Martin baker B57D Build

[JohnPearson]

Hi All

Well it's time to get building for next season, and after looking at a few designs over this year's flying season, i have decided to go with a B57D. This is the USA upgrade of the British Canberra, used as a sky plane by the US airforce in the 50's



The wing span is 106" and it is balsa fuselage and foam wings. I have started building and will post a few pics of the progress so far soon!

johnp

[Fred]

=P~

And that's pretty much all I have to say !  

[Alan_Perse]

Those wings will certainly generate a lot of lift John. Looks like a nice project.

[Happy Days]

That’ll be a more manageable size than the big B52, and I would presume produce far less drag with only two engine pods. Hopefully I'll see this one fly off Big L.


Are you going to make the design yourself John, or will you be using existing plans?

K.

[JohnPearson]

Hi Keith

This one is from existing plans and yes! this model will fit inside the car. I got the plans and vacuum parts in a traplet sale £20.00 the lot, I think? anyhow at 106" wingspan the B57 is a nice size. Here are a few pics of the build so far:



The formers have a ply middle with balsa skins on both sides.



Nice set of vacuum engine pods, I am thinking of installing two fan units into these pods later for flying of the flat.



Long canopy for two pilots nice!!!

So far I have had one problem, after getting the fuselage formers lazer cut from lite ply according to the template provided, the formers are to short according the the plan by about 1/2", therefore I had to move the bottom span up to link with the formers. right pain in the a*!/*

Anyhow hope to have one side finish over the weekend.

johnp

[Happy Days]

John Pearson, Let me get this right???…………..You decided you were going to build this model, from plan, on Tuesday, (2 days ago.) And now you’re telling us that you intend to have one side of the fuselage finished by the weekend!!! :shock:  :shock:  That is Outrageous!!

(Makes me feel totaly inadequate. :oops: )

Just as an aside,…………….. On what basis will you asses what size of fan units and motors to use if you decide to fly this as a powered model? :?:

K.

[JohnPearson]

Hi keith

This model has a large wing span (good lift), therefore if i can keep the weight down, I reckon that two 70mm fans with two hot motors, should do fine. i want the model to fly at a scale speed, so this setup should provide a good thrust to weight ratio.

I will test the model on the slope first to get the CofG right and the control throws sorted, then later add the fans.

[Happy Days]

Quick question………..what do you define as a “Hot Motor” :?:

[JohnPearson]

HET Typhoon 2W-20 3300Kv (700W) Brushless Inrunner Motor, would be a hot motor on a 4 cell lipo

[Alan_Perse]

So far I have had one problem, after getting the fuselage formers lazer cut from lite ply according to the template provided, the formers are to short according the the plan by about 1/2", therefore I had to move the bottom span up to link with the formers. right pain in the a*!/*johnp

I know how you feel. The plan I have for the Skylark 2 is not very accurate as well. I will have to make some adjustment to the formers. I'm also redesigning the wings myself using a different aerofoil. Where did you get the parts laser cut? Did they come from Traplet?

[Ron]

This is interesting and worrying.
Buying plans that someone has drawn up is supposed to mean saving you work.
If the plans have to be 'adjusted' it makes you wonder if you couldn't have drawn the lot from scratch. :?

I have had this problem in the past (so who hasn't), and had naively thought that with modern 3D cad systems it would be a thing of the past.

On the aerofoil.... what software do you use? If any   :wink:
I've seen Compufoil talked about a lot.

Ron

[Alan_Perse]

I have had this problem in the past (so who hasn't), and had naively thought that with modern 3D cad systems it would be a thing of the past.

On the aerofoil.... what software do you use? If any   :wink:
I've seen Compufoil talked about a lot.Ron

Hi Ron. Nice to see you back on the Forum again.
 I am very certain the plan I have was not designed using 3D Cad software. If it was I would say it would be much more accurate. It looks like it's a hand drawn plan (when I mean hand drawn I mean with rulers etc. not free hand).
The software I'm using for the wing is called Profili Pro 2. Its quite a good software. You can get it here http://www.profili2.com/eng/default.htm

[Ron]

Thanks Alan,
Had a few health problems in the family, but getting sorted now.

I didn't think there were any old school, pencil and ruler draughtsmen about still.
Maybe it's an old plan?
Hope the one I've ordered (Skylark 1) is a bit better.

That Profili 2 looks interesting.
I'll give that a try.

Ron

[Fred]

Hi Ron,

You also have Tracfoil (that's what I use), but I usually use those software to export the dat in the CAD program.

[Alan_Perse]

It might be an old plan. But it does say copyright 2007. But looking at it you can defiantly see it its not a Cad plan. There are lots of small errors here an there.