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Jan 07, 2014, 05:06 PM
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MikeSawicki's Avatar
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How to cut out balsa from plans

I'm new to balsa building, having just completed one kit from AerodromeRC.
I recently purchased some plans from AerodromeRC, right after Kay announced it was closing. They include a sheet of peices to assemble. In my first kit, the parts were conveniently laser cut out for me to assemble. Now, I am trying to sort out how to cut them out myself.
I have vague - 40 year plus - memories of sitting beside my father while he traced plans onto sheets and cut them out. I remember most clearly that I was not very good at doing it. I was wondering if there was a tutorial for how to accomplish this. An internet search has failed to reveal much help.
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Jan 07, 2014, 05:22 PM
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lukes221's Avatar
I have not done this but i plan on making a scratch balsa build after my current and i was going to use some stuff called "see temp". You cut it over the plans and use the created templates to make the pieces.
Jan 07, 2014, 06:12 PM
Registered User
Lots or ways to accomplish this. One way is to make photocopies of the planes, cut the paper parts out and glue them to the balsa. Cheap glue sticks work well or spray glue. Then use an exacto and cut them out.
Jan 07, 2014, 09:29 PM
Neophyte hacker
portablevcb's Avatar
A lot of WWI planes have ribs that are almost all the same. Make a ply template and use it to cut out the ribs, make spar notches and any holes you need. The ones located in front of ailerons you just slice them off at the proper point. Doesn't take long to cut 93 of the suckers for a SPAD XIII.

Jan 08, 2014, 01:22 AM
Registered User
Yep, if you can make a copy of the plan, cut the parts out of paper and decide how you want to lay them on the balsa (minding grain direction and trying not to waste too much balsa).

I use Super 77 spray adhesive to attach to balsa (just spray the back of the paper — and lightly, a little goes a long way).

Then cut along the lines.

If you were sparing with the Super 77 you can usually peel the paper templates off the balsa easily enough. If not, mineral spirits seems to take off Super 77 pretty well.
Jan 08, 2014, 04:51 AM
Frequent Flyer
whitecrest's Avatar
CAD programs are useful and powerful tools for modeling, and many are freeware. It is worthwhile learning the basic features in order to create simple plans or to scale available ones. Once you have a plan in a CAD file, it can produce template drawings on demand, and you won't worry about cutting up the printouts. It is not necessary to get too elaborate with your drawings. A few accurate guidelines are enough to build a model. You can use a tracing wheel to transfer your paper drawings to balsa or harder material for templates.
Jan 08, 2014, 05:03 AM
Registered User
mhodgson's Avatar
Photocopy the parts. Cut the part out leaving a 'border', lay it ink side down on the wood and iron the paper. The heat from the iron will melt the ink and pressure will leave an imprint on the wood.
It's just one more way to transfer shapes to wood. They all work well, just choose the easiest for you.
Jan 08, 2014, 09:05 AM
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MikeSawicki's Avatar
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This is great help. As for cutting things out, is it best to use just a sharp knife or are there other tools?
Jan 08, 2014, 09:26 AM
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portablevcb's Avatar
I use a combination of tools.

Xacto (hobby) knife is what I use most of. Jigsaw (or bandsaw) for thicker plywood and balsa. For thin ply (1/32 and 1/64) I use a pair of scissors. Razor saw is also handy for stuff like bass and harder balsa.

If you don't have a jigsaw or bandsaw then get a coping saw. They are really handy for things like plywood formers and ribs.

A razor plane is really nice for shaping longer pieces or balsa blocks.

Jan 08, 2014, 10:23 AM
ARFs Are Me
TomCrump's Avatar
I recently built my first model from plans. You have received several good suggestions above.

This is by no means a definitive answer on how to build from plans, but you may want to visit my thread, to see a little bit about what is involved.
Jan 15, 2020, 12:35 PM
Registered User
larry52's Avatar

cutting balsa

i have found that if you leave a margin of say 1/16 around the part,when you cut it out cut around the margin starting with the grain,if it splinters or flakes it usually happens outside the part,then i glue stick the part to a piece of paper for trim and notching, i also make a clamshell of 2 pieces of basswood and glue a piece of balsa the thickness u r using and glue that between the 2 pcs at the bottom,when glue set pinch the 2 halves together and with a small pattern file file a couple notches large enough for stringer material, usung this have not lost a piece or corner by the notch, if there is a good pw print,i would make a copy and scan-print it onto AVERY 3302 STRETCHABLE FABRIC TRANSFER SHEET,comes out pretty good
Jan 15, 2020, 01:10 PM
Registered User
I have a reputation as a cheapskate so in order to maintain my standing in the community I never make copies of the plans.

I simply place a small piece of tracing paper over the part I want to cut out and trace it. I then very lightly dust the backside of the tracing paper with 3M spray adhesive and rub it on to the balsa. I cut just to the outside of the lines using a bandsaw, coping saw, or hobby knife then peel the paper off the wood. If more than 1 wood part is required, I stack that many pieces of wood together and cut the stack out as a set. The wood pieces can also be glued together with 3M 77 or even taped with masking tape.

A word about 3M77. Don't leave the template on the wood for very long or it will be hard to get off. Also, a little bit is more than enough. Too much of that stuff and it won't let go.

Don't forget to check your cut out wood part against your plans after cutting out!

Jan 15, 2020, 01:52 PM
Registered User
Originally Posted by MikeSawicki
This is great help. As for cutting things out, is it best to use just a sharp knife or are there other tools?
After some kind of drill (eg. Dremel or full size), a scroll saw is the most used motorized tool in my model building. The 1/10 hp, single speed Dremel Moto Shop scroll saw I bought in the early 1970s will even nibble thru 1/4" aircraft plywood. Use a scroll saw to rough cut the item; use sandpaper to trim to exact template.
No need for a top of the line scroll saw and the used market typically has a lot for sale cheap as "scroll woodworking" is a popular past time.

Rubber cement is a good temporary adhesive for sticking paper templates on wood. Cement on one surface is a temporary stick and after peeling off the paper template any residual cement can be easily rubbed off. Rubber cement on both surfaces for a more permanent stick.

Michael in Ontario, Canada
Jan 15, 2020, 11:38 PM
Build Fly Crash - Start Again!
onewonders's Avatar
All of the above are correct I’ve tried them all. But after cutting them out sand to shape using the original plan as the checkpoint. Make sure it matches perfectly. If anything leave extra wood on some pieces and sand once put together.
The notches in the ribs are my biggest challenge. Using the wood that is supposed to fit into the notch as the guide. Each piece of wood is slightly different including square wood. Sand carefully. And the angle of the notches can be difficult. Take your time make it perfect.
Sand corners of formers square and check using a square. TLAR ain’t good enough at this scale.
Jan 17, 2020, 12:09 PM
Registered User
I like to use tracing paper to copy parts to the wood . For notches in ribs I use the exact piece thats going in the notch . Stand it on end where the notch will be cut. Draw a line around it . Then cut in side the line . Sand a little if necessary. With little practice you can cut perfect notches.

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