How do you make bulkheads to fit in aircraft fuselages, pls?

[DavidWomby]

I make lots of old kits that come with no cockpit floors, instrument panels or bulkheads.

I try using a contour gauge to pick up the shape of the inside wall of the fuselage then cut a plastic card bulkhead to, supposedly, fit. I find it works poorly. Too big or too small but never right. I usually end up with bulkheads like the one I am trying to fit to the bomb aimer's area in this Baltimore.



Any suggestions on how to get a precise shape of the part needed and then cut it out of card, please?

David

[59North]

Perhaps you are not being patient enough with your cutting/filling after you've used the contour gauge.
I use the same gauge, always cutting slightly larger than required, and fitting and filing repeatedly until I have a proper fit.
I just did this on the 707's front wheel bay, and accomplished a great fit.

[DavidWomby]

Perhaps you are not being patient enough with your cutting/filling after you've used the contour gauge.
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Very likely the root cause of my problem with this, and many other things!

David

[chrism]

try using old cereal packet or thin card that is easily added too with tape etc to get the basic template - then if you cut it and it dont fit, you can cut a shim more card, tape it to the main piece and trim back to fit, before wasting plasticcard

[DavidWomby]

try using old cereal packet or thin card that is easily added too with tape etc to get the basic template - then if you cut it and it dont fit, you can cut a shim more card, tape it to the main piece and trim back to fit, before wasting plasticcard

Good idea. As you say it will help reduce wasted plastic card.

Thanks.

David

[JamesPerrin]

Contour gauges do not have the resolution to usefully follow the fuselages of all but the largest of aircraft in 1/72. Paul Budzik had a very involved method of create dams and pouring plaster of paris. I have used though with reasonable results children's Plasticine ( coloured clay ). When worked that can be quite soft which helps getting it into the fuselage half without distorting it. Pop it in the fridge to chill and it will firm up. You can remove it and trim the face flat allowing you to transfer the outline and centre line to paper, mirror this by folding the paper along the centre line to get the complete template. Use a very sharp pencil to transfer the outline as otherwise you'll end up increasing the final part by ~0.5mm all round.

[DavidWomby]

That sounds workable. Thanks, James, as I do find the contour gauge pins a bit coarse for the job

David

[JamesPerrin]

Unfortunately I don’t think there is a good instantaneous solution other than cutting a spare fuselage in half!

[DavidWomby]

Tempting, James. Very tempting sometimes.

David

[chrism]

I suffer a similar problem with ship hulls and use cereal packet card in the first instance to help eliminate plassticard waste

[PropWash]

How odd. I had reached-out to Vacant a few weeks ago, after seeing one of his vacuform builds, seeking help with my SeaMaster build. Progress there had all but stopped owing to the issue of bulkheads / spars and how to build them. I had the thought of using a contour gauge too. I purchased one and found out what you had in that the pins are just a tad to coarse. However, I found it gets close-enough to the shape desired that only a little trimming is required to fit. At least it seems that way with the practice plastic I was able to find in my garage.

Still, I will never do a large scale vacuform model again if I can finish this one. What a pain!

[JohnRatzenberger]

Ahem, ready ???

Back in the good old days, way back, the books and magazines (Aeromodeller, anyone?) were filled with 1/72 3-views (or better), most all of which had body and airfoil cross-sections that provided a good start point.

Nostalgia break over