Wood chipper power feed?

[Suess]

Hello,
The municipality where I work has a Valby (sp?) 1,000 rpm PTO wood chipper that has a manual feed chute. It is not effective to use due to the time it takes to prep all branches so they go through the chute. Does a good job of chipping. We would get rid of it but found out it isn't worth any thing less a power chute. I'd like to put a power feed on it. New from valby the power feed is $3,600. It's not in the budget and I have better places for $3,600 in the budget we get to work with. I'm wondering if I can build one that will work? I'm not sure how to design this. I have little experience with chippers. Can I get by with one hyd driven, top drum in the feed chute? Or are 2 needed one top one bottom? I take it that the top drum would need to float up to the maximum the chipper can take 6"? What type of roller works best? Was considering taking one with paddles out of a old forage harvester. Local repair shop suggested rolling some steel and cutting groves into it with a grinder. I'm a bit concerned with branches wanting to rap around the roller(s) and stop it. or the roller not able to feed the branch in. What works best? What things need to be considered? Would put a safety panic bar on the feed and a flow controll for speed. Any ideas very much welcome.

 

[rswyan]

Sounds to me like you mostly have it figured out.

I would think a pair of rollers, bottom one fixed and driven hydraulically, and the top one in a sliding bracket with spring downpressure. Set up the top bracket so the panic bar engages/disengages and locks it down into position.

As far as teeth on the roller goes, I think I'd be inclined to get a fairly thick a piece of round stock (3 or 4 inch ?) and take it to a machine shop (unless you have access) and have them machine it so that it had ^'s the length of it and protruding outwards from the center of the cylinder.

Might want to ask some of the guys here who have Jinma chippers how their rollers are set up.

 

[CTyler]

I have a Jinma 6 chipper that has one feed roller run off a V belt. The roller can raise up to accomodate different sizes and has two heavy springs that provide downforce.

The roller has teeth on it that are just bars welded across with small notches cut into them. Two rollers would work better but this does a decent job. I haven't had any branches wrap around the roller that caused any problems. I have about 8 hours on the chipper. The one time a branch did wrap around it broke then got pulverized fell off and got chewed up.

 

[CTyler]

Adding a hydraulic motor would probably be easier that trying to add belt drive solution. I think this is what most heavy duty commercial units use.

 

[surfran]

Not trying to rain on your parade, but you may want to consider the potential liability the municipality would be taking on if you "Home build" something that someone could get injured on.
At that point the $3600 is probably peanuts as the manufacturer then shares in the responsibility for designing it.

Now if it is for your home use, then your only worrying about yourself and that is a whole different game.

Just something to think about.