Wood max 8m infeed problem

[jjeff]

Hi I have a wood max chipper it's been giving me some minor problems with the infeed roller. Basically bark and small branches wrap around the infeed shaft pushing the bearings out of place. I clean them daily which is a pia. but today the debris was so tightly wound it pushed the bearing off the shaft after 4 hrs of chipping. Seeing if anyone who owns one has came up with a solution or has had similar problems? I'm mostly chipping small birch and popple. Insight is appreciated.
Thanks J

 

[JJT]

Can you let the material dry out before you chip it? I get minor wrapping of small green stuff, but if I pile up my material to be chipped and wait a few weeks, no issues.

 

[ericm979]

I've got close to 80 hours on my 8H, mostly chipping brush. I've not seen more than a small amount of stuff wrapping around the feed roller axle and it's soon gone on it's own. I'm not sure what the fix is.

 

[jjeff]

Yes very good to hear about no problems except for maybe operators techniques and good point, I will wait for it to dry for awhile see how it does then unfortunately when I plan to do something I like to get it done immediately but will wait I'm thinking if it ever rains it will clean some of the dirt off so I'm not beating it against the chipper before I feed. I also am needing to flip the blades they are getting dull thought that may have been part of the issue probably has close to 300 + hrs since 2019.
Thanks for the insight.

 

[ericm979]

I rotate the blades after 20 hours. 300 seems like a long time even taking into account the different material. I wonder if that's the cause of your problem?

Also, while changing blades don't accidentally drop a blade mounting bolt or nut into the housing. It's tough to get out.

 

[grsthegreat]

I get way more than 20 hours on a side, but no where’s near 300 hours. I would rotate the, more often, but it’s an 1.5 hr round trip to get blades to company to sharpen them. I take 4 seats at a time. I wish I could bet my own sharpener, but have had no luck finding info on good system. I have no intention of hand grinding them with my hand grinder.

 

[ericm979]

I probably rotate them earlier than most people would. I think the brush and hardwood I chip is harder on the knives than softwood. Also I wanted to do it when they are not very dull so there's not a lot of material to take off to sharpen them. I sharpened a set sort of following this:

except I put markout dye on the ground side so I could see that I'd hit all of it. I have a couple hours left on my last side, then I'll try them out. My thought is to get the knives through one or two home sharpenings then send them out to a professional.

There's a makita sharpener that's supposedly good for these but it's $450

 

[5030]

I grind chipper knives for commercial tree companies like Davey Tree. Same as your knives, only bigger. It's imperative to hold the cutting angle constant and not burn the edge because you take the temper out of them.

Most knives are set between 27 and 29 degrees.

I grind them on a jig on my surface grinder with plenty of flood coolant. The anvil needs ground as well, not just the knives. The anvil must be ground at exactly 90 degrees and parallel.

 

[5030]

I probably rotate them earlier than most people would. I think the brush and hardwood I chip is harder on the knives than softwood. Also I wanted to do it when they are not very dull so there's not a lot of material to take off to sharpen them. I sharpened a set sort of following this:

except I put markout dye on the ground side so I could see that I'd hit all of it. I have a couple hours left on my last side, then I'll try them out. My thought is to get the knives through one or two home sharpenings then send them out to a professional.

There's a makita sharpener that's supposedly good for these but it's $450

No way can he hold the correct included angle when doing them like he does. It the included angle is too great or too less, the chipper won't chip correctly.

 

[grsthegreat]

The local sharpening company has computerized sharpener, $20 per blade. Does great job and cheaper than new blades.

i looked into wet grinders like they use for chisels, but they can’t handle the large blades. I even contacted a few manufacturers and they told me don’t try to sharpen chipper knives.

 

[arto98607]

No way can he hold the correct included angle when doing them like he does. It the included angle is too great or too less, the chipper won't chip correctly.

Maybe so but he did say he will take them in to a shop after sharpening himself few times so any improper angles will get corrected.

He is obviously trying to save chipper knives metal by not grinding it down to every last little nick, like a sharpening shop will do every time.

I would say it looks like the guy in the video knows what he is doing.

 

[5030]

I'd say he's cheap. When I grind knives if there is a big divot, I don't take it out either. Commercial knives eat a lot more than wood. Nails, spikes and once in a while a chainsaw.

Keep in mind that the knives are through hardened not cased so they are hard through and through.

I've never felt that removing a big divot is beneficial and it takes a lot of time to grind one out anyway.

The problem with his setup is, once he gets the included angle wrong, when jigged up properly, the sharpening person has to bring them back to the correct angle, necessitating a lot of stock removal.

I'd never sharpen his knives for him.

My customers all pay the same rate. 60 cents an inch per cutting edge and squaring an anvil, parallel and square is $15.00.

I constantly have a pile of knives to do. They bring them to me in crates and if they ship them, they pay the freight, both ways.

 

[5030]

I get way more than 20 hours on a side, but no where’s near 300 hours. I would rotate the, more often, but it’s an 1.5 hr round trip to get blades to company to sharpen them. I take 4 seats at a time. I wish I could bet my own sharpener, but have had no luck finding info on good system. I have no intention of hand grinding them with my hand grinder.

A knife sharpener costs around 6 grand. The trick if you will, to making any knife last is 1. run at maximum rated speed and 2. Just chip wood, no metal, stones or other junk. 3. rotate them often. Once a knife looses it's edge from running too long, it takes more power and the chips get stringy.

 

[5030]

I've got close to 80 hours on my 8H, mostly chipping brush. I've not seen more than a small amount of stuff wrapping around the feed roller axle and it's soon gone on it's own. I'm not sure what the fix is.

If you are wrapping the feed roller axle, the knives are dull and stringing the wood chips.

 

[grsthegreat]

A knife sharpener costs around 6 grand. The trick if you will, to making any knife last is 1. run at maximum rated speed and 2. Just chip wood, no metal, stones or other junk. 3. rotate them often. Once a knife looses it's edge from running too long, it takes more power and the chips get stringy.

I was looking at the makita 9820-2. I have read people using them with good success.

im not thinking of a cnc sharpener

 

[sea2summit]

If you are wrapping the feed roller axle, the knives are dull and stringing the wood chips.

Totally false, I've done that on a brand new set of knives and fresh anvil.

OP, what I've found is anytime I have vine like material it will start to build up pretty quickly. I do my best to throw in a good chunk of material with any vine/stringy material and tangle it up as it feeds if possible. Also if I have to put in a few arm loads of vine/stringy without some solid material I try and put in a good chunk of 2-6" material 4'+ long which seems to clean out the works pretty well.

 

[arto98607]

I was looking at the makita 9820-2. I have read people using them with good success.

im not thinking of a cnc sharpener

Looks interesting but it has only 120 - 130 watt motor!

 

[grsthegreat]

Looks interesting but it has only 120 - 130 watt motor!

For sharpening 2 blades at a time. every so often, I don’t see that as a problem. I have a question as to the depth of the chipping blades working on their jig. I emailed them a question about it.

im looking at replacing my Jimna 6 chipper with a wood max mx88 . The Jimna works great, has for 12 years, but its a 2+3 hour ordeal to replace chipper blades, takes 2 people. The mx88 is a clamshell access to blades.....maybe 15-20 minutes, 1 person. That is the main reason I’m thinking of upgrading. Problem is I’m number 275 on waiting list.

 

[5030]

I was looking at the makita 9820-2. I have read people using them with good success.

im not thinking of a cnc sharpener

I've never seen a CNC knife sharpener. All manual as far as I know of. No reason for CNC, you aren't machining anything. Basically, you jig the knives, spark the grinding wheel on the angled face, dial down a couple thou and remove material, rinse and repeat until the face and cut edge is uniform. One thing I do when I sharpen them is I take a DMT diamond whetstone and remove the backside burr that develops when grinding. Whey you remove the burr, you can shave with a sharpened knife. I've cut myself many times on sharpened knives. I tend to apply 2 layers of masking tape to the finished bevelled edge so I don't slice myself. Very, very sharp.

Not familiar with a Makita either.

 

[5030]

Totally false, I've done that on a brand new set of knives and fresh anvil.

OP, what I've found is anytime I have vine like material it will start to build up pretty quickly. I do my best to throw in a good chunk of material with any vine/stringy material and tangle it up as it feeds if possible. Also if I have to put in a few arm loads of vine/stringy without some solid material I try and put in a good chunk of 2-6" material 4'+ long which seems to clean out the works pretty well.

Then the included angle on the knives is wrong. Should be between 26 and 28 degrees. I must ask however, what did you set the knife to anvil clearance at? Hint, use an old credit card to set the clearance.

How you set the knives in a commercial chipper, old credit card.

I don't own a chipper, I roast my stuff, but I sure as hell sharpen a boatload of chipper knives.