1/4 Scale CAC Boomerang

[Mick]

My latest project is a CA-13 Boomerang. At 1/4 scale it has a wingspan of 2740mm or 9 feet. This photo is the actual aircraft that I plan to replicate.

 

 

This is a project started by some friends of mine who made the molds for the entire airframe to be built in composite. They ended up shelving the project when they became concerned that it would end up over 25kg with the amount of nose weight it would require to balance as well as the fact the retractable undercarriage they had designed around would not take this weight. The 2 composite shells were left to languish in a shipping container after the project was abandoned. I kept bugging them about what was to be done with these two airframes which to me looked way too good to do nothing with. Finally I was told "If you think you can make it work, take them and have a go!"

 

So now the project is mine. I have set out on a mission to reduce the weight as much as I can and focusing on the tail end in particular. I have also ordered a set of "Custom Retracts" that will carry more than our projected weight of 25kg. I have a DLE 111cc twin cylinder petrol motor that fits neatly in the cowl.

 

Of the airframes that I have been given, the first one out of the molds has some faults that mean it will never fly, so I plan to paint it up as a static model. It is the green one in the pictures below. The second airframe has had most of the internal structures removed to be re-done as part of my weight reduction program. There is alot of work ahead to complete this model, made more interesting by the fact there is no real plan to follow. Everything has to worked out as I go.

 

I will post more info & pics as significant progress is made.

 

 

 

To give some proportion, the bench the Boomerang is sitting on in the pic below is made up of 2 standard household doors. The model that I am working to fly can just be seen in the right side of this pic.

 

 

 

[Bernie]

Looks good Mick hey to H.

 

I have lost your mobile number Mick can you PM me please with number?

 

Bernie.

 

 

[Kyle Communications]

What material are you going to use for the formers in the rear?.... end grain balsa coated with thin carbon works great a lot of the jets use this super strong and super light. I think someone actually sells it now in sheets. Much better and than liteply. The biggest problem is keeping those tailfeathers light you may need to pull a new set done from nomex sandwich

 

 

[Kyle Communications]

I have access to a Seafury mold about the same size.... always wanted to get it made

 

 

[deadstick]

Kyle, I would pay money for a seafury that size, how do I go about getting one?

 

 

[Kyle Communications]

I will see if David is still using the mold..it was all composite wings and fuse and tailplane.....I was looking for the pictures I had of it must be on a old HD will see if I can find them

 

 

[Yenn]

Nice to see you flying yestarday Mick. I liked the side slip on final and the Skylark always looks good in the air.

 

 

[Mick]

Nice to see you flying yestarday Mick. I liked the side slip on final and the Skylark always looks good in the air.

Hey Ian,

It was great morning for a fly, had been out to Old Station for a touch & go, then to Rodd's for another, then over to the coast & back to town. Best Monday morning I have had for a long time!!!

 

How did you go with the RV-4?

 

 

[Mick]

What material are you going to use for the formers in the rear?.... end grain balsa coated with thin carbon works great a lot of the jets use this super strong and super light. I think someone actually sells it now in sheets. Much better and than liteply. The biggest problem is keeping those tailfeathers light you may need to pull a new set done from nomex sandwich

Hi Mark,

Somehow missed this post? The Boomerang it molded in the same material as the Thunderbolt I flew at Gratton last year. It is a thin layer of glass, then a layer of "core-cork", then another thin layer of glass. This layup is very stiff and requires no formers in the back end.

 

I have used the carbon - end grain balsa laminate you mention in other models for firewalls etc. it's really good stuff!

 

Mick