Activity

I’ve never used 209 on a rocket – the last time I used it was when my hobby was building boats (whitewater and fishing drift boats, mackenzie-style dory) and at that point I ordered it off the web from a…   Read more»

Warren,Thanks for the input. I have also been looking at the 207 hardener as an option but I can’t find it anywhere in the Boulder/Denver/ Ft. Collins area.Since I am adding pigment I think I can probably handle a little…   Read more»

Yes, outgassing is the issue. You can try reducing the temperature of the cure to slow it down enough so that they don’t form or you can try heating it up to accelerate the outgassing and get it done before…   Read more»

Again, like I posted on TRF, maybe try a gelcoat finish rather than straight epoxy? It’s designed as a finish layer, and as such should not bubble.

just a guess but normally as epoxy cures various gasses are released. I’d try it at room temp.j

All good points. It was phenolic and old and brittle at that. Even filament wound FG would have handled it. Ironically, it was an engine charge that blew it up. Put a very long coupler tube inside, and she’s…   Read more»

I don’t advertise this much, but I had one rocket look like Elmer Fudd’s proverbial shotgun after Buggs stuck his finger in the end due to a charge that was a “tad” oversized.I blew up the top of my VA’s…   Read more»

You’re using dual charges? I would stick with a single charge, but dual matches and dual altimeters….but that’s just me….and I’m probably worse than Wilke when it comes to oversized charges. I don’t advertise this much, but I had one…   Read more»

I don’t advertise this much, but I had one rocket look like Elmer Fudd’s proverbial shotgun after Buggs stuck his finger in the end due to a charge that was a “tad” oversized.I blew up the top of my VA’s…   Read more»

You’re using dual charges? I would stick with a single charge, but dual matches and dual altimeters….but that’s just me….and I’m probably worse than Wilke when it comes to oversized charges. I don’t advertise this much, but I had one…   Read more»

You can see where it got me I hope. Also here is a video of one of my ground test.And, I want mine to have that clean separation. I have (12) 12 gram Quickburst canisters–and as far as I know,…   Read more»

Its all about mass and speed and better to be prepared then not. What if when the apogee charge opens things up and it tosses out a little hard and yanks the cone off? or what about if you ever…   Read more»

Why 6-32’s Bruce? Why? Paranoia! My nosecone has weight in it, and like the dart, it should be loaded with inertia/momentum. I just don’t want to take any chances. 4-40’s probably would have worked just fine. That’s what I originally…   Read more»

Why 6-32’s Bruce? I have 3 x 4-40 nylon screws and they hold things together just fine and surely shear when I do a deployment test.Warren

I would recommend doing a ground test with the charge the calculator recommends for four 4-40’s on the four 6-32’s. My guess would be that it will shear the 6-32’s no problem. Then fly with 1.5 times that amount to…   Read more»

I use this calculator, too. I’m using 6-32’s for my nose cone holding the main… the calculator goes only to 4-40’s, so I’m taking a shot for 6-32’s doubling what blasts (4) 4-40’s. Does that sound right?My experience with the…   Read more»

8) Bruce, stand back from the fence!! 🙂 8)

There is an excellent site at ROL http://info-central.org/recovery_powder.shtml that discusses black powder charges and how to calculate them. Doug,I use this calculator, too. I’m using 6-32’s for my nose cone holding the main… the calculator goes only to 4-40’s, so…   Read more»

For that rocket, you should be fine. My dad uses the full charge (and no more) with his PML endeavour, and it works fine (4″ with no piston, loose fit).

There is an excellent site at ROL http://info-central.org/recovery_powder.shtml that discusses black powder charges and how to calculate them. My gut instinct is that the 1.5 grams with the motor will be fine. For my 6″, 24″ chute compartment and using…   Read more»