Processor Raker Depth?

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Moss Man

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I have a firewood processor that uses a 16" bar and chain and I have been filing the rakers to the specs for the chain at 25 thousandths. I only do this a couple time during the life of the chain, but when I do, it seems to bog the machine down. I am thinking .20 might work better because after a couple filings the chains seem to cut better as the raker depth is less. Is .25 too aggressive for the application?

Your kind thoughts?

I have Oregon and Stihl chains, both.
 
25 thousandths shouldn't be too aggressive I would think? Whats your top-plate angle at?
 
Well if it bogs after you lower the rakers, I would look for the answer there. I dont know what kind of horsepower you are harnessing , the torque available and size of sprocket and rpm. Pictures of side view of chain would be good to see as amount of hook would have a bearing on raker height. What chain are you running, chisel or semi chisel. How does a new chain work. Its clearance will likely be greater than .025.
 
First I will clairfy "bog" by saying the chain doesn't travel through the log as fast as it usually does. The tractor that runs the processor is 65hp.

The chain I use is the 21BP Oregon brand Micro Chisel, it is the same as what the machine came with and seems to work better that the LP chain I run on my chainsaws. The LP chains seem more aggressive than the BP.

I run the tractor at the recommended 1700 rpm's, but I am not sure what the chain speed is. When I put a brand new BP chain on. Things seem to work fine so maybe I am getting the top plate angle wrong when I file?
 
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After some reading, I am wondering if my top plate angle is off and my old depth guage might be worn down so that I am actually filing the rakers down more than .25
 
A firewood processor running .325"?????? Any processor I have ever used or sold has had .404" and harvestor chain with .050" raker... Some even with 3/4" pitch but I dont like the 3/4"



Scott
 
I have a hunch your top-plate angle is closer to 40-45 degrees, or your depth gauges are too low as you said.

Got a picture of your chain?
 
Please explain a little more?

Only has half the cutters. Thus pulling less sawdust= less drag. We ran it on our dangle head feller bunchers when we had them. Cuts just as fast as standard chain on a hydraulic powered bar.
 
I have a hunch your top-plate angle is closer to 40-45 degrees, or your depth gauges are too low as you said.

Got a picture of your chain?




IMG_1002-1.jpg


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You seem like the kind of guy to do it by the book, but you ought to try to up the rpm on the tractor. amazing what a few extra revolutions will do.

i have a timberwolf and i'm turning the pump ~700-750 rpm instead of the "recommended" 540 (i'm talking pto rpm) and it nearly doubles the production of the machine. try it once. worst thing you could do is blow a hole in your hydraulic tank (ask me how i know) :laugh:
 


1st thing I wood do is get rid of that chipper chain and goto chisel,, either full chisel or skip tooth.I think I wood try skip tooth. Hydraulic powered saws work better with skip tooth.

You're top angle is good but your gullet depth should be deeper. Rakers look good,, maybe a little too low(but not enough to make a difference) but hard to tell at that angle.
 
the angles of how the saw/bar is mounted, along with the pressure that is used to push the chain into the wood make a HUGE HUGE difference.

It took me about 12 different tries before I found the angles I liked. Sometimes the chain would just grab in too hard, sometimes I had to reef onto the saw to get it to bite. All by changing a subtle angle on how the bar was mounted and pivoted.

On mine, I found a fairly forgiving angle. It doesn't bite too hard as long as I keep something under .025, and when it gets dull, I have to really reef on the bar to get it to bite.
But, it is consistent no matter how thick the log.

If your chain likes less then .025, then run less then 025. The european stuff is geared to small logs and saving wood.
 
I'm no guru on the subject but it looks like the file size might be a bit on the big side. Oregon calls for a 3/16 file for that chain. If that is what you are using, I'd drop back to 5/32 and see how it goes for a few sharpenings. I'm with the rest of them, that 0.025 shouldnt be to aggressive unless the cutters are chewing through instead of slicing through the wood fibers.
 
Please explain a little more? Seems like it would have come with a skip tooth if that were the optimum chain for it.

Don't bother with skip chain Moss. It will only cut slower, especially on a 16" bar. If anything, I'd check the top plate angle and go easier on the depth. Maybe look for a grinder which are fast and accurate.
Skip chain is used too extend a saws power with longer bar on big wood. Slower but you can get through it when the saw wouldn't pull full comp.
 
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I take it that you have a hydraulic drive motor; there may be a pressure relief valve on that circuit that is set too low. The chain really does not look too aggressive. There is no problem with the tractors horsepower but there could be with the chain drive motor. Even if it is new but especially if used it is possible someone got the wrong displacement unit on there that does not produce enough torque. Externally they can look identical. I would try to get a pressure guage ahead of the drive motor if it appears there might be a problem in that area. Wear in that unit could also be an issue no matter how new it may be!
 

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