Jackson T
Elite member
I was actually about to ask that! I put baking paper over the template, trace it with a lead pencil, then flip it over and trace over it again on the balsa. I do it with the FT plans as well. What about you?
4 Metre Glider Scratch Build
- Thread starter Jackson T
- Start date
TooJung2Die
Master member
Haha. The vintage kits I built came with the rib outlines printed on the balsa. That was a major development in balsa kits back in the 1930's. Today we are spoiled with laser cutting. One of my next balsa builds will be from the plan so I've been wondering the same as you!
If you can get some old fashion carbon paper that might be a good solution.
OliverW
Legendary member
Any art store has carbon paper, or a local hobby shop may have it. I have been using it on my pietenpol.Haha. The vintage kits I built came with the rib outlines printed on the balsa. That was a major development in balsa kits back in the 1930's. Today we are spoiled with laser cutting. One of my next balsa builds will be from the plan so I've been wondering the same as you!
Jackson T
Elite member
That's not a bad idea. Nice build by the way!
Jackson T
Elite member
Good idea. What kind of plane are you going to build?Haha. The vintage kits I built came with the rib outlines printed on the balsa. That was a major development in balsa kits back in the 1930's. Today we are spoiled with laser cutting. One of my next balsa builds will be from the plan so I've been wondering the same as you!
OliverW
Legendary member
Thank you very much.
Hai-Lee
Old and Bold RC PILOT
Just an old method of marking the wing ribs on the balsa was to cut a slightly undersized template from a hard material like laminex or plastic. The undersized template was carefully made so that running a Biro pen around it provided the exact shape and size of the required wing ribs. It works very well for those wings with uniform wing rib profiles.
Where you wanted a quick method of cutting multiply ribs was to make 2 exact replicas in the aforementioned hard material and clamp the balsa rib pieces between them. Just cut them all out using the hard edge of the templates to guide and stop the sharp knife. The ribs are perfect each time!
Just a little old tech!
Have fun!
Where you wanted a quick method of cutting multiply ribs was to make 2 exact replicas in the aforementioned hard material and clamp the balsa rib pieces between them. Just cut them all out using the hard edge of the templates to guide and stop the sharp knife. The ribs are perfect each time!
Just a little old tech!
Have fun!
Jackson T
Elite member
I normally use the first method by cutting out the first rib in balsa (full size), then trace around it for the other ribs. I'm not that accurate, so the extra sanding room is fine. I have tried the "sandwich" method, but it was a bit hard to cut/sand that much balsa all at once. I guess it was still probably better than cutting all the ribs out by hand. Thanks for the tips!
Wildthing
Legendary member
They all look so perfect
Jackson T
Elite member
I could go on about their imperfections, but never mind that
. The builder (at least in my case), can often list plenty of imperfections in their work if it's examined too close!
It's a 4m wing.
Your plane will feel heavy, but with that much wing area and your targeted wingloading, she'll float like a feather.
The highstart itself is gonna have some serious pull, though. You're likely targeting a pull at full strech of 3-5x the AUW, so expect some exercise. For reference:
http://www.charlesriverrc.org/articles/design/dickwilliamson_histartphysics.htm
If you're still nervous, budget out how much of your target weight goes where and track the weith of the parts as you build. Then you should have a way of looking into where you may have overbuilt (or under estimated)
Your plane will feel heavy, but with that much wing area and your targeted wingloading, she'll float like a feather.
The highstart itself is gonna have some serious pull, though. You're likely targeting a pull at full strech of 3-5x the AUW, so expect some exercise. For reference:
http://www.charlesriverrc.org/articles/design/dickwilliamson_histartphysics.htm
If you're still nervous, budget out how much of your target weight goes where and track the weith of the parts as you build. Then you should have a way of looking into where you may have overbuilt (or under estimated)
Jackson T
Elite member
I didn't think about that side of things, only the "if the wing will be strong enough" side. Why does it need so much pull tension? Thanks for bringing this to my attention!
Jackson T
Elite member
Good read, very useful information!
In that case, you've built that wing strong, I wouldn't worry about it. The forces will be high, but she should take it fine.
When maiden time comes, you can always start with an "up-start", which is effectively a scaled-down high-start for practice and trimming. IIRC, they're 1/3 the rubber and 1/2 the line, but I've never seen a consensus on that. The Upstart can give you a shorter pull into the air, and by starting easy, be a bit kinder to the wing. At full extension the acceleration will be just as high, but the burst won't last nearly as long. If she takes the upstart without flexing her wings under the strain, the full highstart should be fine.
That and a glide-toss into the wind should still float well for early trimming. Keep plugging away at her. She'll do just fine
CRCC is among the nerdiest of the nerdy flying clubs. They're the prominant club in Boston, Ma area, and as such, pull some of their membership from professors and students of MIT and many of the tech researchers in the area.
Their site is pure gold for flying model science -- RC sailplanes in particular -- and many of the big names in the rc community publish plans and guides there. Well worth digging through
Jackson T
Elite member
In typical Jackson style, I forgot to do the shear webbing before the sheeting . I decided it was important enough to hack into it, so I did.
I cut a 1/2in strip of sheeting out on the underside, then I glue in the shear webbing and glued the strip back on.
These panels are now done!
. I decided it was important enough to hack into it, so I did.
I cut a 1/2in strip of sheeting out on the underside, then I glue in the shear webbing and glued the strip back on.
These panels are now done!
