Need info about AT RMS Hardware

Got a question about the AT RMS hardware. I'll have my first high power bird on the way here shortly and don't fully understand the RMS hardware.

I'm looking at a 29/40-120. What exactly does the 40-120 indicate. I see an H128 reload contains 92.2 g of propellant weight. So is the 40 to 120 the propellant weight that the hardware will handle?

If so as far as high power goes, a 40-120 doesn't give me very many options for high power loads.

Will a 29/180 or 29/240 still take the smaller reloads like the H128? Would they take the even smaller reloads like E and F motors......?

Thanks for any help

Jason

For the 29/40-120 motor hardware, the "40-120" number is the range of Total Motor Impulse that the hardware can handle, not the propellant weight. The 29/40-120 is a 29mm Reloadable Motor System that handles motors from 40 Newton-seconds to 120 Newton-seconds of Total Impulse.

From the Aerotech web site https://www.aerotech-rocketry.com , there's information about their RMS Motor Hardware:

The 29/60 RMS hardware can be used with the F37W and F62T.

The 29/100 RMS can be used with the G54W and G104T.

So, the 29/40-120 RMS can be used with all the above motors.

The 29/180 RMS can be used with the G75J, H128W, and H238T.

The 29/240 RMS can be used with the H97J, H180W, and H220T.

You must select the appropriate casing length to be large enough to handle the Total Impulses of the motors above, but not be so large as to have a large "void" of space. Remember, the rocket motor must come up to pressure to burn properly. The casing should just be large enough to handle the total impulse of the motor, and no more. Use the appropriate-size casing for the motor you select. You may have to buy several different casings to fly a range of 29mm motors.

40-120 refers to the NS the casing is rated for. You won't find any high power loads that will fit in that casing. If you dig around on the aerotech site, it will let you know which casing goes with which motor load and vice-versa. The H128 goes in the 29/180 case.

https://www.aerotech-rocketry.com

Thanks for the help guys, looked into the AT website a little more and learned alot.

Also learned that if I want much selection it could get really expensive pretty quick.

Staying in the midpower ranks, with the occasional SU high power may be my future.

Jason

Jason,

You can generally get a 38mm set of 240, 360, and 480 cases with forward and aft closures and seal disc for about $90 at https://www.alshobbyshop.com. That gives you a pretty good selection of motors to go with.

SU high power is very difficult to get a hold of these days.

Thanks kerm...

The smart guy that I am ordered a bird with a 29mm motor tube, figuring I'd move up slowly, didn't realize at the time how much it was going to restrict me..

Jason

What kit did you order?

Jason said:

"Also learned that if I want much selection it could get really expensive pretty quick.
Staying in the midpower ranks, with the occasional SU high power may be my future."

I'd been thinking of the same thing, but don't you need a LEUP to buy & store SU hi-power motors? Can't imagine why except they wouldn't come in nice 62.5g increments like reloads. Anybody more knowledgable know the answer to that?

Otherwise I'm probably gonna get Pro38's. I know the reloads are more expensive but the casings are CHEAP and there's a lot to be said for ease of assembly. I feel like a traitor 'cause I just love Aerotech. Stumbling across their website last year is what got me totally hooked on this hobby. You can imagine finding all that cool stuff at once for the first time...I still drool over the Astrobee D and G Force.

firemanup, that's a good idea, and I'm more or less doing the same thing. I started with the 40-120 case, because it's invaluable for midpower stuff. I'm planning on getting my L1 this summer, so I'm buying the 29mm high power set (180 and 240 cases - plenty of motor choices). You can get this set fairly cheaply, and fly alot of motors out of it! Also, keep in mind that Dr. Rockets casings are exactly the same thing, but tend to cost less. I know <font color='blue'><a href=https://www.magnumrockets.com>Magnum Rockets</a></font> carries the 29 mm high power set for about $60 as advertised on their specials page. Worth checking into, in my opinion.

Loopy

Thanks guys,

Roc I've got two BSD kits coming, 3" Spring and 3" Horizon.

Jason