Leaf vacuum impeller housing

[sos1]

I'm building this out of heavy gauge steel sheet metal.
How small should the gaps be between the impeller and the housing?

 

[2458n]

I have a leaf vac and the clearance on it is about 3/8 of a inch. I have alot of white oak acorns that get sucked up cleanly. Sticks will still jamb it up when trapped correctly between the impeller and housing. Make it heavy enough to handle the stuff that can be sucked into it.

 

[sos1]

I will. Thanks!

 

[zzvyb6]

As a side issue, my housing has a hexagonal cover plate at the throat of the impeller housing. This cover plate has a 1-1/2" ring welded to it for attachment of a 12" suction hose. This plate attaches to the housing via welded-in carriage bolts with wing nuts used to hold it onto the housing. The housing itself has an hexagonal opening to allow removal of the impeller from the motor shaft without a headache. The impeller is fastened to the gas engine shaft with two allen head retaining fasteners plus a cap bolt that goes into the motor shaft. Its actually hard to get the impeller to stay tight because of all the trash, rocks, twigs hickory nuts and shells and heavy grass that gets pulled into it.

I believe my clearance is much greater that 3/8" but depends on the hose size and the size of the vacuum chamber you need. The impeller chops up all the material coming through and the paddles essentially push it upward to the trailer. The exit chute of the vacuum motor is square and build from 1/4" plate. At this thickness, there are quite a few dents in it at the elbow going to the trailer from 'things" just passing by. In the trailer itself, the entrance has a winged deflector to flow the material downward. At the top is a stretched metal grid for the air release.

 

[Texasmark]

I have a DR and the housing is around 9 ga. steel. The housing is in two pieces bolted together such that if the impeller had to be accessed, the front half of the housing comes off giving you clear access to any retaining hardware attaching the impeller. The back half attaches to the engine. I pick up small sticks accidentally different lengths maybe 10" max and max diameter of the size of your indes finger.

The impeller is attached to the engine drive shaft which is turning at 3600 rpm and it has a lot of mass. If a piece of wood gets that far it is a goner. This year is it's 5th season as I recall and never had a problem there. All the clogs were in the 6" dia suction hoses. For what it's worth, in their current catalogs, they advertise the fact that they did extensive research and found that 8" is the preferred diameter and that's what they are selling nowadays. They didn't say why but I figure it's a combination of weight vs clogging. When you are dragging around 20' of reinforced suction hose it gets pretty heavy after awhile.

My 2c,
Mark

 

[jwmorris]

If you don't want "stuff" sucked into the impeller you can always pull the vacuum on the container itself and as long as it does not get full you will be ok.

Like this leaf blower/vac pulling through two 5 gallon buckets.

Somewhere here there is a photo of a fairly large trailer that is enclosed with and engine and blower mounted high on the rear that is a larger scale of the same concept.