Asplundh Chipper knive gaps

[Barry Stumps]

Hello, I have an older (70's) 12 inch drum chuck and duck chipper. My knifes are dull and the bottom bar is low in the middle so the gap is inconsistant. I have never messed with this before and there is no shops around my area to take these out and sharpen. My questions is: Do I have to take my drum out to get to the bottom bar and is that bar suppose to be sharp like a blade like my 4 cutter blades? Is there a set gap your supposed to have when you put it all back together? Thanks

 

[Hoosier]

Well, my old Chipmore uses a setup like that and if my bar were wore I would flip it over. I don't think I would need to move the drum to do it, but if I had to I don't think it would be the end of the world.

I use a thick piece of card stock to set the gap, I rotate the drum and let the knife blade pinch the cardboard and tell me the gap. I cant remember how thick the card stock is but if you have a spiral notebook the back of it looks like the correct thickness. I let the blade just make a depression into it when rotating by hand. Better to have more gap than you need because I would think that a hot drum/bar would take away tolerance and could crash.

Your mileage may vary.

If your bar is not worn in the middle and is bent then I would be concerned about setting it up and having a collision, so use caution. Check to see if you can remove the bar and have it checked for flatness & square and/or ran on a surface grinder to get it square again, then make sure that when you tighten it down in the machine it does not deflect for whatever reason.

 

[chipdelia]

blade setting

Go to any print shop in your area and ask who they use to sharpen their cutter knife to find a place to sharpen your knives. I am a printer, and thats who I usefor mine. If you send me you e-mail address, I will send you the manual that tells you how to adjust the blades and the big part is how to tighten them so they don't come out while running. You can flip your bed knife. It has 4 sides to use. The manual also tells the size when you have to replace the blades (too small to safely sharpen). The bed knife can not be sharpened per the manual for the machine.

 

[rbtree]

I use a thick piece of card stock to set the gap, I rotate the drum and let the knife blade pinch the cardboard and tell me the gap. I cant remember how thick the card stock is but if you have a spiral notebook the back of it looks like the correct thickness. I let the blade just make a depression into it when rotating by hand. Better to have more gap than you need because I would think that a hot drum/bar would take away tolerance and could crash.

Wrong. I have always set all chippers I've had up with as tight and small a clearance as possible. Even if one knife is so close that it just barely touches, no problem.... The closer the settings, the better the chip.

 

[rbtree]

The bed knife can not be sharpened per the manual for the machine.

I wonder why that is.....? Never had an Asplundh chipper. Every chipper I've had had or has a rectangular anvil, which can be squared up a few times before becoming too short.

 

[chipdelia]

I wonder why that is.....? Never had an Asplundh chipper. Every chipper I've had had or has a rectangular anvil, which can be squared up a few times before becoming too short.

I think it is because there is only adjustment up and down, not in and out. The Bed knife actually fits in a holder of sorts and it would cause play and not lock up solidly when you torque the 3/4' bed knife holder bolts to 280 foot pounds of torque. The bed knife bolts are not that big to support the play. I guess you could shim it if you wanted to.

On adjusting the blades - first you adjust the the bed knife to .218 from the drum. I use 2-7/16 inch drill bits for this. Then you adjust the blades to .03 - .035 from the bed knife. This gives great chips and a very good feed speed.

The most important part though is how you lock up the knives! Real bad things happen when they come out when its running.

By the way, this is for what they call smooth knives. There was a setup in the early 70's with what they called Serrated Blades that had grooves ground in to the flat side of the blade. It looks like they would be a lot easier to set, but I have never seen a machine with them and the setting are totally different and the bed knife is different also.

 

[Hoosier]

Wrong. I have always set all chippers I've had up with as tight and small a clearance as possible. Even if one knife is so close that it just barely touches, no problem.... The closer the settings, the better the chip.

How often do you do this?

 

[B-Edwards]

The manual says to set cutter bar ,have the blades out, use 2 pieces of square stock 1/4 inch and set using those to the empty drum. Tighten everything up and install blades and adjust them to the cutter bar. if blades have been sharpened at correct angle it's brush eating time . I also get the blades as close as possible!

 

[tomtrees58]

match book old school tom trees

 

[Hoosier]

match book old school tom trees

Yeah, the old guy that sold me my chipper uses that method and told me to use the card stock. Turns out it is about the same thickness. It ends up being prety tight once the cutter slices the the card stock a bit.

 

[Barry Stumps]

Bolts cannot be turned

Thanks for the tips. The problem im having now is the large bolts on the bottom that moves the bar up towards the blades is locked on and the bolt head is about to twist off. Is there another way to get the bar out like taking the drum out or is there an easier way than that?

 

[B-Edwards]

There should be two more bolts in front that you have to loosen also. Total of four hold that assembly in place. Then hex head bolts or Allen bolts not sure what they are called to remove cutter bar from this piece.You can then rotate the bar to access four edges.

 

[chipdelia]

Thanks for the tips. The problem im having now is the large bolts on the bottom that moves the bar up towards the blades is locked on and the bolt head is about to twist off. Is there another way to get the bar out like taking the drum out or is there an easier way than that?

If its anything like the ones I had on my 70's unit I would spray them a lot with PB Blaster for a day or so. and then use a Mapp or acetylene torch and get it nice and hot and hit it with an air Impact gun.

 

[Climbing Cutter]

I,ve heard that a couple of quarters work great for setting the blade gap.