they are simply there now (actually they arent there now at all ;-) ) for the test fit.
for flight they will be held together with double sided tape then held to the sled with double sided foam tape. The zip ties hold quite tight, and with the foam tape being "crushed" along with the "stickiness" of the adhesive, they betteries wont go anywhere.
Based on the outcome of one of my earliest DD flights, I recommend adding a zip tie that runs around the batteries and their connectors. I had a setup very similar to what you've described here and the altimeter lost power when the drogue charge fired, resulting in the main not firing. I suspect the connector was able to come free because it was better attached to the sled than the (relatively) heavy 9v battery was. Adding a zip tie around them constrains the connector to the battery, which is how you want it to be. Since then I've used redundant altimeters and lipos for every flight.
pulled the trigger on the parachute, an 8' Rocket Man and also purchased a 15' three loop kevlar harness for the HED system. i was originally going to use 15' of 3/8" nylon with an kevlar piece at the electronics bay end to provide protection from the charges, but opted for full kevlar. there isnt any give, but the full fire protection provided swayed me in that direction. i still have the nylon should i want to change back.
the booster uses a piece of 1/2 tubular nylon that is epoxied to the motor mount (see pictures earlier in the thread). there is then a 20' three loop 9/16" nylon harness from OBH. created a short (18 inch) kevlar tether to connect the OBH harness to the electronics bay. all connections are made with 1/4" quick links (other than the nose cone which has a 3/16 as there isnt a lot of stress there) and where needed the material is knotted and then secured with fabric glue.
the drogue for this project is a 7" wide ultra streamer from Top Flight. ejection charge protection for the booster is an 18" blanket from Wild Man and the HED uses a 12".
i do see times where i will use simple apogee deploy, and with this set up i can easily move the main from the nose cone to the booster.
excited to be close to the end. we are actually moving in the end of June so the timing cant be better.
fingers crossed she gets to fly by the end of the summer!
spent the morning wet sanding the fins. First 800 grit then 1000. Then I masked it off with “yellow” frog tape and shot the fins with bright yellow. The paint laid out great
let it sit for 20min and started removing the tape. Issue #1 is the tape left marks all over the silver it was covering. This is inductive of the paint being soft, but it’s had 5 days to cure, two spent in the sun... not sure why this happened. I do have some vertical black stripes, so I am thinking I can work with this.
400 grit is high as you should go before paint. 320 is typically used as final sanding stage before automotive paint jobs. Anything beyond that will have poor adhesion, if not other issues. 1000+ grit is polishing sandpaper for clear coats, and pre-buffing.
Wanted to correct the issue with the fin but didn’t let the paint cure long enough so it “orange pealed”on me. Pisser there cuz I knew better.
Letting it all cure real good now which will be easy as we are in the process of moving. All is good, for as I’ve said before, with all the COVID lockdowns in place in Northern VA, she isn’t going to be flying any time soon.