Grinder in a box/eerf tracking

K

Kevin Powers

Joined
Jul 23, 2015
Messages
411
I haven't been happy with the tracking of my eerf grinder since I built it. It doesn't track very accurately. I remember reading about a different tracking setup once upon a time. Anyone have pics of their modified tacking setups?
 
What about tracking are you unhappy with? I mean specifically what is the deficiency? Too coarse/fine adjustment? Belt jumps "randomly" or doesn't move consistently relative to adjustments? Etc.

In my experience building 3 grinders from scratch the majority of tracking problems are specific to wheels, wheel axis alignment, wheel concentricity, and belt stretch, with a minor but noticeable improvement in consistency from a 4" tracking wheel rather than a smaller diameter.
 
The way this setup is designed the wheel moves up and down. The belt can sometimes wander and hit the bracket. Killing the left edge of the belt. I'm currently designing a grinder to track on the drive wheel, with that being a little ways out in looking foe the temporary fix. I know I have seen the modified bracket at one point, just don't remember what it looks like.
 
Kevin, if you have the original GIB that did not have a gas shock, you probably just need more spring tension. Lots of GIB owners did a gas shock conversion to get more tension.

I have the GIB V2 that Jamie designed for a gas shock. When I first put mine together it was all over the place tracking wise depending on what tooling arm I was using. In my efforts to get it tracking better, I remembered hearing Nick Wheeler talk about having to have the tracking arm on his KMG compressed down to a horizontal position or it would not track right. Looking at my GIB I saw that there was no way to get the tracking arm down to a horizontal position as the shock would not compress that much and if the arm was not horizontal the axle that goes thru the tracking block would not be in the right plane and would not just move the tracking wheel in and out, but also side to side which is not good.

My solution to this was to raise the height of the vertical support piece as shown in the video below. Another option would be to try and find a shock with a shorter throw that would allow the tracking arm to lower to the horizontal. Once I made this mod to my GIB it tracks dead on. I recently added a forward and reverse switch to my VFD, as I wanted to run a disc grinder off of it as well as the belt grinder. and the tracking is so good it will run in the exact position with the belt going in forward or reverse.

I've talked to other GIB owners that said they had no problem with the tracking with the GIB V2, but this mod takes it from tracking OK to tracking great. At least it did with mine. YMMV.

[video=youtube;53wK5gvC3Xk]https://www.youtube.com/watch?v=53wK5gvC3Xk&t=38s[/video]
 
I forgot about tension. My first grinder was tensioned by a spring, it had at the normal extension, around 30 lbs of tension. The two I built after that have 60 lb gas springs and that was a significant improvement.

When you say it "sometimes can wander" when exactly does it wander? I think poor tension causes tracking deviation when you're pushing material into the belt, especially if the pressure is uneven. Pushing material into the belt creates higher tension behind the part and lower tension above the part until the system catches up, this allows the belt to jump towards the pinch point or whichever direction it's inclined to travel due to alignment issues. That would happen with my first grinder but not the ones with 60lb gas springs.

ETA: the other thing NC Biker's modification does is increase the contact area the tracking wheel has with the belt. Raising the tracking wheel necessitates the belt wrapping around it to a greater degree. I think this can be desirable for tracking for the same reason a 4" wheel works better than smaller diameters, if it's an option give your particular setup.

It's not necessary to have a gas spring directly in line with the tracking arm. To resolve the height issue my gas springs are attached to tapped holes in the side of the arm and side of the frame:

b2qbRD.png
 
Last edited:
NC Biker said:
Kevin, if you have the original GIB that did not have a gas shock, you probably just need more spring tension. Lots of GIB owners did a gas shock conversion to get more tension.

I have the GIB V2 that Jamie designed for a gas shock. When I first put mine together it was all over the place tracking wise depending on what tooling arm I was using. In my efforts to get it tracking better, I remembered hearing Nick Wheeler talk about having to have the tracking arm on his KMG compressed down to a horizontal position or it would not track right. Looking at my GIB I saw that there was no way to get the tracking arm down to a horizontal position as the shock would not compress that much and if the arm was not horizontal the axle that goes thru the tracking block would not be in the right plane and would not just move the tracking wheel in and out, but also side to side which is not good.

My solution to this was to raise the height of the vertical support piece as shown in the video below. Another option would be to try and find a shock with a shorter throw that would allow the tracking arm to lower to the horizontal. Once I made this mod to my GIB it tracks dead on. I recently added a forward and reverse switch to my VFD, as I wanted to run a disc grinder off of it as well as the belt grinder. and the tracking is so good it will run in the exact position with the belt going in forward or reverse.

I've talked to other GIB owners that said they had no problem with the tracking with the GIB V2, but this mod takes it from tracking OK to tracking great. At least it did with mine. YMMV.

[video=youtube;53wK5gvC3Xk]https://www.youtube.com/watch?v=53wK5gvC3Xk&t=38s[/video]
Click to expand...

That's great Chuck. I need to check into that as my Sling grinder has basically the same geometry.
 
kuraki said:
It's not necessary to have a gas spring directly in line with the tracking arm. To resolve the height issue my gas springs are attached to tapped holes in the side of the arm and side of the frame:
Click to expand...

I set mine up intentionally so my gas spring is on an approximate 45* angle. The spring compresses farther than it would if it were perpendicular to the tensioning arm. It makes for a very stable arm. Any vibration being transferred to the spring in order for the arm to have any bounce to it would have to compress the spring a larger distance being on an angle than if it where straight up and down. A rough guess not being at my shop, it takes approx 4-6" of spring compression for my wheel to move one inch.
 
I didn't think of that. That's a great point though.
 
You should consider using a 4 inch tracking wheel and a 40 lb. gas piston . Here is a quick video of a GIB grinder I assembled a couple years ago. Near the end of the video the grinder looks like it is not running but it is actually running very fast and smooth. Larry


[video=youtube;IIqdNZaB-Uc]https://www.youtube.com/watch?v=IIqdNZaB-Uc[/video]
 
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