# Morbark 290 chipper blade question



## Jake Rosenfeld (Nov 16, 2014)

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


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## treeclimber101 (Nov 17, 2014)

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


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## lone wolf (Nov 17, 2014)

Jake Rosenfeld said:


> 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.
> ...


Got pics of that beauty?


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## no tree to big (Nov 17, 2014)

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?


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## Jake Rosenfeld (Nov 17, 2014)

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


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## jefflovstrom (Nov 17, 2014)

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


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## Jake Rosenfeld (Nov 18, 2014)

photos as promised;


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## sgreanbeans (Nov 19, 2014)

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


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## hartbilt (Nov 20, 2014)

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


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## Jake Rosenfeld (Nov 20, 2014)

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


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## hartbilt (Nov 20, 2014)

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


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## Jake Rosenfeld (Nov 20, 2014)

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.


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## hartbilt (Nov 20, 2014)

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


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## hartbilt (Nov 20, 2014)

Anvil clearance is .o45 -.065in


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## Jake Rosenfeld (Nov 20, 2014)

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.


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## CalTreeEquip (Nov 23, 2014)

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.


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## 2treeornot2tree (Nov 27, 2014)

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.


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## Jake Rosenfeld (Nov 27, 2014)

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.


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## 2treeornot2tree (Nov 27, 2014)

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


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## Jake Rosenfeld (Nov 27, 2014)

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.


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## Jake Rosenfeld (Dec 5, 2014)

Friday bump back to the top.

First off, thanks for the hot tip to Alexander equipment, I ordered a new anvil and blades from them and it was a first rate, professional transaction.

Everything showed up today and I installed it all this evening. the new blades are 4" wide compared to the 3.25" that they replaced.
The new anvil looks great and it appears to be AR400 with a bead of hardfacing on the working corner that has been ground to square.
Here's my dilemma though,
At the top of the anvil at the top of the blade I can achieve a blade gap of .040 with the anvil slid almost all the way forward in the slot.
At the bottom of the anvil I can only achieve .120" blade gap with the anvil slid all the way forward in the slot.
The bottom of the top blade is .060 and the top of the bottom blade is .080 so its clear that I have a perfect taper going.

The way I see it I have two choices.
First one is to run it as is and realize that it is out of spec and will not perform perfectly but that I only have 12 acres of brush to chip so in the grand scheme of how you guys use chippers it is hardly anything.

Second choice is drill and tap a new set of holes in the anvil because I have a full 1.5-2" slot to play with and could keep the unit in correct spec as I wear it out.
I know its AR plate but theres a chance for success if I anneal the spot I intend to drill with a torch to dull red before I try. If I fail, it won't hurt the performance of the anvil in the original hole position. I've drilled it before but not tapped so I'm half in uncharted territory.....

How will the gap as I've described it affect the performance and chip size if I choose to run it as is?

I suppose I could try to hog out the slot a bit but it would only buy me a correct adjustment, not a chance of keeping it there.
How long can I expect the chipper to perform correctly on the first set up assuming it is the recommended blade gap.

thanks a ton,
jake


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## CalTreeEquip (Dec 6, 2014)

Just get it as close to spec as you can and run it, see how it works for you. Something isn't adding up but it should still chip pretty good. Sounds to me like maybe you have the wrong anvil or blades. That's an old machine and it would not surprise me if someone is getting their part numbers wrong. What are the dimensions of the blades?


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## Jake Rosenfeld (Dec 6, 2014)

I'll give er' a shakedown tomorrow as soon as I change the oil.
blades are 4"x 7-1/4"x3/8".
honestly, its reading more like it rolled down a mountain and got put back together crooked than anything else.
i'll run it but i'll keep looking for the problem.


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## CalTreeEquip (Dec 6, 2014)

I just occurred to me that the problem might be in your disc bearings. Take a large pry bar and see if there is any movement in them. 
The blades you have are the most common type for old school chippers. Those will fit old Bandits, Morbark and Woodchuck.
I think there is a 4.5" options out there but I'll have to check on that.


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## Jake Rosenfeld (Dec 6, 2014)

The bearings and disc movement was one of the first things I checked when I bought the unit. After finding out here how small the blade gap is I went and took a closer more careful look. There is no play. The outer bearing is fairly new and it leads me to believe that the disc itself is in and working but not in the correct location which is keeping it too far from the anvil (and slightly tipped)
It's almost like I owned it and worked on it in a past life....

It made some chips this morning, couple more things and i'll give it a real try out at the place tomorrow.

I'll post pictures.

thanks.


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## Jake Rosenfeld (Dec 7, 2014)

Well it went fine today, first thing I did is plugged er up tighter than a tick by running too much vine maple thru it at too low of rpm with the chute diverter angled too much.
Once I paid the penance of getting it unplugged and cleaned out I found the happy spot in the motor and flipped the diverter all the way up and chipped the hell out of stuff for a few hours. It did a 6" alder from bottom to top with no sweat. In fact, the only time I heard it even lean into it was when 3, 4" alders ended up in it at the same time.

I may sharpen the teeth on the feed wheels so it gets a better bite but I'm pretty happy overall.

Thanks again everyone for the help and the tips. Not having to second guess myself every step of the way has made it go much quicker.

I forgot to take pictures but as soon a I get her in a photo worthy spot i'll post some up.

later,
jake


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## Gtatreeshrubinc (Apr 25, 2019)

Jake Rosenfeld said:


> The bearings and disc movement was one of the first things I checked when I bought the unit. After finding out here how small the blade gap is I went and took a closer more careful look. There is no play. The outer bearing is fairly new and it leads me to believe that the disc itself is in and working but not in the correct location which is keeping it too far from the anvil (and slightly tipped)
> It's almost like I owned it and worked on it in a past life....
> 
> It made some chips this morning, couple more things and i'll give it a real try out at the place tomorrow.
> ...


I have a morbark model 290 and put new blades and anvil and there’s still a difference in gap on the upper and lower or inside and outside blades it runs smooth just big stringy chips


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