DB Models Auster J1

Joined
Oct 14, 2004
Messages
90
Points
8
First Name
David
I have been prevailed upon to write-up the 87” wingspan David Boddington Auster J1 model that I am building at present; my contention was that it was a bog standard kit and would be of little use to anyone but it was argued that someone may find my tale of building it useful.

The kit was acquired 3rd hand (at least) but had not been started, it was a kit that was produced before the new wing fixing method (see bottom of http://www.dbsportandscale.com/new.htm) was incorporated into the kit which makes it about 6 years old at least I’m informed.

The kit is very complete with all parts accurately cut and the wood selection is also very good, obviously a kit put together by a real modeller. It has a proper well drawn plan which is getting rare these days. My only quibbles to date are a part numbering error where two parts have the same number, this is no problem to an experienced modeller but could cause same head scratching for a less experienced modeller – but having said that it isn’t a model for the novice. Also the instructions, although good, are Roneoed and have a very dated look, in a few places they have been modified and are unreadable but once again it’s no problem to an experienced modeller.

When I used to build Keil Kraft 3/6d kits in the 1950’s it was standard practice to build the fuselage sides of strip balsa on top of each other to ensure that they were the same size, the sides of the Auster are also built up of strip but I built them separately, the result being that they were different to a degree that I find difficult to explain however this has caused no problems but ‘next time’ I’d build them on top of one another.

The fuselage has gone together nicely the only problem up to now was achieving the necessary quite sharp curve in the longerons just aft of the cabin as the fuselage sides are straight to the tail, I used a lot of hot water very carefully and managed to get them to the required curve. If I had read Barry’s tip on using ammonia a week earlier the task would have been a lot easier as I gather from Greyhead that it works very well.

Well that’s where I am up to at present; I’ll post an update when the fuselage is complete.
 
Joined
Oct 13, 2004
Messages
611
Points
16
First Name
Grahame
David

Yes the ammonia really does work but I suggest you work out doors, as the smell is horrendous!

At 87” wingspan you will end up with a most imposing model but one that should handle like a trainer; the photos on the BD web site look very good. With all that “glass” there is every opportunity (need!!) for a convincing instrument panel etc. and I look forward to seeing the model develop, please don’t wait until you’ve finished the fuselage, photo and update the thread at every stage!

I like the “new” wing fixers; will you be able to modify your kit to incorporate these? I assume you’ll be using a Laser!

Grahame
 

wonwinglo

SMF Supporter
Joined
Apr 18, 2004
Messages
6,754
Points
113
First Name
Barry
Just a quick note David,lovely project,when tackling sharp curves like that simply use laminated balsa pieces well glued and pinned,you can also introduce a splice of a 9 to 1 factor,this is common fullsized practise and is very much stronger than bending wood.

All of the DB models are classics and designed and built by modellers as opposed to just kit manufacturers,by the way the prototype of this kit model painted two tone blue was used in the TV series 'Airline' many years ago,I have just thrown the complete series out done on video in my mammoth clearout.
 
Joined
Oct 14, 2004
Messages
90
Points
8
First Name
David
The fuselage is now almost complete and has its undercarriage fitted, once again there were no major problems, just one (of the three) undercarriage legs needed a bit of adjustment. I was wondering if the difference in angle was to add a bit of tension to the unit in some way but decided against this as an idea and tweaked it to shape. I’ve completed the construction of the tail feathers they just need shaping and they can then be fitted to the fuselage.



To answer a few points raised, I have a Laser 70 and a Laser 80 ‘resting’ at the moment so I’ve decided to use the 80, even though the DB Models website shows an Auster flying on a Laser 70, as it fits into the cowling with room to spare and I always like to have spare power. A previous owner of the kit had cut the wing plan sheet into many parts, some of which had got lost, so I bought a new wing plan from DB Models showing the new wing retaining method plus the fitting kit all at a very fair price.

Unfortunately by the time I realised the tightness of the curve in the longerons it was too late but it is a lesson learned and I’ll look at the plan a bit closer next time and maybe incorporate some of your ideas Barry.
 
Joined
Oct 13, 2004
Messages
611
Points
16
First Name
Grahame
Just out of interest, I notice that you’ve used hardwood engine bearers, as Lasers don’t have a “standard” crankcase width did you have to make new formers etc. or was the kit designed to allow for this?
 
D

Dirk

Guest
Hello David,

many thanks for your impressions on the DB Auster. I almost bougth the plane as well, just before my boss sent me to a customer for some weeks working on site. Now seeing your Auster develop, my decision fell indispensably. Buying and building the DB Auster isn't optional anymore. Thanks a lot for your inspiration. Even as I'm not going to comment all your posts (as I won't have the possibility after the holidays) I promise to read every post of this thread the day I'll be back.

Merry christmas to you all,

Dirk.
 
G

GEEDUBBYA

Guest
Howdy guys,

I just wanted to say that the framework is looking great, I hope to see the completed model sometime in the future.

On another note, I have posted this link before, but thought since this thread was on the Auster, I would post it again, Its a card model of the "Auster Antartic" airplane. I thought that maybe you or someone else might like something that is abit quicker to build.

It is a free download (1:72 scale)and can be scaled to whatever size you desire. Simply save the file to your computer, then in a photo editing program, resize as needed. Print on card stock, photo paper or other heavy paper, cut out, and glue together.

What you end up with is a 3 dimensional model (much like a plastic kit).

If you are good with photo editing and or "paint shop", you can even recolor and add different markings.

The model file can be found here:

http://digilander.iol.it/zioprudenzio/auster.jpg

v-auster1.jpg


For other free 1:72 scale cardmodels by this designer, visit: http://digilander.iol.it/zioprudenzio/fok-air.html for aircraft,

http://digilander.iol.it/zioprudenzio/fok-ship.html for ships and

http://digilander.iol.it/zioprudenzio/fok-cars.html for cars,

http://digilander.iol.it/zioprudenzio/fok-train.html for trains.

If anyone has any questions as to whether any other cardmodels of other aircraft or any subject exsists, please feel free to ask and I will do what I can to point you in the right direction.

Merry Christmas,

Greg
 
Joined
Oct 14, 2004
Messages
90
Points
8
First Name
David
Thanks go to OOLILISSIMA for posting photos of G-AGOH on his gallery at http://www.scale-models.co.uk/gallery/showimage.php?i=1383 at present only 7 of the 20 are posted due to a 'technical hitch', let's hope it gets sorted out and we can enjoy the remaining photos.

Grahame, it would seem that DB has set the bearer width to be adequate for the largest motor that could be used with this model and I had to reduce the distance between the bearers by about 5mm, this is easily achieved by increasing the depth of the notch in the two ply formers and then trimming a similar amount from the former sides.

It is suggested that the engine mount assembly is glued with 5 minute epoxy which is a good choice. It is not mentioned in the instruction but there is down thrust built into the assembly and I’ll bet a good few have reached the point of gluing the bearers and formers all nice and square before noticing it! After one false start I built this assembly by gluing the bearers to the side cheeks (remembering the down thrust) and then gluing these to the formers. The completed assemly is then glued to the firewall and the rolled ply fuel tank holder is slid in place and epoxed well as it is part of the structural strength of the fuselage.

I’m pleased that I have inspired you to buy this kit Dirk I’m sure you will not be disappointed.
 
Last edited by a moderator:

wonwinglo

SMF Supporter
Joined
Apr 18, 2004
Messages
6,754
Points
113
First Name
Barry
OOLILISSIMA thank you for the pictures of G-AGOH,a few comments will assist scale modellers of some of the features that are clearly visible in your photographs,for example-

The picture of the undercarriage bungee springing system underneath the fuselage,this is a very early undercarriage spring system used on nearly every Auster aeroplane,it entails two upper tongues with a flange on the ends,to effect springing the aircraft is jacked so that the legs drop downwards,then with a tool akin to a tyre lever the rubber bungee ( usually multi strand rubber encassed in a flax coating ) the material is eased into place and is held tight against the upper and lower flanges,note the wires hanging down from the legs themselves ? well these are the safety restrainers which arrest the undercarriage legs in the event of a failure,and do they work ? well yes they do rather well,a pilot called Brian Mc Allister once doing a long distance flight in an Auster J/5R Alpine G-APFW forced landed in the Sahara Desert,he single handedly managed to repair a broken bungee on the undercarriage of his Auster,he must have had a bit of untold strength as it is no easy job to on your own.

The various clips,pipes and fittings leading to the pitot head,brakes etc are well shown in the pictures.

The Auster is a belt and braces machine,and dont you just love their character ?
 
Joined
Oct 14, 2004
Messages
90
Points
8
First Name
David
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.
 

wonwinglo

SMF Supporter
Joined
Apr 18, 2004
Messages
6,754
Points
113
First Name
Barry
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 ?

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.
 
O

OOLILISSIMA

Guest
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.
 
Last edited:
O

OOLILISSIMA

Guest
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).
 
Joined
Oct 14, 2004
Messages
90
Points
8
First Name
David
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

SMF Supporter
Joined
Apr 18, 2004
Messages
6,754
Points
113
First Name
Barry
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.
 
Joined
Oct 13, 2004
Messages
611
Points
16
First Name
Grahame
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!
 
Joined
Oct 14, 2004
Messages
90
Points
8
First Name
David
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.
 
O

OOLILISSIMA

Guest
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

SMF Supporter
Joined
Apr 18, 2004
Messages
6,754
Points
113
First Name
Barry
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.
 
B

Bluewavestudios

Guest
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.
 
Top