Documenting my Level3 and for sharing with my advisor.

[Ez2cDave]

I've found a source for a 96" long piece of titanium seamless tubing 98mm if that gives you an idea of how fast and high I want to go. I've machined it before and as long as I can find a lathe with enough bed to run it on I'll make myself a motor casing to run higher pressures in. Like I said I'd love to get a 98mm P motor in the air.

Tungsten for the end closures / nozzle ?

 

[TimothyG]

Got my hatch cut today.

 

[TimothyG]

I’ve decided to test fly the electronics bay and nosecone assembly to test a few things at our first launch this season. It’ll be an opportunity to fly a J825 and I’ll be able to practice using my tracker. This assembly will fit my Nike booster and sims as stable. I’ll do main deployment at apogee and visually track it before switching to the egg finder once I see it landing safely. Best of all a few other students will be present to assist.

If I was being completely fair this J reloads been burning a hole in my pocket.

Dave as to your question I have no idea as I haven’t made it that far beyond just looking at tubing prices and contemplation over beers. First I got to get this right. Then a couple other hundred things have to go right before I make it that far.

 

[TimothyG]

Finished turning some charge cups from a piece of scrap aluminum this past week and firmly believe it’s going to take more practice brazing before I’m comfortable doing a fin. Otherwise not much progress and just waiting for my local clubs first launch of the season.

 

[TimothyG]

I flew my electronics bay on my L2 airframe yesterday using the J825R. Learned a few things I'd like to change and what worked and didn't.
Rocket flew single deploy with a larger parachute in order to have a further drift for practicing with the Eggtimer tracking set up I assembled. This backfired unfortunately as it launched during one of the calmest portions of the day around 2pm landing 3-4 hundred feet from the flight line just off to the right. Tracker gave me good data without disconnecting even once during the ascent or descent. I plan on flying it again using a K1103X reload in June if the launch isn't cancelled due to warmer weather causing dry conditions.

Using my 2-56 screws to hold on the access hatch worked fine and as long as I didn't try and hold the screws in my hand while closing or opening the hatch it was easy enough to not loose any screws. I instead will have a magnetic tray that I can stick to the launch pad to hold my screws and I will also have the hatch removed ahead of going out to the pads. My technique for hard packing my charges worked well as both the primary and back up charges sounded like gunshots from 3740 feet up. Packing in a deployment bag worked again for me so I'll be using this technique on the final recovery harness. I forgot my phone back at the flight line so didn't properly test the proton flight computer instead opting for just altimeters and tracker. All electronics are still tight after this flight and no wiring was pinched. Switches all worked and stayed positively engaged. New 800mah batteries had a far smaller form factor making packing the electronics bay far faster and easier. New batteries also do not rely on a battery holder which gave me some piece of mind knowing they wouldn't shift and disconnect. I am now running single cell lithium batteries on both altimeters and the camera while the tracker and proton run on a 3 cell lithium drone pack at 800mah. New batteries also shift the weight of the batteries forward in my sled by 8" center to center allowing for increased stability and reduced weight by 350 grams over old battery arrangement.

After having an incredibly busy flying day at our clubs launch I've decided to make the rail buttons interchangeable to allow me to fly off of 1010 or 1515 rail. There was a 3-4 cycle backlog at times thanks to a huge turnout with most being Lvl 1 and 2 certs. This resulted in a huge backlog for the 1010 rails.

Having spare parts at my future launch will be a requirement due the small screws I use for the access hatch. Thanks to another flier I was able to fly Saturday as they happen to have an assortment of the screws I needed when one disappeared into the dirt.

 

[Nytrunner]

This backfired unfortunately as it launched during one of the calmest portions of the day around 2pm landing 3-4 hundred feet from the flight line just off to the right.

Ah, you've unlocked the secret bonus feature of trackers!

Installing one in the rocket increases the likelihood it will land within sight!

 

[MClark]

I've found a source for a 96" long piece of titanium seamless tubing 98mm if that gives you an idea of how fast and high I want to go. I've machined it before and as long as I can find a lathe with enough bed to run it on I'll make myself a motor casing to run higher pressures in. Like I said I'd love to get a 98mm P motor in the air.

Tripoli restricts motor casing material to composites and aluminum.
Material for airframes and fins is also restricted.
Not to say you can't use it, you will just have to find a venue that allows it and has a high enough waiver.
Always learn the safety rules before spending money.

M

 

[TimothyG]

Tripoli restricts motor casing material to composites and aluminum.
Material for airframes and fins is also restricted.
Not to say you can't use it, you will just have to find a venue that allows it and has a high enough waiver.
Always learn the safety rules before spending money.

M

I understand this and the problems associated with it. Hence why it's a long term project/idea. FAR is one option and honestly if I get to my end goal after a several year process of working up to something in that size and pressure range then I will go through whatever process is required of me to get an officially sanctioned launch be it through TRA or NAR or on my own getting an individual waiver for a launch. This is also something I'm not even remotely working on right now and was only mentioned in reference to goals and why I don't just fly BDR for L3. I'm trying to move towards an understanding of what a project like that entails and takes both educationally and financially. As of right now my initial rocketry goals are drastically different/restrained then when I started high-power a year ago.

 

[MClark]

Working up to a goal is the best way. The student teams trying for space with the first rocket they build has poor results.
Not to harp on knowing the rules but NAR does no research motors and the waiver at FAR (last time I checked) is 50k feet.

M

 

[TimothyG]

Finally had some time to work on this again. Did a test flight of the electronics in full dual deployment setup with all the hardware I’ll be using on my L3. Also found time to draw up my fins in solid works and get them profiled. The machine shop mentor at school helped with setting up the machine since I’ve never used a Tormach (think I spelled that right). Next step is to do some finishing work on the fins and blunt them. They ended up sharp due to a lapse on my part and I don’t want the fins to accidentally cut the recovery harness or chute. Slotting the tube for the fin tabs and then brazing after that then some turning to fit the tube.

 

[OverTheTop]

Nice!!!

 

[jim_kc]

I've found a source for a 96" long piece of titanium seamless tubing 98mm if that gives you an idea of how fast and high I want to go. I've machined it before and as long as I can find a lathe with enough bed to run it on I'll make myself a motor casing to run higher pressures in. Like I said I'd love to get a 98mm P motor in the air.

I just saw this and it reminded me of a thread I saw a while back about turning grooves at the headstock end by holding the casing internally and supporting the other end with a roller stand/steady rest, letting the excess hang off over the end of the bed. Might be an option if you have access to a somewhat shorter lathe and a good steady rest.

Here's the thread, the last couple posts give some methods:
https://www.rocketryforum.com/threads/long-motor-case-groove-machining-help.139471/

 

[OverTheTop]

I just saw this and it reminded me of a thread I saw a while back about turning grooves at the headstock end by holding the casing internally and supporting the other end with a roller stand/steady rest, letting the excess hang off over the end of the bed. Might be an option if you have access to a somewhat shorter lathe and a good steady rest.

Here's the thread, the last couple posts give some methods:
https://www.rocketryforum.com/threads/long-motor-case-groove-machining-help.139471/

That's fairly standard practice for long items on lathes. Same with using a rotary table on a mill.