discussion How do I make....

[Guest]

Can anyone tell me how I would go about making moulded canopies etc for a spitfire for example? I know if you buy a kit it usually comes with it - but if you build from a plan at some stage these things would have to be made or purchased - I guessing that someone can come up with a good simple way of making them.

Thanks

Antony

 

[Guest]

easy mate

you start by making a mould usually from an existing canopy easiest way is to push the canopy into a lump of blutac then fill with resin once the resin is cured you will have a master try to attach the bottom pf the master to a stick or rod of some sort then here is the good bit Get a sheet of clear plastic and hold it over a heat source (elec cooker is best) then as the plastic starts to sag remove from the heat and push the resin mould into it give it 5 secs to stabilise then remove ! you now have a good copy of the original

 

[Guest]

but surley nigel.....if you make a mould out of blue tack, that mould will be slightly larger than the original, then by filling that mould and making a resin mould you then go back to the original size, then use that as a mould for the plastic..which will then be a bit bigger than the original size.

yes i know this is picky but on smaller scales couldnt it make a difference?

or am i going on about a load of rubbish?

 

[Guest]

on a free plan i have for an electric spit fire

if shows the plastic held by piece of wood with the bottom of the canopy shape

then you make a mould out of wood and put the but woof with the plastic in the oven til it heat s up enough then you press the wooden mould into the plastic

 

[Guest]

Richard you are using the male to make the mould so the female would still be to the same scale mate

 

[Guest]

ah! i think i was over-thinking the process.lol

and thats rare for me!!!

 

[wonwinglo]

How to make simple cockpit canopies-Two methods.

Here are my earlier notes regarding moulding cockpit canopies for models,once mastered the technique is easy,regarding the mould simply make the plug undersized allowing for the thickness of the clear material.

First we have-

Cockpit canopies from throw away bottles-

Have you ever been faced with making a large canopy ? well if you dont know how to go about it stick around a minute for a method that costs you no more than your favourite soft drink,the material that large bottles of soft drinks come in is ideal for or task but first we need to make a mould,dont worry it is a simple task,just grab a block of balsa the size of your canopy and mark out first the side view,cut this out with a band saw or if you dont have such a luxury a keyhole saw will suffice,next mark the plan ( top ) view and cut away the surplus wood,finally use a surform or similar to shape the block,smooth the edges with glasspaper.

Next take the large drinks bottle and cut off the top portion at the neck,place the carved block of wood into the bottle and ram in some rag of similar to blank off the open end,now take your heat gun ( you can use an hair drier with care ) and play the heat evenly onto the plastic,what will happen now is the plastic bottle will shrink itself up tightly against the wood former,just be patient and do not get too close otherwise you will burn the plastic,leave to cool off and with your Stanley knife run a line at the base of the canopy and trim up with a pair of scissors,result one new canopy for your pride and joy.

____________________________________

Method two is even easier,as before this requires a simple plug,this can be made from balsawood or even plaster of paris if you are making an undersized mould from a kit canopy ( you simply scrape or sand the plaster to reduce it overall ) the photographs are self explanatory,the method makes better canopies than supplied in kits-

This is the time established way of making small cockpit canopies,simply carve a plug from balsa wood,make a female mould from a piece of ply slightly oversized to allow for the deep draw of the plastic sheet,pin or staple the sheet to the female and heat over a gas or electric ring until the material becomes floppy,then plunge the plug into the mould,wait for a few seconds to cool and withdraw the plug,you will probably need a bit of practise and a bit of wasted material in the process but practise makes perfect and that is the secret.

Never throw away those plastic packing inserts from cosmetic boxes etc hoard them,this makes excellent material from which to make your canopies.

 

[Guest]

Thanks folk - just to add a little more to it - assuming I dont have the original canopy I guess I first need to make a wooden dummy first and then follow your instructions?

Thanks Antony

 

[wonwinglo]

Antony,dont let the plug put you off,this is how you do it-

1/Make a tracing of the side view of the canopy.

2/Make a tracing of the top view of the canopy.

3/Take a block of balsawood and transfer the shapes top and bottom.

4/Carve the canopy to the lines,you can use a small saw to cut off the surplus material,finish off with glasspaper wrapped around a block of wood.

5/You will then have a blank of the canopy shape,all that is now needed is to shape it further to the oval canopy pattern ie three dimensional.

6/Use your imagination as you finally carve and sand that lump of balsawood,you will be surprised as to what can be achieved.

7/Next get a piece of dowel and glue it into the blank that you have made for your canopy,this is your handhold,thats it,job done,next follow the moulding instructions.

PS-Many people fear making things from scratch,but nine times out of ten they have never attempted it,the sense of challenge and the achievement at the end is well worth the extra effort,my advice is give it a go,you could surprise yourself ?

 

[Guest]

Barrys right it takes a few attempts to get it right but you will be surprised at how easy it is

 

[Guest]

Thats great thanks folk. I think what I shall do is make a blank for the aircraft Im currently working on and then compare my attempts with the one supplied with the kit - it will be good practice for the future.

Antony

 

[wonwinglo]

Thats the spirit Antony ! nothing lost but a lot to gain.