DB Models Auster J1 - Page 2

**wonwinglo** · 29-12-2006

David,Glosstex is an entirely different formulation to standard Solartex and would stand out like a sore thumb as the added paint would not soak in as per the Solartex,it has less shrinkage also due to the paint loading in the material.
There is no reason why the JR BB servos should not prove adequate for the elevator ?

Quote:

Originally Posted by Glider Guider

The tail feathers are now built and hinged. The hinges supplied with the kit consist of two identical plastic mouldings that clip together but then have considerable reluctance to move, I’m sure in practice they would work fine but I prefer hinges with a metal pivot and more free moving so I have used Robart pin hinges.

Two things I could do with a bit of advice on

Over the past year or so I have acquired a quantity of new and part used rolls of covering material that I want to use up. I intend to use Solartex to cover the model, my rolls are in a multitude of colours and the model will certainly look a bit peculiar until it is painted. However one unstarted roll is Glosstex, Solartex with a two-part paint finish apparently, my question is does Glosstex paint if roughened first and if I covered the fuselage in the Glosstex is it likely to look totally different compared to painted Solartex when everything is painted up.

My second question is about the selection of servos for this model. My thoughts are that as each aileron has its own servo that I could get away with standard JR BB servos and possibly for the rudder but I doubt that there would be sufficient torque for the elevator. If anyone has experience of this size of model or can point me to a helpful website I’d be grateful.

OOLILISSIMA · 29-12-2006

Sorry, fellow modellers, I hadn't noticed your remarks about my photos, for which I thank you. I have scores more of them but I do want to consult Newark Aircraft Museum and the aircraft's owner as a matter of courtesy before posting the rest of them. This I will do during the first few days of the new year.

By the way, I did try to post a couple more photo's today, but found the upload facility is still playing up. In fact, ever time I try it now says that I have not selected a picture to upload. Hopefully, the problem will be cleared soon.

OOLILISSIMA · 29-12-2006

David, it's a nice project.

Despite my own interest in Austers, Christmas and a few other things prevented me looking closely at your thread until now.

It occurs to me to ask if you've noticed that G-AGOH has the canopy and side glazing of the military Auster Mk 5, rather than of the civilian J/1. Hopefully, DB provided the components necessary to build either configuration. Otherwise, representing G-AGOH with your model will involve obtaining the different canopy and glazing components (as well as modifying the existing superstructure).

Glider Guider · 09-01-2007

The tail surfaces are now covered and fitted to the fuselage. I made three changes from the plan all involving the rudder.

The plan showed the tailwheel leg running vertically up the rudder almost to the closed loop horn, this would have made fitting the pin hinges where I wanted it impossible so I have fitted it to the bottom of the rudder thus making room for the hinge close to the bottom of the rudder not a 1½“ up from the bottom.

The tail wheel assembly on the plan shows the leg just bent whereas the full size aircraft had a yoke for the wheel so I have modelled a yoke in brass and silver soldered it to the cut-short leg. You can see where the tailwheel is epoxied and bound to the bottom of the rudder.

Finally the kit provided a huge 2mm ply rudder horn, nothing like anything ever fitted to the full size version, so I made a brass horn which is epoxied into the rudder with two short lengths of piano wire to stop it from twisting loose.

The Laser 80 is also fitted and aligns nicely with the glass fibre cowl. To get a snake to it for the throttle would be neigh on impossible so I’ve used a SuperTec Naro servo fitted adjacent to the engine.

A bit of fairing around the base of the fin and the fuselage could be covered but I’ve yet to decide what to do about the cabin as having a glass roof it is very visible. This model will be stand off scale at best but an instrument panel and some seating would make it look a lot better. This would be a lot easier with no covering to allow for finger access.

**wonwinglo** · 09-01-2007

I like the throttle direct servo installation David,surprising that more people do not use direct servo links like this ? have also used servo's linked aft to rudder,elevators on occasions,the saving in linkage weight can outweigh the weight of any servo,all that is needed are some long leads which are easily made up.
She is coming along nicely and should make a great flyer.

Greyhead · 09-01-2007

Looking good! Robart pin hinges are always favourite, scale looking and easy to fit. A good tip before fitting is to fold the hinge and then dip the “knuckle” in melted Vasaline, which is drawn into the joint by capillary action, this stops any unwanted adhesions from glue or paint.

The straight connection for the carburettor used by Lasers makes for excellent reliable running and starting, especially when fitted inverted, but can cause some difficulties with the linkage but that is the perfect solution!

Glider Guider · 29-01-2007

The starboard wing is now just about complete. The only problem was with the position of the outmost rib, unfortunately due to the size of the plan I had folded it in half and the detail showing the correct position was underneath. On removing the wing it became clear that I had fixed it at the wrong angle but this was easily fixed.

One nice feature of this model is the wing fixing arrangement using a length of spring steel with a hole drilled for the piano wire wing dowel. The rod pushes in easily enough but will not then pull out until the spring is pulled back away from the fuselage. DB Models sell these separately (£2 per fixing) and they could be used on any large model that could take an 8 SWG wire.

OOLILISSIMA · 01-02-2007

It was interesting to read what Barry (Wonwinglo) said about direct servo installation rather than yards of pushrod. Is it that sometimes we stick with what's always been done without giving much thought to alternatives?

I suppose also that there's a critical size of plane above which direct servos become a must. I'm not sure what size that would be; perhaps someone, somewhere, has done a study on the pros & cons?

**wonwinglo** · 01-02-2007

Direct servo installations are becoming more and more popular,in the days when we had to use unweildy pushrods to cope with bulky servo motors it was the only way,now we have high torque servo motors to suit all applications,running lightweight wires through the airframe is very effective much in the same way as they do it with full sized aircraft with servo tabs.
Also the tiny servos done for lightweight radio installations can be easily buried into parts of the airframe very effectively.
At lot of the older ways were necessary at the time,we need to rethink our control systems to get the very best from what is on the market today.

**Bluewavestudios** · 01-02-2007

I can only agree with you there Barry,

Servo's these days are no longer the size of half a house brick and certainly more powerful now than they used to be.....and the best bit, they are much cheaper now too.

I think dedicated direct servo's are definitely the way forward and would probably help some design headaches of trying to work out control / pushrod runs in some models too. I have seen quite a few models with these recently and it certainly does seem to be the case that dedicated servos with direct control is becoming the norm.

Regards.......Mark.