Converting Gravely 6" disc to leaf shredder/vac

[Kaptain_K]

I'm thinking it should be fairly easy to modify my chipper into a leaf vac/leaf loader. The thing pumps out some major wind from the exit chute. The disc housing (6" disc, 24hp Honda engine) has the feed/feed roller on one side and just a vent/grate on the other side. Could I just plug the grate on the opposite side of the feed and rig up a big suction tube on to the feed and use as a leaf vac? My chipper is mounted to a dbl. axle trailer with a 9yd dump box on the back, it would be perfect for leaf collection. Would you think I would take off the feed roller wheel or leave it there? Anybody know where I can get some of that big tubing to use as the vacuum hose? Like 10-12" diameter corrugated tubing or such?

Thanks,
Kap't K

 

[jokers]

Don`t the municipalities do the leaf collection where you are? They`ve got it wrapped up around here. I don`t see where you could potentially make enough money to make it worth your while to modify your chipper.

Russ

 

[treeseer]

Leaf collection not so great here; I think this idea has merit. Leaves belong in the soil under the tree they fell from; if they're taken away, the trees are being robbed of food. so instead of loading them, blow the laves back into the natural area. If there's no natural area, tell the client you need to make one, or they will either have to pay for mulch, fertilizer etc.

The trees want their leaves back! :blob5:

I have a gravely 6" too, and yes the feed wheel slows things down a lot. It also keeps the operator safe. How to modify safely? Shove a brick under the bar, so the wheel is raised 4", and keep a supply of sticks on hand for pushing leaves through.

 

[Proj Eng]

Kaptain K,
If you underego a project like this, I can be of help in getting you dimensions and such. I've measured the flow rate of the air from the discharge chute at around 1200-1350 cfm on newer model 625's. Also, I think there is an access cover right above the feed wheels you might be able to make use of. I've wondered myself if blocking off the small air inlet holes would force it to pull air from the feed area. And Treeco is probably right about the impellers. The chipper ones are almost strictly for throwing so 2 new impellers might help you out if they're the right design. You also might want to consider caulking up the gaps that aren't welded to decrease the blow-by of suction air, and direct suction to where you want it to pull from (infeed).

I also want to rant a little. I get sick of the True-Green or Chem-lawn guys calling me. I had them aerate once and now they won't leave me alone. I also hate it when people pile leaves on the curb. Mulch em up!

 

[treeseer]

I've wondered myself if blocking off the small air inlet holes would force it to pull air from the feed area. !

Duct Tape Rides to the Rescue yet again! Good tip also on the caulk.

 

[Koa Man]

Blocking the the air holes will make the chipper discharge have very little airflow. A friend of mine with the 12 inch Gravely was complaining about how hard the chipper was throwing chippings. It was beating up the headboard of his truck. We solved that problem by blocking off about half of the air holes opposite the feed entry. His chipper now discharges like your average chipper. It is unbelieveable how hard the big Gravelys throw chips.

 

[Proj Eng]

I think I once calculated the speed of the chip if thrown un-obstructed from the flywheel (on the big 12" units). Something along the lines of 170 mph. Of course, air resistance and hitting the discharge chute reduces that considerably.

 

[Thor's Hammer]

The original Promark 6'' chipper, which became the gravely 625, was actually designed from the outset to also work as a leaf Vac. the back of the chipper housing (opposite the feed hopper side) had a bolt on door, for which you could buy a 10'' dia. hose attachment. the impellers on the back of the disc were 4 curved types, which gave it tremendous suction. I dont know if the design was continued in the gravely, but I have seen a few Promarks fitted out like this. your best bet would be to track down a hose kit. try ebay or try an old promark dealer.

 

[Kaptain_K]

Good advice Thor. I actually do have a Promark 310 according to the manual. The incredible airflow out the discharge chute is really what got me thinking it should also work as a leaf vac. Air in = air out, right?
Our city does not collect leaves, rather, homeowners must buy these ridiculous brown paper sacks for like $1 each, or little green stickers to put on bundled sticks and such.
I think I will look into a hose kit.
Thanks,
Kapt K