I got a scale that measures to the milligram (displays to the milligram, I think the accuracy is listed at 5mg) for only $20 on sale at Amazon.
Hans,
The Path to Level 1: Acquisition, Build, Test, and Certification Attempt Thread
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Hans,
tg08
Well-Known Member
If not, there are cheap jewelry scales on Amazon (20-30 dollars) that can measure to the hundredth of a gram.
This project is now reactivated!
After the Astrobee D’s crash landing, I put the rebuild on the back burner. I ordered new tubes quickly from BMS, but never followed up on an offer of Fin-Lok rings from a fellow builder. A few weeks ago I decided to exercise some independence, quit moping, and order a new motor mount kit from AeroTech.
The new mount features as many remaining original parts as possible, including the fiberboard centering rings, gas cooling mesh and baffle, screw eye, shock cord, and eventually the motor retention threads and cap. The replacement kit came with the older wood centering rings, thrust ring, flange, 1/4inch launch lugs, and motor hook, which are not used. Only the tube and Fin-Loks are new.
My initial inspection of the fins that popped out revealed that they’d taken out a piece of the lip on the Fin-Lok that snapped them in place, and removing it from the fins with my hobby knife didn’t seem like the most effective solution.
I ended up ordering a new set from AeroTech, easily the most expensive part of this rebuild. Tonight I popped off the tabs and sanded them down.
When I install them I will glue them in such a way that that’s not as likely to happen should they pop off.
The replacement body tubes from Balsa Machining do not have slots. Any ideas on how to get them precise enough that the fins don’t look crooked?
The coupler is defective, so assembly of that is on hold. The end is not even all the way around and it features a visible lip, preventing a good glue joint with the salvaged bulkhead. It’s like that on both ends. I’ll request a replacement tonight.
I also do not plan to do any of the spiral filling, scale details, or other cosmetic work, aside from maybe giving it a high-visibility color scheme. Suggestions for alternate names and colors are more than welcome!
After the Astrobee D’s crash landing, I put the rebuild on the back burner. I ordered new tubes quickly from BMS, but never followed up on an offer of Fin-Lok rings from a fellow builder. A few weeks ago I decided to exercise some independence, quit moping, and order a new motor mount kit from AeroTech.
The new mount features as many remaining original parts as possible, including the fiberboard centering rings, gas cooling mesh and baffle, screw eye, shock cord, and eventually the motor retention threads and cap. The replacement kit came with the older wood centering rings, thrust ring, flange, 1/4inch launch lugs, and motor hook, which are not used. Only the tube and Fin-Loks are new.
My initial inspection of the fins that popped out revealed that they’d taken out a piece of the lip on the Fin-Lok that snapped them in place, and removing it from the fins with my hobby knife didn’t seem like the most effective solution.
I ended up ordering a new set from AeroTech, easily the most expensive part of this rebuild. Tonight I popped off the tabs and sanded them down.
When I install them I will glue them in such a way that that’s not as likely to happen should they pop off.
The replacement body tubes from Balsa Machining do not have slots. Any ideas on how to get them precise enough that the fins don’t look crooked?
The coupler is defective, so assembly of that is on hold. The end is not even all the way around and it features a visible lip, preventing a good glue joint with the salvaged bulkhead. It’s like that on both ends. I’ll request a replacement tonight.
I also do not plan to do any of the spiral filling, scale details, or other cosmetic work, aside from maybe giving it a high-visibility color scheme. Suggestions for alternate names and colors are more than welcome!
Also in that order is a BT-52H tube, originally intended as a 29mm motor mount tube for this rocket but now left without a reserved project. I’m thinking a something in the vein of a Goblin, something short and way overpowered for a 24mm mount.
Either that or it can be a longer minimum-diameter fire-and-forget rocket with an absolutely huge single-use motor, something I can fly recklessly (in terms of recovery planning anyway, I would never be an actual hazard on the range) to celebrate a successful L1.
Measure the tube OD and then print out a fin wrap template from payloadbay.com.
Mark off the locations for the fins, and rotate the guide to offset from those initial marks by the thickness of the fin tabs. Use a length of aluminium 90 degree channel to extend lines along the length of the tube from those marks. Use that same aluminium channel as a guide (I like to secure it to the tube with a wrap of tape) and make multiple cuts with a sharp exacto. Once the 'long' cuts are done, cut the ends free.
This is a 38mm LOC motor mount tube:
WOW!!!! That's looking great!!! Looks like you did a great job on cutting that one out! I as I was reading your tube cutting issue, I was thinking of the answer as I was scrolling down to see you did exactly what I was thinking... angled aluminum, cut lines, and then you went a step beyond (great idea BTW), and taped it down to keep from moving!
Sorry to hear about the demise of the rocket.
+1 on the comment about weighing the BP with the cheap scales. You can also use volume (1ml approximately equals 1g) as a reasonable substitute. Just make sure either way you fly what you test.
+1 on the comment about weighing the BP with the cheap scales. You can also use volume (1ml approximately equals 1g) as a reasonable substitute. Just make sure either way you fly what you test.
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