How to mount contact wheel on belt grinder

[Natlek]

https://bladeforums.com/threads/14”-contact-wheel.1768294/page-2#post-20248865

I don t know if it is my bad English or what it is it , but in that thread somehow I turned out bad ................
I drew this drawing to explain once and for all how to mount wheel properly on grinder .
And to be CLEAR when shaft bolt and sleeves/collars/washers MUST be true !
If there is any wobble or run out on say 10 inch contact wheel , the cause in the first three cases in the drawing may be .......... damaged bearings , incorrectly / not precisely made wheel , if wheel is too much unbalanced ...........
If you use threaded rod like in case 4 you have no idea what are you doing !!!!!

One of my small wheel......................that s how I do that ..........

Comments are welcome in this thread !

 

[Stacy E. Apelt - Bladesmith]

I agree. If the holes are drilled precise and true to the plane of the wheel 1,2mand 3 are all good.
Threaded rod definitely doesn't belong on a contact wheel.

Using precision hardened bolts and other hardware is also the best practice.

 

[Natlek]

I agree. If the holes are drilled precise and true to the plane of the wheel 1,2mand 3 are all good.
Threaded rod definitely doesn't belong on a contact wheel.

Using precision hardened bolts and other hardware is also the best practice.

Tell that to the guy in that thread who used them and then share tips on why someone's wheel wobble..................
Threaded rods are good for this and nothing else in my workshop

 

[Natlek]

one more thing ................
In case ONE , hole and thread in tool arm are not drilled straight .No problem if spacer between wheel and tool arm is true . When we tighten bolt everything would be on place , and cannot be a reason for wheel wobbling !
In case TWO , hole and thread are straight and spacer is not true ........problem only with tracking , wheel can not wobble or run out !!

And to finish ...........if we have half inch inner Dia. bearing / 12.5mm/ on wheel and we use 12mm bolt or even 10mm Dia. bolt .No problem ! When we tight bolt , it has no effect on the behavior of the wheel ! When we tight bolt we LOCK inner races of bearings so balls can spin..............
! And that cannot be the reason for wobble or run out !
Remember , wheel spin on two bearings ! For any wobble or run out reason is there..........worn, heavy damaged bearings or poorly made wheel . Problem is NOT in other parts used for mount wheel ...................problem is in threaded rod with nyloc nut as SPACER !
I hope that this will help to DIY guys who make own grinders ....to pay attention to this details so not to wonder later why their grinder don t want to track belt nice !

 

[Stacy E. Apelt - Bladesmith]

We will just have to agree that we disagree on this last post.

 

[Hubert S.]

Tell that to the guy in that thread who used them and then share tips on why someone's wheel wobble..................

Welcome back, Natlek. I am "the guy in that thread", and you are completely mischaracterizing what I wrote. I almost get the sense that you may be a bit angry at me. If anything I posted in the other thread offended you, please accept my apologies, I did not mean to insult you in any way. I really have zero interest in arguing with you, or anybody else for that matter. Since you referred to me in your post and even included an inaccurate depiction of how you think I once mounted a contact wheel, I feel compelled to briefly summarize my view of the other thread for clarification. Stacy initially gave some suggestions what the OP should look at and you questioned that advice. After you claimed that one could mount a wheel with a bearing ID of 12mm on a 10mm bolt without wobble in post #7, I shared my experience trying something similarly ill-advised using all-thread, because that was all I had on hand and I wanted to try my new wheel while waiting for the proper hardware to arrive. I do not recall advocating this method or sharing any tips in regards to mounting a wheel like you insinuate above, other than the implied advice not to do what I did and use a properly sized shaft instead. It all went downhill from there when you suggested that I don't understand the basic concept of how bearings work in post #10. I looked over my posts again and saw that I reacted to that by calling you "a funny character", and I want to apologize if that offended you.

I am quite puzzled that after a two week hiatus you would pick up where you left off and spend all this time writing and making graphics to make the point that all-thread and nyloc nuts are a problem while claiming that undersized bolts and poorly machined spacers will work without issue. The main problem with all-thread is that it is undersized, not that it is all-thread. You cannot generate enough force to keep the wheel in place if there is no crush sleeve between the bearings, which is the first thing I mentioned in post #16 of the other thread. I have no doubt that you can make an undersized bolt work if you have a spacer between the bearings, but in that case, all-thread would also work, it is just a bolt without a head and widely available in the same grades as bolts. If you want to keep advocating that method, feel free to do so, but please, leave me out of it and do not mischaracterize what I said, even if you only refer to me as "the guy in that thread".

In your first post of this thread, you are wondering whether your bad English might be to blame for you "turning out bad". I am not a native English speaker either, but seeing how you took the time to put five exclamation marks after "you have no idea what you are doing" in that same post, I have to wonder if it might not be something other than a language problem. I don't take any of this too personally and generally assume that people mean well, but what you write is sometimes pretty insulting on the face of it. Take that for what it's worth, and again, welcome back!

 

[Natlek]

After you claimed that one could mount a wheel with a bearing ID of 12mm on a 10mm bolt without wobble in post #7, I shared my experience trying something similarly ill-advised using all-thread, because that was all I had on hand and I wanted to try my new wheel while waiting for the proper hardware to arrive. I do not recall advocating this method or sharing any tips in regards to mounting a wheel like you insinuate above, other than the implied advice not to do what I did and use a properly sized shaft instead. It all went downhill from there when you suggested that I don't understand the basic concept of how bearings work in post #10. I looked over my posts again and saw that I reacted to that by calling you "a funny character", and I want to apologize if that offended you.

I am quite puzzled that after a two week hiatus you would pick up where you left off and spend all this time writing and making graphics to make the point that all-thread and nyloc nuts are a problem while claiming that undersized bolts and poorly machined spacers will work without issue. The main problem with all-thread is that it is undersized, not that it is all-thread. You cannot generate enough force to keep the wheel in place if there is no crush sleeve between the bearings, which is the first thing I mentioned in post #16 of the other thread. I have no doubt that you can make an undersized bolt work if you have a spacer between the bearings, but in that case, all-thread would also work, it is just a bolt without a head and widely available in the same grades as bolts.

Hubert S my friend ,you don t need to apologies to me ..........I apologies to you if i do something wrong .
Fact that you try that tell me that you have no idea what are you are doing, you should know in advance that that would not work ? Yes , threaded rod should work too IF there is crush sleeve between the bearings. ALL /except special one / bolts are slightly undersized and that is not problem with wheel assembly if everything else is done right .That is my point .What difference would make 0.20mm undersized bolt with 1.00mm undersized bolt used in this situation ?
Again , Stacy is wrong , bad spacer , undersized bolt can not be reason for wobble or run out on wheel .That can affect only belt tracking ... Not true spacer will just misalign wheel position to tool arm and since tooling ram is aligned with rest of grinder you will have problem with tracking .
Look this pictures maybe they should explain better what I talk about ?
I deliberately sanded that spacer on one side at an angle ..about one mm. difference . NOW if i tight that spacer with that 12mm Dia. bolt ,spacer will align with that steel plate / which is say tooling arm / and bolt will sit slightly in angle compared to plate . Spacer will have contact with the entire surface of the plate no matter that surface is ground at an angle.And since bolt is axle of wheel in our case ,wheel will not be parallel to tooling arm , BUT can not make wheel to wobble or run out .Even bent bolt would work perfectly if everything else is done right !
Are we closer to understanding each other now ?

Bolt tightened firmly.....................no gap between spacer and plate or washer on bolt head side BUT bolt /wheel/ is little angled compared to plate .....Did you understand now ? That s why i say that if hole/thread in tooling arm is not at exactly 90 degree IF you use TRUE spacer wheel will be align with tooling arm ....

One more thing .............when we tight firmly bolt lot of force was created between spacer and tool arm and that is important in this setup , make whole very rigid and capable to fight all forces created by fast spinning wheel .That s why undersized bolt will work as well. When we firmly tighten bolt ,wheel will spin on bearings . We don’t just rely on size/dia. of bolt like in what you try with threaded rod .

Which setup will carry more weight ? In both case same bolt ?

 

[Natlek]

one more thing ................
In case ONE , hole and thread in tool arm are not drilled straight .No problem if spacer between wheel and tool arm is true . When we tighten bolt everything would be on place , and cannot be a reason for wheel wobbling !
In case TWO , hole and thread are straight and spacer is not true ........problem only with tracking , wheel can not wobble or run out !!

And to finish ...........if we have half inch inner Dia. bearing / 12.5mm/ on wheel and we use 12mm bolt or even 10mm Dia. bolt .No problem ! When we tight bolt , it has no effect on the behavior of the wheel ! When we tight bolt we LOCK inner races of bearings so balls can spin..............
! And that cannot be the reason for wobble or run out !
Remember , wheel spin on two bearings ! For any wobble or run out reason is there..........worn, heavy damaged bearings or poorly made wheel . Problem is NOT in other parts used for mount wheel ...................problem is in threaded rod with nyloc nut as SPACER !
I hope that this will help to DIY guys who make own grinders ....to pay attention to this details so not to wonder later why their grinder don t want to track belt nice !

I forget spacer between bearing in picture in that post .......

 

[Natlek]

10mm bolt , 10 inch wheel with 10mm inner dia. bearings , spacer between tool arm and wheel is inner race of worn bearing , and 32 m/s belt speed .Bolt is slightly undersized of course compared to bearing opening . Imagine what can happen if something go wrong .That s way I recommended properly made setup ....What would happen if there is no spacer between bearings and used threaded rod like it is used in small/idler wheels in some grinders ???