Motor Tube Length Question

[JamesBenMoore]

Hey Y'all,

I got my L1 with a Wildman Journey 75 on an H100. I'm toying with the idea of setting it up for dual deploy and going for my L2 on a J435. The dual deploy setup I think I'm ok with, but I'm a little worried about the motor mount to motor length ratio. Currently the motor mount tube in this rocket is only 6" long, and the J435 motor I'm thinking of flying is 14.5" long. Is this too short of a motor tube to fly this motor?

If it is too short, would adding an additional motor mount tube with two centering rings above the current one be an acceptable way to fix this issue? I currently have the shock cord mounted to an eyebolt on the existing forward motor tube centering ring, my idea would be to run the shock cord between the additional two centering rings and the body tube, clearancing as necessary. I assume as long as I get the centering rings perfectly attached to the new motor tube it should work to center the extra length of the motor.

Any thoughts or advice on this is appreciated, and yes I know I am turning this Wildman kit into something of a Frankenstein learning experience but I'm ok with that for now.

 

[David Schwantz]

You could add another chunk, but the MMT is there just to keep the motor straight and to transfer thrust. It is already doing both of those tasks.

 

[Titan II]

Is this too short of a motor tube to fly this motor.

No

 

[gloy]

It will be just fine, send it.

 

[Hobie1dog]

should be fine

 

[86mustang408w]

Use the shorter tube, its fine. Keep in "centered" in the lower airframe. That tube needs to be straight...


I'll add components, to keep my CG/CP, in the middle of your bird. Or lower around the fin area. CP....

I'm building, my NAR L2, right now...lol...

It will also be my exact L3. I've really been building/flying low and "mid", power almost 34 years now I wanted to move up, I need the motors now. I'm 41, myself....

I was getting this built, "this" 5.5", 91.5" Long, Single 75mm, LOC Magnum 3E(Using Aeropack adapters, 3 altimeters, etc....and really any motor from a baby J, to an L2200G, to a 75mm "M", class DMS, or RMS..

That "L2200-G", is. 16Ns away from a smaller "M", but Im really fully disabled.

so this was a goal in 2013 or so, to get in a High Power fight or at least the attempt in to say "I did it".

My "L1", on 11/04/2023 was interesting. For my only second visit(I'm with SPAAR and as last October(one of the many great clubs), that is ironically also holding LDRS-42. Where now after registering in January for it while re-newing my URRGs High Power membership(This was all Saturday, after a great hour almost long talk with Larry W., the clubs "Perfect"...( )President Saturday. I'm assigned to the "High Power Pad One", all 4 days while flying a few "new", builds as well. This build, is really for me but to share its success, or possible failure...

I had planned to fly this, but another build just like this but with a 98mm motor mount for the NAR, L3 Attempt. I'm working on this NAR L2/L3 build as Im sorting now to finish a few especially this "L2", as I wasn't sure about the L3 process 100%.

But I was told, after flying this, almost $1000 dollar L2/L3 in April, then maybe May for a 54mm flight, full DD, but SD for the mid J class flight. Its a stable L3, that will weight about 15 pounds. Almost exactly without any motor in, Im getting that finally weight, today after more doctors appts around 11am today. Then Ill adding more text/pics as the build progresses all the way, now maybe to L3...Its a busy day, as always but Im around, 24/7 usually.

If your interested, it may give you an some ideas to help you out?

A lot of this information, You can have to further yourself in rocketry.

Very, very busy though...But here 24/7....

Michael B(This for educational purposes, onky. Im sharing this a little bit. Its gonna be, very cool. Either way..... ).........

https://www.rocketryforum.com/threa...ummer-2024-attempt.184076/page-5#post-2547592

 

[Handeman]

If you had the room in your rocket, you could fly a 40" motor with that 6" MMT.

 

[Theory]

If you had the room in your rocket, you could fly a 40" motor with that 6" MMT.

Best idea ever!!!!!!!!!!

 

[JamesBenMoore]

Thanks for the advice everyone, sounds like I'm just gonna send it! Will update after the flight. (Hopefully March 2nd)