Sig Giant Kadet Senior ARF
01-03-2010, 11:36 AM
#53
Senior Member
RE: Sig Giant Kadet Senior ARF
Here's the steps that Ifollowed to convert my red ARFto a tail dragger. This was my first effort of modifying any plane as it was performed on the ARFafter9 flights (took 9 to solo - what can I say - Kadet Seniors are soooooforgiving and easy to fly - they make you look soooooo good). I'll addnotes as to how I would do it today (after 8 builds).
Parts:
Parts:
- [*]covering - 1 roll each of Aerokote transparent red and white.[*]1/4" plywood sheet (main landing gear)[*]1/8"plywood sheet (tail gear)[*]3/8"balsa tri-stock[*]3 1/4-20 blind nuts and 6 1/4-20 nylon bolts (3 are spares)[*]Great Planes Scale Tail Gear Assembly (GPMQ4245)[*]Great Planes main gear[*]balsa &hardwood scraps[*]2-56 pull-pull push rod kit[*]scrap inner push rod tubes[/list]Main landing gear: Goal - replace the bottom balsa sheeting that is front of the former positioned at the leading edge of the wing with reinforced 1/4" ply.
I wanted the finished result to be cosmetically transparent.Tail landing gear. Goal is to replace the bottom balsa sheeting. The rear is is purely stick construction unlike the front of the fuse. My plan was to add a hard backbone from the rear of the fuse to the front of the fin to act as a "nailer"if you will. In retrospect Iwould create a plywood laminate - 1/8" lite ply on the outside that would cover the entire balsa frame and a 1/8" ply that would fit on the inside of the balsa frame. Yea a bit heavy but LOOKATTHEFIREWALL- there is a ton of lead up front so additional weight back here will only result in tossing a bunch of lead.
The idea is to remove the bottom balsa sheet where the main landing gear is located (axles in line with the wing's leading edge - or a bit in front). The plywood plate covers the bottom between 2 adjacent formers. The covering is carefully removed. The hole is carefully cut so not to carve up the side balsa sheet that extends to the bottom.
Reinforce the inside of the hole with 3/8 or 1/2 tri-stock glued to sides and the two formers.
Fabricate the plywood to fit in the hole - Don't glue yet. Make the fit tight. Install the plate and the align the main gear on the plate. When you get it aligned (axles at or just in front of the wing's leading edge) mark the holes and the outline of the gear on the plywood. This is the way I did it (my first ARF bash) - I took the ply and gear, aligned them and secured them in a vice. I then used several sized bits to drill the holes thru the gear base AND the plywood base starting with 1/8" and finishing with 1/4". After removing from the vice the ply holes were expanded a bit to allow for the blind nuts. Partially Insert the blind nuts, add a bit of 30 min epoxy under the blind nut flanges then fully seat the blind nuts. Have alcohol, paper towels & cotton swabs available to clean up any excess epoxy.
Install the plywood base into the fuse with epoxy. Keep things clean. Clamp or weight the base to keep it flush
Again, I wanted the finished result to be cosmetically transparent
Remove the covering & balsa sheeting from the rear of the fuse up to mount point of the fin.
Add structure - again this is what I originally did - cross members were fabricated to provide lateral support between the frame and add vertical support to the plywood base. A chunk of hardwood was added to provide the screws with a hardwood base. Today, I would use 2-56 bolts and blind nuts instead of the provided screws.
Before I fabricate the plywood bottom Iused the balsa bottom as a model to locate the slot holes for the pull-pull cables. Today Iwould make a drill guide and long drill bit to make a precise angled hole for each cable. They were located to ensure a straight run between the servo arms and the arms on the land gear. It MUSTbe a straight line PERIOD! Install the tail gear frame using a 1/16" bit and the provided screws.
Fabricate the plywood bottom using the balsa model. Mark and drill the 1/16" holes for the tail gear.
Install the plywood bottom using epoxy. Keep things clean.
Install the tail gear. Run the pull-pull.
Done deal ...
With all of this said, I would do it a bit differently today - I had been doing RCstuff for about 2 months at most. Today I don't buy ARFs anymore - only build kits. Just wanted to give a newbie an idea of what someone else did - a talking point - that's all. Look at your tool inventory. Look at your spares inventory. Do you have a LHSwhose owner is a builder / tweaker (no, not a meth head). Talk to your experienced building friends. Check the dumpsters at your field - snag a few spare pieces that could help making these mods.
Btw - that Aerokote looks fine until it doesn't - dents and cuts easily. I really like the Senior ARFcovering scheme - but not the covering material.
01-15-2021, 06:50 AM
#54
Old Sr
I built my SR from a kit. Increased the wing span total by 2 spar spans, added ailerons, made it a tail dragger, Installed a Saito .82 4-cycle engine because a .52 4-cycle has a hard time bucking the wind at are field and a .90 size engine is way too much. Made the wing one piece which may make it harder to transport. Pay attention to listed control settings. It is a great plane.
The following users liked this post:
capt1597 (01-15-2021)
