Are FOP really progressive depth raker generators?

[lambs]

Thanks BobL!

Further to my Feb 8th post, last Saturday I finally got a chance to try out my half-used chain, freshly ground and with the 4 degree angle per the Beal Tilt box on new Stihl chain. I made sure my cutters were about the same length, then hand filed one depth gauge down until the Tilt Box showed 4 degrees on the used chain, and used that to set up the grinder for the rest of the depth gauges.

What a difference! Saturday the saw pulled me through the wood as if the chain were brand new.

I've since ordered and received an FOP. Members here on AS report it will work fine with Stihl chain, but I have yet to try it. I think it will be going into the woods with me from now on though. Haven't looked up the online instructions yet, but from just fiddling with it, I think it agrees with the depth gauge settings on the chain I experimented with.

Thanks BobL, for the detailed explanation about how the geometry works on these chains. Thanks as well to all the AS contributors to this thread who provided their insight. I'm sold.

Now if I can just come up with the funds for that MS441, I'll really be in business.

 

[Kmaxwell102]

Is taking a bit of the depth raker off with a file what you guys would do, and eye balling the rakers. Is that ruining the chain? I did that and noticed a better cutting chain

 

[parrisw]

Is taking a bit of the depth raker off with a file what you guys would do, and eye balling the rakers. Is that ruining the chain? I did that and noticed a better cutting chain

Yes use a flat file for the depth gauges/rakers. I don't eyeball it, I use the husky combi gauge.

 

[Kmaxwell102]

Yes use a flat file for the depth gauges/rakers. I don't eyeball it, I use the husky combi gauge.

I think il look into buying something like that. Thanks!

 

[SawTroll]

Husky combi gauge is better I think, its more progressive. The pivot point is a little farther back then the FOP gauge.

The answer to the original question is a simple YES! :biggrinbounce2:

The Husky guide works about the same way, and works great on Stihl chain as well, provided you choose the right one. I guess it is the same with the FOP, but never actually tried.

Anyway, the FOP can't be modded to fit Stihl cutters, as the Husky combo ones can, but they may not need to (never tried that either)......

 

[Sierra99]

An old but good thread. Another way toget the same result, maybe easier for some, is to use several raker depth gages. It turns out that if you divide the gullet length by 10, you get the required raker depth to produce a 5.7 degree angle.

For example, a new chain with 0.25" gullet, divide by 10 you get a raker depth of 0.025", the "standard", that yields a good 5.7 degree angle.

If the gullet is 0.40" long, dividing by 10 gives you a raker depth of 0.040" (for the same 5.7 degree angle).

So you can pick up a range of "constant" style depth gages and get the "progressive" result just by measuring the gullet width and divide by 10. Might be faster than the digital gage, and bonus! doesn't need batteries!

--Happy cutting in the New Year! 18 F and light snow falling in western Nevada sage brush country.

 

[madhatte]

Moved and stickied as requested. This thread is a classic.

 

[Naked Arborist]

BobL's ur uncle GOOD STUFF!!!

Well, THANKS Bob, you solved the riddle "why?".
When I use those Husky chains with the long cutters vs the Stihl chain, simply put, they cut the worst at 0.030 depth when worn down to the little triangle. I did eventually figure out to grind almost the whole raker off. I used them for stumping till they pitched off some cutters and headed for the scrap pile. I could never figure out "why" they, the Husky chains really needed 0.060-0.065 raker depths to cut well opposed to only needing 0.040-0.045 on the Stihl chains. The Huskys have wider cutting teeth and longer cutters. Very good explanation you have there. Nuf said on that! :hmm3grin2orange:

As for the rounded rakers on the leading edge, (that I've always been told "makes no difference" yea right) every time I get into large white oaks the saw always got this weird up and down harmonic vibration in the bar and chain. It also made a very wide kerf down in the cut. You could see it plain as day the cutters wanted to run away from each other and like almost leave the bar until it got hot, started smoking a bit and damn near bit the chain. I'd always stop pull the saw out and wonder why I'd get a puff of smoke, thinking it's a hot saw now, in bad way. Then, she'd free right up and the chain would be wet. I always wonder why the oiler quit and came right back. The oiler never quit, it just vaporized the bar oil from horizontal friction. I got that part but, could never figure out why, why wtf? Why does this #### happen to me? lol. Now I get it. I thought it was me, the bar or slightly miss matched cutter face angles, apparently not so. I won't even go into how bad it got cutting 15"-25" dead black walnut and black locust, geeeeeez... Obviously the chain was also poorpussing lol. My spelling sucks, so what... looks good in print though hu :biggrin:

You gave me a great idea to work on for a one step no fuss no muss bar mounted jig for nailing that angle. You'll be the first to see it.

Now more to the point, THANKS a whole bunch for saving me a wholelota time, agg, dough and my hands for the future.

 

[imagineero]

I've been using the DAF method for 2 or 3 months now, picked up this unit from carbatec. I got it on special for about $60 from memory. It works well and seems like a quality tool which will last a long time. I've found plenty of other uses for it too, a handy thing to have.

I do all my shapening in a good quality bench vice mounted on a heavy duty bench I built which is bolted to the floor and wall (concrete) so there's no movement there. I made a little bracket/jig to hold the DAF level to get true readings. I make each measurement with the tooth in the same position on the bar. The jig is true vertical.

One thing I've noticed is that the readings aren't very repeatable. If I set every raker at 6 degrees, then go round again and re-measure, they'll still be out by +/- 1 degree or more. The other weird thing, is when I spin the saw round to do the other side, if I re-measure the rakers I just did again from this side, the reading is completely different. I've tested the DAF and there's nothing wrong there.

I guess it doesn't mean anything since my chains are throwing fat chips, run smooth and stay sharp longer without being bitey.... so something is right. Just wondering if you other guys are getting these sorts of readings all over the place?

Thanks again BobL for your typically rational well thought out scientific and common sense approach to solving problems.

Shaun

 

[2strokenut]

well the old FOP will be put in the back of the tool box
thanks bobl for the info/lesson :msp_biggrin:

 

[Philbert]

Classic thread.

Referred to it yesterday at a GTG.

Needs a BUMP for newer guys.

Thanks again Bob!

Philbert

 

[Philbert]

P.S. found the Wixey digital angle finder on sale locally for $30. Another thing I didn't know I needed before A.S. . . .

http://www.arboristsite.com/firewood-heating-wood-burning-equipment/191921.htm

Philbert

 

[Raganr]

Bumping this great thread back up in case Bob can fix the picture links

 

[PogoInTheWoods]

Bumping this great thread back up in case Bob can fix the picture links

I'll be damned if I didn't actually get an email notification for your post! Yay. Maybe they're making some progress on that front.

 

[BobL]

Just a short note to say that for your viewing pleasure I have gone back and added in all my images, and also to round it out here is vid showing how I set the rakers with the DAF

Of course I don't do this every time I touch the rakers.
Normally I touch up the cutters after every tank if mix and touch up the rakers by hand after evert 3-4 tanks - just a couple of swipes with a hand file.
Then at the end of the day or couple of days of use I will reset them with the DAF.

And for completeness here is how I touch up the cutters.

Sorry for the screechy file sound - it doesn't sound anywhere near that bad in reality.

 

[Philbert]

Thanks BobL for restoring this classic thread.

Philbert

 

[Philbert]

Added back in some additional photos.

Philbert

 

[Raganr]

Up again. Thanks BobL, a real classic with outstanding info.

 

[bluesportster02]

thought i would bring this thread back to the top. it is very informative, thanks bobl

 

[Ranchers-son]

Thank you BobL. This thread is the most informative thing I've ever read about chainsaw chain sharpening.