Here's a view looking up at the bottom of the 2" (50mm) version:

Sorry - Totally got me.

I have a lot of questions but what is the big bolt and what is the hole in the end of the plate for? It looks like the plate where the hole is in the plate is shown too long and sticks out further than what it is suppose to in the bottom view.

The plate is shorter in the End View. Anyway what is the big bolt doing? Not part of the sliding carriage?

Thanks again for going to the trouble of doing a another drawing.

Col

The big bolt, nut, washers is the pivot for the plate (what actually "safes" the trigger).
Hole in end of plate is for the pull rope to release the safety.
All the parts are the same size in both views.
Carraige should engage trigger ahead of safety mechanism (though it can overlap the spring if using bearings only per original design). Rear leg attachment points would need to be ahead of the safety and could serve as a rear carriage stop.

Thanks very much I completely understand it now. I did not know the plate pivoted.

I have to go and buy some more trigger tubing first and if made it would definitely work great as long as there was enough pressure on the trigger tube so it moves down. The carriage is putting a lot of pressure on the release pin trying to stop the trigger leaver moving down with the pressure from the bungee cords.

Thanks again.

Originally Posted by CV12Steve

The big bolt, nut, washers is the pivot for the plate (what actually "safes" the trigger).
Hole in end of plate is for the pull rope to release the safety.
All the parts are the same size in both views.
Carraige should engage trigger ahead of safety mechanism (though it can overlap the spring if using bearings only per original design). Rear leg attachment points would need to be ahead of the safety and could serve as a rear carriage stop.

the carriage also made from aluminum sheet? what thickness? I'm trying to use T-Slot extrusion for my build as I have some left over from my 3d printer, just need to figure out the carriage material

Thanks

Originally Posted by skellator

the carriage also made from aluminum sheet? what thickness? I'm trying to use T-Slot extrusion for my build as I have some left over from my 3d printer, just need to figure out the carriage material

Thanks

My aluminium sheet attached to the top of the carriage is 1.5mm and the arms holding the plane are 3mm. There are sizes earlier in this thread which I may have copied from. Those sizes seem great. Some do not use sheet but just a couple of arms.

I have to redo the trigger and the eye bolts on the top left of the photo may go underneath. I have not worked out the bungee attachments fully yet.

The second photo is not mine but I just kept it for ideas.

Rc : Rc plane Homemade X8 skywalker 2300mm wing the biggest!!! (3 min 35 sec)

Bolt down a Cross Bow. About Mach .7 at separation.

Of the wing.

Rc : Rc plane Homemade X8 skywalker 2300mm wing the biggest!!! (3 min 35 sec)

Any new catapults being built?
Different trigger ideas?
Different bungee arrangements?
Or substitutes (compressed gas/steam, linear induction, black powder, etc.)?

Any single rail pvc options? Maybe the carriage inside or outside of a pvc pipe for the launch rail.

Carriage-inside-rail would require a split tube and I don't think PVC (or probably any tubular material) would be stiff enough to not twist and/or bend. Some sort of an extrusion with an internal guideway should actually be stiffer than a plain tube, square or round.
I'm not sure PVC is stiff enough to use as the rail in this design, as opposed being a passive guide for the plane taking off under its own power or via a bungee that places minimal loads on the rail(s).

I recently purchased the Go Discover FPV flying wing from Hobby King. All I can say is wow......what a great flying plane, but like all wings you have to hand launch it. I'm in my early 60's now and after having had rotator cuff surgeries on both shoulders with screws installed in each shoulder to help hold them together, throwing a loaded up five pound plane over my head is not good for me so luckily I found this great thread. My hats off to brettbb who started this thread, sharing his skill in building one of these launchers and to the others who have pioneered this venture.
I made a trip to the Home Depot store and found some of the parts I needed and then ordered the rest online so I should be able to begin construction in a few days.
I had a concern about some people saying that the metal bearings were cutting ridges into the main launch tube since the steel edges of the bearings are much harder than the soft aluminum tube. I did order a set of skate board bearings, then I began to think of what I could use that would not cut into the aluminum tube. I ended up ordering an 8 pack of mini shoe skate wheels on eBay shipped for less than $8.00. The have a nice smooth, finished exterior to the actual wheel with ABEC-5 rated bearings at the center and their total diameter is only 1 inch.
If it ends up working out I'll post the results & some pictures here.
Regards,
Tom

Looks like a great idea. I have gathered all the stuff to build one of these and had not started yet. I'm glad I waited.

That looks better than my inline roller-hockey wheel idea.