KennyPete
ArboristSite Operative
I was given a harbor freight chain grinder yesterday, so I figured I would tinker with it and see if I can improve on it a little before passing it on to someone else. Out of the box it's what you would expect from Harbor Freight. It works, just not very well. So here is my less than 2 dollar fix.
I identified a few problems:
Here is how I fixed them:
These fixes made a vast improvement in this cheap machine. While it is nowhere near as precise, adjustable, powerful, or durable as my EFCO grinders, it is roughly 1/16th the cost. If you're willing to put in a little work to make it function better, it's perfect for anyone who can't justify spending $350+ for a good grinder to their wife haha.
I hope this helps you guys out somehow. I have gained a lot of knowledge from here in the past couple months, bought and sold a few saws, made a few friends, and I would like to give back to the community.
I identified a few problems:
1.) The bike handle clamp mechanism sucks. Even with the adjustments all the way out it didn't provide sufficient clamping. It did not hold a consistent height, and it liked to get hung up.
2.) The spacers between the rails were at .088, so there was a lot of play.
3.) The grinding wheel sucks.
4.) The pivot lever had a lot of play in it and didn't provide consistent cuts. The pin is .390 and the holes on the grinder were at .432 - tons of slop.
2.) The spacers between the rails were at .088, so there was a lot of play.
3.) The grinding wheel sucks.
4.) The pivot lever had a lot of play in it and didn't provide consistent cuts. The pin is .390 and the holes on the grinder were at .432 - tons of slop.
Here is how I fixed them:
1.) To fix it hanging up, I disassembled the clamp and took a file to the rails and clamp piece and knocked off the sharp edges.
2.) To fix the space between the rails, I replaced them with some .060 washers, putting the old spacers (split ring lock washers) on the outside, and tightening it down.
3.) The chain advance mechanisms were .050 so I left them in place. If I were doing it again I would toss them and put washers in their place.
4.) The cable had a lot of slop where it goes in to the clamp, so I put 2 layers of adhesive heat shrink on it to tighten up the gap. Seems to be a good fit.
5.) I added a .125" thick washer to the clamp piece to tighten up the cable. It made a hell of an improvement.
6.) Finally, I addressed the big problem - the shaft play on the pivot lever. While the holes in the base were fairly tight, the ones on the ginder side were very sloppy. I milled two brass bushings - .390 ID .503 OD (3 thousandths oversize for a tight press fit). Then I took a 1/2" drill bit and bored out the holes on the grinder. The bushings took the majority of the slop out of the unit.
7.) OPTIONAL - I made a cheap stand for it out of some scrap lumber and a old tire rim I had laying around. I also put a piece of aluminum tape on the plastic depth control base, as it was getting hit with sparks. I'm going to pass it off with the crappy grinding disc it came with, but advise them to get a good one from Baileys.
2.) To fix the space between the rails, I replaced them with some .060 washers, putting the old spacers (split ring lock washers) on the outside, and tightening it down.
3.) The chain advance mechanisms were .050 so I left them in place. If I were doing it again I would toss them and put washers in their place.
4.) The cable had a lot of slop where it goes in to the clamp, so I put 2 layers of adhesive heat shrink on it to tighten up the gap. Seems to be a good fit.
5.) I added a .125" thick washer to the clamp piece to tighten up the cable. It made a hell of an improvement.
6.) Finally, I addressed the big problem - the shaft play on the pivot lever. While the holes in the base were fairly tight, the ones on the ginder side were very sloppy. I milled two brass bushings - .390 ID .503 OD (3 thousandths oversize for a tight press fit). Then I took a 1/2" drill bit and bored out the holes on the grinder. The bushings took the majority of the slop out of the unit.
7.) OPTIONAL - I made a cheap stand for it out of some scrap lumber and a old tire rim I had laying around. I also put a piece of aluminum tape on the plastic depth control base, as it was getting hit with sparks. I'm going to pass it off with the crappy grinding disc it came with, but advise them to get a good one from Baileys.
These fixes made a vast improvement in this cheap machine. While it is nowhere near as precise, adjustable, powerful, or durable as my EFCO grinders, it is roughly 1/16th the cost. If you're willing to put in a little work to make it function better, it's perfect for anyone who can't justify spending $350+ for a good grinder to their wife haha.
I hope this helps you guys out somehow. I have gained a lot of knowledge from here in the past couple months, bought and sold a few saws, made a few friends, and I would like to give back to the community.
. I use one for .325, one for .375, and one for the rakers.
