Morbark 290 chipper blade question

[Jake Rosenfeld]

Hi folks, jake here from NW Oregon
I'm new to this forum but not to forums in general and would like to tap into the knowledge that I'm sure is here.

I recently picked up a very used morbark 290 on craigslist. its been beat and re-beat several times over but I'm gonna coax some more mulch out of her on my place making better forest out of my forest.

The unit was missing the chute among other things but the previous owner said he had used it to chip pvc pipe which he then refined back to raw plastic and sold. I guess the plastic didn't come out of the chute very well (I surmise that its too heavy) so they removed it and built a shorty wood abomination. the original chute did not come with the purchase.
I've built a new chute as well as completing 35 items on my 75 item punchlist.
Although I'm not done working on it yet I spooled her up to check all the functions and tossed some fence boards and a 2x4 thru it to make some chips. It had no problem chipping the wood but I'm questioning the thickness of them.
I guess after all this my question really is; is it common practice to have a 3/16" spacer behind the blade?
The flywheel (anvil?) has two blades on it, one inner and one outer, both of them are spaced with a shim between the blade and the wheel.
I realize that this shim would affect the thickness of the chip and I'm wondering if it was placed there to reduce the plastic pipe better and if I would be better served to remove them before chipping what will mostly be small alder and scrub maple with some fir here and there.

The blades do need to be sharpened but I can give em' a touchup while installed with my mini grinder.
My plan is to do this to give it a real shakedown before I dump too much time into something that ends up being truly wore out. I already know i'll be hot-wrenching the blade bolts off of it and I won't tackle that until I have new blades or the shims need to come out.

thanks in advance for your time

best,
jake

 

[treeclimber101]

The best measurement for a knife is the fat side of match pack meaning that your bed knife which is located on the side of the cutter box should have that clearance to the knife or blade whatever you wanna call it

 

[lone wolf]

Hi folks, jake here from NW Oregon
I'm new to this forum but not to forums in general and would like to tap into the knowledge that I'm sure is here.

I recently picked up a very used morbark 290 on craigslist. its been beat and re-beat several times over but I'm gonna coax some more mulch out of her on my place making better forest out of my forest.

The unit was missing the chute among other things but the previous owner said he had used it to chip pvc pipe which he then refined back to raw plastic and sold. I guess the plastic didn't come out of the chute very well (I surmise that its too heavy) so they removed it and built a shorty wood abomination. the original chute did not come with the purchase.
I've built a new chute as well as completing 35 items on my 75 item punchlist.
Although I'm not done working on it yet I spooled her up to check all the functions and tossed some fence boards and a 2x4 thru it to make some chips. It had no problem chipping the wood but I'm questioning the thickness of them.
I guess after all this my question really is; is it common practice to have a 3/16" spacer behind the blade?
The flywheel (anvil?) has two blades on it, one inner and one outer, both of them are spaced with a shim between the blade and the wheel.
I realize that this shim would affect the thickness of the chip and I'm wondering if it was placed there to reduce the plastic pipe better and if I would be better served to remove them before chipping what will mostly be small alder and scrub maple with some fir here and there.

The blades do need to be sharpened but I can give em' a touchup while installed with my mini grinder.
My plan is to do this to give it a real shakedown before I dump too much time into something that ends up being truly wore out. I already know i'll be hot-wrenching the blade bolts off of it and I won't tackle that until I have new blades or the shims need to come out.

thanks in advance for your time

best,
jake

Got pics of that beauty?

 

[no tree to big]

The blades should not be spaced off of the disk. I assume this was done to get bigger chunks of plastic using the same setup on wood may result in clogging do to the bigger pieces not wanting to discharge
Why would u need to burn the blade bolts out?

 

[Jake Rosenfeld]

Excellent, thanks everyone.

I dig the match book shim gauge.
I will shoot some photos if I can get home before dark this week.
Upon re inspection it looks like only one knife is shimmed, not sure what I was looking at when I said both were.
As to the bolts, I already put the wrench to them once. I've wrenched on enough stuff to know when a bolt isn't going to loosen and I'm not into herking on stuff with enough wank to break off 1/2" bolts anymore. I could just heat them up but they're nylocks and will need replaced anyway.......

I'll keep after it and report back. everyone likes to look at pictures

thanks again,
jake

 

[jefflovstrom]

We have a lot of Morbark's.
To adjust the anvil to the knife clearance, there is a gauge for that.
It is a pos, We use a saw blade, the closer the better,, just start it up slow and listen.
When it sounds like a helicopter taking off, you have it dialed in. Leave the belly pan open when chipping and not too much grease on the clutch zerk. That one only requires 2 shots every 10 hours, all the others,, grease away,, really,, and everyday you need to grab a set of wrenches and walk around all that vibrating machine cause it will wiggle itself silly.
We replace all the knife bolts on the third change. Complete service every 300 hours.
Anyway, this is why I responded,

"As to the bolts, I already put the wrench to them once. I've wrenched on enough stuff to know when a bolt isn't going to loosen and I'm not into herking on stuff with enough wank to break off 1/2" bolts anymore. I could just heat them up but they're nylocks and will need replaced anyway....."

You don't know how many times they have been wrenched?
Just saying, better safe than sorry.
Jeff

 

[Jake Rosenfeld]

photos as promised;

 

[sgreanbeans]

That thing is a dinosaur! Get it dialed in and it should work great. Needs a little paint tho!

 

[hartbilt]

Shims not needed. Install new bolts/nuts/flats, and adjust the anvil and you'll be good.

 

[Jake Rosenfeld]

Update;
ok, got the blades off without using the torch but it wasn't the easiest thing I did today...
I shot some photos of the shimmed blade on the flywheel and also the ridiculously worn out bolts themselves (good call on replacing those btw)
I also pulled out what I'm assuming is the 'bed knife' which was mentioned earlier and tried to capture some photos of h0w worn it is.

questions;
is the blade gap that you all speak of measured between the blades and the bed knife as they pass each other? the bed knife was at the ends of its slots and i'll need to build it up with some welds in two directions to be able to make this happen.

I will build up both the edge and the face unless one of you tell me that it is missing a piece altogether and I need to buy a new one.
it sort of looks like its been hardfaced before, either that or its snapped an edge clear off of it and its missing completely.....

thanks for your thoughts.
jake

 

[hartbilt]

The anvil or bed knife can be flipped 4 times to a fresh edge, but that anvil is rough, id replace it. Yes the clearance is betw the anvil and the knives. As far as adjusting, spin the disc with cover open to see clearance. Call Alexander equipment for your parts if you dont have a dealer near, they stock all 290 parts....the anvil is a hardened AR400 steel alloy

 

[Jake Rosenfeld]

Thanks for the fast response hartbilt.

I don't see how this particular bed knife can be flipped even once, the back of it (or the side closest to the feed wheels is bent at a 45* angle so that material slips past it.
its a one position deal. However, its 3 bolts ride in slots that allow it to move towards the flywheel...

I've been looking online for a schematic but I'm not having much luck. I feel like my lack of correct terminology is hindering productive conversation.
i'll keep looking and report back.

 

[hartbilt]

Yes the slots are for the adjustment, and i just looked closer at your pics..your right, your anvil cant be flipped, some years of them did have multi wear edge flat anvils

 

[hartbilt]

Anvil clearance is .o45 -.065in

 

[Jake Rosenfeld]

perfect. thanks for the visual!

I do a decent amount of stuff with T-1 and I could tell it was not A-36 when I put it on the bench. I think t-1 and ar400 are along the same lines of hardness so I feel fairly confident that I can build it up well enough to get by for a while while I seek out replacement parts.
I'll preheat, build up with dual shield and then cap with hardface rod then grind to square.

I appreciate the help.

 

[CalTreeEquip]

Nice welding!
Your probably better off with a new anvil. And check the dimensions on the blades, make sure they didn't put in something that doesn't belong.

 

[2treeornot2tree]

You don't want the shims in there. The anvil spacing should be 40 thousands of a inch.
You can get replacement anvils from morbark for that machine for pretty cheap.

 

[Jake Rosenfeld]

New anvil and blades have been ordered. I built the existing anvil up and hardfaced it but can't get anywhere close to the right blade gap.
There must be more missing from it than I thought. I will finish up with the wheel bearings and take it off the blocks too before I try to set the gap,
there may be enough twist in the frame to affect how the blades and anvil interact. You wouldn't think it but why take a chance.

I'll keep everyone posted.

 

[2treeornot2tree]

if you have that much twist in your frame you got a lot bigger problems then blade gap

 

[Jake Rosenfeld]

Yeah, I get that. Not saying I do, only that I'm aware that non normal conditions can affect more than you would expect. So i'll eliminate it.