Topic: Whitehead P-38 Lightning

Someone at work whom I respect immensely reckons the 2 weeks off for Christmas might help. Hope he's right!

I've now set up the one throttle servo I hooked up on the radio. I realised the other engine (the one I haven't installed yet) was siezed up so this morning I stripped it and cleaned it up. It's ready to go back together now, along with a new pair of Firepower F7 plugs for them both to remove as many possible differences as practicable.

I have guests over for dinner this afternoon, but I might get away with reassembling the second engine on my lap during the sofa time we'll inevitably have before and after the actual dining part. 

Must get back into the "do something every day no matter how small" frame of mind - it's always so hard to get back into something when it's been a while and so easy to slip into "I can't be donkeyed" mode.

Alan

It's been a struggle but I am now back into the "something done each day routine". Even it's just a bit of sanding, or cut one piece of balsa.

And another trick I have learned is when finishing off a building session, just prepare a simple job for the next day so when you come out the next day you achieve something straight away.

And another trick I have learned is when finishing off a building session, just prepare a simple job for the next day so when you come out the next day you achieve something straight away.

I'll give that a try. Sometimes the worst part of trying to get going is knowing that you've got the whole of a horrible job to do. For example I need to drill the firewall for the fuel tubing which I forgot during the actual build. The first one was a sod to do, and I'm not keen on doing the other. At least the snake is in for the other throttle though. I had to drill the holes for that turning a twist drill between my fingers. Blistered my forefinger and thumb doing it 

So much for planning ahead 

What is taking so long.  On another thread i asked about Waxy on glassing.
Z-poxy leaves this?  Maybe i am missing something.  Even if the term Waxy means something bad the most one needs to do is sand a bit... Don't we sand anyway???
Merry XMAS and holidays to you and yours.
Albert

Hi Albert.

The model has been quite easy to build - most of Gordon Whitehead's designs are designed to be built simply. My issue has merely been one of time and/or enthusiasm for hobbies in general. Some of this is down to work, some to preferring to spend time with my young daughter and some just down to my nature.

This model was glassed using Z-Poxy resin. The waxing shouldn't alter the end product (and doesn't) but compared to the Meteor which was glassed using L285 resin it did need many more hours of sanding. The waxiness clogs the paper, even when using it wet. The L285 resin merely stops flatting after a while until you realise the paper is blunted. The additional pot life of the L285 is certainly useful for working resin around awkward shapes such as the P38's booms. It's less of an issue on a flat wing, but even then you have to completely wet out a large flat surface within "one pot life" because the resin you applied at the beginning will be gelling by the time a fresh pot is being applied to complete the wet-out.

T'other engine is reassembled by the way. Today I'm at work. Tomorrow I'm at work but Christmas lunch/night out starts at 11am so that'll be a write off modelling wise. Wednesday I'm off (probably feeling ill), Thursday I'm back in and Friday I'm off until the New Year. Hopefully I'll get this finished and maybe flown before I go back to work!

Both engines in and throttles set up now. I've got a pain in my bank account this afternoon though, having accidently bought a new laptop for Mrs D. 

Both engines in and throttles set up now. I've got a pain in my bank account this afternoon though, having accidently bought a new laptop for Mrs D. 

You have a Duff laptop... 

And great news on the engines..... The P38 is coming to life...... 

It's not April Fools day before anyone who knows me goes to check, but I'm pleased to announce:

FINISHED!

Well, strictly speaking I need to make the turbos but that can wait until it's been test flown. Likewise I need to dig out the plan and do a final confirmation of CofG, but right now it balances on the main spar with no ballast so it won't be far off.
Lastly, I bought a pair of nylon undercarriages and four 3.5" wheels which will be joined about 12" apart with a pair of trestles. I went with one of the earliest suggestions on this thread and have decided to make a dolly for it, partly so I can confidently fly it alone and partly so that if the maiden flight doesn't go well I'll know it's the model and not a bad hand launch.

Final weight without fuel is 4lb 6oz or about 2kg in metric. Quite a porker for the wing area and likely lack of power. Setting up the engines is the only other remaining thing to do. Anyone know a good starting point for the slow running screw on the OS Max .15? I've had both carbs completely stripped but have never owned instructions for one. I'm confident I could set them up regardless, but a good starting point would save a bit of time 

Here she is - please excuse the mess in the background!

Nice work Jamie, it looks lovely.

That must have been some spurt you had over Xmas!

You'll just have to wait for the weather now

Alan

Thanks Alan.

It didn't really seem as though I spent much time modelling over Christmas, although in hindsight I had thought ahead and pre-ordered everything I thought I'd need. That removed my usual excuse of lacking an essential thingamajig, so the time I did spend was fairly productive. That and doing it indoors with company rather than being locked in a shed on my own!

I think I read that Gordon's original model weighed 72oz, and on the scales mine weighed 2021g. That equates to a fraction over 71oz; probably because I didn't make the tail de-riggable and had the benefit of modern servos. I don't know if Gordon's weight included any fuel or not, but the tanks are little 4oz jobs so it won't add that much when they're full.

Nice.

That looks a bit nice Mr Duff 

I hope it flies as well as it looks 

When's the big day.

Charlie C

That looks really nice Jamie, excellent weathering finish 

Good luck with the maiden 

Muds

Thanks chaps.

Not sure when I can fly it yet. Today I'm changing a brake caliper which will hopefully improve the car's fuel consumption to merely "very thirsty" as opposed to making Concorde look like a cheap runabout 

Also, Baba #2 is due in a fortnight so she could arrive any time really.

Lastly, my Tx battery doesn't hold it's charge very well so I'd like to get a new one, but I've spent a fortune this month on car parts and decorating so it'll need to wait until February for that. I would happily do a flight or two on the battery. If cycled it will take near enough a full charge. Leave it a week and it's down to 6v again though and the Tx won't even power up 

To be fair, most of my Tx and Rx packs are knackered through lack of use and need replaced. Once the rain stops I need to go replace the disc and pads on the other side of the car!

Nice one Jamie!

I think 71 ozs doesn't sound bad at all....

Regards your 'slow running screw' on the Os15....I've not had a 'Max' for quite some time, but they never used to have a slow running needle....are you sure it is not just an 'Idle Stop' screw? (basically superfluous with RC).

Best of luck with the maiden....get each engine running happily by itself...and as long as the rpms are 'close' (200-500 rpm ish)... then go fly!

Take care,

Steve

Are you referring to the "air bleed" screw?
If so, then the starting point would be with the bleed hole half closed by the screw.

Excellent work  and good luck with the flying!

I'd hoped to run the engines today but it started raining mid-morning and has stayed drizzly ever since. Never mind...

I spent this morning constructing this:



I'm going to call it "Big Beautiful Dolly". Beautiful it isn't, but it's fit for purpose I think. I've never made one before but I thought it prudent to give it a few degrees positive angle of attack to help fly out of it. Time will tell if it works 

This was a lot more exciting in person. Unfortunately a pair of puny little 8x6 props aren't very photogenic 



Port started first attempt and ran fine with the glow clip attached. After a bit of fiddling with the air bleed screw it throttled reasonably and ran ok without the glow clip. It's running on Model Technics Super 10% by the way.

The starboard was a total sod to get running. It was willing to fire up but just wouldn't settle and run consistently. After a load of faffing about with the air bleed screw and mixture needle it eventually decided it was ready, and ran wonderfully.

Port then felt a bit upstaged and refused to play for a while. A long while...

I'm freezing cold and have sore knees and a sore back so it can wait for another day to be compared on the tachometer etc.

It runs though  I'd forgotten how filthy glow engines are. Yuck! Still, it's a giggle.

What will you use to protect the underside for landing ... or do you have a very soft grass flying field? 

It's just ordinary "vanilla" grass Paul - but it won't be frosty when I fly it 

Did that before with a foamy F16