Torque those knives!

Reed2179 said:
Every time I do a knife change. I deal with 99.9% conifers or softwood, Aspen, cottonweed, ect. Some have center decay, like chipping sponges. I gap the anvil to .025" and use all 4 edges as TreeLogic does. FWIW: I sharpen the feed wheel edges and adjust the brakes regularly too. Just wish I could run rope in my winch like a lot of you guys. Damn rocky mountains!
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Reed, how about some advice on sharpening feed wheel edges? Something I've thought a bout many times. Thanks.
 
Reed2179 said:
Logic- For the long blade style edges I use a 4.5" grinder. For the tooth looking ones I use a air right angle cut off tool. Really helps get a bite on wet material.
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Thanks Reed. So, maybe a stupid question, but do you take the rollers out first or sharpen them while still installed? Thanks.
 
Inside the mouth. I go earplugs and muffs, it gets f'ed up loud in there with a grinder. Probably hit them once or twice a year. I only worry about the top roller on my Morbark, it's doing all the work it seems like. Obviously Morbark felt the same, no bottom roller on our new unit.
 
Reed2179 said:
no bottom roller on our new unit.
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Wait, Morbark went back to a single top feed wheel?

Edit: Just checked Morbark's website. They eliminated the bottom feed wheel on all the RX (reduced weight) series chippers. (M12RX, M15RX, M18RX). The R (regular version) of those 3 chippers still have the bottom wheel.
 
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Reed2179 said:
Inside the mouth. I go earplugs and muffs, it gets f'ed up loud in there with a grinder. Probably hit them once or twice a year. I only worry about the top roller on my Morbark, it's doing all the work it seems like. Obviously Morbark felt the same, no bottom roller on our new unit.
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So what kind of grind are we going for here? Sharp pointed edges or squared off? Thanks again.
 
Jeff said:
Wait, Morbark went back to a single top feed wheel?

Edit: Just checked Morbark's website. They eliminated the bottom feed wheel on all the RX (reduced weight) series chippers. (M12RX, M15RX, M18RX). The R (regular version) of those 3 chippers still have the bottom wheel.
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My new unit is a M14R. I ordered it because I asked for what we've been running M15R. In 2012 Morbark went to a 4 knife design on them and because that doubled the cost of a knife swap I felt the better biz move was to stay with 2 knives. That is what my sales guy offered.

TreeLogic said:
So what kind of grind are we going for here? Sharp pointed edges or squared off? Thanks again.
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I get the edge back on the blade ones to a fairly sharp edge. Last time I even hit them with a 100 grit on my air tool. The toothed ones I just get points back so they'll grab the wood.
 
classictruckman said:
wouldn't a 4 knife machine cut better with less fuel and hp since it's taking a smaller bite with each knife?
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I would agree with you for material 12” -15”. My biz model is to keep and split 10” and larger for firewood to resell, I pay to tip mulch. I look at it as a knife swap costs me $150-$200 for two knives, four would add 65% to the cost. We swap knives about every two weeks and that cost would outweigh the fuel/time savings of the added two knives. Things like this are just hard to accurately quantify.
 
Reed2179 said:
I would agree with you for material 12” -15”. My biz model is to keep and split 10” and larger for firewood to resell, I pay to tip mulch. I look at it as a knife swap costs me $150-$200 for two knives, four would add 65% to the cost. We swap knives about every two weeks and that cost would outweigh the fuel/time savings of the added two knives. Things like this are just hard to accurately quantify.
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Too bad you can't find someone to sharpen the blades Reed. I have a Bandit 200 XP with 4 blades. There's a lady locally that sharpens all 4 perfectly (all remain equal sized and balanced) for $40/set. I keep 3 to 4 sets on hand and send a couple out to her at a time.
 
TreeLogic said:
Too bad you can't find someone to sharpen the blades Reed. I have a Bandit 200 XP with 4 blades. There's a lady locally that sharpens all 4 perfectly (all remain equal sized and balanced) for $40/set. I keep 3 to 4 sets on hand and send a couple out to her at a time.
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I do but with shipping it's about $125/set of four. I ship mine to Baliey's in Cali. Still the overhead costs of changes too.
 
Reed2179 said:
I do but with shipping it's about $125/set of four. I ship mine to Baliey's in Cali. Still the overhead costs of changes too.
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Yeah, I guess "locally" is the key word here. Blades are heavy and that shipping is killing your profit margin.
 
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classictruckman said:
wouldn't a 4 knife machine cut better with less fuel and hp since it's taking a smaller bite with each knife?
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Funny thing, I have a guy working for me who is an engineering student at Colorado School of Mines. I asked his thought on 4 vs 2 knives. He thinks four will lend to more cuts per revolution, slowing the drum. I relate this to skip tooth chain on a saw. Skip is great for soft wood and sucks on hard wood. He also pointed out to me the anvil on a chipper doesnt control the "bite" of the blade it controls what volume of chip goes out the shoot on each pass. The "bite" is the cutting edge to the drum. Guess I never really thought about it. Brand new knives do sometimes throw out bigger chip.
 
I recently was doing a knife flip on my chipper blades with one of my friends visiting. He is and engineer, certified welder, and pretty darn good fabricator. As i was putting the knifes back on he asked me what the torque spec for the bolts on the knives were. I of course responded all of it as i mistakenly thought "cant have to much on these puppies." i was quickly informed that over torquing the bolts can be as hazardous as under torquing them. As it was explained when you over torque them it causes the bolts to stretch shortening the life of them and could weaken them to the point of failure while in use - which ultimately is what no one wants. a quick call to the manufacturer can get you the proper spec for your unit.
 
TreeLogic said:
Yeah, I guess "locally" is the key word here. Blades are heavy and that shipping is killing your profit margin.
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Logic- you're getting a smoking deal at $40 a set. Lowest I've found is $.65/inch, my knives are the 10.5" type, two sided. So like $15 a knife if they don't have to two pass them because of deep gouges. Last guy I shipped to that was $.75/inch took forever to get them back to me and just didn't do a great job keeping them even. Last time I paid $.85/inch at Balieys. Then there's shipping. Food for thought...
 
Reed2179 said:
Logic- you're getting a smoking deal at $40 a set. Lowest I've found is $.65/inch, my knives are the 10.5" type, two sided. So like $15 a knife if they don't have to two pass them because of deep gouges. Last guy I shipped to that was $.75/inch took forever to get them back to me and just didn't do a great job keeping them even. Last time I paid $.85/inch at Balieys. Then there's shipping. Food for thought...
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Point taken. Guess we're pretty lucky to have her. All I know is the lady has rougher hands than me, and she has a $75,000 machine that she puts the blades in and forgets about them. My blades are two-sided, probably 6" (since it's a 12" chipper), and of course there are four in a set.
 
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