1/72 Vacform help...

[Courageous]

Thoughts please.

 

I've just purchased a 1/72 Beardmore WB III by Joystick that I will build at some point in the future. Like all bi-planes in this scale it's tiny, and I've noticed that the wings have no under-wing parts to mate with the upper surface part.

To those that know, should I be doing extra stuff to get thicker wings, lower-wing surface detail, strengthening and fixing points for struts and stuff.

[Paul Thompson]

A single sheet thickness is perfectly good enough in 1/72nd to be accurate. The only trick is spending enough time scraping and sanding the trailing edge to knife sharpness. The front and ends of the wing inderside need careful sanding to flatten them out as well. Underside rib detail is usually catered for by marking the positions off a plan (or carrying around from the top wing ribs) and then either scribing  or using decal sheet strips to indicate the rib tapes. I use 2 scalpel blades superglued together to produce a pair of parallel lines, and a piece of Dymo tape as a guide..

 

I have this particular kit (in progress), and the wings are thick enough you can drill a shallow hole to locate each strut.. The whole model will be very light when done, so you don't need much strength to it. If it worries you, you could leave larger locateing pegs when you make the struts, drill locating holes right through the wings, and cut and sand them down after the top wing is on, but then you'll have to repair the paintwork of course. No problem with a paintbrush, involes mucho masking if using an airbrush.

 

Paul.

 

 

Paul.

[stevehed]

As far as Joystick goes I agree with Paul. I've built the Albatros J1 and have the Aviatik BII in progress. In both cases the wings are thick enough to allow locating holes to be drilled. However I had to butt join the lower wings as I couldn't drill holes to receive support rods into the wing ends, far too thin.

 

Regards, Steve

[Paul Thompson]

30 minutes ago, stevehed said:

As far as Joystick goes I agree with Paul. I've built the Albatros J1 and have the Aviatik BII in progress. In both cases the wings are thick enough to allow locating holes to be drilled. However I had to butt join the lower wings as I couldn't drill holes to receive support rods into the wing ends, far too thin.

 

Regards, Steve

 

I wasn't thinking about joining the wings Steve, but you're right. My approach in that case is to join the lower wings before painting (otherwise I complete major painting before assembly to reduce masking) and use a liquid cement like Mek. If it looks dubious after setting up overnight I might err on the side of caution and flow some liquid CA into the joint for reinforcement, cleaning up any CA that gets on the wing or fuselage surfaces immediately with a damp cotton bud. Seems to work okay.

 

Paul.

[Courageous]

Thanks for getting back guys.

I have built vacs before but nothing this small and I was a bit worried about the joining of such thin parts like the wings and struts. Fortunately the model is light and shouldn't have many stress points to worry about.

I have done some rigging before; blinds in the upper wing and 'through' in the lower wing, should I think about a different rigging technique for such a delicate creature?

 

Stuart

[alancmlaird]

I plunge-moulded a scratch-buit DH6 many (many, many) years ago, and I too had the problem with the thinness of the sheet card.However, in my case laying stetched sprue to give raised ribs and then a fair few coats of paint on afterwards gave me a great result as the paint on the wing underside (left to dry facing up) pooled a bit and filled in the concave underside to give a really nice tapered aerofoil section - attention to the leading and trailing edges is necessary as previously mentioned. If you are an impatient sort, and can't take the pass-time of watching paint dry you might need to try another method to save your blood-pressure!

[Brandy]

I have a 1:72 vac on the go at the moment, a Sopwith Tabloid. It's my first vac of any sort. My main problem was as stated above - the wings are so thin I couldn't get a strong join for the lower wings. I added the upper wing first using brass rod for the central cabane struts and that gave me a second join to keep the lower wings secure. The WIP is on here if you wish to take a look...it's a double build with a Sopwith Baby.

 

Ian

[Courageous]

Hi Ian,

 

Funny, I was looking at your WIP yesterday, interesting reading about your experiences, hopefully I'll learn from them.  Still trying to get my head around the thin wings, its lack of anchor points for the struts and rigging. I haven't started it yet, just gathering data and I hope that things measure to scale to avoid your problems but that's modelling.

 

Stuart

[stevehed]

Butt joining wings is not my favourite pastime. Whenever I can I will add metal wire or brass support rods. With rods or even small pips it makes getting the wing in the correct position easier. When butt joining I have to mark the wings position on the fuselage with a pencil. Then I add a small amount of polystyrene cement to the wing root, let it go tacky, and then position. I do one wing and let it dry with supports under the wing tip. When the cement has dried and I'm happy with the position I run liquid CA along the joint. Then repeat for the other wing. As for rigging I find my technique varies according to the aircraft. Sometimes the upper wing is thick enough to allow a blind hole to be drilled and in these cases I would drill through the lower wing. In other cases I razor saw a tiny nick into the top and bottom of the struts. I loop invisible thread around the struts into the nick and secure them with CA before cutting off the excess. Neither method is perfect but in many cases there has to be compromises.

 

Regards, Steve