On 05/18/2011 10:53 PM, Terry Adams wrote:

Ernst,
I agree with Ed, good you gave it a try.  You learned some things while making the attempt. 
Perhaps testing with an electric motor might be good.
In our cabinet shop we had a dust collector which would really wind up in RPMs.  It was a cast impellor and housing and it was tough enough to suck up dust and wood chips.  Unfortunately that was years ago so I can't give you any details about RPM, suction, size, etc.  But have a look at a dust collector at a tool supply house, maybe you'll get some new ideas.

Excellent idea, Terry!!

Really, I have the dimensional design worked out.  There is all sorts of things that "people who really know what they're doing" do to the impeller fins in order to go from 80% efficiency to 85%.  I'm already starting with a sub-optimal configuration, and I've decided that constructability outweighs getting the ultimate in efficiency at this point.  I've been looking around to see if there is a commercially available impeller that I could re-purpose.  I've search backpack leaf blowers to no avail, but haven't even thought about dust collectors.

Jarrett, if I sent you a CAD drawing, could your CNC cut me an impeller?

I found the oil leak in my gearbox last night, and it wasn't even close to where I thought it was.  The oil is still clean so it is really hard to tell where it is coming from.  I stood it upright and poured some dark two-stroke oil into it.  Spun it a bit, and let it sit overnight.  Had a nice little blue streak pointing straight at the culprit this morning.