DB Sport and Scale Auster J1 Autocrat

[Ron Gray]

Love the engine kill switch ?

[Danny Fenton]

Fabulous! I hope mine flies half as well

Thx for sharing

[Colin Leighfield]

This is the AOP6 I owned 1/5 of for a while. The flaps are the obvious difference to other versions. Perhaps I can do this one day, converting a DB kit would certainly be the easiest route. It look’s interesting.

[Danny Fenton]

Hi Colin, there is a lot of hacking around to do around the cockpit to make the DB one work, I also wanted to hack those chunky ply formers away, but it is the heart of the design. I think you may be better off drawing your own. The rear upper glazing wont work either. If like me you would have to use friese ailerons than they take a bit of work too.

So my suggestion if you want it to be a good approximation, draw your own or take a look at the Jerry Bates 108" 1/4 scale plan?

 

 

 

Cheers

Danny

 

 

[Colin Leighfield]

Thank you for going to that trouble Danny, I’ll take a good look at it. I’ve found out today that the AOP6 is now in the Czech Republic! It was built in 1946 and originally served with the Royal Auxiliary Air Force, I think 664 or 644 Sqn, something like that. We were allowed to fly it in its original military markings. 

[Danny Fenton]

Not been well for a few days, always happens to me, relax and I get ill, ah well better now.

So thought I had better face the music and attempt to run one of these oily's.

First I had to bend the pipes in the tank. Fortunately a bit of advice from Andy S had me filling the brass tube with salt, with the ends plugged with bamboo. Then what a faff to get them in the tank! a strong light helped me see what was going on. With hindsight a clear tank would have been easier.

 

 

 

 

 

 

I then made a test rig to clamp into my workmate.

 

 

Why am I petrified, should stick to electric...... wish me luck lol

 

 

 

 

[cymaz]

Bolt it to the work bench .....clamps will slip off when you're not looking

 

[Danny Fenton]

Well I must say that was interesting.

It was either pouring fuel out the carb, or spewing oil all over the garden. Started nicely with a good firm flick. Not sure what you are supposed to do so aimed for a fast idle, with some blipping. no high revs. Ran two tanks through it. Not hot at all, well the exhaust was lol, but the head and crankcase wasn't.

 

 

Cheers

Danny

[Ron Gray]

Your tank lettering threw me a bit, I thought why is the fill (F) pipe going to the carb!

[Danny Fenton]

9 minutes ago, Ron Gray said:

Your tank lettering threw me a bit, I thought why is the fill (F) pipe going to the carb!

LOL told you I was a novice, F is feed to carb, well it was in my head lol. The others being vent and drain.

[Ron Gray]

It doesn't really matter as long as you know! 

[Danny Fenton]

Lol indeed

[Danny Fenton]

Okay guys, my next step is to turn this stand upside down and try and start it again. I am worried about vapour locks and flooding running the engine inverted. Any words of advice? I will be hand starting again as it starts really easily, well certainly the right way up it does......

 

Cheers

Danny

[Denis Watkins]

8 minutes ago, Danny Fenton said:

Okay guys, my next step is to turn this stand upside down and try and start it again. I am worried about vapour locks and flooding running the engine inverted. Any words of advice? I will be hand starting again as it starts really easily, well certainly the right way up it does......

 

Cheers

Danny

I have an inverted Saito in my Cub,

And the tank is mounted on a ply plate on the floor of the tank bay

Thus, most of the tank is below the carb, and it starts and runs without issue

[Danny Fenton]

Thanks Denis, any tips regarding starting?

I am worried that fuel was draining out the carb while prepping to start, a friend has suggested the needle is set too rich, if it is just dripping out.

This is set at the factory setting of open 4 turns. With the engine the right way up it will drip out of the carb spray-bar onto the floor, no foul. However with it inverted that fuel will be dripping into the crank?

 

Am I just overthinking this?

 

Cheers

Danny

[Denis Watkins]

Just double check your needles with the " blow test " Danny. You know, blowing pressure, while listening with fully open barrel, and then turn the needle in.

When fitted to the model inverted, and the tank lowered I doubt fuel will flow on its own.

When I suspect siphoning at stand still, just turn the motor, by hand backwards, and if pipes are visible, you should see the fuel go back to the tank direction.

I have to say that dripping carbs and syphoning are usually pretty rare, when set up in a model, the motor runs cooler in the air.

A motor can get quite hot on the test stand and capillary take place. 4 strokes do get flipping hot.

Edited April 7, 2021 by Denis Watkins
Mis-spelling

[Bob Cotsford]

With it inverted, just rock the prop back before starting to open the exhaust valve and allow excess fuel to run out.  There's much less chance of hydraulic lock with a 4 stroke compared to a 2 stroke if you do this.

4 turns does sound excessive, certainly all the OS, ASP/SC and Lasers that I had ran with the main needle open 1 1/2-2 turns open once they had run off a tank.  There's certainly no need to run it slobbering rich, just don't overload it.

[Danny Fenton]

35 minutes ago, Bob Cotsford said:

With it inverted, just rock the prop back before starting to open the exhaust valve and allow excess fuel to run out.  There's much less chance of hydraulic lock with a 4 stroke compared to a 2 stroke if you do this.

4 turns does sound excessive, certainly all the OS, ASP/SC and Lasers that I had ran with the main needle open 1 1/2-2 turns open once they had run off a tank.  There's certainly no need to run it slobbering rich, just don't overload it.

Thanks Bob, the Saito forum said never lean to less than 1 1/2 turns out, so I guess the Saito procedure at 4 turns is on the safe side. I didn't want to start leaning it out too soon, but it does appear the run in period is only a couple of tankfuls. next run i will give it some rice, and lean it out a bit.

 

Thanks chaps

Danny

[Danny Fenton]

Decided I needed some detail therapy so started some stitching and rib taping.

I make the stitching in a way that was shown to me by Richard Crapp, works well for me so have stuck with it. Tried using crocheting thread instead of cotton and think cotton is more defined. But it will do.

 

Firstly you run a layer of double sided tape along the wood, and peel the paper off to leave the sticky surface.

Then stick the paper side of another piece of double sided tape to this. Wrap thread around at the required spacing for the scale of your subject.

 

 

 

Cut along both sides, to separate the thread.

 

Then cut strips about 3mm wide, lift the strip and attach it to the airframe.

 

Next take your pinked tape, preferably at 1/5th scale, this is 1/6th Mick reeves doesn't differentiate between 1/5th and 1/6th, not sure why.... And iron down the edges, then between the stitches. They don't want to be too well defined. Remember "less is more"

 

The finished rudder. Stitiching adds a lot of bother, and you really need to be keen to do it. Rib tapes are fairly easy and any fabric scale subject 1/6th or larger deserves them.

 

One thing about rib tapes, they have a clearly defined sequence as to how they are added, leading edge always overlaps rib tapes, however you really must study your subject as there are inevitably exceptions to the rule, and I have seen the trailing edge/periphery tapes over-lap rib tapes as above, and beneath......... The reason is to stop the tapes being lifted by the airflow.

 

Cheers

Danny

[Manish Chandrayan]

You did not tell, the real skill is getting those perimeter tapes down the way you have them there on the curved portion of the rudder. Not a single wrinkle, at least none seen in the picture. Lovely work?   

[Danny Fenton]

Thanks, no wrinkles either side ?

I should have guessed you would spot that. Its fairly easy provided the tape is no wider than this. Run the iron along the perimeter, and with each pass increase the angle a bit, after 20 or so passes it should shrink and be flat ?

Cheers

Danny

[Danny Fenton]

Been a bit pre-occupied with family stuff, been making a bass guitar with my daughter, finally it was done today and she could play it, so back on to modelling....

I thought I would look at a tail-plane half, all pretty straightforward apart from the leading edge.

 

Manish, for you I attempted the half inch wide pinked tape around a quarter leading edge, and I think that's about as far as you can go, even then I got some really tiny wrinkles. They wont be noticeable after the primer is applied and sanded. They need to do a tape between the two widths ?

 

 

 

Cheers

Danny

[Danny Fenton]

Tail-plane and elevators covered, I only applied the stitching to the upper surface, the underside just got tapes and no underlying stitches.

 

Cheers

Danny

[Manish Chandrayan]

17 hours ago, Danny Fenton said:

Been a bit pre-occupied with family stuff, been making a bass guitar with my daughter, finally it was done today and she could play it, so back on to modelling....

I thought I would look at a tail-plane half, all pretty straightforward apart from the leading edge.

 

Manish, for you I attempted the half inch wide pinked tape around a quarter leading edge, and I think that's about as far as you can go, even then I got some really tiny wrinkles. They wont be noticeable after the primer is applied and sanded. They need to do a tape between the two widths ?

 

 

 

Cheers

Danny

Lovely job ?

[Danny Fenton]

4 coats of thinned (not by a lot) dope, then the rib tapes, then another coat of dope to seal the tapes.

Primer coat next to see if we have sealed the Ceconite. Pleased to say we have. so 5 coats of dope in total.

 

 

The edge on the tapes is too harsh in my books, so the additional layer of dope, and a sanded layer of primer softens all those tape edges.

 

That's the rudder ready for paint now, just have to get the rest to this point.

 

Had a bit of a change of heart on the scheme, I was going to do Echo Echo G-AJEE but I have heard from another modeller who is doing this one, and just in case our paths cross at some flying event I thought I would choose a different subject.

Might choose BH as its quite a challenge to paint.....

 

 

Anyway I have lots of silver Klass Kote ?

 

Cheers

Danny