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German twin : Vac Do-335 nightfighter


Loic
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Many many thanks guys, your support is my fuel ;)

 

As said, there is still a hudge lot of things to do, especially on the engine block and in the middle of the "V" as this area is crowded on the real thing.

 

At the moment I am scratching my head on how to replicate the exaust interface.

This is normally a machined area, the shape is rather complicated (too complicated to be easilly replicated by punch/die or similar) and the most problematic point, it is not parallel / aligned with the cylindre head surface... The more it goes, the more I realise I will certainly face troubles with these 12 bits... any idea would be welcome.

 

Also need your help as I have a question for you guys:

 

Well, as I might go into a cast/sale process with this one (that is not yet decided but it is a possibility...) I want to know your mind about wiring.

 

Most of the time, with AM stuff, there are lots of cables/wiring details added and you only have to paint them.

They add lots of details and that is good.

This said, for ignition plugs wiring on V12 engines, those wirings are often too flat to my view. Because of the necessity of casting, the cables have to be glued to the engine body but in real life, they have a more "loop like" routing.

 

What would be your position about wiring (mainly ignition):

 

Option A : you consider those wiring are a must have on an AF engine kit

Option B : you would prefer that all the necessary holes/locators are replicated and you add your own wiring by yourself

 

Thanks in advance for your feed back ;)

 

...OK, You've passed your pattern making test, well done...:D (welcome to 'my world':))...

 

If I can see some good pictures of the exhaust interface, I may be able to come up with some workable suggestions for you?

 

As for the wiring, the Germans tended to be more methodical and tidier than we were when it comes to tidying away and routing cables, so most of them would probably be nice runs and radius curves all very neatly clipped in place. However, you can add loops and gaps if you wish. Have a look at the 'grabit' hook that I recently made as part of the GMF Spitfire flotplane conversion (vendors forums). The trick is to add a very thin membrane in the loop, then it will cast OK (the modeller need only 'push out' the very thin resin membrane and clean up any slight resultant line) - I use thinned PVA wood glue for this purpose. I will be using this technique quite extensively on my current WIP Spitfire bomb carrier master pattern wiring.

 

HTH

 

Derek

Edited by Derek B
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That is looking sweet so far.

I vote for not including the wiring on the master pattern. In 1/32 scale and larger it always looks better when you add the wires yourself. I think if you care about accuracy enough to buy an aftermarket engine,then you would probably also want to add the wires yourself. I may be alone on this though. I also like vac kits with no scribing(for the same reasons)

J

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That is looking sweet so far.

I vote for not including the wiring on the master pattern. In 1/32 scale and larger it always looks better when you add the wires yourself. I think if you care about accuracy enough to buy an aftermarket engine,then you would probably also want to add the wires yourself. I may be alone on this though. I also like vac kits with no scribing(for the same reasons)

J

Nope, not alone, Jerry. I agree.......Harv

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Thanks a lot for the feed back on the wiring guys.

I too would prefer to add the wires myself but I would like to have an overall view on the question.

Please keep the feed back coming (if you feel like it).

 

@ Kagemusha:

yes, this will be the NJ prototype :speak_cool:

 

@ Derek:

thanks mate!

I understand I now have the "right" to try make pattern !

That feels good ;)

 

I know about the trick on moulding the wiring but I fear that would be kind of fragile. Isn't there a risk of breaking the cables when getting the part out of the mould? With 12 cables per engine, you must have a very low braking rate unless almost all engines will have at least one broken cable.

 

As far as the exaust interface is concerned, here is a pic ( courtesy of google ) :

 

DB-603.jpg

 

OK, this is not a 30° angle we have here, rather a 3 or 5° so nothing that a bit of sanding could not do but the point is to have all 12 at the same angle...

 

At the moment, I think that I will used flat piece, glue them on the cylindre head and the try my best sanding to get the slight angle... but any better advice is welcome :hmmm:

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As far as the exaust interface is concerned, here is a pic ( courtesy of google ) :

 

DB-603.jpg

 

OK, this is not a 30° angle we have here, rather a 3 or 5° so nothing that a bit of sanding could not do but the point is to have all 12 at the same angle...

 

At the moment, I think that I will used flat piece, glue them on the cylinder head and the try my best sanding to get the slight angle... but any better advice is welcome :hmmm:

 

My immediate thought would be to sand an angle on the cylinder blocks - as you have described - then stack 12 thin pieces of plastic card together, by whatever means you so wish, and file and shape them all in one go to the correct manifold aperture shape. Once this is done, glue the separate pieces onto the cylinder banks. The individual ports can then be drilled, dressed and detailed as you see fit?

 

Derek

Edited by Derek B
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Thanks Fozzy !!

You are too good to me and you are not bad either I must say ;)

 

Derek,

thanks for the input my friend. The more I look at it, the more I think you are right and the angle is more into the cylindre head rather than in the machining of the interface... the later is marginal indeed.

So, I think that the all point is that the angle I gave to my cylindre heads is slightly too little at the moment...

 

I also have had an idea on how to have a better control on the sanding ops: I will use styren guides ... was so obvious that I did not think about it I think :BANGHEAD2: . I will have an other day off on friday so I should work on this area then.

 

Talk to you later my friends :speak_cool:

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Guest Vincent

Hi Loic !

 

Super work on the engine !

 

There is something that bugs me about the shape of the front reductor. It just does not look right, too bulbous when the real one is more conical. Is that still possible to change ?

 

If you can/want to reuse some of the part of my DB605 (injection pump, air ramp..) just drop me a PM, i have many extra castings for these...

 

Best

 

V

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Hi Vincent,

 

well, just triple checked and I am afraid you are ... right !! :deadhorse:

 

There must be a bit of lence distorsion effect on the pics as the part on my desk is less bulbous than on the pics but still it is.

I triple checked my ref and depending on the drawings, it is more or less straigh/bulbous....

I triple checked pics of the real engine and they show very straight lines...

 

I have unfortunatly mainly been wrorking from the drawings so I think I must redo this part :doh:

 

This is just the proof that a 100 pair of eyes worth more than 1 pair :rolleyes:

Thanks for the head up my friend !

 

As far as reusing some of your parts, I am having lots of fun on this project so I want to try doing everything by myself.

If I face problems, I might drop you a PM. Thanks a lot!

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Guest Vincent

As far as reusing some of your parts, I am having lots of fun on this project so I want to try doing everything by myself.

If I face problems, I might drop you a PM. Thanks a lot!

 

I know the feeling, that's a good way to tackle and learn !

 

Best of luck in the project !

 

V

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Hi Loic

 

Excellent progress.

 

One issue with looking at DB 603s in museums is that you may not be looking at the same version of the engine twice. many different prototypes with detail differences and possible that museums inherited engines that were retained due to being interesting prototypes. Agree about reduction casing though - does need to straighten a little.

For the manifold outlets, could you not make one and then make a simple 'wafer mold' and cast up the required number? They'd be identical then.

 

As for wiring, my vote is leave them off but put in the locating holes.

 

Matt

Edited by mattlow
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Hi Matt,

 

thanks for the kind words.

I agree with the museum pic variations... sometimes, they are quite different (not even talking about pics of DB-605 labeled DB-603...).

I have corrected the shape of the reductor already, it is straighter but not absolutly straight... I have also take the opportunity to redo all the bolts as I was not too happy with the previous results ...

 

I will posts pics cause it is already very late in here ;)

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Hi guys,

 

thanks Maru for following and for the kind words.

 

Here are a couple of pics of the modified reductor:

- housing was straightened.

- the bolts on front ring were shortened a bit.

- the bolts on the rear "ring" were all redone, they are shorter and smaller in diameter (looks much better to me).

- the DB logo on top of the reductor housing was corrected, repositionned (lower) and the housing was corrected to add the according slot/groove (I missed that detail initially...).

 

DSC05625.jpg

 

DSC05629-1.jpg

 

My lessons learnd on that matter (appart from "when you think you have understood a shape: check again ! ") is that no matter how much you f... up a part, it is always possible to correct your mistake... it can be "painfull" but it is possible :closedeyes:

 

Thanks to all of you for following, thanks for your feed back and inputs and thanks for your encouragements :speak_cool:

Edited by Loic
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