# Woodsucker dust collector impeller failure



## Mahoney (Jan 27, 2018)

A heads up for any of you who might have one of the Woodsucker dust collectors still in service.

About 8 days ago the impeller on one of our 4 Woodsuckers "blew up". The heavy steel of the fan housing contained the shrapnel, but the internal damage was extensive. Inspection of the impeller showed no external reason (chunk of wood, etc.) for the failure, but only 3 welds on the top plate (closest to the motor) between the plate and the airfoils showed signs of being severely stressed. The rest were cracked neatly down the middle. This particular machine was on the miter saw for 8 years of it's roughly 14 year service life, and arguably saw the most "on-off" cycles of any of our dust collectors. I developed a theory that the repeated flexing of the impeller during start-up may have fatigued the welds and caused them to crack. Or perhaps the welds were poorly made originally.

During the past week we have disassembled the other 3 Woodsuckers. One impeller was perfect, one had 2 cracked welds, and one had cracked welds over one third of the wheel, and was probably only a few welds away from failure. All cracked welds found were on the plate mounted to the motor.

So despite the nuisance that it is to drop the blower housing/cyclone and expose the impeller for removal and inspection, I encourage any Woodsucker owner to do so.


----------



## bigblockyeti (Sep 9, 2013)

That's scary, I can't personally imagine the start-up torque would be significant enough to strain the welds but I would believe acute deflection could occur from the air resistance of blades flying around on a plate spinning ~3450rpm, resulting in fatigue failure over time. What model/HP was it? Do you have any pictures of the carnage you could post?


----------



## Mahoney (Jan 27, 2018)

The Woodsuckers were all 2Hp, and they used a steel caged airfoil impeller, which is more efficient than the usual backward curved blade design used in almost every other dust collector. The torque needed to accelerate the bottom steel "doughnut" caging the airfoils has to be transmitted through the airfoils and loads them sideways, flexing them where they are welded to the top plate. All but 3 welds on one of the 4 impellers we inspected were on the same side of the airfoils, whether by design, or simply convenience for the welder. But it left the airfoils free to tip away from the unwelded side.


----------

