Beyond The Sprues

Current and Finished Projects => Physical Models => Aero-space => : Tophe January 13, 2018, 11:14:29 PM

: MiG-3Y Utka
: Tophe January 13, 2018, 11:14:29 PM
I got from Unicraft a Mig-3 model, that I plan to build in a canard layout (YTKA in Russian, pronounced Utka). ;)
I thought it was a Novo injection kit but it is a vacform... ???
: Re: MiG-3Y Utka
: Tophe January 13, 2018, 11:16:34 PM
Here is the project, but what glue to use? how cutting, how holding? solid?
: Re: MiG-3Y Utka
: Frank3k January 14, 2018, 04:28:14 AM
Tophe, vacuforms are usually made from styrene or (less likely) ABS so your average model glue will work. Clear parts for vauform kits are usually made of Buterate; you can us PVA  (polyvinyl acetate) to hold it in place.

Here's a good primer (there is no part 2): http://www.clubhyper.com/reference/vacformbg_1.htm (http://www.clubhyper.com/reference/vacformbg_1.htm)

 
: Re: MiG-3Y Utka
: Tophe January 14, 2018, 12:50:45 PM
Thanks a lot for these directions, very helpful! :smiley:
: Re: MiG-3Y Utka
: Tophe January 14, 2018, 05:14:36 PM
Of course I may imagine a Zwilling version, I may draw it, but I will not build it.
: Re: MiG-3Y Utka
: Tophe January 14, 2018, 07:30:59 PM
I have started separating parts. I love the presence of 4 (half) tailplanes. As I am never building a perfect model for every side including from below, just acceptable on some photographs from precise angles, I consider this model will have 2 set of tailplanes: foreplanes and T-tail planes.
: Re: MiG-3Y Utka
: Tophe January 14, 2018, 10:49:47 PM
I consider this model will have 2 set of tailplanes: foreplanes and T-tail planes.
Like this (and I think I will not use the fragile propeller):
: Re: MiG-3Y Utka
: Brian da Basher January 15, 2018, 02:32:36 AM
I really like that last concept, mon ami!

I can imagine it in WW II 1940 Armée de l'Air camouflage.

Frank has given you some rock-solid advice on glues. One thing I usually do with vacforms is insert a bit of sprue running through the fuselage wing root to hold the wings on. This will give you a stronger attachment than just butt joining them.

Best of luck and I know I'll enjoy watching this one come together!

Brian da Basher
: Re: MiG-3Y Utka
: elmayerle January 15, 2018, 01:24:51 PM
Going for a second-stage experimental to follow the MiG-8?
: Re: MiG-3Y Utka
: Tophe January 15, 2018, 11:38:54 PM
Yes, maybe this is the Historical/technical explanation (in our dreams) ;)
: Re: MiG-3Y Utka
: Tophe January 20, 2018, 06:09:50 PM
Even cutting the parts separate is not easy... The best tool I have found is scissors...
: Re: MiG-3Y Utka
: ericr January 20, 2018, 08:55:38 PM

vacform is not easy, but with patience you can do it  ;)
: Re: MiG-3Y Utka
: Frank3k January 21, 2018, 02:00:22 AM
If you can build - and finish a Unicraft kit, then a vacuform should be easy. Just think of it as a plastic model with far too much flash on the parts.
: Re: MiG-3Y Utka
: Tophe January 21, 2018, 11:06:15 AM
(With my poor standards in quality) I love Unicraft kits, yes I do.
Simply, vacform seems a new learning for me and I fear I may fail, I will see.

One of my major failures in the past was the handling of thermoformed clear canopies, and I keep that strongly in my mind. Even if the white thermorformed parts here may be a success at last, I will not use the thermoformed canopy of the MiG-3, just painting black the "canopy", and this is a reason to invent further, like this:
: Re: MiG-3Y Utka
: Tophe February 01, 2018, 02:40:46 AM
One thing I usually do with vacforms is insert a bit of sprue running through the fuselage wing root to hold the wings on. This will give you a stronger attachment than just butt joining them.
Do you mean a vacform model is intermediate between an injected plastic model and a paper model?
: Re: MiG-3Y Utka
: Tophe February 03, 2018, 05:24:23 PM
The parts are now separated/cut, ready to build, but I fear this will not be easy, maybe with adhesive tape holding parts during glue drying?
: Re: MiG-3Y Utka
: Tophe February 03, 2018, 11:07:45 PM
My adhesive tape try is not very good but it shows the project:
: Re: MiG-3Y Utka
: perttime February 04, 2018, 12:15:02 AM
I recall some articles mention reinforcing fuselage and/or wings. I've been wondering if polyurethane glue and water can be used to fill a vacform component.... I think it takes just a little water to start it foaming.
https://www.youtube.com/watch?v=QOB87l-r6Io (https://www.youtube.com/watch?v=QOB87l-r6Io)
: Re: MiG-3Y Utka
: Tophe February 04, 2018, 05:08:12 PM
I have not this product. I just started to glue, holding it with tape while drying, solidifying... (I hope):
: Re: MiG-3Y Utka
: Brian da Basher February 06, 2018, 10:52:47 PM
One thing I usually do with vacforms is insert a bit of sprue running through the fuselage wing root to hold the wings on. This will give you a stronger attachment than just butt joining them.
Do you mean a vacform model is intermediate between an injected plastic model and a paper model?

I'm sorry I missed this, Tophe. I've been ill with flu which is less fun than PSR.

I didn't mean to suggest that but now that you mention it, one could think of vacforms as intermediate in structural strength when compared to paper and plastic models. Whether or not you want to reinforce the wing joint might depend on the plastic. I've had some vacs where the sheet was so thick it didn't need any reinforcement. I often use scissors myself on these kinds of kits. The ones from the former Eastern Bloc countries are especially tough.

I really like where you're going with this model and I think you will soon have us delighting in your latest marvel, mon ami!

Brian da Basher
: Re: MiG-3Y Utka
: Tophe February 07, 2018, 12:57:35 AM
Thanks for these details!
I have used your sprues recipe, thanks for that too!
And I have put a thin layer of putty, not to dissolve the fragile plastic. There will be more and more later. :smiley:
Good recovery from the flue, Brian.
: Re: MiG-3Y Utka
: Tophe February 08, 2018, 02:34:47 AM
And, as well, a first little layer of putty on the underside, reinforcing the spars:
: Re: MiG-3Y Utka
: Tophe February 10, 2018, 07:07:09 PM
The silhouette is more attractive with the spinner glued in place. I will have putty work to operate there also.
: Re: MiG-3Y Utka
: Tophe February 11, 2018, 06:41:36 PM
4 half wings will be biplane or tandem wings
: Re: MiG-3Y Utka
: Brian da Basher February 12, 2018, 04:00:48 AM
That's coming along quite nicely, mon ami!

You have some serious vac skills!

Glad I could help a little, Tophe.

Brian da Basher
: Re: MiG-3Y Utka
: Tophe February 25, 2018, 01:29:35 PM
Thanks again.

Well, I went on a little, sanding the propeller basis bulbs on the spinner, alas that produced holes (see below, left), thus more and more putty (below, right):
: Re: MiG-3Y Utka
: Tophe March 02, 2018, 01:07:51 AM
After the first sanding, it takes shape, but lot remains to be done...
(http://www.kristofmeunier.fr/011-mig3-sanfing1.jpg)
: Re: MiG-3Y Utka
: Tophe March 11, 2018, 01:53:10 AM
Now that the paint work of the other model (Gee-Bee Zwilling) is finished, I have been authorised (by myself) to continue the sanding of the MiG-3, then starting to glue the lifting areas...
: Re: MiG-3Y Utka
: Brian da Basher March 11, 2018, 02:41:59 AM
It looks like you're having a wonderfully productive weekend, mon ami.

There is something meditative about sanding. I've been doing a fair bit of it myself lately.

Watching with interest,

Brian da Basher
: Re: MiG-3Y Utka
: Tophe March 11, 2018, 08:13:36 PM
Continuing to glue and support with pieces of sprues. This is impossible this way for most of you, serious modellers, but as I ignore the underside, it is all right for me... ???
: Re: MiG-3Y Utka
: ericr March 11, 2018, 09:00:47 PM
Continuing to glue and support with pieces of sprues. This is impossible this way for most of you, serious modellers, but as I ignore the underside, it is all right for me... ???

that is an interesting method  ;) you are right, it makes it possible to strengthen the things from below
: Re: MiG-3Y Utka
: Tophe March 11, 2018, 11:17:16 PM
Thanks!
And this is less shocking with a few drops of paint making the extra parts and "normal" parts look like each others:
: Re: MiG-3Y Utka
: Tophe March 12, 2018, 12:57:49 PM
Painting the main side now, like a normal (solid) model:
: Re: MiG-3Y Utka
: Tophe March 13, 2018, 12:23:08 PM
The model is finished! The first vacform of all my life! Almost a success (according to my poor standards)!
: Re: MiG-3Y Utka
: ericr March 13, 2018, 03:21:36 PM
 :smiley:

the cockpit is very streamlined

: Re: MiG-3Y Utka
: Brian da Basher March 13, 2018, 05:28:11 PM
That really finished up nice, Tophe!

It has a very fast, sleek look, like a racing plane.

Well done, mon ami!

Brian da Basher
: Re: MiG-3Y Utka
: Tophe March 14, 2018, 02:29:54 AM
Thanks!

the cockpit is very streamlined
In fact, the cockpit is flat, like on a few racer prototypes of the 1930s...
: Re: MiG-3Y Utka
: Robomog March 16, 2018, 05:49:03 AM
I tend to treat vacforms as a scratch build project, good luck with this on Tophe, it's looking good so far.


Mog
>^-.-^<
: Re: MiG-3Y Utka
: Tophe March 17, 2018, 10:21:19 PM
good luck with this on Tophe, it's looking good so far.
Sorry, there will be nothing further for me: my models have no landing gear, no roundels, no engine exhausts, seldom propellers... ??? ;)