Fliplock build, J&H Aerospace kit

[Rktman]

Hmmm.......so, does the model NOT have an engine hook? Can you add one?

Non-engine hook setups have worked badly for me. Either I don't put enough tape on to hold the motor, or I put too much tape on, and I can't get the used motor out without damaging the model.

No engine hook (to keep things as light as possible I guess). I just may give in and install one even if it means adding more clay to the tail end. Getting tired of the too tight/too loose motor thing.

 

[Maxout]

Follow up
Maidened the FlipLock yesterday on a 1/2A3-2T but the motor didn’t have enough oomph to get it much higher than about 40’ (unless the motor malfunctioned?). Fortunately the short delay deployed the wing opening mechanism before it hit the ground but…unfortunately it also ejected the engine (my bad, apparently didn’t use enough tape to friction fit it tight enough) so it wasn’t glide-stable.

Well that royally stinks. I'd assume it's a bad motor given that I've had pretty good launch height from that motor on this airframe, and that's across all the various versions of it that I've built. Still, not fun for sure.

No engine hook (to keep things as light as possible I guess). I just may give in and install one even if it means adding more clay to the tail end. Getting tired of the too tight/too loose motor thing.

There's a separate piece of logic. I fly off pistons regularly and design our various kits with that in mind since many competitors also prefer the advantages of that method. I've flown models with engine hooks off pistons, but it's a little bit of a pain and so, well, I opted to eliminate those on our kits.

 

[Crawf56]

There's a separate piece of logic. I fly off pistons regularly and design our various kits with that in mind since many competitors also prefer the advantages of that method. I've flown models with engine hooks off pistons, but it's a little bit of a pain and so, well, I opted to eliminate those on our kits.

OK, what are "piston launchers"?

 

[Maxout]

OK, what are "piston launchers"?

I seriously need to put together a video on this topic...

Pistons capture the low pressure gas at the beginning of startup and use them to propel the rocket upward until the engine reaches full pressure. In the case of 1/4A gliders, I see about a 50% increase in launch height from pistons. They can be a little hard on lightly built models since the separation can slap the piston tube against the tail.

 

[Crawf56]

Here is a link to a piston launcher as described by Apogee Rockets:

Interesting, but not my cup of tea.

 

[Maxout]

Here is a link to a piston launcher as described by Apogee Rockets:

Interesting, but not my cup of tea.

It'll be your cup of tea when I release one. Most of the ones out there are excessively complex. Either way, the launch acceleration has to be seen to be believed. It's pretty spectacular, and if you like gliders, you'll love how much higher you can launch them.

 

[BEC]

It'll be your cup of tea when I release one. Most of the ones out there are excessively complex. Either way, the launch acceleration has to be seen to be believed. It's pretty spectacular, and if you like gliders, you'll love how much higher you can launch them.

You wouldn't be planning to a 13mm piston kit any time soon, would you, Josh? Please?

 

[Danh]

You wouldn't be planning to a 13mm piston kit any time soon, would you, Josh? Please?

For a 13mm piston tube All you need is to order is some 34” long bt-5 tubing and 1pc of bt-5 coupler. From balsa machining or your favorite tube supplier. Cut a piece of coupler 1” long and glue inside the body tube . This is the stop . Next you will need a piece of wooden dowel 1” - 1-1/2” long . this is your piston head . Place the piston head inside the tube with the stop on the bottom.

Now for the rocket prep make sure the motor is sticking out maybe 3/8-1/2 “. insert igniter and remove paper from the leads. Bend the leads over the outside of the motor now insert the motor into the piston tube it’s should be a tight fit. Adding a layer of tape may help.

Now put your assembled piston tube over a launch rod this will slide the piston head up to the motor. you are ready to launch.

That’s a very basic piston that will work. There is a lot of theories on piston head design and length of pistons . I’m just keeping it simple.

Most people only use the piston tubes once during a competition but for sport flying you can get several launches out of one tube.

https://www.nar.org/wp-content/uploads/2014/05/Piston-Launchers-Stevens.pdf

 

[BEC]

For a 13mm piston tube All you need is to order is some 34” long bt-5 tubing and 1pc of bt-5 coupler. From balsa machining or your favorite tube supplier. Cut a piece of coupler 1” long and glue inside the body tube . This is the stop . Next you will need a piece of wooden dowel 1” - 1-1/2” long . this is your piston head . Place the piston head inside the tube with the stop on the bottom.

Now for the rocket prep make sure the motor is sticking out maybe 3/8-1/2 “. insert igniter and remove paper from the leads. Bend the leads over the outside of the motor now insert the motor into the piston tube it’s should be a tight fit. Adding a layer of tape may help.

Now put your assembled piston tube over a launch rod this will slide the piston head up to the motor. you are ready to launch.

That’s a very basic piston that will work. There is a lot of theories on piston head design and length of pistons . I’m just keeping it simple.

Most people only use the piston tubes once during a competition but for sport flying you can get several launches out of one tube.

https://www.nar.org/wp-content/uploads/2014/05/Piston-Launchers-Stevens.pdf

Thanks. That is rather simpler than most of the information I’d already turned up.