Max 29mm motor length?

[DynaSoar]

I'm working on a mid-power bird with plans to also use it for my L1 flight. It's a 29mm minimum diameter design. I want it to be able to hold any 29mm motor so I need to plan ahead for anything. What's the longest 29mm motor available?

 

[hokkyokusei]

Apologies if this appears twice, the first try didn't seem to work...

Anyway, the longest 29mm motor I can think of, off the top of my head would be the RATT works I90. It's about 36 inches long.

 

[Karl]

Sorry to change the subject a little here , but I have a BSD Diablo , and ive used the motor retainment that came with the kit......
Say if i wanted to change brand of motor , for example , from Aerotech to Congreve (When the realease) , would i have to change my motor retainment to suit this motor?
Thanks
Karl

 

[shockwaveriderz]

dyna:

assuming you mean ONLY RMS, ie reload casings, the AT 29/360 RMS is 13.1" in length......

If you also include SU 29MM I don't know....

I assume you plan on using spacers depending on engine length? Thats how I have designed my L1 model ....so I can also use any possible 29mm RMS reload......

 

[shockwaveriderz]

Karl:
probably NOT....

 

[DynaSoar]

Originally posted by shockwaveriderz
dyna:

assuming you mean ONLY RMS, ie reload casings, the AT 29/360 RMS is 13.1" in length......

If you also include SU 29MM I don't know....

I assume you plan on using spacers depending on engine length? Thats how I have designed my L1 model ....so I can also use any possible 29mm RMS reload......

I mean, wide open, any type, any brand, any and all 29mm motors, RMS or no. If I'm going to design it to fit a range of lengths, I might as well design it for all possibilities.

 

[shockwaveriderz]

dyna:

Ok so you are gonna make me work on this one huh?

Ok, lets first assume that you have a 29mm motor mount tube....and lets make it an arbritary length say 20".... as the maximum length 29mm rocket motor....

at the 20" point on the motor mount tube you glue a coupler that acts as a thrust ring or engine block but in this case it a spacer block...

once you purchase an engine, then all you have to do is create a spacer coupler...


so lets say you purchase an engine that is 10" in length...

and you want it to stick out say 1" from the 29m motor mount tube...

20-(10)+[1] = spacer length = 11 inches

10(engine length)+11(spacer length)= 21 inches ....

21-20 = 1 length engine sicks out

so just insert your engine length + whatever length you want the engine to stick out the motor mount....
and replace 20 with whatever value you think the longest motor length might be


Ok lets say the engine is 13.1 " in length and you want it to stick out .9"...


20-(13.1) + [0.9] = 7.8" < spacer length

13.1 +7.8 = 20.9 "

20.9-20= 0.9" < length motor sticks out

This is how I modified my Executioner to be able to take most 29mm engines....It has an internal 29mm motor tube and I glued a coupler at a known distance at the top of this motor mount tube....

Now whatever 29mm motor I use will fit as I just have to make a spacer coupler tube......

hope this helps

 

[solrules]

There is always the Ellis Mountain I69 that is 16" long.

 

[rocwizard]

Not to long ago, Dave Griffith and the other RATT guys certified the 29mm J160, it is 4 feet long!!!

 

[daveyfire]

Don't forget Frank's I800 (now recerted as I560, makes sense)... 23.53" of solid propellant brute force. 0.76 second burn with 436 N-sec!

 

[rocwizard]

oh yeah, that one too:kill: