I have cut, drilled and installed a 3/8" piece of ply under the plastic landing gear mount on my NexStar. Now I need to repair the spar that is broken. You can see it in the pic. On the left side of the pic it's broken and about 1/4" of it is left behind the bulkhead. On the right side it's broken almost flush with the bulkhead. I know I shouldn't butt the new piece up to the old and glue it but it would be difficult to make a diagonal cut on the right and impossible on the left without cutting more of the balsa out. What is the best method for fixing this spar without tearing too much else up or should I remove more of the skin for better access?

Yellowhawk,
Those parts are stringers. They aren't a critical structural component as they don't bear loads. They are there to maintain the shape of the skin. On your pictures I would cut the forward stringer at a diagonal and then cut a piece to match it and simply glue them together at the diagonal cuts. Then glue them into the notches in each fuselage former. That will be more than enough strength in the repaired area. Then resheet your balsa over the top of the stringers.

Hope this helps

Ken

Follow what Ken says, but also add some 1/8" sheet cut to size along the each side of the stringer about 1" either side of where you'll do the splices. If you can do a diagonal cut, or scarf joint, on the aft portion you'll have a stronger joint.

Also those longerons are structural. Your landing gear mount plane attaches to the bulkheads these run through. Just a bit of extra material to help strength the area and help transfer the loads out of the area. Before you re-sheet, put a small piece of fiberglass cloth between the landing gear plate and bulkheads. Also use some sheeting as doubler material where the sheeting will join - this will make up for the strength lost with the cut sheeting and butt joint that you'll end up with splicing the new sheeting in, and give a little shelf to help attach the sheeting to.

Hogflyer

a photo its a huge help, I think I posted this in the last thread but make sure the gear is tight in the slots.
some triangle stock to brace the plywood area at the formers on each side is not a bad idea or fiberglass as suggested.
the stringers are a easy fix,just split the former and replace them, just CA them in and they will be fine the main load is taken up by the plywood piece the gear slides up against, the sheeting will support the load of the gear plate after all the parts are glued in.
when you re-sheet the area you might want to wet the sheeting with windex or alcohol and water 50/50 to make the wood more plyable for bending arround the fuse I have done this repair twice on my NEXTAR and it seems to be a weak spot until you have a pair of gear totally destroy a fuse on a hard landing.
as long as the gear slide in tight you will be good to go the plastic lock won't work well unless it slides in smooth and without any slop I found this out the hard way when I repaired mine the first time and my gear wouldn't lock into place and wanted to fall out had to re-repair it, then I broke them again but it was a easy fix after the first run through,trainers are made for crashing and repairing.
mine still lives semi retired waiting for a, recover,floats, and a wing straitening,so it looks more like a Cessna, planning on powering it with a OS61.
trainers never die they just turn into something else,unless you turn them into a pile of sticks.
good luck your repair doesn't look too bad at all I crashed and repaired mine much worse than yours and it flew really good still.

Thanks for the help fellas. Hopefully I'll be up and flying again soon and much more careful with the aircraft.

What was the cause of your crash?

Yellowhawk, read this short "How To" on sheeting repair. It will show you the best way to lay down the new sheeting once you have the stringer fixed.

[link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=98]Sheeting Repair[/link]

MinnFlyer, How do find time to fly ? Your articles and reviews are great , but you have to be suffering from stick withdrawals?

Fly???

Ken

Who ever said I knew how to fly???