Mick Reeves 25% Spitfire Build

[Rob Crawford]

Santa says it's not too heavy just a bit awkward.

I was told the other day that the fuse was more than 9kg from the box but after weighing with the wings fitted I'm very happy with the weight so far 7.2kg.

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[Dave Osborne]

Nice job on the Spitfire.

I was just looking at the section in your thread about casting the tyres. I have been considering doing this myself so it was very useful (i know it was a bit earlier in the thread). You say you could not provide a picture of the foam core for the tyre. Is it possible for you to provide a description of how you go about placing the core into the mold so that it it is held correctly before pouring the polyurethane into the mold. This is that part I am struggling with.

Thanks.

[Rob Crawford]

It's looking fantastic well done. I'm building the all wood version could you post some more detailed photos of the aileron hinges please.

Thanks Terry

I don't believe i have any closeups of the hinges but when i get the chance i'll take and post them for you.

[Rob Crawford]

Nice job on the Spitfire.

I was just looking at the section in your thread about casting the tyres. I have been considering doing this myself so it was very useful (i know it was a bit earlier in the thread). You say you could not provide a picture of the foam core for the tyre. Is it possible for you to provide a description of how you go about placing the core into the mold so that it it is held correctly before pouring the polyurethane into the mold. This is that part I am struggling with.

Thanks.

Thanks Dave

Forget about cutting a foam core,it comes out too heavy and the poly is hard to pour without getting bubbles on the part.

I came across a product called black gun foam which comes out like dense sponge mixed 1:1 like the poly rubber.

Mix some poly rubber and brush it into each mold half,keep brushing until it starts to go off,this will give you a 2mm thick skin on your core.

Straight away mix the gun foam(you have about 18 seconds to mix and pour) pour this into each mold half and when it starts to expand slam the two mold halves together and weight it down.

Wait 20 mins and you have yourself a tyre which i found really rather gratifying.

And it really is that simple it just takes planning to get the timings sorted.

Anyway hope this helps.

Rob

[Rob Crawford]

This is what i used for the core.

http://www.mbfg.co.uk/foam-materials/bl ... -foam.html

[Dave Osborne]

Thanks for the advice. I will try it.

Dave

[Rob Crawford]

Why did i get the one with the less than plumb vertical stab?

Ah well,time to get the heatgun out.

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[Rob Crawford]

A lot of heat and a bit of fuse twisting and it's almost there,i don't know what all the complaining was about

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[Rob Crawford]

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[Rob Crawford]

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[Rob Crawford]

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[Rob Crawford]

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[Dave Wilshere]

Rob

Scanning through the build. You are a craftsman. Concerns are, you really using 3.2kg plastic geared £8 servos on the ailerons?
What is the projected final weight?
I'd hate all the hard work to go to waste!

Dave

Also what battery you running the cooling fan on?

[Rob Crawford]

Cheers Dave.

No,ha ha, they are just for test fitting,20kg digitals on every surface except rudder on this one.

The electric starter and fan will each have their own ESC running from a 4s lipo,3s would probably do the job though.

Rob

[Rob Crawford]

Sorry Dave i expect the final weight to be 23-24kg,i spoke to a guy online who said his flew great at that weight it just means extra strengthening.

[Rob Crawford]

Thanks friends for your comments it helps,at the minute there's no adrenalin buzz just drudgery and tiredness from being a full time dad !,it's inspiration to carry on
cheers!

[Rob Crawford]

It's looking fantastic well done. I'm building the all wood version could you post some more detailed photos of the aileron hinges please.

Thanks Terry,that keeps me going.

How's the build going? Any pics?

[Dave Wilshere]

Rob

Its more the capacity to run 9 mins plus, it will need 5000 mAh. Then next question is will the motor cope with that heat wise?
EDF units like that are used to running in cool air and for 4-5 mins.

Glad the servos will be suitable :-)

[Dave Wilshere]

Rob

Its more the capacity to run 9 mins plus, it will need a large capacity, maybe 5000mAh. Then next question is will the motor cope with that heat wise?
EDF units like that are used to running in cool air and for 4-5 mins.

Glad the servos will be suitable :-)

[Rob Crawford]

Dave,thanks for the help,this is my explanation of the cooling system.

The fan will be pulling cool air through the rad's and throwing it onto the heads via an engine shroud i molded for the kolm(almost like the air cooled vw's),the hot will exit through dummy exhausts so no worries about heat as the cool air passes the edf before reaching the engine(the fan was reverse orientated in the pic i posted above) ,the esc will be cooled via the spit carb intake.

It's better to have the fan running slow because when it's in the air it'll more than likely restrict the flow of cool air so it might have to be turned off altogether.

I tested it on the stand and it keeps the engine cool from less than 1/4 throttle.

It's all in the shroud,every last drop of air is running through the fins and if it gets drawn away as good as i think it will it'll be sweet.

Of Course i'm using telemetry so i can monitor the temp on both heads.