SonexBuilders.net

mike.smith wrote:Here's my Kitlog entry from the FIRST time I replaced my bushings:
http://www.mykitlog.com/users/display_l ... 271&row=58

Thanks!

Just an update for future searchers: So I placed various bushings in my friend's hardness tester. Here's how it turned out:

From left to right:

70A - The sonex bushing
75A - the blue bushing from Amazon
85A - Ninjaflex printed polyurethane
95A - Too hard printed polyurethane

My personal plan is to fly with the sonex bushings (with washers) and see how it goes. If encounter significant droop I'll (someday) try the 85A bushings.


(kitten paws for scale)

So again at 58 x hours I’m looking to have to address my engine mounts. Flying well but a vibration starts to creep in and I just know the accessories plate is hitting the engine mount pins.

Looking for a long term answer. The extra heat shields I added I guess didn’t do the trick. The original Sonex engine mounts on my other Aerovee are now about 6 years old and haven’t sagged hardly at all.... the older mounts surely have had to be made of something harder?

Just bought a 3d printer with ninjaflex e85a material. Will have a go and see what they perform like.

The stiffening bar I added between the top and lower engine mounts didn’t really seem to make much difference. Going to try some harder mounts.

cool! For printing the ninjaflex I'd recommend first doing a test print in something easy (like PLA). Then switch to the ninjaflex and print _very_ slowly (30mm/s or so) and turn off the default "retraction" settings in your slicer app (because retraction and flexible filaments can cause jams during printing).

Cheers for the advise. I'm a complete noob to this so hopefully I'll get the hang of it. I think my daughter has done some classes on it at school so that may help my case. Looking into getting a roll of the 80a material as well to see how they turn out...

I'm also planning on making larger mounts also. Prob wont make much difference for the issue I'm having but might reduce vibration...not sure. We'll see.

Fitted the Ninjaflex 3d printed mounts tonight. They actually look really good. Made them overall larger at 42 mm OD so they have a bit more surface area on the 3rd face. Will see how they go. Ran the engine and it seems no more or less vibration than normal. Will test fly it on the weekend. Test will be to see if they last longer for me than the original ones. Prob won't as I assume I have something else going on wrong as not many others have the issues I seem to do with them.
I'll try and put some pics on the blog some time. I'm seriously loosing all interest in this lately so I'll see how it goes.

ooh - I look forward to your report!

Flew the plane today. Normal ops and feel the same as the standard bushes. We'll see how long they last.

Hi , has anyone had success with polyurethane engine mount bushes for a aerovee .