NR prop holes to tight

[avidflyer]

Ok, but I don't have a spacer between the prop hub and the prop shaft face. On a brighter note, I hung a spare warp drive prop on the engine and got it fired up today for the first time. Bit of a milestone. JImChuk

[alexM]

This supports my theory that NR, Luga and Meglin have some common "shared resources". The hub supplied with my Meglin 3 blade is also tight. To be fair, the first time I went to install my Sensenich prop it didn't fit either. I called my engine importer to ask him what to do. He was very opposed to the idea of taking a reamer to the holes, and suggested that because the temperatures in my hangar were below 20F I should try warming everything up.

I did that and got the Sensenich hub on - just barely - with some light tapping using a rubber hammer while making sure everything is going on the lugs perfectly straight. Now that it has been torqued and removed a few times I can get the Sensenich prop on/off. I haven't repeated the process with the Meglin hub yet but I'm looking forward to trying it out after I get my engine running.

[avidflyer]

When I tried to fit the NR prop, it was about 70 degrees F at the most, so I don't think expansion or contraction or expansion should be the issue in my case. I had no issue getting the Warp Drive prop mounted and used the same drive lugs. And really, why should they be super tight, the prop shouldn't walk back and forth on the prop shaft. JImChuk

[avidflyer]

Just a follow up on this post. I ended up machining a set of new drive lugs on my lathe. I milled the part that goes into the prop flange down about .005" less than the area that goes through the prop flange on the engine. These should work just fine I'm sure. The one drive lug in the pictures is an original Rotax one I pulled out and measured. JImChuk