Martyn's Dalotel

[Martyn K]

Progress update.. I am spending rather a lot of time on this and don't seem to be getting very far. Working on two areas, the cowl and the undercarriage and then doing bits like adding cap strips while I have a few spare minutes.

There is only one accurate 3v that I can find and this does not appear to be too accurate(!) The cowl shape is wrong - it appears to be too narrow compared with the few photos I can find.

As I mentioned, the engine will be inverted. A quick test fit and the tank was still too high - so this has been lowered again. It will need a small cut-out in the wing to accommodate - that. I will need about 6mm removing from the upper wing centre section. Hey ho..

Anyway. The cowl. Basically built as per plan but taking care trying to get the shape right - especially around the rear curves or straights. I still haven't decided which is really correct.

All still a bit rough - WIP

The original was a Glass Fibre cowl and sat on top of the basic fuselage shape. the drop is intended. I'll glass the cowl in 18gm cloth - it will add a bit of resilience. I said it was still a bit rough...

Surprisingly, the cylinder head doesn't protrude too far. The bottom part is (or will be removable) for access. The FS exhaust with exit at the rear opening. I'll need to get a new manifold for this. There is a vent from under the cowl at the rear which will be expanded. The inner side of the cowl will have a dummy radiator fitted both halves. This will be useful for deflecting the air to the cylinder head I hope.

The undercarriage has been fun as well. Using HK retracts, I am trying to replicate the some look as the prototype. I was originally intending on using oleos but the ones I bought were too big. However the stanchions were the correct size. Heat shrink represents the rubber gaiters.

The leg is fastened to the retract unit using a stub of 4mm piano wire. To prevent it rotating in the stanchion, the leg was slotted (using a diamond cutting wheel on the Dremel) and pinned through using 16swg piano wire and then all slow epoxied into place. The little grub screws supplied stripped the aluminium thread the first time I tried to tighten them. You can see the pin holes if you look closely. Not much suspension but the tyres (are slightly oversize) but VERY soft. That is the springing.. I'll need to land this carefully.

One challenge I have is to fabricate the doors so they open outwards at an angle when the undercarriage is lowered but close up and move upwards when the undercarriage is retracted. Its all about trigonometry. I just have to work out the angles and linkage lengths.

The wheel well bay has a 1/32 ply reinforcement ring on the inside

The bay itself has been doped and sealed and a coat of fuel proof grey paint added. I am not adding any wheel well walls.

That's about if at the moment. The aileron fitting is the next airframe bit. Doing Trigonometry is the next thinking carefully bit.

 

More to come but this is slow. May get it finished by Christmas at this rate.

Martyn

Edited By Martyn K on 24/04/2018 15:26:14

[Martin McIntosh]

Hope you bring it along on Saturday.

[Martyn K]

A little bit more progress. Having spent quite a bit of time trying to sort out the undercarriage doors I think I have finally succeeded to get it almost right.. The problem is that the doors need to open and maintain alignment with the the oleo. Sounds straightforward except my retract units are not angles forward, but the legs are.. Using the same mechanism that was used on the full size, the doors sit higher on the wheel when retracted, but when lowered they move downwards and outwards - if that makes sense.

5 attempts to get the left leg lined up the right leg was right first time. It means that the hinges for the door need to be raked which means that they are very slightly skewed inwards when extended, but that is a compromise I can live with..

The video show the operation but basically, the link pin is set so that the door is pulled closed when retracted, but as it extends, because the door hinge is further out that the leg hinge, it pushes the door downwards and outwards.. Really pleased with that.

Ailerons have been built and I thought a couple of bare bones shots would be worthwhile..

and

and

The angled wingtips have also been finished. Today I have wired in the aileron servo extension leads and sheeted the bottom of the wing.

Quite pleased with this..

More to come

Martyn

[McG 6969]

Coming together nicely now, Martyn.

Happy for you that you managed to succeed with your retracts.

Keep up with the progress...

Cheers

Chris

[Martin McIntosh]

Tried that on my Mustang but gave up in the end as I attempted to hinge the door on the end of the retract unit.

Is the rudder LE still to be rounded off?

[Martyn K]

Thanks Chris

Martin, there is a bit of final fettling on the rudder before it gets covered but its about right.It does have a clight bevel/curve on the rudder, the fin edge is square

Martyn

[Martyn K]

A bit more progress. For a mass build model this is taking an age...

Tailwheel

The fullsize had a piper cub tailwheel on an extended leaf spring like this.

The pivot for the steerable tailwheel was at the end of the leafspring and steering was accomplished by using two springs back to the rudder. Just like a model I guess

I decided that I wasn't going to make it steerable, the pivot would be too small so settled for a fixed wheel but will put in a dummy steering mechanism

Leafsping from a strip of brass with the 16swg piano wire 'leg' soldered on top. I'll fair it all in before painting.

The springs will go to a dummy horn plugged into the fuselage

Cowl has been fun.

The cowl blister has been added and also a joining strap using Danny's method of creating panel lines. There are some rivets (they could have been bolts on the prototype but the image was rather grainy).

Not very clear. Sorry. The strap goes top and bottom but clearly interrupted by the engine and silencer

Holes now cut for the exhaust and rear vent (I am modelling the original incarnation of the prototype - the later one had a different exhaust arrangement). It will eventually have a couple of nice angle aluminium pipes coming through the lower holes

Finally, the 'belly pan' under the wing has been built as well. Conveniently, the full size had a similar arrangement with joins in the same places (as far as I can see).

The cowl has just been painted with a little more hi build - hopefully it will get 2 pack this weekend and then I can cover the fuselage.

Still need to complete the cockpit detail, I want to try a couple of ideas for this.

More to come

Martyn

[Paul C.]

Coming along nicely Martyn some models just take an age to finish for some reason. Wasn't too keen on the dalotel originally but it is definatly growing on me, looking forward to seeing the end result.

Paul.

[Martyn K]

Thanks Paul.

If the weather remains lousy this weekend then it may get some Solartex applied..

However, I am *still* working on that cowl. It needs to be right.

I am trying to get it to the 'Stand Off Scale' standard where I can take it to a Scale Fly-in and hopefully it will be viewed as something just a little more than a sports model. I think that it's just a little too small to be a proper contest model but may fit in rather well with the new Light Scale class being promoted by the BMFA Scale Committee.

[Martin McIntosh]

Cannot help feeling that after going to all that trouble why you did not use it as a plug for a gf mould, or are you just not into that sort of thing?

I was wrong about the rudder shape, yours looks correct.

[Ian Jones]

Sunshine all around us, perhaps a bit draughty today though. Whatever the weather get the covering on, it's going to be a beauty,

[Martyn K]

LOL - thanks Ian.. Still didn't get it painted this weekend. Planning to paint the Foka and this at the same time so working getting the Foka ready for paint as well.

Martin - it's a one off and I certainly didn't expect to spend so much time on this. I have done some moulding in the past but I cant pretend that I have been very successful..

[Martin McIntosh]

All of mine, bar the Lanc. etc are one offs and nearly all of my models have a GRP cowl. It is indeed a lot of work and does not always go to plan but once the technique is sussed they are much more durable, light and give the maximum room inside. Not everybody`s cup of tea of course.

[Martyn K]

It is something that I must master Martin.. I always end up using too much resin or it pools while it is setting..

[Nightflyer]

The DM165 always looked quite a smart aircraft augmented I guess in part by the colour scheme. It appealed to me some years back when RC Scale Aircraft Quarterly (if I remember correctly) did an article and free plan. I built one and powered it with a four stroke. With how electric has come on it might be good to find the plan and build an electric version.

I remember seeing the HP Dalotel once I think at Sandown one year.

Good luck with your build Martyn.

[Martyn K]

Thanks NF

I always thought it actually looked like a scaled up model aircraft.. Even the colour scheme is the sort of thing a modeller would go for..

Martyn

[Martyn K]

. I'll update the blog tomorrow when i have access to a proper keyboard. In the meantime, would anyone know if the Dalotel used rib tapes over the open structure? I can't see any in any of the photos but they are a bit on the old and grainy side.

Thanks

Martyn

[Stuart Z]

Martyn

As you say, difficult to see any evidence in the photos, even the one here - **LINK**

Will anyone see this level of detail at this scale?

S

[Martyn K]

Although its quite a small model, its actually just less than 1/6 scale Stuart. They would definitely be visible. I am fairly sure they aren't used though but only coz i can't see them on any photo.

[Stuart Z]

Martyn

Fair enough. Mine won’t have the same level of detail, but keeps me aware of what detail it won’t have. More “stand off scale” as it were.

S

[Martyn K]

I hadn't realised you were building one Stuart. Apologies

[Stuart Z]

Martyn,

It’s next on the board. Just sorting a wing for a Magician. Fuselage already finished.

S

[Martyn K]

Its that time of year where maintenance has to take precedence over building. I have still got 3 models on the go but the Dalotel will definitely get finished first.

I eventually got to the state where I was happy with the cowl and its had a coat of white.

Its the wrong shade of white but that will get fixed later. The step between the cowl and the fus is also a little large but there is nothing I can do about it now..

I have also started detailing the cockpit areas, Its a shame the floor is so shallow, but again, nothing I can do about that either.

Fuselage getting covered. It was at this point I realised I had ordered the wrong shade of Yellow Solartex. This is too light and even worse, its translucent so will need to be painted. Something I was hoping to avoid.

There is a single 3mm wide stringer that runs down the length of the fus. It makes covering the fus quite tricky

Basically, taking my time, I just got on with the covering. You can see the cowl is the wrong shade of white here. Not a problem, as the white solartex will have to be painted anyway.

and

The translucency is easily visible here.

A quick coat with rattle can yellow on the under surface of the tailplane does help though.

So the next job is to get it masked up and painted..

Weight so far with radio gear and retracts but no engine is 1.6kg

More to come

Martyn

[Peter Miller]

That is really nice. The weight sounds very reasonable too.

I would be surprised if it did not have rip tapes. On fabric covered aircraft the fabric is normally sewn to the ribs and the tape covers the stitches.

I seem to remember one or two aircraft where the fabric is held down with screws but I cannot be sure opf that.

[Stuart Z]

Martyn

Staying tuned as interested in the painting process. You’ve used rattle cans so far, was wondering if spraying acrylic would give same effect?

S