Raker checking

I don't know how you guys check your rakers on your ripping chains but I find those metal U cross section doohickey things made by oregon etc for regular chain, sorta flap around on top of a rip chain like a one hinged outhouse door in a storm. When I decided to check my raker heights with a feeler gauge I found one side of the rakers was too high and the other to low. I don't like using feeler gauges cos I'm never sure if all the planets are aligned so I came up with the following method. Maybe you guys do this already - apologies to those that do - or have a better idea.

Clamp 2 bits of straight metal either side of your bar snug up against the bottom edge of the chain rivert, (chain should still be able to move). I used angle but even thick plate should work just as well - as long as it is straight.

Using a vernier caliper place the tail of the vernier on the metal and the base of the vernier ontop of a tooth - like this

Now - zero the vernier.

Move the vernier to the raker

and repeat the measurement.


It is important - but not critical to have the pieces of metal more ore less a consistent distance from the chain. I was able to get it to with 10"' across 5" which is less than 1"' between any tooth and its raker.

With this set up you can file rakers and check heights till you get it right.

What I found was I had rakers on one side between 15 and 20 " and around 30" on the other side.

Hi Bob I just use a Carlton file o plate , works very well

I use my file, I lay it across two teeth on the same side of the chain and look for the gap between it and the raker. Any straight edge will do. After you have been doing it for years its easy.

Matildasmate said:

Hi Bob I just use a Carlton file o plate , works very well

Click to expand...

Me to. Quick and easy. Although not very adjustable. The depth of the raker stays constant to the wear on the cutters.

I measure mine on the grinder with calipers but I just measure directly from the raker to the cutter using the same end of the caliper you are.

aggiewoodbutchr said:

I measure mine on the grinder with calipers but I just measure directly from the raker to the cutter using the same end of the caliper you are.

Click to expand...

Darn it - why didn't I think of that!!!!
How do you ensure you're vertical while doing the measurement?
I might attach a little bubble thingo to the caliper.

Bob,

Here are a few pictures of the gauge I made for measuring the depth of the raker. I had a spare dial indicator so why not...


The bar is set over the cutting edges of the chain, I the run the 10-32 allen head screw down that has been machined flat and polished smooth down to the top of the raker. I then take the piece with the dial indicator that has been zeroed on a piece of machined steel and set it on the bar with the machine screw protruding and measure the distance. Once you get the knack it's pretty fast.

jerry-

BobL said:

Darn it - why didn't I think of that!!!!
How do you ensure you're vertical while doing the measurement?
I might attach a little bubble thingo to the caliper.

Click to expand...

Eyeball usually. I'll take the measurement a few times to check consistency and sometimes I'll use a small engineer's square to double check myself.

Matildasmate said:

Hi Bob I just use a Carlton file o plate , works very well

Click to expand...

+ 1. Works great on standard full comp chain. I never tried it on anything else.

Thanks for all the ideas fellas. Very helpful!

aggiewoodbutchr said:

Eyeball usually. I'll take the measurement a few times to check consistency and sometimes I'll use a small engineer's square to double check myself.

Click to expand...

...same here... I put the flat wheel on the chain saw grinder and just eyeball what looks like about the right depth to take off, then set the grinder at that height and go to town on the rest of the chains. Once in a great while, I'll actually check the distance with my caliper free hand, sort of quick and dirty, but more often than not I don't. Yes, once in a while I get to filing them a little too short, and then the chain wants to grab and jump around in the cut a bit more than it should till that next sharpening or two, but no big deal. Just means I have to be a little more careful handling the saw. I know I should be more accurate with this, but it's something I just don't bother with, and been doing it enough that I can usually eyeball it good enough to where it works fine. On the other hand... pretty good idea Bobl, great little jig for those that want to do it right.

woodshop said:

...same here... I put the flat wheel on the chain saw grinder and just eyeball what looks like about the right depth to take off, then set the grinder at that height and go to town on the rest of the chains. Once in a great while, I'll actually check the distance with my caliper free hand, sort of quick and dirty, but more often than not I don't. Yes, once in a while I get to filing them a little too short, and then the chain wants to grab and jump around in the cut a bit more than it should till that next sharpening or two, but no big deal. Just means I have to be a little more careful handling the saw. I know I should be more accurate with this, but it's something I just don't bother with, and been doing it enough that I can usually eyeball it good enough to where it works fine. On the other hand... pretty good idea Bobl, great little jig for those that want to do it right.

Click to expand...

I've got a couple of those grabby chains around right now.....DOH!!!! :angry2: :angry2:

Yep- it happens sometimes. The 084 doesn't seem to complain too much though.

EDIT: The images of using vernier calipers are gone, but here's Bob's write up on using an angle gauge:

http://www.arboristsite.com/communi...gressive-depth-raker-generators.114624/page-3