Spacer for higher RPM

[JustADudeInSweden]

I see some videos of people using a spacer for higher RPM of their Tormeks, as a noob I'm curious - is it really needed?

[highpower]

As the wheel stone wears down and it's diameter gets smaller, it's circumference gets smaller as well. This effectively slows down the cutting rate of the wheel going past the edge of the blade as it turns. The RPM doesn't change, but the distance around the stone does. It's the same reason multiple lanes around a running track have different starting lines drawn for each lane. The outer lanes travel a longer distance than the inner lanes. Adding the sleeve just helps to restore the cutting rate back to 'normal' by increasing the RPM of the wheel when it gets smaller. 'Speeds and feeds' are an important factor when it comes to machining different materials. If you ever watch a video of a CNC lathe running you'll notice how the spindle speeds up or slows down depending on the diameter of the part where it is cutting. The machine is programmed to maintain the surface speed of the material going past the cutter location at an optimal rate for that material. But I digress...

Is it really needed for sharpening conditions on a Tormek? I will defer to the experts here to answer that one.

[BeSharp]

Please note that speeding up a Tormek could void the warranty.

For most, the Tormek is great as it is. For commercial sharpeners like I, speed matters.Knives at farmers markets can be incredibly dull. (One customer told me they hadn't been sharpened in 43 years...). So I need speed (and low grit wheels).

Tormek says the T8 runs at 90 rpm. I believe this is for countries with 50 Hertz electricity. Here in Canada with 60 Hz power, I measured my Tormeks running around 110 rpm (= 90 rpm x 60 Hz/50Hz).

I have sped up three of my machines. They run at 154 rpm, or 40% faster. However, water splashes everywhere, so I shield the water trough front and back. The machine and shields sit in a standard restaurant 12" x 20" x 4" high stainless steel buffet pan.

I kept my fourth Tormek stock for 400 and 1000 grit wheels. At those grits you don't need speed. In fact, Vadim says to NOT speed up the Tormek with 400 grit and above as the burr then gets unnecessarily big.

I've spent the last three months developing a machine running at 600 rpm, but it would be improper to talk about it here. Almost complete...

So, in conclusion, most owners should NOT modify their Tormeks to run faster.

[Ken S]

I make no claim to being an expert. Going back to Swedish Dude's question, the increased speed is certainly not necessary, especially for a beginner. The answer is different for a rapid turnover time, high volume farmers market sharpener.

Terry Beech, an internationally known expert Tormek sharpener, solves the diameter wear problem by replacing his grinding wheels when they are worn to 220mm. He considers them inefficient when they reach that point. For him, he values the extra time involved more than squeezing the last millimeter out of the grinding wheel. I suspect most of us are not in that league.

The speed increasing sleeves are not expensive. In fact, I made one out of a short piece of plastic pipe. It is not a machine shop, although it works. I also purchased one from Knife Grinders. Both are now stored in my misc. Tormek parts box. I have not needed to use them for several years.

Incidentally, both the speed increaser and the oversize support bar were originally used with long discontinued Tormek specialized knife sharpening machines. Our late clever member, Wootz of Knife Grinders, saw new potential uses for both.

Ken

PS Chip, your last sentence gave me a smile. It reminded me of the TV court dramas where the attorney realizes the other attorney will object. The first attorney then says "withdrawn" knowing that the jury heard the question.   

[cbwx34]

I did it with blue painters tape... easy way to try it for yourself if you have access to some...



... (p.s. most other tapes don't work).

[JustADudeInSweden]

I really like this place.

Sometimes I write a block of text and get one/two line asnwers and other times I write one line and get loads of info back