MIRO 2

[Rod]

Hi Chris good spotting. I forgot to take a photo of the 2 ply engine mounts with the balsa discs glued to them. The film is to give the discs a smooth bearing surface at idle and startup. When the motor is pulling I think the discs pull apart slightly. In the assembled photo you can see the screw in the middle holding everything together so I can fit the rubber rings.

The firewall just pushes up against the mount and is glued in with epoxy mixed with cutup fibreglass. The fire wall assumes the same angle as the nose ring. I made a slight error with the nose ring (too much down thrust) and have corrected it with a ply ring sanded to the right angle. There is 1.5 degrees down and 2 degrees right thrust.

The first model flies so well I havent adjusted anything yet. But I have promised myself I will start doing the trim checks.

[CSpaced]

Ahh...gotcha, that makes sense now thanks. Do you tighten up the center bolt so it is snug or do you leave a little play in it so that the front half of the mount can "float" on the rubber when the engine is pulling?

[NZ Scythe]

I was going to ask the same question... I didn't really know how the Hyde Mount worked either but after a bit of googling I found Ola Fremming's page: http://home.online.no/~ofremmi/HowTo.../HydeMount.htm

He has a bit of a step by step guide on how to make a hyde mount, it is very similar to Rod's however it looks like he uses a rubber disk in the middle instead of two smooth film covered surfaces back to back... he claims it "generates friction damping when engine is at idle" Any thoughts on these two methods Rod?

[Rod]

Chris the bolt in the middle is just to hold things together during assembly. I will fill the central hole later.

I have looked at Ola Fremmings page and look at this one also I think it has more development.

http://www.rcaerobats.net/mount1.htm

I have just copied that.

[Rod]

Patrick the friction damping at idle, rubber pad idea is interesting. On my OS 140 the idle is reasonably smooth so no problem. I have no experience with the YS but I wonder how it would go on the YS kickback?

[Rod]

For the nose ring mount I am going to use a slightly modified version of the system on the Central Hobbies site. I have thrown in a picture of one of my most used tools.

[Rod]

Glued in the small ply mounting plates. I temporarily spot glued them to a cross piece of wood to hold them flat to each other while the epoxy cured.

[Rod]

Had to offset the T nuts to make it work. Added a little more thickness to the ply to get the O ring in the right spot on the motor. Again have drilled for the T nut spikes.

[Rod]

Now you can see why there are cutouts in the motor mounting jig. Unlike the Central Hobbies system I am using Countersunk screws to hold things together.

[Rod]

Just have to glue in the Tnuts and fuel proof everything and it's done.

[brusty]

Rod, You're a real Whizz, master craftsman at work. I really enjoy seeing everything created from the ground up. I wonder how many others there are hanging on this thread with bated breath, waiting for the next post... and clicking between this and the Sukhoi !! I hope you don't have to go back to work for a while, we just have to get these projects finished !!

A wonderful effort, keep it up,

Cheers, B.

[Rod]

Thanks for the kind comments Barrie. Have 2 1/2 weeks work from monday, not too bad really.

Decided I needed adjusters after all. Here is the drawing and some raw materials. Went with cotton grade Tufnol, the red stuff in the foreground. It was the hardest.