Leaf Blower

Broken pulley

“What’s it got to do with building a Long EZ?!”, you say.

You see, sometime in the life of a project the opportunity to score some easy points with one’s better half presents itself. These are almost as good as cash, and can be redeemed at a later date, for example when one would rather go flying than mowing the lawn.

So, when Gina suggested she should go buy a new blower because the old one could not be started, I caught the rebound and decided to score by showing how those pesky CNC machines I spent so much money on, could actually save us some cash this time.

Upon further examination, it turned out the pulley sheared some of its teeth for the second time in a few months.  

Exploded view of the leaf blower

Plastic teeth on starting pulley

Obviously the plastic teeth are no match for the steel clutch fingers, so I thought I'd rebuild the darn thing out of metal.

Closeups of the damaged teeth

Another look at the damaged pulley

I started by recreating part of the clutch mechanism in CAD, as an insert to be installed into the plastic pulley.

Pulley insert

The insert would be made out of a 2.5” bar (6.3 cm) of 2024 aircraft grade aluminum.

Same stuff I use on the Long EZ

The busted clutch teeth had to be removed, and this was easily accomplished on the mini-lathe.

Removing the busted plastic teeth

Meanwhile, the mini-mill got in on the action too by machining the pulley’s new teeth.

Machining new teeth on the pulley insert

The insert’s fit and finish came out really nice, and the end-mill pattern on its surface was absolutely smooth.

Pulley prior to damaged teeth removal

Pulley with teeth removed and insert pressed into it

Pulley with insert

A better look at the new teeth

Rewinding the spring was a total pain, and it had to be done at least half a dozen times before I figured out how it really worked.

Upgraded pulley back in its place

Closeup of the starting assembly

Testing the action of the spring

At last the darn thing went back together again, and I could verify its operation.

Final leaf blower starting test

This was a pretty fun and challenging project that kept me busy on an actual rainy day. 

Crisis averted, points collected, and payback on the horizon.