UPDATED:Vibration issue with W/C Slow Speed Grinder

[Mark Pruitt]

The slow speed grinder from Woodcraft comes with wheels that have a 7/8" hole with bushing to fit the 5/8" arbor. Is there a balancing system that will work with these sizes? The Oneway Balancing system requires 1" holes in the wheel.

Or, is there some other issue going on that might be causing some vibration?

Any suggestions? TIA.

Mark

[Frank Fusco]

I don't know about a balancing system. But you can buy adapter arbors. I got mine at the local hardware store.

[Andy Hoyt]

Mark - The Oneway Balancing kit worked wonders for my crummy grinder.

Here's their page about it - http://www.oneway.on.ca/sharpening/balancing.htm

In the top right corner there's a listing of the various arbor diameters they worry about and while 7/8" is not shown; I'll bet that if you call them, they'll be able to fix ya right up.

They're good people.

[Mark Pruitt]

Mark - The Oneway Balancing kit worked wonders for my crummy grinder.

Here's their page about it - http://www.oneway.on.ca/sharpening/balancing.htm

In the top right corner there's a listing of the various arbor diameters they worry about and while 7/8" is not shown; I'll bet that if you call them, they'll be able to fix ya right up.

They're good people.
Andy,
I called the Oneway folks yesterday and talked with a very kind and knowlegable person who said "I'm sorry I can't sell you something.":( I laughed and said "you will eventually." I described my situation to her and she said there was nothing they could provide that would work with a 7/8" hole. It looks like I would have to replace my wheels to use their system--not something I want to do since these are the good a/o wheels not the crummy gray ones.

Other than replacing my wheels, my options are to use 'em till they wear out and then replace them with wheels that will accept the Oneway system, or find a system that will work (if there is one).

Any other ideas?:confused:

Mark

edit: This also has me wondering if arbor runout might be contributing to some of the vibration. I'll break it down sometime this week and check it with a dial indicator.

[Andy Hoyt]

Go to a machine shop and get a bushing made to reduce the wheel hole diameter. 7/8" to 5/8" makes for a thin bushing, but it might work? Maybe?

[Mark Pruitt]

Go to a machine shop and get a bushing made to reduce the wheel hole diameter. 7/8" to 5/8" makes for a thin bushing, but it might work? Maybe?
Actually, what I need is a bigger hole not smaller. I wonder if I could bore the 7/8" hole out to a 1" hole. I actually have a 1" spiral twist drill bit; the only concern is that I not shatter the grinding wheel while boring it out. Or worse yet, unknowingly produce a hairline crack that explodes when the wheel gets up to speed. I'd be a little nervous about trying such a thing.:eek:

And here's an interesting tidbit of info: I just called Woodcraft Tech Support and the gentleman there said that he knows of no balancing system that will accomodate 7/8" holes in conjunction with a 5/8" arbor.:(

It's really kind of comical, the situations I am capable of getting myself into. But thank you for your time, Andy. If you have any other ideas I'm all ears.

Mark

[Jason Christenson]

Have you tried running it without balancing it? Maybe you will get lucky!

[Mark Pruitt]

Jason, I've run it enough to put an Ellsworth grind on a couple of bowl gouges and a fingernail grind on a spindle gouge, plus sharpen two skews, a parting tool, three scrapers and a "normal" grind on two other spindle gouges. Additionally, before doing any of that, and frequently during the process, I have dressed the wheels. The grind I am getting on my chisels is acceptable, but the vibration, while not severe enough to cause damage, bothers me enough that I really want to even things out and take it to the next level.
Mark

[Andy Hoyt]

Mark - Now that I think about it, I seem to recall that a couple of guys here have had similar issues with the same machine. I believe they solved a bunch of issues by replacing a washer/flange thingie.

You might want to rename this thread to better get their attention and subsequent insight.

[Joe Melton]

I have the same grinder and the same problem. One wheel was really bad and I replaced it with one I found in my shop, one made in Israel. The grinder doesn't bounce around as much, but it is still out of balance. Dressing hasn't helped.
I think the only solution is to buy the oneway wheels and the oneway system. Maybe for Christmas.
Joe

[Dick Strauss]

Mark,
Have you thought about making your own? Can you buy a large diameter thick washer that will fit the shaft for your grinder? You could drill and tap 6-8 holes around the perimeter of the washer and use double-stick tape to connect it to the wheel. Then just put in very short screws that don't protrude to do the balancing.

Good luck,
Dick

[Frank Fusco]

Actually, what I need is a bigger hole not smaller. I wonder if I could bore the 7/8" hole out to a 1" hole. I actually have a 1" spiral twist drill bit; the only concern is that I not shatter the grinding wheel while boring it out. Or worse yet, unknowingly produce a hairline crack that explodes when the wheel gets up to speed. I'd be a little nervous about trying such a thing.:eek:

And here's an interesting tidbit of info: I just called Woodcraft Tech Support and the gentleman there said that he knows of no balancing system that will accomodate 7/8" holes in conjunction with a 5/8" arbor.:(

It's really kind of comical, the situations I am capable of getting myself into. But thank you for your time, Andy. If you have any other ideas I'm all ears.

Mark

Mark you have me really confused. Admittedly, that is not a hard thing to do. :o But, you say you have a wheel with a 7/8" hole that needs to go on a 5/8" arbor. My bad days are Fridays, Tuesdays I'm usually OK. So, I'm pretty sure that your 7/8" hole is already bigger than your 5/8" shaft (arbor). So, how would drilling out your 7/8" hole to an even bigger 1" hole help you? Befuddled minds would like to know. :confused: I'll risk sounding like a know-it-all, but will repeat. Arbor adapter kits are available. Mine cost about $2.00 at a local hardware store. There are several adapters in the kit. They are made of nylon. Easy slip on. Problem solved. BTW, don't try drilling that wheel.

[Mark Pruitt]

Mark you have me really confused. Admittedly, that is not a hard thing to do. :o But, you say you have a wheel with a 7/8" hole that needs to go on a 5/8" arbor. My bad days are Fridays, Tuesdays I'm usually OK. So, I'm pretty sure that your 7/8" hole is already bigger than your 5/8" shaft (arbor). So, how would drilling out your 7/8" hole to an even bigger 1" hole help you? Befuddled minds would like to know. :confused: I'll risk sounding like a know-it-all, but will repeat. Arbor adapter kits are available. Mine cost about $2.00 at a local hardware store. There are several adapters in the kit. They are made of nylon. Easy slip on. Problem solved. BTW, don't try drilling that wheel.
Frank,
The SSG from Woodcraft has a 5/8" arbor and comes with wheels that have 7/8" holes and a 5/8 ID-7/8 OD bushing to fit the wheels onto the arbor. The Oneway balancing system is designed for setups where you have an arbor that is smaller than the hole in the wheel. They have three sizes for the balancing system--each for a different size arbor and each for a 1" hole in the wheel. The Oneway balancing system actually replaces the bushing. The one that would fit my particular machine would be a 5/8 ID-1" OD, but only if I replace the wheels I presently have with wheels that have 1" holes. I hope this makes it clearer. Thanks for the ideas.
Mark

[Steve Clardy]

Is the grinder itself vibrating without the wheels, or with the wheels on?

[Mark Pruitt]

I haven't tried running it w/o the wheels.

I was unable to do anything with it tonight. I plan to spend tomorrow evening on it. Going on Andy's suggestion, I looked at SMC archives and found this (http://www.sawmillcreek.org/showthread.php?t=32819) thread started by Corey several months ago; some of those comments gave me additional ideas of what to check out. I have a dial indicator and should be able to set it up to get an accurate read for possible arbor runout.

[Ken Fitzgerald]

Mark I have the same grinder and had a similar problem. Mine turned out to be a bad nut holding the right grinding wheel on. The hole in the nut was not drilled and tapped perpendicular to the face of the nut. When you shined a light on it, you could see that only a very small portion of the face of the nut was touching the washer. This allowed the grinding wheel to wobble at grinding speeds. I located a replacement at a local Ace hardware store. With the new nut, the entire face of the nut makes contact and it works fine now.

[Corey Hallagan]

Mark, mine was actually perfect until I took the fender off so I could sharpen a larger skew. Some thought it was because I took the fencer off. The truth is that if you remove or loosen the set up at all you will not have a perfect true running wheel. I have found that the grinder is very very finicky. I now have it running almost perfect. It is kind of a balancing act trying to get the wheel and arbor pieces all to work together. Like someone else said, it isn't totally perfect, but it is very closel. Until your post, I didn't realize the balance kit wouldn't work with this unit. Bummer!

corey

[Mark Pruitt]

Mark I have the same grinder and had a similar problem. Mine turned out to be a bad nut holding the right grinding wheel on. The hole in the nut was not drilled and tapped perpendicular to the face of the nut. When you shined a light on it, you could see that only a very small portion of the face of the nut was touching the washer. This allowed the grinding wheel to wobble at grinding speeds. I located a replacement at a local Ace hardware store. With the new nut, the entire face of the nut makes contact and it works fine now.
Ken, I noticed the comment you had made about the nut. I'll check the one on my grinder closely when I get to it hopefully tonight. Thanks for pointing this out. I might have never thought to look at that.



Until your post, I didn't realize the balance kit wouldn't work with this unit. Bummer!

corey
Corey, Oneway's balancing system will work, but only after replacing the wheels with ones that have 1" holes (which doesn't seem to be a good use of $$ given the fact that the existing wheels are aluminum oxide).

Thanks again guys. I'll post what I find after I investigate this furhter.

Mark

[Frank Guerin]

I don't know anything so don't listen to me. Mark both wheels in the same possition. Loosen one wheel and turn it 45 degree and tighten. When and if you find a sweet spot then fine tune. Sometimes it works.

[Mark Pruitt]

Going on the tips I've gotten from you, here's what I've done tonight.

1. Steve asked if the grinder was vibrating as much with the wheels removed. It does not. Very little actually.
2. With the wheels removed, I used a dial indicator to check for arbor runout. I was surprised. On the left side, the runout is only .0012 and on the right it is .0018. I don't know what the acceptable tolerances are, but this is pretty doggone good, especially for an inexpensive import.
3. Ken mentioned an issue with the arbor nuts not resting firmly upon the flanges. I turned the nuts onto the arbor "wrong side out" (there is actually a "good" side on the nut) and checked for variance in lateral movement (I think I'm using the right term) while turning the arbor. The runout was less than .001 for each nut. Again, pretty doggone good.
4. Satisfied that the vibration was not caused by arbor runout or poorly machined arbor nuts, I placed the wheels back on the grinder and tightened the nuts, then I turned the machine on and what do you know--the vibration was far far less than it had been before.

It turns out that apparently Frank's solution was the answer--at least for as long as I use these wheels. I got lucky and found a "sweet spot." Of course, when I do replace the wheels I'll buy better ones, and a Oneway balancer. But for now, this problem has been at least partially alleviated.

Thanks again, those of you that helped me with this.

Best to you,
Mark

[Corey Hallagan]

That is exactly what I do... the assembley is very finicky and I found by moving thing around a bit I could get it to be almost perfect. Glad you got it to work better!

corey