Building my own designed plane

[Craig Spence]

Hi all,

 

well i have left many threads on here reference designing and building my own plane and I have now finally made a start. The main wing is based on the Frantic fun fly (although a little longer) and the fuselage and tail has been totally redesigned, I have transformend a design to be a mid wing (hopefullt 3d plane) with a turtle deck and hopefully it will look good and fly great.

 

I have already started so ill download the photos later, I cut all my own parts and it will be obvious to some lol!. The exterior will look fine and the interior will be a bit scrappy (but totally strong and flight worthy) ie... not the best cuts on the inside of the formers.

 

Ill show the pics later.

 

Cheers all.

[Craig Spence]

Hi all,

 

sorry I will download the photos later, however I was wondering peoples thoughts on this.

 

If I changed the design of the wing how would it effect the flight of the plane?, so the wing as it would be made is a straight forward thick straight wing, I would like to change it to a tapered wing. Straight at the front and tapered at the rear.

 

Thoughts please?.

[Craig Spence]

Hi all,

 

not that there is much interest in this but heres what I have so far.

I havent had the patience to photo the whole build like my last one but this will do and I will update it as and when I have created something new.

 

Cheers all.

 

 

There needs to be ply and balsa here for the undercarriage, however I have left it off.

The fuel tank will be a very tight fit and I dont want ot change the plan. So the tank will be permanetly fitted.

Top hatch removed and spar tube on show, I still have to tidy things up here. There will be some magnets for the hatch as well.

This extra little bit will be cut in half and profiled either side of the fin.

[Peter Miller]

A tapered wing is more likely to tip stall at low speed.

 

If the taper is slight this will not be a problem. A taper of 10" at the root down to 8" at the tip would be OK.

 

A blunt leading edge will also reduce the tendency.

 

Don't be worried about this, just be aware of the possibility.

 

 

[Peter 'Ivanna Crashalot' Savage]

Already looks awesome! *bookmarked!*

[Craig Spence]

Hi Peter Miller,

 

thanks for the info there mate, I think a slight taper would make the plane look alot better than the wing I have in mind.

Ill take your advice on that, however I will build the original wing for the first flights and model and if all is well I shall make a tapered one.

 

Many thanks Peter.

[Craig Spence]

Hi Peter 'Ivanna Crashalot' Savage,

 

many thanks there mate, ill keep you posted on the progress.

 

Cheers.

[Peter 'Ivanna Crashalot' Savage]

The problems of people stealing my name XD means you have to say my surname too!

[Craig Spence]

Hi all,

 

did a bit of building last night, I must say that working with glue, magnets and wood should never be done lol!.

 

The magnets at the front are very strong and slightly larger than the ones at the back.

In this photo they are just glued to some ply and this is more than strong enough.

 

The same method used at the back, only the magnets are sligthly thinner and a little less powerfull but belive me it has more than enough strength for the job.

 

And the top hatch, the front ones have been drilled into the balsa and are flush to the wood while the aft ones just sit on top of the wood.

 

Had to cut the former to fit the fuel tank.

 

Hole cut for the fuel tank, this may cause a slight problem as it wont be right in the centre of the engine, but ive done it before and it works fine, also you can see the hatch attached.

 

Cheers all.

[Doug Ireland]

A very "futuristic" looking design going by the date on the pictures

 

Seriously though, looks good from what I can see!

[Craig Spence]

Hi Doug,

 

lol!, you know what I didnt even notice that until you said it.

Thanks for the compliments, I only hope it flys well.

 

Cheers.

[Peter Miller]

The tank will be in the right place if you use a sidewinder engine.

 

My own answer to the problem when using and upright engine is to use a Sullivan Slant Front tank. This allows the pipes to come through the former abover the engine moun t.

[Craig Spence]

Hi Peter,

 

thanks for the help there im going to look into that. Im going to be useing a Panic mount though I think this is mainly due to CofG reasons and I would also like to keep the nose as short as possible.

The original fuselage had a short nose but I have added an inch and a half as it is now going to be a mid wing and I need the room for the tank.

As the build progressess you will see what I mean, I hope you follow this thread as I really would appreciate your help and advice, this is a new area for me and I can use all the help I can get and I know you have a great wealth of experience and skill.

 

Many thanks Peter.

 

Oh I started witling the canopy tonight out of balsa for a vac former and will post pics tomorrow.

[Peter Miller]

A couple of thoughts from studying your pictures. Nothing important but would be worth considering for your next model.

 

When sheeting the bottom of a fuselage (And top if it is square) have the grain running across the fuselage. This helps to hold the sides together in a minor crash. With the grain running lengthwise it can split and allow the sides to spread.

 

I like to have a sheet infill under the tailplane. IT gives much more glueing area than just sticking the tailplane to the sides.

 

Those fuselage sides look pretty massive.. What are they made from?

Edited By Peter Miller on 01/07/2010 08:04:36

[Craig Spence]

Hi Peter,

 

thanks for the tip on the grain there, the reason I have done this is so I can do it in one peice (you are talking about the fuselage sides arnt you?) and not seperate peices.

 

The only sheeting I have done really is the planking on the top of the fuselage, this was a first for me but I enjoyed it.

 

Could you explain a little more on the sheet infill on the tail plane please, Im thinking that you mean put some sheeting in the tail to support the Stab, I was considering doing this but not until I have shaped the fin and dry fitted it.

 

The fuselage sides are made from 5mm balsa sheet with very thin ply doublers up front, I could sand them down alot more I suppose.

The fuselage in itself has two ply formers, more to get the shape at the start and then it has angled balsa strips inside (like triangle lengths) so in affect its almost built like a box fuselage.

 

Tonight after I have finished witling my canopy I will be buiding the Stab and fin and dry fitted them, I would very much appreciate your feedback.

 

Cheers Peter.

[Craig Spence]

Hi all,

 

I built up three blocks last night and fitted them to my removeable top hatch, I have started carving them down and soon I will sand to the shape of what I hope to be a good mould for a canopy.

 

Of course nothing is simple and I have been advised by my local model shop who have a vac former that once I have the shape I want that I cover the wood in a car filler and sand down as well with a lip for fitting.

 

Any suggestions for fillers anyone for a vac former?, could you not just use a finishing resin?

 

Cheers all, here's some pic's.

 

[Peter Miller]

 5 mm sides.! You only need 1/8".  But looking again. I don't see any plywood doublers. so it should be OK

 

I was talking about the bottom sheet with the grain across.  The sides are always one piece.

 

Take one of my normal models where the taiplane sits on top of the fuselage sides. I glue sheet between the sides and flush with the top for the tailplane to sit on. Have a look at any one my plans and you will see what I mean. Even the Tailwind.  This gives a big gluing area.

 

If the tailplane is just sitting on the sides one knock and it will come loose. That can really spoil your days flying.

 

What ever you use to seal your canopy pattern, remmeber that it is going to have very hot plastic stretched over it, the heat must not affect the sealer/filler.

[Craig Spence]

Hi Peter,

 

yeah the plywood doublers are very thin, so far out of all the models ive built ive always used this thickness of balsa, but then saying that they have all been fun flys and one glider. I will use 1/8" as you suggested on future builds.

 

I understand what you were saying about the grain now, the forward underside has not been covered yet and when I do it will be as you say, but with a couple of strips of ply as well for the undercarriage.

 

I also understand what your saying with the tail plane now and I will do as you say on that one for sure, Ill leave it out for dry fitting just to get the sizeing right though.

 

As for the canopy, what filler would you suggest?

 

Cheers Peter.

[Craig Spence]

Hi all,

this is my canopy almost complete now, theres a few bits of wood left to add and also to add filler but I will leave this now untill later on in the build.

 

 

Cheers all.

[Peter Miller]

Glad that I have been able to help.

 

With canopies I have tended to use bare wood. For a littlehwile now I have been using pine to make the pattern but that is hard work.

 

I know that Tufcote is pretty resistant to heat. I think that David's Isopon might work.

 

In the past Vortex Vacform have taken my balsa canopy, made a canopy from it and cast a resin canopy which they have then finished properly to make a really smooth pattern. Not sure what resin they use.

[Craig Spence]

Hi Peter,

 

I got told not use bare wood, it must just be because the wood sticks.

 

What would you think about useing glass cloth, finishing resin and then sanding it back down to the cloth.

 

Cheers Peter.

[Craig Spence]

Hi all,

 

a little more progress made, I have now drilled the holes for the bobbins and attached the bobbins. Also fuel proofed fire wall and top hatch.

 

Tomorrow I will be installing the fuel tank and possibly a snake.

[Peter Miller]

I really can't comment further on finishing the canopy pattern. I can only talk about what I know and I have reached my limit with regard to finishing them.

 

I have made patterns by building up and filling with ordinary plaster used for walls. That tends to break up after one use. Plaster of Paris might be an idea but never tried that.

[Craig Spence]

Hi Peter,

 

thanks for the help again, Im going to look for a car filler I think as this may have the strength and finish im looking for.

 

Cheers.

[Craig Spence]

Hi all,

 

well I have come to fitting the tank and its tight, not so much for room but for being near to other things. I padded it out with some foam to stop it from ratling about and if the unfortunate should happen it will soak up alot of fuel.

The tank is fitted in a secure position, the fuel tubes are soft brass so I can bend them later when mounting the engine.

 

At this point I should have thought about putting the snake for the throttle in but I forgot lol!, no problem though.

Heres the view of the tank and you can see the top of the former has been cut out for fitting, this has been replaced.

Here I have glued some ply for the undercarriage.

 

Here you can see the former being complete and boxing in the tank, this was a problem when I remembered about the snake lol!.

 The rest of this is just balsa with the first strip of grain going the wrong way dough!.

At this point I still havent remembered the snake lol!.

And when I come to sanding the stuff down it bekons on me about the snake lol!, I managed to thread sone wire through and then move the snake through, lucky considering I had to push it through foam as well.

 

Well this is my last night building for three weeks as im off to work on the rig's, cheers all, speak then.

 

 

Edited By Craig Spence on 02/07/2010 23:46:17