Take one Dynam Spitfire...

[Steve T]

I had same problem with the retracts, I will have a look when I get home and post a photo, it worked fine in the end but I remember cutting away quite a bit of plastic!

[Colin Leighfield]

If I remember rightly I used a couple of packing washers to get the right angle on the u/c with the E-Flites, then needed to put the legs in the vice to bend them slightly to get everything to clear up and down and sit flush in the up position. Result works perfectly and also the "sit" is better on the ground. The track is wider than scale anyway, but apart from that all looks good. I don't remember cutting any plastic. It's up in the garage loft for the winter but I can get it down at the weekend if you want me to have another look at it and refresh my memory.

[Steve T]

Ok I had the usuall Dynam problem of one retract refusing to act, never mind retract. So E- Flites, same as Colin, perfect now. You will have to bend the legs slightly by just clamping in a vice, and not going heavy handed. I will post the photos tomorrow, I did have to cut just a section of the grey plastic away to allow for the coil section on the E-Flites. Worth the extra expense and effort though.

[Colin Leighfield]

Perhaps I did cut something, it's a year or more ago. I'll have a look.

[The Wright Stuff]

Hi Colin, Steve, Many thanks for your comments. Colin, I recall reading in an older thread that you re-used the Dynam legs. It looks like the metal core is bent inside the moulded plastic. I think the plastic can be prised off where the two halves join. I am wondering if it is possible to remove the plastic surrounds from the metal centres and re-use the plastic on the E-Flite metal, after bending to fit inside. This would have the advantage of adding the coil spring to absorb shocks on landing, but would require cutting to length and then bending at all the correct places to follow the curve.

If either of you have some photos, that would be absolutely marvellous. I'm a bit reluctant to rush this bit because once I start hacking / bending, there's no going back!

Cheers,

TWS

[Colin Leighfield]

I'll have a look at it over the weekend. To be honest, this model is so light and lands so slowly I don't think that there is the slightest need for the coil springs. It's hard to imagine a situation in which they'd do anything. The key thing is not to add weight if you can avoid it. This models not over-powered. It flies very nicely, but being heavier may well increase the wish to up-rate the motor and ESC.

In the same token, going to the lengths you have with the flaps is very satisfying for scale effect, you've done a great job. However it's already very docile at low speed and the stalling speed is already low. The first time that you drop those flaps I would make sure that you do it high up, it's likely to stop dead in the air! Seriously though, you don't know what the trim change will be, so don't use them for a landing until you've worked out at a safe height what the trim change is. It will very likely need some correction on the elevator and it could be in either direction. When you have worked that out, you can mix it in if you wish and then it's a doddle, but a step at a time.

[The Wright Stuff]

Indeed, thanks Colin.

You make a good point very well - whilst I have been keeping an eye on the inevitable weight increase, I'd overlooked the 'big hit' that beefing up the retracts to coils would have.

Once again, I think this is another of those cases where the simplest solution is probably the best!

[Steve T]

So photos were done last night, and as I went to hang the Spit back up on the ceiling....I caught the section with the cannon, only slightly, enough to break it off! This really is an extremely weak point. Coincidence also as I was not aware until I read it in your thread.

First, pic, what to do about the awful pilot and very plain cockpit.

OK it was only a suggestion, it works for me, I have Shere Khan in my Hurricane and Winnie the Pooh in a Waco.

Original Dynam retract next. By the way I had balanced everything up as I wanted before replacing the retracts. On completion I found the sprung E-Flites made absolutely no difference, I didn't have to change anything else.

[Steve T]

I am not being daft here, posting a photo of the original, it is so you can make the comparison. After unscrewing and removing the retract door and removing the wheel I seem to remember I cut off the 90deg angle section of the leg and simply twisted the simulated hydraulic section off. It was not easy but it works. There was a very slight opening of the plastic around the centre section as I prised it off with the leg clamped in a vice and rag in the jaws of pliers. Once removed I put a tiny dab of ca where it had opened up, clamped it up and you cannot see the repair. Now you have to measure it up to allow for the spring and cut to size, good old Dremel disc. Bending the E-flite leg to the correct angle is surprisingly easy, you can't quite do it by hand but very little effort is needed once clamped up in the vice again.

[Steve T]

And after gentle butchery:

[Steve T]

The hardest part was removing the rad and cutting the foam away to the centre section for the new retract cables. I had already fully assembled my Spit when a retract died. I have found from other reports on this forum that Dynam retracts are notorious for this problem. What is actually worse is the fact that it is intermittent, some days they both work, then one will jam up while the other continues to function. If it jammed down you could still land but of course it always jammed in the up position. You will of course want to refit the retract doors so, cut plastic from the bottom of the leg! I'm sure it could be a very simple mistake to make but you are at least forewarned.

[Steve T]

And as you have now pointed out, the cannon section is more than dodgy, I repaired mine with POR. You can just see a shocking pink peg clamping it all together. Everything slightly wrong way round of course, front Spit has had a nice paint job but still has original retracts, these have worked fine so far but the replacements are in a drawer waiting to be fitted. After Shere Khans Hurricane is the Spit in the original appalling blue paint but with E-Flites fitted. I hope the photos are self explanatory? It really is not that much of a job, even bending of the legs I did by offering up until they were both the same!

[Steve T]

One final point, don't worry about the fact that there was a slight bend in the Dynam leg inside the plastic. Bend your retracts at the spring to get the correct angle when retracted and leave the rest of the leg straight, epoxy the plastic at the bottom just to hold it in place, allow for the doors though! that's how it works without making things far too complicated enough already. OK?

Edited By Steve T on 27/02/2015 12:28:54

[Steve T]

I shall now be re-working both of mine, you've talked me into it but I am not fitting flaps, if I did they would be purely for scale purposes, not working. Other than retracts which is more than a tidge (a lot!) annoying, these are fine planes, I look forward to seeing your complete baby, then I shall attack mine with a bit of vengeance anyway. PHEW! You can have your thread back now, I'm posting all this from an IPad and typing is slow, slow, slow. I'm going to get my blanket and have a lie down.

[Colin Leighfield]

The Deagio Spitfire pilot from Pete's Pilots goes straight in and looks perfect. It doesn't cost a lot.

[The Wright Stuff]

Brilliant. Thanks Steve, and I apologise for causing you to damage the model - I'm tempted to shorten the cannon a bit to reduce the tendency to rip it off during the inevitable nose-overs. Terrific model room you have there!

Thanks for the pictures, I see that the offset produced by the coil of the spring is enough to keep the plastic clear of the retract body. It also looks as if you've set the door closer to the leg than on the original moulding, which is a good way to compensate for the lack of bends further down the leg. Just one question: am I correct in thinking that the only bending required effectively acts to 'unwind' the coil spring by a few degrees?

Colin! Thanks - he's on order!

[Steve T]

Are my posts and photos any good Colin, have I told all I need to?

[Colin Leighfield]

Looks fine to me Steve, there's always more ways than one to skin a cat. I'm surprised about the problems with the cannons though. I've nosed mine over, shoved it into the long grass and even flew it through a fence once, breaking a wing panel off. I stuck it straight back on with epoxy, you'd never know. However, in all of this, I've never had a cannon come loose or break off. Good move on the pilot TWS.

[Steve T]

Yes you are uncoiling the spring very slightly but these springs are so tight and hard that it will make absolutely no difference to their function. In fact if you hit the ground hard enough for these springs to take much of the impact out you may very well pull the retract from its mounting! The plane is so light that the springs really are almost more for show. On a much heavier model yes they will perform but at this weight they will do very little. The originals had no springs and provided they came down they did the job. And yes I think I had to remove some plastic to get the door closer, that is what I was thinking of earlier. My retract fit was also a year ago and I don't remember getting 'old timers' but I seems to have arrived!

[Steve T]

The section where the cannons fit is for some reason partially cut through on the underside of each wing, no I dea why so as said I have just stuffed POR and clamped, that's learnt it !

[The Wright Stuff]

That's clear now Steve. I must admit, I'm looking forward to getting this done and in the air. There are lots of accounts of how great they fly. I can't believe how lightly loaded it is: only a few grams heavier than the PZ Spit and a significantly bigger wingspan.

I know ne'er cast a clout till May be out, but the occasional sniff of springtime flying weather is a great motivator!

[Steve T]

Thanks for the comment on my sanctuary (sorry, I meant workshop!) to use up.even more of your thread....more photos!

[Steve T]

And it's goodnight from me

[The Wright Stuff]

Well Steve, I'm envious!!!

On with my 'build'. The most time consuming part was actually making the decision, but in the end I went with the new E-Flite legs. The plastic surrounding the Dynam legs actually came apart quite easily when prised with a sharp blade, and the comparison between the two pieces of bare wire is shown below.

Bearing in mind Colin's weight warning, the Dynam leg comes in at 9 g, and the E-Flite one with the coil, 12 g. That's a six gram addition for the pair, but I will shave a bit off that when I come to shorten the E-Flite ones to length.

As others have said, the E-Flite legs bend easily enough when shown a vice, and so I managed to produce the following:

The plastic surrounds have been chopped either side of the angled section, and cleaned up and epoxied back on. I went for bending the end of the leg and refitting the plastic shell as a means of saving weight - since the fittings that come with the retract kit are quite heavy. I cut the end off a little shorter than the Dynam leg, since there are a few millimetres proud of the wheel collet that I can do without, as shown by Steve's photo at the top of this page. The final photograph shows the bend at the coil, as described in the above posts.

Thanks for the help, guys. I'm back in business!

Edited By The Wright Stuff on 03/03/2015 18:20:25

[The Wright Stuff]

On another note, my pilot turned up today. I'm very pleased with him! He does look a little pale, though! Maybe he's seen the contraption he's expected to fly!