What's wrong with using poly coated idler wheels in a belt grinder design?

G

gixxer

Joined
Sep 21, 2006
Messages
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I have this idea in my head about a horizontal edge grinder design. So, I am looking around for bb idler and drive wheels, and most everywhere I looked I found all metal wheels for $40 and up. I then found a joint on the internet that makes steel or aluminum core bb idler and drive wheels for around $20 apiece!
http://www.sunray-inc.com/4X175BB.asp

Do I really NEED all metal wheels, or was this a good find? Opinions?
 
I've heard of SunRay, but I haven't gotten any reviews yet. I think one or two folks have ordered from them recently though. Nothing at all wrong with a coated wheel as an idler. Just remember that if you're using it for tracking, you'll want it slightly crowned. Heck, even drive wheels from Beaumont are crowned. that said, you can generate enough of a crown with a few winds of electrical tape on the center of the wheel to do the job.

-d
 
I orderd the 2x4bb wheel and the 2x8 wheel with a 5/8 hole both wheels are aluminum with 96a poly i will be making a grinder like the coot grinder these look like very nice wheels
 
After you have the grinder together you could split a belt in half and run it on either side of the wheels, and on the opposite side carve a crown with a sharp chisel. You would put the chisel at a 90 degree angle of the wheel. After you are done with one side you track the belt to the other side and carve the other side of the wheel. You just have to make sure that everything is lined up right so the belt doesn’t slip off.

Tell me if this makes sense.
 
Mr. Evans, I recommend you try the tape trick before you go carving your wheel. Carving a spinning poly wheel with a chisel like it is turning wood is an accident waiting to happen, IMO. If you ever decide to try the trick RRybicki is suggesting, I recommend you try it with a big wood file (not rasp) and leave the chisel in the drawer. Even then, if you don't get it nice and even, you'll ruin your wheel for tracking. the other problem is that after you have "side 1" carved, you're trying to track a half belt on an angled surface. It'll fly off.

I didn't even want to say anything on this thread, but if that "chisel" bites, gets jerked out of your hand, and thrown, it could get very dangerous quite quickly. Just my 2cents.

Mr. Rybicki, I apologize for disagreeing with you, but for the sake of safety I urge caution.
 
fitzo said:
Mr. Evans, I recommend you try the tape trick before you go carving your wheel. Carving a spinning poly wheel with a chisel like it is turning wood is an accident waiting to happen, IMO. If you ever decide to try the trick RRybicki is suggesting, I recommend you try it with a big wood file (not rasp) and leave the chisel in the drawer. Even then, if you don't get it nice and even, you'll ruin your wheel for tracking. the other problem is that after you have "side 1" carved, you're trying to track a half belt on an angled surface. It'll fly off.

I didn't even want to say anything on this thread, but if that "chisel" bites, gets jerked out of your hand, and thrown, it could get very dangerous quite quickly. Just my 2cents.

Mr. Rybicki, I apologize for disagreeing with you, but for the sake of safety I urge caution.
Click to expand...
i only wanted to say the wheels i orderd looked like they would do the job wasnt asking how to make them work
 
Every quality knifemaker's grinder I know of has at least one crowned wheel. You'll find that if the pressure on the contact wheel isn't perfectly even across the wheel, the belt tries to skitter away to the side opposite the greater pressure. There are some times you'll want to apply that pressure unevenly on purpose, like when you are dressing a plunge. The crown on the idler creates a resistance to movement and also keeps the belt running truer.

If you run into that wandering problem you may want to try the tape trick. One of my grinders is an old Bader 2 that has always been skittish. It has winds of tape on top of the crown to help.

If you knew all this or are simply uninterested, perhaps still someone else may find the explanation of interest.

Happy Thanksgiving to you!
 
fitzo said:
Every quality knifemaker's grinder I know of has at least one crowned wheel. You'll find that if the pressure on the wheel isn't perfectly even across the wheel, the belt tries to skitter away to the side opposite the greater pressure. There are some times you'll want to apply that pressure unevenly on purpose, like when you are dressing a plunge. The crown on the idler creates a resistance to movement and also keeps the belt running truer.

If you run into that wandering problem you may want to try the tape trick. One of my grinders is an old Bader 2 that has always been skittish. It has winds of tape on top of the crown to help.

If you knew all this or are simply uninterested, perhaps still someone else may find the explanation of interest.

Happy Thanksgiving to you![/QUOT i
Click to expand...
 
I apologize, i feel that i have been misunderstood in this thread. thank you for any advise that you can give me, it is greatly appreciated. i orginially only posted on the wheels from sunray, gixxer was asking about. i ordered the wheels to build a grinder, when i received these wheels i thought they were quality wheels. and wanted to help in anyway i could.
 
Jeremy, there is nothing for you to apologize for. You have offered no insult to anyone that I see.

I am quite interested in how your grinder will be made and how it both turns out and holds up. Sharing about these topics is certainly the very foundation of this forum. Good deals on parts that make good grinders offer valuable alternatives to those unable or not interested in dumping a huge amount in a "pro" grinder. The important part is to come back after a period of hard use and tell us how well it worked. I wonder sometimes when we don't get a follow up to tell us these alternatives were actually a good idea or not. If the wheels blow up (poor bearings, bad urethane bonding, etc.), it's important to share that, too.

There was a guy on another forum who really braggingly razzed everyone who "wasted" their money on an expensive grinder when he had made one for $75 out of 2x4's and industrial casters that was "just as good." I admired it when he had the courage to come back after only a few months and say how arrogant and wrong he'd been because his grinder had fallen apart after only brief use.

My only concern here was for advice I considered possibly unsafe if done wrong. I don't want to find out someone got hurt where it might have been prevented through my voicing that concern.

After that, I sought only to offer advice that you or others might find useful who read this thread now or searching the archives later. At the same time, I didn't want to seem presumptive when I don't really know how much you know.

If there is any misunderstanding, it is only in how words are meant when written versus how they are read. I, too, hope I didn't offend you.

I admire that a man will apologize when he may feel uncertain whether he may have been misunderstood. Thank you for that. :thumbup:

Happy Thanksgiving!
 
I have ordered some wheels from 'em. The bonding of poly to the metal
is impecable. One thing I wish they did is to hollow out the 8" contact wheel
(one of many I got). No point in spinning all that extra mass.

Anyway, for driving and idler I most highly recommend:

http://www.surpluscenter.com/item.asp?UID=2006112307142698&item=1-2875&catname=wheels

I got a few here.

They are very true and assuming you can access to a lathe, takes a minute
to true up the poly. This one is great as both contact and idler (you can contour it for better belt tracking).

To make it into driver, you'd need to fashion a keyed bushing and press fit it
in in leu of original roller bearings.


The roller bearing comes out with 2-3 gentle blows of a hammer.
 
Fitzo no apology is necessary. Thank you for objecting.

I was afraid that I did not explain myself well about the procedure I outlined above. I left out that I use a flat platen as a tool rest. I left out an important detail and with that said, I believe suggesting something like I did is irresponsible. I would feel bad if my advice got someone hurt. Most of what we do does involve dangerous machinery and now that I think about it I would not feel comfortable explaining how to use any of it on an online forum.

I use the procedure outlined above to re-dress my contact wheels but I do not suggest that anyone else does.

I am sorry for not thinking befor typing.
 
RRybicki said:
......
I was afraid that I did not explain myself well about the procedure I outlined above. I left out that I use a flat platen as a tool rest. I left out an important detail and with that said, I believe suggesting something like I did is irresponsible. I would feel bad if my advice got someone hurt. Most of what we do does involve dangerous machinery and now that I think about it I would not feel comfortable explaining how to use any of it on an online forum.
..........
Click to expand...

RRybicki, I admire you for coming back and saying that. You make a very important point. We develop our own unique techniques for doing a task, and it works very well for us. So well, in fact, that we may overlook an important piece of info when trying to convey it. Your first sentence in the quote above suggests in the back of your mind something was nagging away.... "you didn't say this!"

I wonder, too, all the time, about whether I've said something right. A lot of times I haven't. I do a lot of editing. :o I'm afraid of offering too much in the way of chemistry to people, because I don't want them hurting themselves because I failed to properly judge their ability to safely use what I've told them.

The best we can do is to try and watch out for one another, and ask a question, or raise a flag of caution when something doesn't add up enough to seem "right". I hope ANYONE here will be willing to speak up if they feel something could present a hazard. That old saying "better safe than sorry" has been around a long time for a reason. If we all watch out for each other, we do each other a service.

May I ask your first name, RRybicki? This place sort of takes on the aspect of an extended family. I enjoy knowing the people here a little, and feeling friendly. Thanks. I hope I have not offended. The last thing I would want to do is put you off from sharing what you know. The stuff we can all learn here by sharing is what makes us better knifemakers. I know it has for me.
 
FWIW If anyone wants to turn/trim down a spinning object,be it a wheel,a shaft,a wooden disc,etc, use a large bastard file.(You can do it on the machine ,a lathe,or on a drill press.) It will sand away at the turning surface safely,as there is no sharp edge to catch.Sometimes this is referred to as rotary draw filing.
When I saw the post on putting a chisel on a spinning poly wheel, my hair stood on end.
Stacy
 
rashid11 said:
I have ordered some wheels from 'em. The bonding of poly to the metal
is impecable. One thing I wish they did is to hollow out the 8" contact wheel
(one of many I got). No point in spinning all that extra mass.

Anyway, for driving and idler I most highly recommend:

http://www.surpluscenter.com/item.asp?UID=2006112307142698&item=1-2875&catname=wheels

I got a few here.

They are very true and assuming you can access to a lathe, takes a minute
to true up the poly. This one is great as both contact and idler (you can contour it for better belt tracking).

To make it into driver, you'd need to fashion a keyed bushing and press fit it
in in leu of original roller bearings.


The roller bearing comes out with 2-3 gentle blows of a hammer.
Click to expand...

Wow, sorry it took so long for the thanks (vacation will do that I guess). Anyhow, thanks for the replies. I never could comprehend the concept of a crowned wheel for tracking, it just never made sense. Anyhow, that's what works, no need to pull my hair out trying to figure it out. Just do it I guess. Anyhow, are roller bushings a viable option to BB's? Roller casters are even more inexpensive than the Sunray's. Sooner or later there is a point where you get into "cheaper" stuff compared to only being less expensive so to speak. Who knows, if you ask nice they might cut a slight crown for ya.

How are you guys running a horizontal sander with a 1/2" wheel? kinda like the small wheels that Beaumont sells for instance.
 
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