paper sharpening wheels - when your time is important to you

[richard j]

you will have to buy a new one. that was your fault and there was nothing wrong with the wheel except for the damage you did. if the gouge is not too deep, you can cut the wheel down with a jigsaw and then sand it true and use it. make sure to leave it a litle big when you cut it and sand it down to final size. make sure to cut the slots before cutting it down. you can use the slots to help lay out where to cut but cutting the same depth on each slot.

i got used to distractions when i did a lot of fundraisers. the biker fundraisers were the worst. drunk guys bumping into the table while you are sharpening their knife. i was always fast enough to pull the knife back before they hit. i explain things sometimes while sharpening if i'm teaching someone how to use the wheels.

[Bill Hoffman]

That's called "catching a crab". You're lucky the crab didn't bite! I caught
myself just getting ready to polish a blade with the edge opposite from where it should
have been. I was fortunate I stopped in time.

Suck it up, buy a new wheel, and be thoughtful every time you sharpen. The wheels
work better than I thought they would. You just have to pay careful attention.

Bill

[TheBishop]

I've had the mind drift to other things a few times on approach to the wheels.
Thank God before contact it snapped back in yelling "Pay Attention!"

Thankful you weren't hurt.

[DJG097]

I just bought a new wheel from grizzly. I find they have the best pricing. I might try to cut the old one down like Richard suggested or I might just toss it into a dark corner of the shop.

[Rapt_up]

Well I've been using my wheels for a couple weeks now... And been very pleased with the results. In fact last night I just achieved my sharpest knife ever using them.

Its a japanese folding carpenters knife. With carbon steel blade. Its so sharp that it easily cuts free haning hair, so easily that I can't use it to whittle hair because it just severs them immediately.

This is way sharper than my commercial disposable Gillette razors. It cleaned the back of my hand without any sensation of the hairs being cut or pulled. Truly the sharpest knife I have ever handled.

Thanks to Richard J and this thread for introducing me to paper wheels.

[DJG097]

Re gritted my wheel and got the new slotted wheel today. Back in business now. I think im going to bevel the edges on the old one for easier recurve sharpening.

[Wrace]

the wheels can only do v edges just so wide so no to a scandi on the grit wheel but you can use the slotted wheel to buff any edge. if i do a scandi edge i use my belt sander to work up the burr and finish it off on the slotted wheel.

This is something I've been wondering about as I've recently purchased three scandi's. What grits do you use on the belt sander before switching over to the wheel?

Thanks
Wayne

[Wrace]

thats not a bad price. is it a 1/2 hp motor? i think the lower rpm is a lot better. i tried a 3400 rpm buffer once and i think i'll stick with the 1725 rpm motor i'm using.

Richard,
Is the low rpm (1725) pretty much a hard and fast rule or is there some flexibility there. I ask because I have this buffer/sander that I had hoped to use the wheels on, but it's 3600rpm. What I like about it is the long arbor shafts get the wheels away from the motor for a bit more working room. Thanks

http://www.harborfreight.com/6-inch-buffer-94393.html

[richard j]

i have posted before that 3400 rpm is too fast in my opinion and 1725 rpm is much better and for beginners it gives them a safety zone should they place the blade down on 1 side first (the corner of the wheel) instead of flat. if the motor was a 3400 rpm motor and a beginner did that, they would put a pretty good notch in the blade where it touched (the corner) instead of a shallow one.

my setup is a 1725 rpm single shaft motor and i only run 1 wheel at a time. it only takes a few seconds to switch wheels. in a previous post i tell how i make the wheels easy to switch from grit to slotted.


as for the belts, i never go any finer than 400 grit since there is no need to. i did have a 19 micron belt that was over 20 years old but a few weeks ago i broke it. i was highlighting some grind lines in a sword i was working on.

[OHALLUM]

Richard,
Is the low rpm (1725) pretty much a hard and fast rule or is there some flexibility there. I ask because I have this buffer/sander that I had hoped to use the wheels on, but it's 3600rpm. What I like about it is the long arbor shafts get the wheels away from the motor for a bit more working room. Thanks

That is the same buffer I use, and I have had great results with it. I would prefer a slower machine, but this one will work. You do need to be careful as Richard said, but the wheels are rated for that speed.

On another note, I found out that you can use too much buffing compound on the slotted wheel. I was applying the compound before every use, and it built up so much that it was not working properly. I sanded most of it off and now it works much better. I am much more frugal with the buffing compound now. Just a lesson learned from using the wheels.

Omar

[richard j]

omar, did you clean the compound out of the slots? an old hacksaw blade works good for that. just slip it in the slot and lift up to remove any built up compound.

[OHALLUM]

Yes, the slots were not clogged up, just too thick of a buildup of the white compound on the wheel. Works great now. I left a thin layer of the compound on, just will only add it when needs it now, instead of every use as I did before. It may have been on so thick that the slots were not in the mix. I think the slots are the reason the wheel is so effective as a strop. I can get hair splitting results with the right type of steel, and no external strop needed. Amazing product.

Omar

[Bernoulli]

Richard,
Is the low rpm (1725) pretty much a hard and fast rule or is there some flexibility there. I ask because I have this buffer/sander that I had hoped to use the wheels on, but it's 3600rpm. What I like about it is the long arbor shafts get the wheels away from the motor for a bit more working room. Thanks

http://www.harborfreight.com/6-inch-buffer-94393.html

Mike, the owner of Razor Sharp uses and recommends the high RPM. I'm with Richard in that I prefer the lower speed. I think most of us develop our on skill set depending an what we have and how we learn. In Australia, normal single phase electricity is 240VAC/50Hz - which means that motors here operate at about 1425/2850 RPM rather than 1725/3450 RPM -- (5/6 of 60Hz speed).

Machine tool turning (cutting) operation is generally measured in surface feet per minute - that's the number of feet of your wheel surface that wold touch your work surface. The equation is S= pi X diameter X RPM -- all divided by 12. You can compare 8" to 10" wheel sfpm at various motor speeds. Obviously a 10" whel will have a greater sfpm than an 8" wheel operating at the same RPM.

After all that, I believe that if you understand your basic goal, you'll figure out how to achieve it. Trial and error is not so bad here. The learning curve is short for most people.

[Bill Hoffman]

I use a 1/4 hp Baldor Buffer at 1725 rpm. Works wonderfully. Haven't been
able to stall it without burning the heat treat out of a blade. (did it once just
to see how hard you had to push to ruin a blade) The two long shafts keep the
wheels far enough apart so they're not in each others way.

Bill

[Bernoulli]

Baldor is an excellent motor. My guess is they don't lie about the true horsepower - like most motor manufacturers do. Sounds like a very good setup to me.

[OHALLUM]

The good part about the paper wheels is they are relatively light, and do not require a lot of pressure. So, not a lot of power required to use them. I have never understood why mfgs need to lie about the ratings of their products. I guess it is a marketing ploy to compete against the other competitors. Kind of like politicians I guess.

Omar

[richard j]

when mike gets back from his vacation (50 years married) i'm going to see if he will update his info about motor speeds.

bill, i tried a 1/4 hp motor a long time ago and i was able to stop the motor with the slotted wheel mounted by pressing with the back of my thumbnail. maybe there is a difference between a 1/4 hp motor and a buffer.

[Bill Hoffman]

Richard,
This thing would take your thumbnail off! Seriously, it barely slows down
under heavy pressure, and I'm running it off an inverter from my Jeep battery.
I use the inverter at our local farmer's market where power is not
available. Sharpened lots of blades, power not a problem.
Bill

[Bernoulli]

One of the well known U.S. air compressor companies lost a class action suit several years ago for inflating the horsepower of their electric motors - sorry I don't remember the name of the company.

What many have done is state the amount of horsepower when the lights go out rather than operating horsepower. From memory, 1Hp at 110VAC is about 12 Amps - operating amps. So, a 1hp motor should draw about 12 Amps at 110VAC- which could be 20+ on momentarily on starting. That's why there are slow-blow fuses and circuit breakers are not instantaneous. A 1Hp 220VAC (in the U.S.) motor would draw about 6 amps. A 1/2 horsepower motor at 110VAC would also draw about 6 amps. Amps are a better indication of power than the current Hp ratings on motors.

These are approximations from memory. I've been in Australia long enough that I'm forgetting all that stuff.

[richard j]

did someone get hurt by the motor having more horsepower? i'm curious as to why someone would complain for getting a more powerful motor.

bill, can you post the model number of the buffer you are using and the price? if its cheaper that might be an even better deal than the 1/2 hp grinder at lowes.