Skateboard wheels and bearings for grinder wheels?

i thought about it a long time ago and that was about as far as i got. a waste of time is what i thought.
 
Yes, you thought right.
My son was a pretty good skateboarder and got a lot of boards and wheels free from sponsoring manufacturers. We had boxes of wheels and bearings sitting in the workshop. They both wear out will little use. On a grinder, they would last minutes at the most.
 
Dang,Had my hopes up for a minute.The wheels for my flat platen setup are worn and tapered pretty bad.Cost a small fortune from Wilton.Anyone know where to get them aftermarket?Wilton Square Wheel machine.
 
You may try Sunray http://www.sunray-inc.com/ they have really good prices. All they need is the size you are wanting and they will make it for you. I have purchased two 8", two 4", and a 3/4" wheel from them. One of the 8" wheels is a tad bit off balance, but other than that they work perfectly.
curtis
 
Well I'll be the odd duck, and say that while not a grinder, we have used skateboard bearings for bandsaw blade guide bearings on our bandsaw FOR YEARS! it gets used maybe a total of 30 minutes per week, and they've been on it for atleast 15 years now, with no problems.

Jason
 
You may try Sunray http://www.sunray-inc.com/ they have really good prices. All they need is the size you are wanting and they will make it for you. I have purchased two 8", two 4", and a 3/4" wheel from them. One of the 8" wheels is a tad bit off balance, but other than that they work perfectly.
curtis

Thank you,This may be a possibility.The rollers are quite specialized the way they adjust but sunray looks like a good try.
 
Back in the days when dinosaurs roamed the earth and urethane skateboard wheels were new (thats the mid to late 70's for you youngsters) the top quality wheels like later Sims or Powell-Peralta actually used very high quality sealed bearings. I think some of them were NGK. REally cheap toy store wheels still had loose bearings. Those of us that didn't have wheels with those good bearings (like Cadillac wheels, the original urethane wheel maker which used a low quality sealed bearing that would unseal itself in short order) would sometimes replace the ones in our wheels. We were shocked at how quiet and FAST the boards were. Unfortunately, surprised usually means you do a face plant when the board is that much faster. LOL i suspect that after years of building these wheels, the manufacturers probably figured out that skateboard wheels didn't need high quality industrial grade bearings.
 
The wheels wouldn't work very well. The 70a durometer polyurethane of a skate wheel(designed with a 500 lb. working load in mind at 4000 FPM) is different than the 70 polyurethane of the contact wheel because. . . Abec-8 bearings are only rated for 32000 RPM. . . Wait. Maybe it's that the back of a belt is so much rougher than the asphalt/concrete. . . Nope, that's not it either.

Yes, I know they won't work, but not for the reasons given. 70 durometer polyurethane is the same, the bearings are the same. Unless you're build a 1x30 grinder, you're going to have a hard time finding 2" wide wheels.
 
The wheels wouldn't work very well. The 70a durometer polyurethane of a skate wheel(designed with a 500 lb. working load in mind at 4000 FPM) is different than the 70 polyurethane of the contact wheel because. . . Abec-8 bearings are only rated for 32000 RPM. . . Wait. Maybe it's that the back of a belt is so much rougher than the asphalt/concrete. . . Nope, that's not it either.

Yes, I know they won't work, but not for the reasons given. 70 durometer polyurethane is the same, the bearings are the same. Unless you're build a 1x30 grinder, you're going to have a hard time finding 2" wide wheels.

The problem isnt the size of the wheels. I found skateboard wheels that are two inches wide.
 
Lots of BS here. I've used longboard wheels that are 2" wide 3" in diameter. No they aren't as high quality as real wheels, but everyone knew that already.

The problem is that they're conical, and you have to make them cylindrical/crowned.

Also an idling wheel is not a high stress job. You've got ~20-40 lbs of even consistent force spread out among 4 wheels on a KMG type setup, and realistically about 3000 fpm or 35 mph, 55mph max unless you go with crazy belt speeds, meaning 4000-6000 rpm, really only 33% more rpm than a 4" drive wheel. Stop kidding yourselves. What skateboard wheels lack is precision.
 
Last edited:
What skateboard wheels lack is precision.

Yup.

There is nothing inhearently wrong with skateboard bearings for their intended use. They're generally intentionally loose bearings and work reliably and with low drag as skateboard wheels. But for knife grinding you're going to want graded bearings, probably abec 5. (surface grinding 7 or 9)

If ya'll think your knife grinder bearings are spendy, you should look into spindle bearings for real milling machines, lathes and (gasp) surface grinders. The last time I put bearings in a mill the bearings alone were nearly a thousand dollars.

It doesn't pay to use cheap bearings (false economy) but it is also silly to spend too much on overly fancy bearings. abec 5 will be good and won't break the bank in the size you're talking about. Abec 3 for idlers should be okay.

BTW, better bearings frequently get hotter than cheap bearings, at least during break in. But then they run a long time without play and vibration.
 
I was going to use abec7 ceramics. But for the hassle, I would just assume buy some wheels from Sunray. But I got to admit I would like to experiment with some skateboard wheels.:thumbup:

EDIT: I might have to make that plain abec7, I don't know if they make ceramic abec7.
 
Last edited:
I have abec 7 on my skateboard. I bought it one day went for a ride, started going too fast, fell off, and it has been collecting dust ever since. :D
 
I have abec 7 on my skateboard. I bought it one day went for a ride, started going too fast, fell off, and it has been collecting dust ever since. :D

I used to rollerblade literally every day. I switched from Abec 3 to Swiss. WOW! Took some getting used to. Amazing what a difference a high tolerance bearing can do. But that was quite a long time ago.
 
Back
Top