How hard is it to get straight Balsa Sticks?

[Joe Ed Pederson]

I decided to build my old Top Flite Tutor (45" 410 sq in).  The fuselage blank is warped. and only a couple of the sticks for the wing were straight.

I ordered six replacement rear spars (1/4" X 1/4") only two were usable over the 24" length required.
I ordered twelve replacement middle spars (1/4" X 3/8") only two of the twelve were usable over the 24" length required.  There are four spars.
I ordered six replacement leading edges (3/8" X 3/8") only one was usable.

So, out of 24 sticks ordered, five were usable.

Is this par for the course?   Is it that difficult to get balsa sticks that are straight over a 24" length?    Would I get a higher percentage of straight sticks if I cut them from sheets?    How about splicing the straight part of two sticks to get the needed length?

I ordered two fuselage blanks (1/2" X 4").   One was usable and when I lay the other blank flat the sheet is 1/8" off the board at the end of the length needed for a fuselage.     

Joe Ed Pederson

[RC Storick]

What I do for straight 1/4x1/4 is select a piece of 1/4 x3 sheet with straight grain and cut my own. Use a straight edge and cut with the grain not the sheet sides.

[john e. holliday]

I went tp Hobby Lobby and bought some spar material for the planes I have finished.   They had most of what I needed and it was straight for the full 6 inches.   Had some sizes I had to go to hobby shop for.  It was not perfect but I made do with it.  Yes the Hobby Lobby stuff was more expensive.   But in the past when I ordered in bulk from Lone Star the strips were not perfect but I made do with them and the wings came out straight.   The extra pieces of spar material I have bundled together with a straight piece of thick wood and so far the ones I have had to use were still straight.

By the way I've done as Sparky says when I can't get what I need.

[Mike Griffin]

Jo Ed I do what Robert suggested but instead of a straight edge I use a balsa stripper.  You can adjust it for different size strips.

Mike

[Balsa Butcher]

Many can be straightened by using the old Free Flight trick of rubbing them across the edge of a table, chair or whatever. Draw them across while holding light to moderate pressure while bending them opposite way. Too much pressure then they break or bend the other way. It may take a little experimentation but with a little finess and patience many bent sticks can be transformed into a perfectly useable model aircraft structural components. 

[Dan McEntee]

  Plus one on what Balsa Butcher says. It can work on sheet balsa also. When stripping wood, always true up the edge of the sheet first. Sheets and sticks sometimes have curves because when the wood is cut and processed, it creates stresses.  Sometime the wood bends right away, sometimes later, temperature and humidity affect it also. So if you decide to strip some wood, no matter how hard  you try, not every strip will be straight or stay straight, and you will have to correct it anyway if it is bad enough. This is why I think the best training anyone can have in building good flying model airplanes is learning how to build  and fly free flight stick and tissue models. It teaches you how to build light, straight, and what affect trim changes have when you make them. If you can build and fly a rubber power or gas model free flight and get it to perform consistently and predictably, you can build and trim a stunt model.
  Type at you later,
   Dan McEntee

[Randy Cuberly]

The real key in getting straight sticks, in my humble opinion (actually I'm not very humble  ), is to carefully select balsa of the proper thickness and very, very straight grain, and (this is very important), uniform density through out it's length...and carefully slice it with as little pressure as possible.  Meaning a very sharp...that's very sharp...blade.  Replace the blade often!!!

It's probably the only way to insure that the sticks stay straight for any appreciable length of time!

Any change in density along the length, and cutting it relieves stresses that invariably cause it to curve or twist!

Any sanding done on the sticks afterward should be done very lightly with very fine paper!

Randy Cuberly

[RandySmith]

Its  way easier to get straight sticks from heavy straight grain balsa, its  much harder  to get it from light balsa, even a straight  "A" grain light sheet  will  bow ,twist , warp when cut with a sharp knife  or a balsa stripper , so  the  advise of ways to do this are good, but be prepared to waste a lot.  and go slow and easy when your  cutting

Randy

[Dave_Trible]

I make the rounds of the hobby shop and every Michael's, Hobby Lobby etc. in the area and cherry pick everything they have.  I'm sure they say "there's that guy".  Over a period of time I gather a pretty good supply of straight sticks.  When i do mail order, i'll order 20, expecting to get 4-6 usable pieces.  That's about par.

Dave

[Phil Krankowski]

Improper storage, heat, moisture changes... many ways to get funky sticks.  There are ways to make funky sticks straight with heat, moisture, and solid restraint until the moisture has equalized.  Buying or stripping good straight sticks is likely the best answer.  Store your strips flat, where the moisture stays low, and the temperature stable.  A bag of sticks in the attic will all but guarantee they are funky by next year.

Phil

[Joe Ed Pederson]

Thanks everyone.  I copied and pasted all responses to a Word document and saved it on my computer. 

 

Joe Ed

[Dennis Toth]

Joe,
One of the simplest ways to straighten balsa is heat. Get a heat gun with a flare tip (MonoKote style) warm the surface you want to straighten and bend in the opposite direction of the warp, hold for a few seconds. You will get a feel after a bit of how much heat and how far to bend. It doesn't take much. I also re-pitch wood props this way (and no they don't lose their pitch in the sun).

Best,    DennisT