Improved GIB tracking

Mike Martinez

Mike Martinez

Well-Known Member
After fighting for a few months with the tracking on my Grinder In a Box, I decided to take Ed Caffrey's advice on the spring set up. Being limited in options, I decided to do this as simply as possible. I had an extra piece of 1 1/2" x 2" piece of steel left over from the original build so that made things easy as it was pre-tapped with a 1/2-13 thread. Using a 1/2-13 bolt (cut to size) 1/2 Flange nut, JB Weld, 1/4" threaded rod, (2) 1/4" lock nuts and a 4" spring, this was the result.

*Ed, thank you for the idea. The tracking wheel still needs to be positioned better but now the belt does not move at all from side to side as it did before!

DSC_0006.jpgDSC_0009.jpgDSC_0010.jpgDSC_0007.jpg
 
Great Modification. I appreciated Ed Caffrey's modification and his explanation of why this is an improvement, but I like the way you have done this. I think I have that same piece of 1 1/2" x2" steel left over from my GIB build, the result of a not very straight tap. Thanks for posting the pictures.

Jay
 
One thing I did change from my original mod, is to use a piece of 2 3/4" threaded rod rather than a cut bolt and shortened the 1/4 Bolt to stick out just 1/2" past the nut on the bottom. The JB weld works very well... honestly, the downward pressure pushing down was enough to hold it even without the JB weld (never considered it as a full time solution, just did it to see if it would work). The spring came from a hardware store, I found it for $5. Its nothing special just a regular compression spring. A more expensive Die spring would work but it isn't necessary.
 
Another aspect of the tracking that helped me was to change the pivot location on the idler arm. I drilled another 1/2" hole as close to the back end of the idler arm as possible, and mounted it that way.....this puts the idler wheel slightly forward of the spring, which was/is an improvement over having the spring located forward of the idler wheel (as far as aiding belt tracking)

What this does is give a longer travel area for the belt between the drive and idler wheels.....and it made a very noticeable difference as far as tracking precision on my machine.
 
A tracking mod I did on mine(due to a the part slipping in the vise when drilling,) was I had AC Richards mill me a new tracking wheel mount piece thingy(thanks Chuck!)....without slop between the parts. The original parts had some slop and I could see a slight amount of play in it when adjusting the tracking.
I-Phone 237.jpg

It seems we all have problems drilling and tapping this piece?? :les:
 
Mike928 said:
A bit of a stupid question, but do rubber covered drive wheels sport a crown?
Click to expand...

It depends on how you order it? Crown or no Crown is possible. My drive wheel on the Hardcore grinder is the bottom 5" of the platen set up! It makes a big diff with how smooth the machine operates. No belt slippage .
This wheel isn't crowned.
By the way Mike, Thats a great looking Handle on the idler arm. Did you turn that yourself?
Nice Touch of class on the grinder!

Laurence

www.rhinoknives.com/
 
Yes sir, I turned the handles on it out some less than great burled wood. The large handle is made of stabilized redwood burl and the smaller tracking handle is made from lace maple burl. Left overs from brush handles and Japanese Wa handles.
 
So after playing with the GIB for over a year now, I've used many different configurations with better results each time. The first was stock and the tracking was all over the place due to a bad tap and not enough tension on the belts. The second configuration was with the idler arm in its natural position with a 20 Lb gas spring in place near the tracking wheel and this improved the tracking some but the belt would move on me when the amount of pressure changed on the platen or wheel while grinding. So, I thought number three would be the winner; in this configuration, I replaced the gas spring with a regular compression spring but did not move it away from the idler wheel. This helped but again, the belt moved while grinding, much less but still too much for my liking.

After posting on this thread Mr. Caffrey gave me some sage advice and I moved my idler arm forward and changed the position of the spring closer to the end of the arm. This helped a ton but the spring would vibrate like crazy and it made a horrible sound while it was in use so I changed it to a 40 lb gas spring in the same forward position described by Mr. Caffery. Again, this made things a little better but as I got more comfortable grinding, I ran the motor closer to 100% and as I changed the speed, the tracking would have to be adjusted to compensate for the small amount of give that gas spring had at higher speeds.

Not being able to get the tracking where it should have been, I nearly gave in and junked the whole grinder. Frustrated and out of options, I ordered a 60 lb spring and gave it another go. Amazingly, this was the answer! In the last two months (with some of the heaviest grinding I've done in a while) the 60 lb gas spring and "Caffrey," configuration have changed an OK grinder into one that runs great. Now the only tracking adjustments that it needs are done when I want to move the belt and not when the grinder decides it wants to play with my plunge lines.

Thanks again KnifeDogs and Mr. Caffrey for the may tips and advice of the past years!

Appreciatively,
Mike
 
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