Are FOP really progressive depth raker generators?

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BobL I have a problem/question I lowered my RA to 6* my TPFA is 25* My chain no longer makes a wide enough cut and and drags so much it overheats the chain in two cuts 18" burr oak Stalled the saw to. Thought it was cutting too aggressive until I tried to pull out and it stalled in open cut. I was cutting cookies so their were no external forces on the log. What could cause this? I've learned a lot about sharpening from your post but the more I learn the less I seem to know!
 
Wow is all I can say. I can't free file worth a crap but my son gets em extremely sharp. I think it's his form of OCD. He can't stand to watch me file so he just takes over which doesn't bother me especially on the 36" bars. Now I am going to take what I have learned here and sneak a few chains in on him and see if he notices. I'm sure it will take some trial and error to get all this down pat. Thanks BobL!
 
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.

I know this is an old post, but as the thread still is active, I comment on it anyway.

That method may well work, if you are taking the correct measurement, meaning that you need to be precise about what "gullet width" is. I assume you really refer to the distance between the top of the raker and the "point" of the cutter).

Regardless, a major inherent problem with the raker guides that rest on two cutters remain though - a good result depends all the cutters being exactly the same length/height (which is ideal, but not very practical).
 
This is some good stuff here.. WOW! I cant w8 to give it a try and see what my current measurements are FIRST.. so i can laugh at myself for how bad i currently do it and then make them right!
 
Sorry if this has already been posted here, but I wasn't gonna read the whole thread again to find out!

So....

Since the FOP is basically NLA, get the Husky depth gauge. Available for .325, 3/8, 3/8mini(LP), and .404 but won't work on humped safety chain. Only way to go for hand filing.

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Sorry if this has already been posted here, but I wasn't gonna read the whole thread again to find out!

So....

Since the FOP is basically NLA, get the Husky depth gauge. Available for .325, 3/8, 3/8mini(LP), and .404 but won't work on humped safety chain. Only way to go for hand filing.


still kinda the same as a "fop" as the tooth get shorter the angle decreaser so the chain has to much bite.
 
Hallo to all, first post for me in this wonderful forum, a big hallo especially to BobL who has inspired me a lot with this thread here :)
BobL, you call this stuff 'ultra geeky' - don´t agree with that one, but with the rest of your statements.
In the meantime I have built my own raker gauges and I could do that because of the very helpful information in this thread.
Of course I aim for a constant 'cutting angle', so my selfmade gauges are progressive.
In order to produce a gauge as perfect as possible for my needs I invested some of my free time to create a software tool that can calculate two different types of raker gauges and predicts the corresponding cutting angles depending on the wear of the cutters. So you´ll know before creating your gauge how it will perform in the future.
No need to buy one, you can create one for your personal needs (soft wood, hard wood, mega soft wood... ;) ), one type is VERY easy to create and at least for 3/8 chains I already know that my gauge is more linear than the buyable ones.
I have finished the software tool today, I still have to take some photos to explain and open a new thread to present the tool and explain its functionality.
Till soon, I´ll give a link to the thread here :)
 
Now my software tool is ready to release, I have now included at least 2 presets (different chains) to start with.
I´ve taken some photos, so only the new thread is missing.
That´s a little bit complicated because if I have read it the right way, a post in this forum can only be edited within 24 hours. I know from other forums, that you can edit infinitely so you can always keep a starting post up to date. Here I´ll have to be very accurate and pack all infos into the starting post at once because it would not be very convenient to find all necessary infos spread around within a whole thread.
I´ll work on this thread tomorrow offline and hope that I don´t forget critical informations ;)
I have used my selfmade raker gauges today on several chains and the calculated numbers seem to be right :)
Now let´s see if I can motivate some of you to build your own raker depth gauge(s) instead of buying ones, doing blindly a certain number of file strokes or fiddling around with sensitive measuring equipment ;)
 
Hey all
Question for the group

I got my hands on one of the husky gauges and have tried it out here on the west coast softwoods. Question is I see everyone backing it up on the back of the preceding tooth and against the following tooth to catch the angle of the gauge on a full comp chain. Well I’m running skip and ended up having to go from cutter tip across the depth gauge and then down on the tie straps on the chain since the cutter spacing is larger of course. Will this still give the proper angle to meet the goals or am I doing it incorrectly
 
It does just straddle the tie strap regardless of skip or full comp. Key is how the raker sits in the slot corner. The soft end will obviously straddle the tie strap closer to the raker, but you want that raker up against the rear corner of the tool regardless of where the saddle slot straddles the tie strap.

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It does just straddle the tie strap regardless of skip or full comp. Key is how the raker sits in the slot corner. The soft end will obviously straddle the tie strap closer to the raker, but you want that raker up against the rear corner of the tool regardless of where the saddle slot straddles the tie strap.

Thanks great visual. Looks like I’m ok
 
Great thread! Answered a lot of questions I had, just ordered me a wixey DAF. Can’t wait to see what some of my chains are at. Anyone know if @BobL is still around.
 
I came across this thread via google, it's got some good advice in there.

In the funny way that it happens, I became convinced that this angle was my issue. I've tried sharpening (after measuring all my teeth and getting them all pretty close to one another, and spending a fair amount of time getting a good hook and chisel on them), setting depths, etc etc using all the advice I could find, and I just couldn't get it to cut well in this wood.

After reading this thread, I went and ordered myself a DAF because I need one in my shed for other things, but in the interim I did up a quick little reference on paper. Photos attached. As has been pointed out, 6 degrees is approx 1 in 10 (i.e. Tan(60) = 0.10510, which is about 1 in 9.5, conversely atan(0.1) = 5.7 degrees). So I ruled a line that was 200mm long, and a line perpendicular to this that was 20mm high, and then drew the angle.

I had my chain off the bar, and held it taught so that the tops of the teeth were on the line, and looked at where my raker depth was at compared to the line. Lo and behold, actually pretty close to 6 degrees.

If you want to be really precise, just vary the dimensions to the correct ratio for whatever angle you want to measure.

So the angle isn't my issue. I'm coming around to the fact that I'm just trying to cut super dense, hard, old wood that's a bit dirty, and it's just going to be hard work. These are 100 year old stumps from my house, I believe they are grey ironbark. Chopping into 250 to 300mm lengths to split for firewood.
 

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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.

This has got to be one of the best bits of information ever posted on this website! Simple, accurate, easy to remember, and of inculculable value to folks who take sharpening seriously.

Thanks Sierra99
 
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