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inkscape... how to keep scale on a and b folds?


Active member
I've watched a few videos now on scaling plans with inkscape... I've played with it a bit and it's pretty kewl but I'm struggling to figure out how to keep scale on the a/b folds... does anyone have a video on that part?... also I know I'll need to maintain scale on the servo cutouts and such which is easy enough... but those a/b folds are frustrating me... I have a basic idea of what to do but no matter what I do they don't seem to come out right :(

any help or a video on it would be epic... thanks



Old and Bold RC PILOT
I scale a few FT plans but not as most do!
For reductions I stick to 60% and build out of 3mm FB.
For scaling up I fit a strip of Balsa along the fold to "Fill it out" to the enlarged dimension. So to double size I insert a strip of 5x5 balsa.

This adds strength without over complicating the whole plans reworking idea. For lesser size increases I just measure the gap and cut a strip of the appropriate thickness balsa to the same width as the FB is thick. Curves are no problem if you know how to bend Balsa using Hot Water or steam.

Very quick, Very strong, and often hardly any serious weight increase.

Just what works for me!

Have fun!
Ive scaled the ft alpha plans %200 and decided to cut 25 mm ( 1 inch ) strips and use to fill in the 5 mm gap left by doubling the scale,, even perhaps use full pieces as stiffeners where required
Yeah, I would just double up on the A and B folds. That is, unless it’s not an increment of 100% scaling cause the foam sheets would then be unproportionate.
Living in the UK I have access to 5 mm foam board instead of 4.5 mm, also the foam board sheets are usually bigger (59 x 84 cm instead of 50 x 71 cm).

I plan to scale everything 110% and everything should fit. Is it correct?


Well-known member
Size wise everything should be ok with the upscale. The issue becomes with the CG more than anything. Depending on the weight of the foamboard used and the electronics and or placement, the CG can vary drastically.

The heavier the foamboard you use, the more extreme the tail heavy build tends to creep up on you. Up-scaling the design will amplify this more often than not.
I always assumed that if you identified which line on the plans forms the edge on the outside of the fold, you just make your 5mm (or whatever FB you use) mark offset from that in the same direction at the plans from there. I've seen some cases where I really don't expect that to work where there is a stepped edge (Mig3) or tabs that fold through the A/B fold (super bee). In that case I assume you have to determine where things scale based on FB width and where it just scales based on model size.