Czech 1/72 Ba-33 Vacform

['V']

Under construction , err, yes.

A make, or break attempt to make another aircraft kit. Excessive pressures on standards seemed to kill my enthusiasm

for building any more models. The very last build was in 2015.

Even then I've started with the impossible, but with the advantage of no real detail information, so anything goes ??

I doubt it, someone will have knowledge, but at least this is an unusual subject, and when was the last vacform shown "In progress" ??

 

A  MH Vacform

 

 

To make the parts, you remove from the backing sheet.

 

 

These are now ready to sand down. The injury you get is 'burnt' finger tips from sanding small parts and your finger tip cop for a thorough sanding.

This is the slow part, as you must take enough off to get very fine trailing edges.

 

Let's see how well this progresses - NO promises !!

 

'V'

 

 

['V']

O.K some minimal progress.

I thought this was such an unusual subject that I'd just add a little background information.

Well I doubt that any other Britmodeller member has heard of the Ba-33. It was one of the explosion of bi-plane designs being built and flown

throughout Europe between WWI & WWII. The new Czechoslovak Republic was a hot bed of ideas.

At one time the IPMS(UK) had a Czech & Slovak Special Interest Group and having made many contacts & friends there I was the guy who formed it !

While I am no expert I did develop a library of books that means few in the U.K have better reference material at their fingertips.

 

But what of the Ba-33 ? I had the kit and there were no drawings, dimensions, or any detail at all. Not a particularly good starting point !!

Looking at my books, this was, I thought, the limit of my information

 

 

 

Delving further I found my copies of the in depth Czech Aviation history books, Pt.1 & Pt2. As a pure fluke there were drawings on the sleeve of Pt.1 that

included a plan outline and side view of the Ba-33 !!!

 

 

 

So this is the limit of my research. Can a half decent model be made from this ? I hope so as I wasn't expecting the help those outline drawings provide.

 

The fuselage is now cut-out and while not having marked all the part outlines with a marker to help with trimming back This is so small it shouldn't

make life difficult. However I am now remembering the mess trimming and sanding cut out vacform parts make while turning into usable parts.

 

More tonight . Ahh I'm currently Covid-19 positive and as such confined to home. IF ever you needed a reason to sit indoors making a mess this is it.

 

'V'

['V']

Without any plans it's difficult to calculate when to stop trimming vacform pieces.

I suppose if it looks about right it can't be too far out - The roughest rule of thumb !!

Anyway the bulkhead - not that the aircraft ever had one - fits touching the sides, not that you can see much !

 

 

Now it's getting all parts off the sheet and attempting to sand down enough to get acceptable thickness wings. The top plane

would seem to be flat, no dihedral, while the lower wing has a small lift built into the flat sheet of parts. This bit should be 'fun' !!

 

 

Soon I'll arrive at the point similar to opening an injection moulded kit box - if I'm lucky.

 

'V'

 

 

 

[Hook]

Oooh, a vac! Always good to see an esotheric subject.

 

Cheers,

 

Andre

['V']

Hi Hook, Just me being crazy.

 

One advantage is Nobody knows anything about it !! (Including me ??)

An example of that is the cockpit interior. Bland sheet plastic sides it didn't have.

So I added a few lengths of micro-strip to look like stringers. The kits two bulkheads

providing the start & finish locations. They didn't exist either, but it needs the strength.

 

 

I've started adding a few teeth along the joining seam, one of the best old fashioned ways of joining

very thin vacform parts together. A long single length just introduces distortion.

 

Oh and I suppose I should look at a book, or two to decide just what the control yolk may have looked like.

Still I think that's enough for today.

 

 

 

['V']

Now for laughter !!

When I see all the accurate plans, aided by superb quality kits it amuses me as to what things used to be like.

The Ba-33, Plans ???? No chance, Photographs, there are odd distant black & white shots that are no help to any model builder.

Add to that making a vacform ? Is it mission impossible ?

When sanding down the fuselage halves it's all about 'Eye' and guess work. There is no such thing as a recommended build sequence.

and the best guide was the lower wing half which was moulded as a one piece with built in dihedral. It turns out my guess was within

0.25 mm and I decided that I'd cut away the lower fuselage to inset that lower wing.

 

 

 

This should when final trimming, filling and sanding completed give a nice fit/finish. My Green Putty now like a stone, not used for at least

5 years. I do have some Humbrol, is it any good ? Only time & use will tell.

More laughter, here you see the landing gear supporting frame. a few thousandth of an inch raised detail - fancy cutting that out accurately ?

 

 

Even more 'Fun' will be trying to make something to replace the inter-plane struts. Seen here moulded in a blob of some 1960's resin ?

At least the air screw and wheels have some potential, I think !!

 

 

I may be gone some time !!

 

To try and make something that looks like an aircraft I have to make a Jig that will fit the fin and keep the fuselage vertical while I work out

how to set something like the required dihedral  as the lower wings are fitted into the 0.4 thick plastic fuselage shell.

 

Tea ? No I think this needs Brandy !!!

 

'V'

[Patrik]

I am sorry I am a bit late to the thread. This booklet should not be that hard to find. https://www.scalemates.com/books/avia-bh-33-3-ji-i-vrany--106486

I have one at home, but as I am on vacation now, I cannot check if it contains Ba.33 plans too. But I guess it does, so if you like, I will scan them for you when I am back. Which is in about two weeks' time, I am sorry to say.

['V']

Thanks for that fine offer Patric.

I would be pleased to take you up on that offer.

As far as I'm aware the BH-33 had a different up-rated engine fitted. I doubt that there were many

airframe changes, perhaps a few to keep the centre of gravity within the accepted range.

 

Be aware that this isn't going to be a museum quality build. I sort of fell out of love with building aircraft

models. I blame excessive over-load, too much, too concentrated, too long !

During 'My Time' I've been in the Prague Museum and in fact had many contacts in the Trebic Model Club

and fondly remember spending 'Party' time together at the IPMS (Deutschland) exhibitions in Berlin back

around 2006.

 

In my last carnation I wasn't into bi-planes, but larger modern aircraft. With Vacforms more sanding and

preparation went into the tail-plane of a 1/72 VC-10 than a fleet of inter war aircraft !

My current approach is more relaxed, but just a hint of what 'killed' my enthusiasm. This is from an old

Airwaves vacform with home printed decals - I no longer want to work THAT hard !!

Still just a little colour candy, loaded with memories.

 

 

'V'

 

 

[Tim R-T-C]

 Just found this thread, a very interesting production and its always fascinating to see vac-form kits in progress. Look forward to seeing more.

 

Czech aircraft are quite fascinating and their love of aviation design seems to have transferred down to the model plane world where it must be considered the centre of European kit production. In fact from the interwar period I just ordered a Zlin XII and BH-9 kit from a new Czech 3d print manufacturer - a lot easier to work with than vacforms for sure!

['V']

Thanks Tim R-T-C,

 

I must say I do like the Czech Republic, but now outside my range.

 

Nothing much to show, but I had a panic attack when putting some Humbrol filler over one of the underside joints.

Far too liquid and very aggressive - Ouch, this is very thin plastic. A quick sanding covered with a splash of paint

hides the unfilled join line almost as well as the rear filled join. Perhaps a cleaner cut joint would have been better than

trying filler !!

 

 

The tail plane comes as a one piece that you have to cut into respective side wings. Before I attached I decided to open

out small triangles back to the rudder post. I assume this is for maintenance access. I had the time so why not ?

 

 

Undercoated to see exactly what the finish was going to be, hiding various marks I've put on.

Now to a problem and the iffy way I'm going to get around it. You are supplied with an instrument panel, but I couldn't think

of any way to attach square and in the right place to one very thin fuselage side. I shall attempt to saw down the joined

fuselage and then slide the panel into the slot.  Wish me luck !!

 

 

Patrik's kind offer of possible plans will now start adding to delays on the project. Somehow I need to make interplane struts. Doing

this from the very poor and broken representations that came with the kit is going to be difficult to impossible. I once had some

fine aerofoil brass strip. Initially my thinking is to make up with one brass length to take the weight adding Aeroclub plastic aerofoil

sections to make up the 'Z' ?????????

 

'V'

[stevehed]

Looking good. I also prefer to create a centre section cut out for the lower wings when possible. Much better than butt ends I find. Vac form struts and undercarriages are best regarded as templates to scratch rod or strip replacements.

[Courageous]

Vacuforms can be a bit daunting. My most recent vacuform was this:

...and although I swore a few times, I found it quite enjoyable. I have a few vacs in the stash of those rare aircraft types but if that's your only option...

The main lumps do get used but as @stevehed says parts like struts, undercarriage, cockpit details are more templates, even the wheels tend to get replaced. Stick at and don't worry to much about accuracy, get your confidence level up.

 

Stuart

[Tweener]

5 hours ago, Courageous said:

Vacuforms can be a bit daunting. My most recent vacuform was this:

...and although I swore a few times, I found it quite enjoyable. I have a few vacs in the stash of those rare aircraft types but if that's your only option...

The main lumps do get used but as @stevehed says parts like struts, undercarriage, cockpit details are more templates, even the wheels tend to get replaced. Stick at and don't worry to much about accuracy, get your confidence level up.

 

Stuart

That they can be... and to think, I just bagged a vacform DH.90 and Fairey Hendon as well... To the back of the stash for a decade, do doubt!

['V']

Some nice potential there Tweener,

In the meantime it adds to loft insulation !!

I gave my Fairey Hendon away, it was well on the way, but I passed it on to someone who would finish it

as I had severe doubts that I would. If I recall correctly he did a cracking job.

With Stevehed & Courageous it seems there are still a few who happily accept the challenge. It really takes

a different 'Mind Set' and who the heck would expect to see a kit (or is that too advanced a word) of the

Heston Type 5 Racer ?????????

 

I've just located some aerofoil brass in my 'stuff', perhaps the ideal thing for inter-plane struts.

 

I notice the main wings of the IL-76 still laying around. Think I'll keep well away from that.

 

'V'

['V']

Having been out of this hobby for quite a few years I could do with some help

regarding the available fillers.

I used to love Squadron Green Putty. I don't think this is available now ?

I have some Humbrol and it's far too liquid

What else is there ?

Revell Plasto, or whatever it's called, what's that like ? I'll see if the local Toy/hobby shop has some tomorrow.

 

'V'

[Ray S]

2 hours ago, 'V' said:

Revell Plasto, or whatever it's called, what's that like ?

 

Hello @'V', from another vacformer (recently completed an Aeroclub Felixstowe and a Scaleplanes Bristol Scout), I would stear clear of Revell Plasto, at least if my tube I bought recently is anything to go by. It was so liquid I could pour it out (in fact, I did!), but someone on here suggested to 'work' the tube with the lid on to mix it up a bit. It worked a little, but it would still be too 'hot' for a thin vacform I think. I too used to use Squadron Green Stuff and found it excellent, but I have not found any recently.

 

You are doing a grand job with this model, and I certainly commend your more laid back approach now. I am looking forward to seeing the progress.

 

All the best,

 

Ray

['V']

Hi Ray S,

 

I hope there is something, I did wonder about some Halfords car filler, stuff like 'Davids Isopon'.  I never was happy with milliput I always ended up

with messy hands & couldn't get the  fine surface filling to work in the way I wanted.

Why fuss over fillers ? Perhaps this picture shows how much I've used fillers. Here a Matchbox Victor K2 being reverse engineered into a short span B1a,

or was it a plain B1 - duff memory !!

 

 

'V'

[Marklo]

I too was a green stuff fan. Tbh I haven’t succeeded in finding a single alternative. 
 

Squadron green isn’t bad, but it can separate in the tube. The last lot I got I ended up decanting the whole tube into a glass jar and remixing the whole tube back up. That said it was fairly convenient to have it in a jar instead of s tube. I find the white squadron filler just a bit too grainy.

 

Tamiya putty is probably the nearest but doesn’t sand as well as Greenstuff.

Perfect plastic putty is useful but as it’s water based it doesn’t quite stick as well, but it can be cleaned up with a damp q tip so can be handy for filling late in a build.

 

Finally milliput is really good for building up a profile, just be sure to mix it thoroughly and in equal parts. 

[Jonners]

Nice one, V, that's a great little project. Keep it up. Glad to see it's progressing without getting bogged down by obsessing over accuracy as you described in your other post. A couple of years ago I scratchbuilt a Short Gurnard amphibian; it isn't completely accurate or especially detailed, but it was great fun to make and a really satisfying exercise in trying new techniques. I've ended up with something that looks really unusual which, to my mind, more than makes up for the shortcomings. I think that this Avia is unusual enough to be a talking point once complete irrespective of the level of accuracy or detail, so that's the attitude that I would certainly adopt.

 

If you have found sufficient brass aerofoil strip, would you be able to cut, trim and carefully solder it to create the interplane struts? It's a delicate operation, but I've managed it on a couple of occasions by drawing a template on a piece of ceramic tile using a fine permanent pen and then taping the individual pieces over the template using thin strips of Tamiya tape. A tiny dab of flux, some careful soldering using a little bit of solder and Bob's your uncle. Here are the Gurnard's undercarriage legs 'in progress':

 

Jon

['V']

Thanks Marklo & Jonners,

 

While kit standards have leapt forward it seems fillers have gone backwards ?

 

I do have enough brass so I may well try that. Time for soldering !!

 

'V'

['V']

A job to put off - Or why did I think this was a good idea ?

 

Here is the instrument panel. I'm hoping to saw down the fuselage just at the front

of the cockpit to slide the panel into the slot.

This is why I've been checking out modern fillers, the slot will need hiding. If I can't

find anything suitable I suppose I'll have to fill the scar with fine strips of plasticard.

 

 

Trying Jonners idea regarding interplane struts. My brass is about 30% oversize, but IF I can

do a decent soldering job this should be VERY strong.

At least I have the original flaky resin to try and size out my drawing. More filing to get the brass

to fit tighter, but it looks doable.

 

 

A slow down now as my Covid-19 isolation now over and as Chairman of the local model railway

club I have some people to see and some work to catch up on.

 

'V'

 

['V']

I've decided I'll have to make a jig.

Soldering 3 small pieces together isn't too difficult BUT I need a matching pair

Here is my first attempt, as can be seen the lower strut is about a mm out.

Practice will test my resolve, if not achieve perfection !!

 

 

Back to making a plywood and pin jig

 

'V'

 

[Tweener]

Personally I have never had luck with any variety of filler. Last one I used was called Mr Green Stuff, and before that was Vallejo Water Based. Both tubes popped after using about 1/4 of the product, both shrank a moderate amount after drying, and neither sanded well. 

[Vesa Jussila]

Late in the party. Nice project and something that I haven't heard of. There is lot of planes between wars that have vanished in the history. Thanks bringing this to light.

['V']

Thanks for the interest Tweener & Vesa Jussila,

 

As to fillers Tweener I used to love the Squadron Green Putty that I used to get back nigh on 20 years ago.

The trouble is we get rut-bound, know & understand how to get the best out of a particular product and become

completely lost when the product is no longer available.

 

Vesa, Poland used the B33H, but that had a different engine and rake on the bi-planes so this kit wouldn't do.

 

I've mentioned before my age, pushing on towards 80 early next year. This means I have some very old ideas and

experiences. One of those is the use of superglue to build up damaged corners, particularly on Vacformed models.

A small pile of Bicarbonate of Soda ( a regularly used baking product) is used to quench a blob of superglue placed

on/over the area that needs build up.

Here you see the rather rough air-screw. Like most of the so called resin detail parts with this kit they need much refinement,

or as in the case of interplane struts complete replacement.

 

 

Here needing more refinement, but the damaged tip built up.

 

 

I must also thank Patrik in the Czech Republic for an offer of copying plans for me from a book. This week I've sorted

out more of my library and found I have a copy of the book !!  All my aviation books were put away in boxes when we moved

house in 2013 and as I'd stopped modelling aircraft I didn't unpack !!

Blame it on my age !!

 

'V'