The glider wing and rudder parts are cut from 1/16" thick balsa.
I hand picked out some balsa with very little grain.
I rarely use the Hobby Lite filler. It's not really good for general rocket building but should be lighter than CWF and primer/filler.
The filler was dry and needed water and a lot of stirring to mix to a good consistency.
The filler was rubbed into the grain with a fingertip and the excess removed with a credit card.
The rear of the glider tube gets a round disk, Estes called it a NB-20B. I don't have that part handy.
To get close to the thickness, I laminated four layers of 110 lb. card stock. A glue stick was used and the layers dried in a heavy book.
A pencil tracing was done around the BT-20 tube.
The disk is cut our with scissors. Any bumps are rounded out with sandpaper before gluing onto the tube end.
Here's the flat bulkhead glued onto the tube.
The overhang was sanded to match the outside diameter of the BT-20. A wrap of masking tape prevented me from sanding down the tube end.
SAM modelers - one in particular - taught me to take my 4-oz hand scale into the shop and pick out the lightest slabs of wood. I'm glad to know I'm not the only one still picking through the wood box. The latest OT, 2002 vintage I believe, also has 1/16 x 1/8 basswood leading edges to resist dings.
ReplyDeleteHi Tim,
DeleteI can usually find better than the kit balsa. I look for a certain density for sport models. I hate the spongy stuff.
I'll have to see if I can find the 2002 instructions for the basswood edges.
DeleteLet's not forget some age-old techniques such as:
Delete* rubbing cement (e.g. Duco) into the wood to harden it (i.e. basically do this to the leading edge) - nowadays it's probably not recommended to directly expose your skin to solvent glues (how many of us are old enough to remember days when gasoline was used at times as a cleaning agent -- I remember using gasoline to clean off grease, oil and grit off bicycle parts in preparation for repair - parts came out clean as a whistle, and hands reeking of gasoline for a few days)...
* gluing fold-over strip of paper on the leading edge. Variations I'd on "foamie" aeroplane is to use packing tape (I've used Mylar adhesive tape - though irritating trying to use the cutter in the cellotape dispenser that it often came in), as well as gluing strip of Tyvek (often cut from shipping envelops).
Chris, I worded that poorly (and I can't go back and edit). What I meant is that my most recent OT is a 2002 re-release kit and I substituted my own contest grade balsa for the glider wings using basswood on the leading edges. The edges get pretty badly dinged unless you toughen it up.
DeleteI should proof read better before hitting the publish button.
Hi Tim,
DeleteNo problem! I just remembered where I might find the 2002 O.T. instructions - Shasta Sadie! http://www.ashasta-sadie.com/wp-content/uploads/Estes_Plans/Posted_From_Estes/001259_ORBITAL_TRANSPORT.pdf
To Naoto -
DeleteOh, I've handled many solvents without using gloves when I was younger.
Regarding fin strengthening - Some builders go overboard and add too much weight to the low end by papering with cardstock. Tyvek on the leading edge might work well, it might be hard to smooth over though. I have occasionally used a wipe of CA glue on leading edges.
Yikes! papering with cardstock would indeed be going a bit overboard in my opinion. As for papering of fins, I'd lean toward model aeroplane tissue on the fins using dope (though nowadays I'm more apt to use thinned white glue rather than dope to avoid fumes -- I live in an apartment complex, so I'd like to avoid getting complaints over strong fumes).
DeleteHi Chris and Naoto - I think that Estes has the 2002 OT plans available on their web site, too. I had forgotten about Shasta Sadie.
DeleteCA on the leading wing edges would harden them well enough to resist dings w/o adding weight, I think. I've flown stick and tissue over rough Kansas wheat fields and know what can happen, that's why I use the basswood leading edges. Doesn't add appreciable weight, done well isn't noticeable, and adds strength to the wing.
What a great invention CA is; remember what it was like prior to it being available? A lot of solvent based products we used in our youth have gone - Aerogloss and Ambroid to name just two. I guess it's a good trade.