[Black Magic and twin diesel build]

Hi Malcolm.  I had looked around for inspiration on the build and the BB plan is the one I am using, although I bought it without  a kit. We are hoping for the same sort of power as the PAW 19 (a nice engine, I have one myself) but as the twin is a home built one we are not sure what we are going to get.

 

Regarding the tendancy to climb, I have heard both points of view, but yours is good info as it is from flying a kit model.  Unfortunately I went with the zero incidence option, but I can always pack up the wing if it does climb.

 

Thanks for the input, I appreciate it, and sorry for the delay in replying, I was busy working on one of my other models.

[Black Magic and twin diesel build]

Thanks for the compliment Timbo, I will pass it along. It is going to be interesting getting the engine into a good running order and I think it will sound superb when we get it going on song.

 

By the way Timbo, if you see anything I am doing wrong on the forum please let me know.  This is a steep learning curve as well.

[Black Magic and twin diesel build]

Hi Dave, thanks for the interest.  I have to admit that I am just the airframe fitter( an interesting enough job in itself!) and the engineering brains are with my brother.  It should be an interesting trip.  The next engine he will be doing will be a 4 cylinder version of the diesel, and I think the hardest part will be working out how to start it.........

[Black Magic and twin diesel build]

First off, a brief explanation of the model and engine build.

 

The building of the model is really secondary to the building of the engine. My brother has an interest in making engines and liked the look of the "Fig Tree Pocket Twin" diesel so we decided on an vintage model to build as a test bed.  The engine is from plans and as we did not have any idea of the power output we thought that the Black Magic, at 60 inch span, was a reasonable airframe for a 4 cc diesel.  The engine will have a throttle and so can be throttled back if the power exceeds our expectations! This build log will show the progress of both the airframe and engine and will be added to as progress is made.

 

First up, the engine is well under way and a picture of the static components is shown below:-

The crankcase and cylinders are made as a single component (after many happy hours!) and the other various housings shown are either finished or requiring only finishing off.

 

To give the engine some size comparison I have included below a view of the crankcase on the plan to show where it will be mounted.  How it is to be mounted is yet to be sorted as there are no mounting lugs as found on a standard single cylinder engine.  There will be brackets fitted to mount the engine from the bottom of the crancase, so much changing of the internal engine bay structure will be required.

As the engine progresses I will include photos and put a 6 inch rule in the frame to give it some scale.

 

The airframe is a standard vintage style cabin model made up from longerons, cross braces and formers. I have increased the size of the balsa used to take the strain of the engine and any antics that can be performed in rc mode rather than the original free flight mode,  I have gone for quarter square balsa for the longerons and used 1/8th by 1/4 for the braces. I have also gone for a 0-0 incidence between the wing and tailplane as experience with previous vintage models have shown a tendency to climb very quickly under power if the angles are left as per the free flight design. Where possible I have kept faithful to the shape of the model the original character.

 

The formers at the front and rear of the cabin are made from 1/8th by 1/4 strips laminated and overlapped to form the 1/4 square components.  These were attached to the first side, ensuring that they were square.

 

As I get to uploading the next build photos I will show the completion of the rear end of the fuselage.  The front end depends heavily on how I will be mounting the engine and so will have to wait until I have an engine mock-up to work out what I need to change.

 

[The November Grand Prize Draw]

It must be mine as it has my initials on it!

[The October Grand Prize Draw]

Me please, it will go well in my fleet!

[The September Grand Prize Draw]

Put me in for draw please.

[The July Grand Prize Draw]

Perhaps this time........

[The June Grand Prize Draw]

Count me in please

[The May Grand Prize Draw]

Yes please!

[The April Grand Prize Draw]

This would be an excellent one to win.

Cheers