Hi all. I attended a tool show recently and had a chance to use the tormek T8. I fell in love instantly. It would pretty much make all my other sharpening gadgets obsolete. But, as you know, super pricey. So, two questions. 1. Does anybody here have any experience with one of the knock offs (Wen, Grizzly etc.) and have any reviews or suggestions to make about them? 2. Does anybody know how (other than by stepping down with some seriously large pulleys) to find a motor that will spin at around 100rpm? I'm having 0 luck googling any AC motors that go that slow. I figured DC would be easier, maybe a gear motor? ) but I know zip about DC motors (not much about AC either). Any general advice there. Yes, if I could find something reasonable to power it, I'm considering making my own "Tormek-like" sharpener. I'd have to buy the wheels and make some jigs etc. but, in the end, we're really still talking about a motor spinning a stone wheel. I figure it's gotta be doable. (famous last words)
Gear reduction is the way to get 100 RPM. Most motors need some speed for their fans to keep them cool.
The ratio you want is about 20:1 for a common four pole AC motor. This would mean a 1" sheave and a 20" sheave which isn't going to be very pretty. Even less pretty when you use multiple belts and shafts. The slowest commonly found AC induction motor is a six pole and they clock in around 1200 RPM. You will see these from time to time on Kijiji. Yes, more poles is slower, it's also more copper and usually cost more money. Some multi-speed furnace blower motors go down to 600 RPM. You might be able to salvage one of them and use a 6:1 reduction. What the band saw hackers use to slow a wood cutting band saw to metal cutting speeds is a reducing gearbox. https://www.surpluscenter.com/Power...r-0-50-HP-56C-Left-Output-13-133-20-L-56C.axd If I was going to hack something together, I would use an old variable speed corded drill, strap it down and chuck an arbor that can hold the stone. (chuck meaning insert into the chuck not chuck in the garbage can). It will sound very much like my Porta-Band when running...all whiny and grrrry. The wildest one I have seen used multiple sprockets from bicycles and chains for gear reduction. However cool that was from the high school mechanic DIY perspective, it was awesomely ugly and very pinchy looking. Or you can wait for this to go on sale at 50% off: https://www.canadiantire.ca/en/pdp/maximum-pro-2-3a-tool-sharpener-0556758p.html Dan
I saw the CT one on sale recently and seriously thought about it. Then I starting reading about duty cycles and its stats weren't great. I suspect I was being too picky though. Dumb question but is the gearbox meant to be powered by a simple pulley on the end with a belt?
So a geared motor of any quality at all is going to cost you 3 or 4 hundred dollars. DC motor/controller setups are capable of 100:1 turn-down and still provide full torque. Again you are likely looking at $400+ for a proper setup. I suspect Tormek are using a purpose built motor to provide the 100 RPM. That CT option could worth a look...
I was just thinking of this this afternoon. My belt grinder goes down to zero fpm LOL but not everyone has one. The search is on and the solution may be a belt sander salvaged for the wheels and platen then hook up a reduced speed electric motor or air wrench drive. commercial sewing machines can be air driven but the motor and controller are $400 plus range so that is out. I have a variable speed burnisher that could be set up with home made wheels to go with the sanding drums but again $500 range. Seems to be a theme here, even the tormek are $400 to $800 There is the option of a belt grinder and diamond belts and last I saw that was in the ball park of $100 each USD http://www.eastwinddiamondabrasives...sin-bonded-belt/Resin-Bond-Diamond-Belts.html make the closer to $150 https://arrowheadlapidarysupply.com/products/2-x-70-resin-diamond-belts-by-eastwind/5562/c104/
I was working on an idea for a small bicycle frame belt grinder, very odd maybe but part of it was a two belt size arrangement.
You know, speaking of bicycles,..... You could kick it old school, and power it yourself. You want slow speed and decent torque, some old sprockets from a mountain bike might fit the bill. Or maybe do it like the old foot powered singer sewing machine.
I bought the copy from Canadian tire, and then bought a few actual tormek goodies from Lee valley for it. The stone grader, the knife jig, angle gauge, polishing paste. It works well but I don’t use it enough to justify the space it takes.
I have the Crappy Tire Maximum Tormek knock off to. I am getting great results, probably the best results I have gotten so far (I see sharpening as probably my last true hurdle before selling my knives, as I am currently satisfied with my fit, finish and heat treat). It’s slower putting a micro bevel on a brand new knife, that suits me, I like taking my time. You can get an okay toothy edge on just the 240G wheel and strop. I get a better working edge with that wheel and going to a 400g water stone and then strop. I go even finer on a kitchen knife of course, but the initial edge is still done on the wheel. I like that it’s water cooled, I don’t fret about ruining the temper (that is not a knock on those who sharpen on the grinder, I don’t do that because I am clumsy and would ruin a knife lol). All in all what this machine has done more than anything is make me pine for the real thing. I’d love a Tormek, and the multiple stones that they offer.
Hey Griff, where did you find a 400g stone? I have a the WEN sharpener and it's pretty great too but I've been looking for a cheaper version of the Tormek japanese stone and, though i can find them out there, nobody seems to carry or ship them.
What is the stone size and hole diameter? I ran across a supplier last summer and would have to find them again
Todd I meant setting the edge on the stone wheel, and then moving onto a regular flat/ oblong water stone. I have a 400/1000 stone I use. I have yet to check if the Tormek wheels will fit on the knock off’s. I think the arbor is different, it’s why knock off wheels wobble an Tormek’s don’t haha.
Okay here what was said on a Tormek forum. Again I haven’t measure the CT Maximum bore size yet. ‘The bolts, nuts and washers which hold the things together are essentially the same parts. The shafts have the same diameter, only the length is slightly different. The T7 uses a 250 mm diameter grinding wheel, hence the SG 250 designation. The T4 uses a 200mm diameter grinding wheel, the SG 200. The T7 wheel is 50mm thick;the T4 wheel is 40mm thick. They share a common 12 mm bore size. Incidentally, a 250mm wheel is not quite the same as a ten inch wheel, which is why some of competitors' wheels barely fit.’
Not sure if you have seen Jeremy Goertz's video on the CT Maximum sharpener. Might be worth a watch, especially for someone pondering one of these types of machines. Dan
