Help with belt grinder tracking - general design

T

taviii11

Joined
Feb 16, 2023
Messages
23
Hello guys! im on the final route of finishing this diy grinder, its been two days of work trying to get it to track correctly, but i am not being able to do it.

i dont know if i failed design wise or whats the issue, im gonna post some pictures so u can see it, i know that the first thing to get right is wheel alignment, i tried to get them true with a wooden straightedge that ive cut on the circular saw. i played with this for hours but every change i make results on the same, the belt doesnt track correctly.

the only crowned wheel in my setup is the aluminum drive wheel, the rest are straight grilon wheels. i tried to give the tracking wheel a crown with tape but the results are the same.

im trying to get a laser level so i can align everything better. in terms of belt tension i think my spring is strong enough, but maybe im wrong.

the hinge on my tracking wheel is not perfectly perpendicular to the grinder body, but ive seen other designs that are similar. sometimes adjusting the screw gives me the opposite result wanted, whent the belt should be going right it goes left and viceversa.

ive runed out of budget i want to make this setup to

https://imgur.com/a/kNkjtIU
 
I think I see what you are describing - with the belt running to the outside, tweaking the tracking wheel you're able to pull the belt to center, instead of staying in center it moves on to the inside of wheels? Is that the case? You're able to move belt from side to side, but not able to stop it in the center - is that what I'm seeing?
 
I could be blind, but I do not see much of a crown on the drive wheel - it seems pretty flat/straight to me. I would try a different tracking wheel - short one, with a decent crowning. So that the belt contacts primarily on the center of the wheel (on the crown top). Amateur opinion only of course - but that is what I have on my grinder and seems to work ok.
 
Crag the Brewer said:
It looks like you are tracking.... Or is it moving too much?
Click to expand...
yes, i can get it to track, and i can grind, but is far from perfect
Ken H> said:
I think I see what you are describing - with the belt running to the outside, tweaking the tracking wheel you're able to pull the belt to center, instead of staying in center it moves on to the inside of wheels? Is that the case? You're able to move belt from side to side, but not able to stop it in the center - is that what I'm seeing?
Click to expand...
yes! this is my main problem, ive seen a dozen of videos online in which the tracking adjustment is milimetric, whit a little turn of the adjustment screw the belt moves little by little, in mine a little adjustment throws the belt either completely to the left inside of the wheels or to the right and the half falls of the wheel.
pafka said:
I could be blind, but I do not see much of a crown on the drive wheel - it seems pretty flat/straight to me. I would try a different tracking wheel - short one, with a decent crowning. So that the belt contacts primarily on the center of the wheel (on the crown top). Amateur opinion only of course - but that is what I have on my grinder and seems to work ok.
Click to expand...
yes you could be right, i dont have money for a new wheel sadly, although ive tried to give the tracking wheel a crown with tape but ive got the same results :/
and yes the drive wheel is pretty flat, the crown is not that much pronounced
https://imgur.com/a/VD3V3D9
 
Tom Lewis said:
I think your tracking wheel needs to be crowned.
Click to expand...
Maybe i could take it to a turning shop to get it crowned.

And about the tracking wheel hinge, does it need to be perpendicular to the grinder body? Or its also ok if its angled just a bit?
 
First, is it just optical illusion or these white wheels have inverse crown? Or are they true flat? Can you check that?
Second - it looks like material is some kind of plastic. I too have completely diy grinder and I made tracking wheel from bike hub center. I used angle grinder to roughly shape it, then mounted in place and with belt (and wheel) running, sanded it in place. Yes, it is safety concern to do that, so be advised. With plastic wheel you can try to shape crown totally by hand - with marking and measuring tools, knife, files, sandpaper, whatever tools you got. In my opinion, to take this wheel to turning shop is wasted money. Better buy (or order in that turning shop) aluminum tracking wheel. And yes, all your problems is because tracking wheel lacks crown. Hinge can be angled, can't see why not.
 
lynx85 said:
First, is it just optical illusion or these white wheels have inverse crown? Or are they true flat? Can you check that?
Second - it looks like material is some kind of plastic. I too have completely diy grinder and I made tracking wheel from bike hub center. I used angle grinder to roughly shape it, then mounted in place and with belt (and wheel) running, sanded it in place. Yes, it is safety concern to do that, so be advised. With plastic wheel you can try to shape crown totally by hand - with marking and measuring tools, knife, files, sandpaper, whatever tools you got. In my opinion, to take this wheel to turning shop is wasted money. Better buy (or order in that turning shop) aluminum tracking wheel. And yes, all your problems is because tracking wheel lacks crown. Hinge can be angled, can't see why not.
Click to expand...
Man youve got a great eye, ive just checked the wheels and they do have an inverse crown, although Is just 0.5mm or maybe less, but theyre not perfectly flat, and yes the wheels are Made from grilon (nylon), Is a pretty hard material.

Can you send me a picture of your tracking wheel?
Yes maybe i can put the crown on by myself, i hope you are right and it Solve my problems, i really want to start to making some knives with this grinder.

A new aluminum tracking wheel Is not an option right know cause they are really expensive where i live, i must get it right with what ive got.

Also good to hear that the hinge doesnt change anything by being angled towards the body.
 
You might need to narrow your tracking wheel too, so the crown is useful?

Being wide might screwup the tracking
 
So, you have two adjustments you can make to your tracking setup. At least that's the way it looks to me.
First is the screw you are adjusting in the video, it moves the wheel up and down.
The second is the screw that holds your tracking wheel to the arm. If you loosen that, you'll be able to adjust the tracking wheel forward and back.
Between the two you should be able to get it all tuned up, once you get your idler and tracking wheels flattened.
 
A.McPherson said:
So, you have two adjustments you can make to your tracking setup. At least that's the way it looks to me.
First is the screw you are adjusting in the video, it moves the wheel up and down.
The second is the screw that holds your tracking wheel to the arm. If you loosen that, you'll be able to adjust the tracking wheel forward and back.
Between the two you should be able to get it all tuned up, once you get your idler and tracking wheels flattened.
Click to expand...
Yes thats correct, i Will try to get the tracking wheel crowned and see how it goes, you think that the iddler wheels being inverse crowned are causing trouble? I just checked them with a feeler gauge and the low spot at the Center Is 0.25mm or 0.00984in. wouldnt that be negligible?
 
taviii11 said:
I hope you are not right šŸ˜…, im gonna give it a crown with the current width and see how it goes. Because if it Is like you say i would need a new wheel.
Click to expand...
Or just washers to take up the distance you remove from the tracking wheel width.

Probably need a certain ratio of radius per width to be effective
 
taviii11 said:
Yes thats correct, i Will try to get the tracking wheel crowned and see how it goes, you think that the iddler wheels being inverse crowned are causing trouble? I just checked them with a feeler gauge and the low spot at the Center Is 0.25mm or 0.00984in. wouldnt that be negligible?
Click to expand...

If they are dipping that might explain the lag in responsiveness to you turning the screw?

When I turn my threads it react s instantly
 
Crag the Brewer said:
If they are dipping that might explain the lag in responsiveness to you turning the screw?

When I turn my threads it react s instantly
Click to expand...
Yes, ive seen that also on various grinders in YouTube, the adjustment screw causes an instant effect, but not in my case šŸ„².
So
-get tracking wheel crowned (if it doesnt Work get a narrower one. It should be the same width as the belt? (75mm). The current ones are 98mm.)
-get the iddler wheels flat
 
Most tracking wheels are a little wider than the belt to allow for tracking to one side or the other without the belt coming off the side of the wheel. An 80-85mm wide wheel should be about right if those are 75mm wide belts. A crown would definitely help. Could be that the top platen pulley is not perpendicular as well. Do you have a contact wheel to put on to see if it behaves any different?
 
Contender Machine said:
Most tracking wheels are a little wider than the belt to allow for tracking to one side or the other without the belt coming off the side of the wheel. An 80-85mm wide wheel should be about right if those are 75mm wide belts. A crown would definitely help. Could be that the top platen pulley is not perpendicular as well. Do you have a contact wheel to put on to see if it behaves any different?
Click to expand...
I dont have a contact wheel to try :/, what do you mean with top platen pulley? The upper iddler wheel? Im trying to borrow a lƔser level to check all the alignments.
 
Yup thatā€™s what I was referring to. If those are off it can cause some tracking issues.
 
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