer with regular 3/4HP Buffer?
How important to have different speeds on a buffer?

Thanks,
Alex
Click to expand...

The horse power is not the issue, its the speed. Go with around 1700 rpm or as close as your step pully's will get, and you will be fine with the 1.5 hp motor. I think 1.5 hp is overkill for a buffer but you need to use whats available. Later when you get your second or 3rd grinder (and you will) you can use the 1.5 hp motor for that and get a smaller motor for your buffer setup. I cant think of any reason why you would need to speed up a buffer past 1700 rpm.
 
More often than not buff choice or buffing technique are the causes of problems not the buffer speed. In fact buffer speed, in excess of 5000 surface feet per minute, is necessary for quality finishes on stainless steel.

My buffer runs at 1750 RPM but I vary my surface speed by changing buffs, larger diameter buffs have greater surface speed than smaller diameter buffs......In fact I stop using buffs when they get worn down to 12" from my preferred 18" diameter. The reason is simple, the more effective your buff is the less time you spend on the buffer and that results is less risk.

ALL of my buffs are circular sewn with 1/2" spacing between rows of stitching and do not catch as easily as loose buffs. I do not use loose buffs unless I am doing large flat plates with no holes in them otherwise they will catch on the loose buffs and injure someone...me.

Horse power has nothing to do with buffing safety, technique and proper choice of buffs are the problems in every case.
 
If you are spending more than 5 to 10 minuts on a buffer you need to go back to hand sanding or belts. I go to trizac A4 which I believe is 4000 grit. I dont have more than 5 minuts per side on the buffer for my mirror polished knives.
 
alexmin said:
Guys,

what is a formulat to calculate surface feet per minute?

Alex
Click to expand...

Don't worry too much about that. Knifemakers have been getting mirror polishes with 6,8 and 10" wheels with 1750RPM buffers for many years now.

You don't really have to have so many grit steps in grinding either. I use 40, 120, 320, 600 or 15 micron and buff, or hand sand, whichever type of finish I'm going with.

Steve Johnson goes from 40-60 grit to heat treat to 400 grit cork then 600grit cork and them buffs to mirror polish. Can anybody say his finishes are substandard? I sure wouldn't.

I use a loose buff with white compound for handles and find it works great and has for years. It's about 6" diameter now, worn down from the original 8 or 10".
It's a matter of choosing the right compounds more than anything, IMO. Keep each buffing wheel in a ziploc bag, with the compound written on the side of it, near the arbor hole so you don't use it for the wrong application.

Use one wheel only for each compound. Keep them covered when not in use if they're on the buffer.

I despise buffers and use them as little as possible, so I make sure my finish is such that I won't have to spend too much time on one.

It's just what works for you.
 
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