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I have the 24/40 case right now, and frankly I don't find the motor assembly to be that much trouble. Before I used it the first time I did a couple of dry runs at home, pre-installed the propellant and delay in their liners, etc., so when I got to the launch, I was able to put them together in just a couple of minutes and had two perfect flights.

My main driving factor is a lack of HAZMAT shipping. Nobody local to me carries composite motors, nor are the couple of LHSs are even intrerested in stocking reloads, except on a special order basis, in which case I may as well buy online.
 
OK, well here's maybe a dumb question, guys. Is "hobby line" a brand name of motors, or some other kind of designation? Is it a line of AeroTech motors?
 
lcorinth said:
OK, well here's maybe a dumb question, guys. Is "hobby line" a brand name of motors, or some other kind of designation? Is it a line of AeroTech motors?
Click to expand...

Good question. "Hobby Line" refers to Aerotech and it includes at least the 29/40-120 hardware/reloads and I presume their 24mm and 18mm hardware/reloads. Perhaps the single use 18mm and 24mm motors as well? I'm guessing it was branded as such because this is what you would ordinarily find in a Hobby Shop? If that's true, then that would be present day. Back in the 90's you could buy high power stuff at certain Hobby Shops. I bought my 54mm hardware set at the HobbyTown USA in Las Vegas back in '93 or so... Pretty sure you could find high power reloads at Mike's Hobby Shop in Lewisville, TX as well, although my memory is a little fuzzy on that one... Those were the days!
 
pyrobob said:
Good question. "Hobby Line" refers to Aerotech and it includes at least the 29/40-120 hardware/reloads and I presume their 24mm and 18mm hardware/reloads. Perhaps the single use 18mm and 24mm motors as well? I'm guessing it was branded as such because this is what you would ordinarily find in a Hobby Shop? If that's true, then that would be present day. Back in the 90's you could buy high power stuff at certain Hobby Shops. I bought my 54mm hardware set at the HobbyTown USA in Las Vegas back in '93 or so... Pretty sure you could find high power reloads at Mike's Hobby Shop in Lewisville, TX as well, although my memory is a little fuzzy on that one... Those were the days!
Click to expand...

Alrighty... Just purchased my first 29/40-120 hardware!
 
So a question I have is can you build up an Aerotech reload days prior to launch? Or do you build it the day of? I have some reloads I want to try using as I have an Aerotech Tomahawk itching to fly. What is the guidance on building a reload "early"?

Mike
 
For Aerotech reloads with cardboard liners, you can build them well ahead of time, with one caveat: leave out the black powder and leave the closures loose. Take a piece of masking tape and wrap it around the motor (so you can't put it in the rocket ;)) to remind you to tighten the closures and add the BP on the day of the launch.

This is necessary because AT's seal system relies on the o-rings being compressed by the threads between the closure and the liner. If the case is left fully assembled with tightened closures for too long, the cardboard liner will "relax" under compression and the seal will be lost. This is particularly critical for hobby line loads which use a face seal in the delay well cavity. This is also the reason to leave the BP out-- with the closures loose, this face seal is not functional, and it's possible for BP to leak down into the delay well. Hopefully AT migrates the hobby line to the piston-seal RMS+ design at some point.

For larger motors with the hard black phenolic liners, you're good to assemble pretty much whenever. (I still loosen the closures out of habit.) The new RMS-EZ loads or loads using the case spacer system are also good to go ahead of time, since AT moved to a piston seal on those.

CTI, Loki, Kosdon, and Gorilla motors all use a piston seal design, so they can be built ahead of time and stored indefinitely. For the snap ring-style motors with graphite nozzles, be sure to apply a heavy coat of grease to the outside surface of the nozzle to prevent galvanic corrosion of the case.

Hope that helps! :)
 
PS If you're just wanting to load up a few the night before the launch, there's no problem with that at all-- 12-24 hours under compression shouldn't hurt anything. Plus it's much easier to assemble in the comfort of the workshop than out at the field!
 
daveyfire said:
For Aerotech reloads with cardboard liners, you can build them well ahead of time, with one caveat: leave out the black powder and leave the closures loose. Take a piece of masking tape and wrap it around the motor (so you can't put it in the rocket ;)) to remind you to tighten the closures and add the BP on the day of the launch.

This is necessary because AT's seal system relies on the o-rings being compressed by the threads between the closure and the liner. If the case is left fully assembled with tightened closures for too long, the cardboard liner will "relax" under compression and the seal will be lost. This is particularly critical for hobby line loads which use a face seal in the delay well cavity. This is also the reason to leave the BP out-- with the closures loose, this face seal is not functional, and it's possible for BP to leak down into the delay well. Hopefully AT migrates the hobby line to the piston-seal RMS+ design at some point.

For larger motors with the hard black phenolic liners, you're good to assemble pretty much whenever. (I still loosen the closures out of habit.) The new RMS-EZ loads or loads using the case spacer system are also good to go ahead of time, since AT moved to a piston seal on those.

CTI, Loki, Kosdon, and Gorilla motors all use a piston seal design, so they can be built ahead of time and stored indefinitely. For the snap ring-style motors with graphite nozzles, be sure to apply a heavy coat of grease to the outside surface of the nozzle to prevent galvanic corrosion of the case.

Hope that helps! :)
Click to expand...
It does help indeed. Thanks!
It does


Launching rockets (and missiles in my case) is so easy a chimp could do it. Read a step, do a step, eat a banana.

Sent from my iPhone using Rocketry Forum
 
I picked up an Aerotech 24/40 reload case about a year ago and love it. Lots of engine choices in the E and F range without Hazmat, and better pricing on both the case and the reloads than it's 29/40-120 counterpart. I have even flown it with E and F reloads in my 29mm Arreaux with the adapter and great results.

I have not (yet) picked up the 24/60 case due to the limited number of reloads made for it, but have been tempted several times when I have seen them going for cheap on E-Bay.

I recently got the 29/40-120, but have not used it yet. I have been itching to put a G76-G I have in that Arreaux, but recent launches have either been called due to weather, or winds were not favorable for putting something up that high. Oh well, maybe next week.

Enjoy your foray into reloads. It has helped me understand more of the science, so I feel more like a rocket scientist.
 
I would just start in with reloads; at least that's what I did, but then you may not feel comfortable. I remember the first one I assembled and I was kind of anxious, but once you build a few they really aren't that bad and in the long run you save money. You can pick up a hobby line case for under $40 in most cases and the reloads are as cheap as $10 on WM website. I would suggest becoming a club member for the added savings. You could also go with CTI, which I hear are much easier to assembled, but I never owned CTI hardware so I really wouldn't know. Others on here have and they could probably be more of help to you.
 
lcorinth said:
I'd like to start gaining experience with composite motors, and possibly (probably?) reloadables.

I have four rockets to build which have 29mm motor mounts (one Quest Big Dog, and three Estes Pro Series II on the way soon), so I'd like to get something for those. I'm not sure if I should start with single-use motors at first, or if there's really not a good reason to hold back from getting a reloadable casing.

I'm not entirely sure what I should shop for. I'd like to do my reading first, and actually look at the thing I'll be using before I start using it, and make sure I know how to take it apart and put it back together (if it's reloadable). I am not HP certified, so I only need something that will hold maybe an F or G motor, but I do hope to attempt a certification some time maybe next summer, so if there's a reloadable that can be upgraded to hold an H or I grain, that would be good. Otherwise, I'll just get something bigger when the time comes.

I'm looking at this as an investment, so, while I don't wish to spend the most money possible, I don't feel I need to go as cheap as possible on it either.

I don't know, apart from diameter, what size (length) motor I should maybe go for, or what brand. I've read some about both AeroTech and Cesaroni, but I don't know if there's a usability difference between the two, or if there's one way a beginner should lean. I was hoping I might get some advice.

I just started reading High Power Rocketry, which I'm sure will have information I might need for a mid power motor, but I wanted to ask actual users what they thought.

Any advice, preferred brands, sizes I should look for, etc? I'm thinking I might even get something at the BuyMotors.com Black Friday sale, if I can make a decision by this weekend. Actually launching it, I'm not in a hurry - I plan on doing my homework before taking anything out on the field.

Thanks!
Click to expand...

Any way you go, you will be OK. If you choose a X level case or Y manufacturer, there will always be someone on hear that will take it off your hands if you change your mind and go a different way. If you are building Rockets that can benefit from a re-loadable Motor you are past the beginner stage, just consider the Motor as another part of the build.
 
Also, if you have never witnessed a composite motor flight, your ears will be in for a treat!
 
Amen! Even a little E18 makes a great roar that brings a smile to your face every time.
 

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