Chainsaw Repair

Some Other Notes

- As noted, the faster wheel speed worked better.  Some of these wheels are rated up to 18,000 RPM, which is 5X the maximum speed I tried.  A die grinder mounted to a bench might be an interesting way to try these higher speeds.

- I would also want to test the coarser wheels at the higher speeds to see if I could get fast material removal with less deep scratching.

- One, 2-inch diameter wheel was tried.  It worked, but was not as convenient, or as fast, as the 3-inch wheels.

- I also tried one, 6-inch diameter by 1/2-inch wide, soft, fine wheel on the slower motor.  The faster edge speed helped, but did not make up for the slow cutting speed.  The wheel was still too thick, and the larger diameter restricted positioning of the cutters more than the 3-inch wheels.

- Thicker wheels might work with chains that do not have the reduced-kickback bumpers, due to more clearance between chain components.  I wanted something that would work with all chains.

- 1/8-inch wide wheels would also work, but the price difference is minimal, compared to the 1/4-inch wheels, which have twice as much abrasive material.

- It is still possible to nick your newly sharpened cutting edges if you are not careful, but you can also do this with a file, Dremel, etc.

- All of these test subjects were reduced-kickback style chains.  Regardless of whether they had bumper drive links or bumper tie straps, the bumpers were harder to round, and took more time to round, than the depth gauges(!).  It took 1 to 1.5 seconds to round each depth gauge.  Bumpers took about 3 seconds each.

- Shaping the rounded profile of the depth gauges was easiest to control with the flat depth gauges held perpendicular to the wheel edge.  Holding the depth gauges parallel with the wheels produced a smoother finish, even with the coarser wheels, but increased the risk of contact with the sharpened cutting edges.

- As the wheel wore and formed a concave edge, I periodically flipped the chain (polished from the other side) to keep wheel wear even.

- Remember that these wheels remove metal fast! Spend too much time focusing on the smooth curve and you might remove several thousandths more than you intended, ending up with a more aggressive chain!

Philbert

- As noted, the faster wheel speed worked better.  Some of these wheels are rated up to 18,000 RPM, which is 5X the maximum speed I tried.  A die grinder mounted to a bench might be an interesting way to try these higher speeds.

- I would also want to test the coarser wheels at the higher speeds to see if I could get fast material removal with less deep scratching.

3M guy confirmed that wheel performance would improve with the faster speed, and that they would act like a finer grit at those 18,000 RM speeds.  Said that they would also last longer at higher speeds.

Philbert

P.S. - my neighbor suggested that I try a Harbor Freight die grinder 'for about $20'.  Got me excited.  But they are more like $50.  And I need variable speed to limit it to 18,000 RPM. . . . will keep an eye out at garage sales.

The day I use a grinder on my depth gauges is the day I'll  pack 'er in

I've seen a lot of guys post on A.S. that only file their cutters, but are happy to grind their depth gauges.  Took me a while to grind them without burning, especially on low-kickback chain with the extra bumpers.  Now it goes fast.

Philbert

Al, could not agree more.

I don't have to cut wood for a living and it is really a hobby for me.   Since part of the enjoyment is finding out all the technical aspects of the hobby, I like fussing over a chain and learning all I can to make it cut straight and fast.   Heck if did not like it why spend a good chunk of change on a square grinder.   Not only I did I enjoy learning how to use it but I really liked the results too.  So we all come at this with alittle different perspective.