My first RMS case....WTH?!?!?!

OK, so I picked up my first RMS case today, an Aerotech 24/40. I got a few reload kits for it as well.

I've studied the "instructions" a few times and everytime I look through them I find myself more and more confused.

Is there a easy to follow tutorial online somewhere?

Thanks

I think you can find them on Apogee's site.

Yeah, I looked and couldn't find anything. The shop I bought them from suggested I check aerotech's website but I keep getting a 503 error when pulling up the site

This one might help?
https://www.apogeerockets.com/Advanced_Construction_Videos/Rocketry_Video_19

Go to Youtube and search for Apogee RMS the Apogee videos are on youtube, they just embed them on their site.

Check out youtube, or the Apogee website

https://www.youtube.com/watch?v=g0GsbQS7GKI

Yea I understand. The first time I loaded a E18 in mine it took half an hour.The instructions were spot on if you know the terminology at the time I didn't Now it takes me a few minutes to load one but I still look at the instructions just because.

Just warning you, I've heard that the Apogee video tells you to do something wrong, I think the placement of an O-ring. Apparently it's because Tim was following the instructions for a different case when he made the video.
The instruction seem to make sense, but I too will try to find a good tutorial. Let me know what you use.

Apogee has the video for a G64 in the 29/40-120 case, so the instructions will differ. I had someone sit down with me for my first reload kit, and since it has been smooth. The first one is always the hardest.

In my opinion it would be difficult to write assembly instructions for the Aerotech RMS motors that are more obtuse than the current ones. I've assembled quite a few and I still have trouble following these directions. First of all, an exploded view of the assembled motor would be of tremendous help. Second, it would make more sense to me to have the instructions start with the forward end of the motor and work towards the nozzle end in a logical progression.

I managed the tech pubs group at an aircraft parts manufacturer and our manuals would have never been allowed to be written like this. The big aircraft manufacturers would have rejected them without hesitation. The international standard is to use simple English at about a 6th grade level for aircraft maintenance manuals; the same style should be used here.

I love Areotech motors, but their instructions are for the birds.

If you follow each individual step while referring to the parts list you should be able to put one together with no problems. It's not like it's rocket science or anything and you're a smart feller. The illustrations are a little dark but look closey and all shall be revealed. If you have specific questions along the way I'm sure someone here can answer them. If I can figure it out I know you can.

This is why I plan on loading the motor the day before the launch. That way, if I have a question I can't find the answer to, I can ask you guys.

Ah...didn't even think that instructions for a rocket motor would be found under Advanced Construction!

OK...after watching the video I got most of the assembly and it does some pretty straight forward. However I am confused with a couple steps. I am using an D15 reload kit and it has a grain adapter tube. So, if I understand the instructions correctly, I insert the grain adapter tube until it is flush then put masking tape on one of the ends over the groove. Then the end of the tape goes in towards the grain adapter tube?

If that is the case, I assume the assembled propellant grain liner slides in with the grain adapter tube closest to the delay? So there is a gap between the propellant and the delay?

Also, there is a little black washer (not the three rubber o-rings)....is that the "forward insulator"?

paul.nortness said:

Ah...didn't even think that instructions for a rocket motor would be found under Advanced Construction!

OK...after watching the video I got most of the assembly and it does some pretty straight forward. However I am confused with a couple steps. I am using an D15 reload kit and it has a grain adapter tube. So, if I understand the instructions correctly, I insert the grain adapter tube until it is flush then put masking tape on one of the ends over the groove. Then the end of the tape goes in towards the grain adapter tube?

If that is the case, I assume the assembled propellant grain liner slides in with the grain adapter tube closest to the delay? So there is a gap between the propellant and the delay?

Also, there is a little black washer (not the three rubber o-rings)....is that the "forward insulator"?

Click to expand...

By Jove I think you've got it! You are correct on all accounts.

HURRAY!

Gonna go pack up my gear and launch my first composite motor tomorrow morning! I did a couple test fits and this 24/40 case fits perfectly into Estes rockets made for their "E" engine....thinking maybe Big Daddy gets a taste of Aerotech tomorrow

Thanks for all your help guys!

The Big Daddy is a great rocket for the 24/40 and the E18 will give it a nice ride.

Did you check the grain liner for fit? Sometimes they can be really tight.

Also make sure you have all of your cleaning supplies with you at the launch, baby wipes are your best friend.

Instructions....just another mans opinion!! Seriously, I dont see where the confusion is. If you can read, the instructions plainly say what part goes where, and even gives the thicknesses of the orings to help avoid confusion. Just read carefully and dont be intimidated. Yes, its a rocket motor, but I have found that the Aerotech line to be very forgiving. If you make minor errors they will usually work ok.

paul.nortness said:

HURRAY!

I did a couple test fits and this 24/40 case fits perfectly into Estes rockets made for their "E" engine....

Click to expand...

If you file down the forward end of the motor hook, they will fit any Estes rocket make for their "D" engine also.

I always build my 24mm Estes models stock with the filed down motor clip and then use the 24/40 reloads. I use everything up to the F39 and have never had an issue with the rockets.

I know the AT website was down earlier, but it is up now. I found these drawings useful:

24 mm assembly
24 mm dimensions

For some reason, I could not find the assembly drawing link on the "Resources" pages, but I had a copy downloaded and found the link w/ Google. The dimensioned drawing links are listed there. I don't remember where I found the assembly drawings, I guess AT re-vamped their website and left those links off the navigation page.

FWIW, here are links to other hobby RMS motors

18 mm assembly

29/40-120 assembly

Uhh, it's right there. "RMS & Kosdon by Aerotech (KBA) Motor Assembly Drawings".

https://www.aerotech-rocketry.com/resources.aspx?id=6

Honest question not intended to start a debate... What is the attraction of the AT reloads (particularly 24 & 29mm) when they are apparently so time consuming to load? I only fly SU from AT and use CTI for everything else. I can load any CTI in less than 15 seconds without instructions but see people fumbling and spending a lot of time to get the AT motors (particularly small ones) ready to go.

Since CTI doesn't have an 18mm line, I have considered getting the RT/AT 18mm cases but when I see a lot of threads like this and folks fumbling around at launches it makes me think twice.

jimzcatz said:

Instructions....just another mans opinion!! Seriously, I dont see where the confusion is. If you can read, the instructions plainly say what part goes where, and even gives the thicknesses of the orings to help avoid confusion.

Click to expand...

One thing I've found helpful when assembling an Aerotech motor is to read through the instructions first and laying out the parts in order that they will be needed. This especially makes it easier to keep the o-rings straight.

-- Roger

CarVac said:

Uhh, it's right there. "RMS & Kosdon by Aerotech (KBA) Motor Assembly Drawings".

https://www.aerotech-rocketry.com/resources.aspx?id=6

Click to expand...

DOH! I skipped over that link because I saw Kosdon, and thought it was all HPR motors...I am an RMS noob too, and still getting used to the lingo. Thanks!

I personally don't have any problem with the assembly of the RMS motors. But then, there weren't any options for 24mm and 29mm back in the day. The draw for me is price. On a quick look, the AT 24/40 loads can be had for about half the price of the CTI. And you can't beat the price of ten bucks for a G64. I still use some SU, mostly for possibly non-recoverable rockets (mainly due to field issues). That being said, it's nice to have a diversity of motors available and think my next HPR buy will be the big CTI 29mm case. Here, the diversity of the types of propellant would over-ride other considerations.

jimzcatz said:

Instructions....just another mans opinion!! Seriously, I dont see where the confusion is. If you can read, the instructions plainly say what part goes where, and even gives the thicknesses of the orings to help avoid confusion. Just read carefully and dont be intimidated. Yes, its a rocket motor, but I have found that the Aerotech line to be very forgiving. If you make minor errors they will usually work ok.

Click to expand...

I will respectfully disagree.... I had a "minor error" of inserting the delay grain and spacer the wrong way and had quite a wild ride with the ejection going off just as it cleared the rod and the rest is, well, history. So, it's important to put it together according to the directions. Just read through the instructions, become familiar with the parts, try a dry fit, and then go for it.

BTW, if you use these with modified Estes motor clips, add a couple of wraps of tape around the clip and motor. They can pull out of the clip even if it seems secure! Maybe not every time, but it only takes once. Those little things are darned hard to find on the field.

CTI E reloads for $15 each plus hazmat, Aerotech E reloads 3 for $16 USPS shippable. That's more than enough incentive for most people to endure the minor learning curve for assembly. Yeah the AT stuff takes a few minutes to load and dropping a greasy o-ring on the dirt is enough to make the pope swear and clean up takes a few more minutes but three flights to one?

Now I've thought about buying a CTI 1 grain 24mm just for the E75. Sounds like a really cool load for some of my heavier MPR stuff. If I had a local CTI vendor I probably would buy one.

Really though, assembling an AT RMS motor isn't that big a deal.

JPVegh said:

CTI E reloads for $15 each plus hazmat, Aerotech E reloads 3 for $16 USPS shippable. That's more than enough incentive for most people to endure the minor learning curve for assembly.

Click to expand...

I often use Aerotech reloads even for larger motors where the cost difference isn't as much of a factor, though I really appreciate the ease of using CTI motors. Having more choices for motors is great. One specific reason for using Aerotech is that I really like the look of White Lightning motors - lots of smoke and a bright white flame.

-- Roger

rstaff3 said:

BTW, if you use these with modified Estes motor clips, add a couple of wraps of tape around the clip and motor. They can pull out of the clip even if it seems secure! Maybe not every time, but it only takes once. Those little things are darned hard to find on the field.

Click to expand...

I take it one step further. No doubt, the regular clips need some supplemental tape to ensure the reload case is retained. But I like to add a couple wraps of tape for friction fitting as well. One of the guys I fly with, who mentored my L2, showed me that trick.

I don't do quite as thorough a job as when using only friction fit, but I take a little extra time and try to get the case snugly in the motor tube. That way, if the motor retention (clip) should fail, I don't lose my 30|40|60|100|xxx dollar case.

It's cheap insurance.

Doug

.

Disaster_Guy said:

Honest question not intended to start a debate... What is the attraction of the AT reloads (particularly 24 & 29mm) when they are apparently so time consuming to load? I only fly SU from AT and use CTI for everything else. I can load any CTI in less than 15 seconds without instructions but see people fumbling and spending a lot of time to get the AT motors (particularly small ones) ready to go.

Since CTI doesn't have an 18mm line, I have considered getting the RT/AT 18mm cases but when I see a lot of threads like this and folks fumbling around at launches it makes me think twice.

Click to expand...

Aerotech was first on the block with the mass production of 18 and 24mm reloads. I believe the draw is price and availability(hazmat shipping). CTI,although a fine product line, is a relative newcomer to the hobby line of reloads. And theres shipping to consider also.