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fyrechaser

Builder of flying things
TRF Supporter
Joined
Apr 1, 2009
Messages
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Location
Blackwell, TX
Hi Guys,

Now that the level 1 cert is out of the way, I'm statrting a new project. It will be a 4" x 60" 3FNC using LOC tubing with anti-zipper and baffle. I will build two nose sections...one for single event/apogee main deployment, and one for altimeter based deployment. I don't want to get in over my head here because of my inexperience, so my thought here is to work toward my L2 gradually, getting more experience with basic L1 flights using motor ejection and then working my way up to altimeter based apogee deployment with motor back-up...and finally to dual deployment. Once I feel comfortable with avionics/electronics, I'll build a new bird and go for L2 (or use this one if it's not in pieces by then)
It will probably be a little on the heavy side because I tend to overbuild, but I think at this point I need reliability versus altitude to gain some experience.
Once all the parts have arrived, and I begin construction, I'll post pics of the progress.
Does anyone have any other suggestions? I'd be pleased to take them.

Onward and Upward!
Jim B.
Odessa Tx
NAR L1
 
sounds like you have a good plan.
What size motor mount you planning on?
 
I thought I would go with a 38mm mount, I have 2 rockets with 29mm mounts now which are fine, but I want to be able to have a little versitility. I can always adapt down to 29 to use my 29mm hardware. I haven't ruled out 54mm yet though.

Onward and Upward!

Jim B.
Odessa Tx.
NAR L1
 
I would think about using TTW fins...... It's a lot stronger and will be good practice getting ready for a L2 rocket......
 
This has been posted a zillion times I am sure. Go with the 54mm mount, you can always adapt down.
 
Randy, I agree about TTW fins. I plan to glass the internal mmt and airframe fin joints as well.

Todd, I may well use 54, I just have a lot of 38 laying around the shop.

Can't wait to get started!

Jim B.
Odessa Tx.
NAR L1
 
Originally posted by fyrechaser
Randy, I agree about TTW fins. I plan to glass the internal mmt and airframe fin joints as well.

Todd, I may well use 54, I just have a lot of 38 laying around the shop.

Can't wait to get started!

Jim B.
Odessa Tx.
NAR L1

If you are going to the trouble to build the fincan so strong, put the 54mm mount in and use your 38mm tubes to make an adapter. Since you are incorporating an electronics bay you may want to fly this bird on the bigger motors later.

or....

Put in a 3" motor mount and make a cluster adapter for (2) 38mm motors. Then if you are feeling frisky you can fly it on a cluster of (2) J-570's or an M-1315 for your L3.

....look it's raining paper and plywood:D
 
seriously now,

This was one of those things I learned the hard way about my 3rd year as a BAR. I had built a Loc Magnum to do my L2 cert. I did everything you are talking about (glassed it, reinforced fin joint etc.). Originally did the cert flight with motor ejection then made a new payload section to fly it on electronics.

The problem now is that I am stuck with a 54mm mount, when the rocket can safely handle all the 3" loads. The rocket has not really grown with me. I still fly it on 54mm loads once in a while but now it is more of a hanger baby.

If you plan on flying this rocket for awhile put the biggest Motor mount, within reason, in it. The AT and Pro54 J and K reloads are super cool and would fly in your rocket easily.

...you only need the Kevlar umbrella if it is coming ballistic:p :p
 
Todd, your points are well taken, and make perfect sense. While I plan on glassing the fin joints internaly, I had not intended to glass the airframe on this project, hence my tendency to stay with a 38mm mount. I had originaly thought about a 54mm mount but became somewhat hesitant thinking it might be a little too agressive for an unglassed airframe. I'm a rookie, so I could certainly be in error on this point. Should I still go with the 54 with an unglassed airframe?

Thanks for your input,

Jim B.
Odessa Tx
NAR 83161 L1
 
Originally posted by fyrechaser
I'm a rookie, so I could certainly be in error on this point. Should I still go with the 54 with an unglassed airframe?

Sure, I've flown rockets with unglassed 3" bodytubes on 54mm motor mounts before. I did glass the fin fillets though.

Aerotech: J275, J460, J415,
HyperTEK: various 440cc tank/orifice combinations
 
Originally posted by fyrechaser
I'm a rookie, so I could certainly be in error on this point. Should I still go with the 54 with an unglassed airframe?

I agree with hokkyokusei on this one. The smaller 54mm from AT are fantastic and would be fine in an un-glassed 3" airframe. I have seen lots of M flights with no fiberglass used at all.

I would still recomend putting in the 54mm mount. Worst case scenario is you never use it and costs you a few bucks. Cheaper than building a new version from scratch because you want to flly the bigger motors now.
 
PML has great kits that have that kwickstitch mmt system in witch you can use 54mm,38mm, and 29mm I just just got my AMRAAM4 together that Ill be cert1 on then cert2 later even the AMRAAM3 has the same system if ya want a smaller bird
 
Originally posted by Bowhunter
PML has great kits that have that kwickstitch mmt system in witch you can use 54mm,38mm, and 29mm...

On thing to watch out for with the quickswitch, is that it limits the length of motors that you can fit.
 
I appreciate all the great advice. Rocket people really are the some of the nicest and most helpful people I have ever met.

Time to get in the shop...

Thanks folks!

Jim B.
Odessa Tx
NAR 83161 L1
 
I haven't had a lot of time to spend in the rocketry forum in the last few months, but I wanted to update what has happened with this project since waaaay back in June when started this thread. I also wanted thank all the folks that gave me some great advise. I apologize for not keeping the thread current during the build but time for me was at a premium the last few months. :)

Plans changed during the build with the final design for the project turning out to be a 4" X 67" 3FNC with dual-deployment with anti-zipper for the booster.
The project was finished around mid August. First flight was in McGregor TX in Sept 04 and was my first dual-deployment flight. A great flight with with perfect recovery.

This rocket has flown 3 more times since then with the last flight taking place in Hearne TX on 2-12-05 with a CTI J330 for a successful NAR level 2 flight. The flight went to 3661', drouge (streamer) at apogee and the main at 500' and a soft landing.

I'll post a few pics as promised a long time ago...

Thanks folks,

Jim Ballard
NAR 83161 L2
 
Good deal and congrats on the L2 cert flight..... nice looking bird..

Hard to tell in the pics but looks like you went with the 54 mm mount..??

I just build a scratch 3"x60" 3FNC all paper rocket with a 54mm mount in it.. should go up this season with either an AT K550 or Pro 54 K445.... No glass at all....hopefully i'll have a good report on it too in a month or so..

https://www.firemanrocketry.com/mach1.htm
 
Jason,

That is an awesome rocket man! I'm betting it's going to do just fine on your motor choice.

To answer your question, I wound up not going with 54mm mount, I went with 38mm. I ordered 54 but got 38 by mistake. I then had so much 38mm tubing I just said to heck with it and used the 38.

Good luck with the K motor flights. I'd love to see some pics and video when it happens.

Jim

https://www.rocketdreemz.com
 
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