Triangular stock balsa

[barryt]

I make lots of square stock with my balsa stripper. Is there an easy diy way to make triangular stock?

[Piers Bowlan]

Good question Barry ?

[FlyinFlynn]

Got a 3D Printer?

 

Triangular balsa stripper

 

[Ron Gray]

Table saw with blade at 45 degrees for the big stuff, 3D printed stripper as what FF did just post for the smaller stuff!

Edited May 22, 2021 by Ron Gray

[Piers Bowlan]

No, I don't have a 3D printer but that looks excellent for smallish triangular stock. ?

[barryt]

1 hour ago, FlyinFlynn said:

Got a 3D Printer?

 

Triangular balsa stripper

 

That is just the job! Thank you FlyinFlynn.

[kc]

But does that 3D printed gadget actually work on long lengths of balsa?    Cutting right through balsa with a blade in one pass is very difficult in 1/4 or 3/8 sizes.

If the principle works then no doubt one could make a one size version in hardwood.

 

[FlyinFlynn]

Yes, I have used it on 36" lengths of soft square stock. The sharp edge of the blade touches the rear face of the 'dies' so the wood has no chance of squirming out, the design is easily modified to include a second guide arch behind the blade as a belt and braces approach..

 

https://drive.google.com/file/d/1PrduH40ssMFs5w6eqWgQNXEfGsOTIFOF/view?usp=sharing

 

I use a Stanley knife blade but you could equally use an old fashioned razor blade, although the thinner the blade the more it can flex. The largest size is 12mm across flats, and 9mm and 6mm by using the additional dies. I'm sure anyone needing a different size could modify the die internal size. It seams a little odd to me that such a thing is not commercially sold, there are plenty of square balsa strippers available

[Martin McIntosh]

Get a scroll saw and rotate the table to 45 deg. Any size you like up to about 2". At the rate of balsa price increases it would almost pay for itself if you use a lot! Well worth investing 100 quid anyway.

In a rash moment I bought a Proxon table saw because they were on offer and seemed a good idea at the time. Now invaluable for accurately stripping balsa now that it is 86p per single length of 1/4sq.

[kc]

Martin,  scroll saws normally tilt along the frame direction & only allow 12  or 13 inches before the wood hits the saw frame.   Also very difficult to cut straight.  Unless the scroll saw has a fence ( rare ) the wood falls away when tilted 45 deg and makes it even more difficult to cut straight.  Perhaps you meant table saw or bandsaw?

[Martin McIntosh]

No, I meant a scroll saw. Most have a 16" throat, admittedly not enough to turn a 36" piece round and attack from the other end. You can always clamp a guide to the table although I have never needed to.

[Nigel R]

for (short lengths) corner filling type applications, I have used a piece of square section and simply carved away with a knife / scalpel... does not give an accurate 45deg face but enough for filling corners on former reinforcements.

[kc]

The 3D printed gadget seems to be for splitting a 1/4 sq or 3/8 sq into 2 triangular bits of balsa,  and as that's what we are talking about here I assume that is what Martin says one can use a scroll saw for.  Frankly I find it very difficult to saw a 1/4 sq down its diagonal to make 2 bits of triangular!   I can get a few inches of decent stuff but there is no way I could get a long length of both halves being decent usable triangle.  By sacrificing one half as offcut maybe I could get a usable length by sanding as well. 

By cutting a corner off a 3 inch wide sheet it may be easier.  

Personally I would use a razor plane to plane a corner off a 3 inch sheet, then turn over and strip the piece with a balsa stripper.   It wastes half the strip as shavings but is quick and easy.  if an easily made or cheap to buy gadget is available which converts square strip to two 45 degree triangle strips then i want one!

My doubts about the 3D stripper are that it usually needs 2 or 3 light cuts to strip 1/4 balsa, so I wonder whether the 3D stripper can actually do 1/4 or 3/8 in one pass.   Perhaps the blade is angled along the cut so it cuts gradually?

Edited May 24, 2021 by kc

[Martin Harris - Moderator]

Well, I printed one and tested it on a bit of (soft) 1/2” square this morning. Perfect triangular stock resulted!

 

Time will tell as the blade gets used a bit more but first impressions are very favourable!

[Piers Bowlan]

10 minutes ago, kc said:

 

My doubts about the 3D stripper are that it usually needs 2 or 3 light cuts to strip 1/4 balsa, so I wonder whether the 3D stripper can actually do 1/4 or 3/8 in one pass.   Perhaps the blade is angled along the cut so it cuts gradually?

Yes I was wondering about fitting the blade at an angle, like a guillotine!

Throwing half of the strip away seems a bit of a waste if you can cut two in one pass with the printed cutter. I find i/2in triangular section the most useful. 

[Piers Bowlan]

2 minutes ago, Martin Harris - Moderator said:

Well, I printed one and tested it on a bit of (soft) 1/2” square this morning. Perfect triangular stock resulted!

 

Time will tell as the blade gets used a bit more but first impressions are very favourable!

I want one. ?

[Gary Manuel]

Anyone willing to print me one?

Quite happy to cover all cost plus a bit for time and effort.

 

Drat! I thought I was first in the queue. Piers beat me to it.

 

Edited May 24, 2021 by Gary Manuel
Double drat.

[Piers Bowlan]

Cash waiting! Is anyone offering to make some Gary? Must be quite time consuming to print the parts, not that I know anything about it.

[Martin Harris - Moderator]

Mine’s not up to serial production at the moment as I can’t seem to find any decent bed tape at the moment - I only got it to print a useable example on the third attempt and that’s warped a little on the base. Maybe time to consider a bed upgrade now that HK don’t seem to do their nice thick blue sticky pads. 

[Gary Manuel]

No problem. Thanks anyway Martin.

[barryt]

Well an overnight run on a mate's 3D printer resulted in this. Worked perfectly on a full length length of 6mm medium balsa. Although the cut was accurate, the resulting triangular stock warped immediately. No big problem for me though because I rarely use pieces over 120mm long. Thanks once again FF. This handy tool is going to make my projects less of a pain in the fillet department.

Already dreaming of a small trailing edge version!

[Martin Harris - Moderator]

1 minute ago, barryt said:

Already dreaming of a small trailing edge version!

Now there’s a thought!

[kc]

Well we are aeromodellers and that means woodworkers so we should be able to make one in wood shouldn't we?    I hate to plagerise someone else's designs but this is really a variation on the classic home built balsa stripper but with a guide to take square stuff.   Ingenious though.

I reckon it's easier to make in wood than get involved in 3D printing.  One for a fixed size is easier and easier to make one for 1/4 and another for 3/8 in wood than make interchangeable guides.

.  So I suggest a base of hardwood with a V cutout and a top of similar material with another V cutout.  Held together with bolts and wingnuts.  A Stanley knife blade would need some screws or pins locating it in place and angled across would be better.

So food for thought- are we into computing or woodwork?   ARTB or DIY?

[Martin Harris - Moderator]

I’m happy to take advantage of any technology - or do you still build with razor blades and balsa cement?

[kc]

10A scalpel blades and PVA !

 

Of course I could take full advantage of modern technology and get my credit card out and have a plane completely built ready to fly and delivered by the postman --but using the hands and brain seems better to me.