rye

My Feedback: (10)

hi
i would like to make my hobbic 60 trainer into a bolt down wing ,where would i look for this fourm ,thanks

jester_s1

I doubt there's a procedure posted anywhere for it, but it's a mod that lots of guys have done. I will tell you though that it's more trouble than you probably think it is. You have to build up blocks to take the rear bolts, build structure in the front of the wing for the dowels and precisely drill the bulkhead in the front of the wing pocket to accept them (possibly building a bulkhead there if the existing structure isn't suitable), and you have to make the back of the wing solid so the bolts don't crush the wood or pull out. It all has to be done with epoxy and the parts have to be fitted well to be strong enough. Converting from bands to bolts is a pretty big redesign of a very critical structure. It's not impossible by any means, but it's also not a 2 hour job either. Lots of guys start thinking about doing it when they get tired of stretching rubber bands every time they go out, but bolts aren't really that much quicker. The one benefit I see is that you'll get precise wing alignment every time, but you can also do that by making some marks at the front and back of the wing and fuselage to line up. The reason trainers use the rubber bands is because if you cartwheel a landing or nick a tree, the wing will have some give and likely will make it through.

52larry52

My Feedback: (1)

rye, I also own a Hobbico 60 trainer and several years ago I did a refresh on it as the crappy original covering was really showing its age. It had no crash damage, already been converted to a taildragger, so just new covering AND bolt on wings were scheduled. After extensive thought and study I couldn't come up with a simple way to dump the rubber bands. The front of the windshield area on that plane is not tall enough to allow the standard "two horizontal front dowels into the former" method and I don't like the looks of two front and two rear bolts. Either way would have required extensive structure rebuild inside of the sheeted center area of the wing and while it could be done, it wasn't worth the effort to me. I made it look nice with a red and white fax Cessna trim, and it still flys with rubber bands. To do it right, will require quite a bit of rebuilding of the wing center and fuselage cabin area.

KitBuilder

I added bolt on wing to an Eagle II and this wing also sits atop the fuselage. It was a bit of work on the leading edge but it can be done as the dowel needs to protrude down at 40 degree angles as opposed to straight out like normal. If your a builder and want to spend a few hours on it can be done but if your not a builder, I wouldn't recomment it on these type models as there is a bit of re-engineering to do.

For example you would need to add a secondary bulkhead at the leading edge inside the fuselage to better accept the downard facing dowel more properly. I only added one dowel in the middle, opening up the bottom center section and locating that dowel through to the wing joiner, sandwiched on each side by forward section ply replacement ribs with downard facing tongues to sandwich the dowel with filler top and bottom and the whole shabang wrapped in carbon fiber thread and epoxied. Its bulletproof but I probably wouldn't do it again. Just got tired of the rubber bands going bad over time, etc.

acdii

I dont know how it compares to an LT40, but I did the bolt mod on it when I built it. The hold down blocks are the easy part, the structure up front is the difficult part, it heeds a ply doubler to reinforce the F2 for the dowels or tab, some guys use a tab instead of dowels.  To make it work I added a 1/4 plywood block to the back of the leading edge that was just shy of the width of the inside of the fuse, and epoxied it to the back of the leading edge, and the center ribs on the wing, and it extends down about an inch so the dowels have some meat to catch on the fuse.  Where the bolts go I use 1/16th plywood top and bottom and carved the balsa in the trailing edge to make it flush.

It can be done after the plane is built but takes more work.   It has been in a few crashes, but aside from some epoxy on the Fuse, its holding up very well.