RMS 38mm cases -- which to start with??

[techrat]

I am planning my L1 with a 29mm "Baby H" (as they are known) rocket, because I'm more familiar with the whole thing.
I've already launched my rocket on F and G motors, I am using a RMS 29-40/120, and am already comfortable doing that.
However, I have a couple of rockets in the middle of construction that use 38mm motor mounts, and I predict that once I get L1, I will transition to 38mm.

So, what is the deal with the 38mm RMS cases? Is there are a partcular case that has more reloads available, like the 29-40/120?
Or can you buy any case as long as it holds all the grains and then the rest is done with spacers (and making tape)? It looks like the RMS 38mm cases also have a forward closure, so they also provide an ejection charge, which would be a good thing, as none of my rockets have electronics (yet).

 

[tsmith1315]

Check out Aerotech’s Master Motor Matrix. It shows everything available, single use, Quest, RMS, etc.

Logically grouped in approximate order of total impulse, the 4th column shows the motor hardware required, if any.

All reloads requiring a certain case will be grouped together, any special closure requirements for a load are in the far right column under notes.

https://d11fdyfhxcs9cr.cloudfront.net/templates/170652/myimages/aerotech master motor matrix 4-2-23_1680480598242.pdf

 

[kswing]

Many folks get a slightly larger case (maybe 38/720 or 38/1080) with an aft closure and then get the reload adaptor system (RAS) which includes two spacers and the floating forward closure which provides an ejection charge well. This setup lets them fly motors of 3 different sizes using a single case.

 

[Jmhepworth]

If you get the 480 case and the adapter system, you will have more than 20 reloads. Then get the 1080 case and you can use all but one high power reload. I don’t bother with the one grain case. If I want to launch G motors, I can use a 29mm and an adapter.

 

[Seatechnerd83]

If you get the 480 case and the adapter system, you will have more than 20 reloads. Then get the 1080 case and you can use all but one high power reload. I don’t bother with the one grain case. If I want to launch G motors, I can use a 29mm and an adapter.

I don't think the 1080 case can use the RAS if I recall?

 

[Jmhepworth]

I don't think the 1080 case can use the RAS if I recall?

That’s correct. I had forgotten that it takes 3 spacers to get from 1080 to 720, and it’s not certified to do that. I think I’d still get the 480 case as the starter, and then add the 720 and 1080 later on.

 

[Pinetree]

I posed that question at our last launch and received the same advice.. 38/480 case and the RAS spacers.

Wildman has them in stock.

 

[rocketace]

Just to second what everyone is saying here. Get the 38/480 complete motor with seal disk and RAS. Once you want to move up to bigger get the 38/720 casing. The 1080 & 1320 are just special and only get those if/when you're ready to fly the few motors that fit it. Apogee has a good table that shows you what casings you can use the RAS with.



https://www.apogeerockets.com/Rocket_Motors/AeroTech_Accessories/AeroTech_38mm_Reload_Adapter_System

FYI if you get any of the Warp9 motors, you need to use electronics as the delays cannot be trusted to stay lit. The End burner Warp9 motors required a plugged closure to prevent burn though.

 

[DigBaddy]

Another vote for 38/480 and the RAS. Boatloads of fun to be had.

 

[wsume99]

I'd say it depends on what you plan to do after getting your L1. If you are going to stay L1 for a while and plan to fly a lot of L1 rockets then definitely get the 38/480 with the RAS. That will give you the ability to fly 38mm motors across the 240-480 Ns impulse range which is basically mid-H to mid-I impulse.

However if you plan to progress fairly quickly to L2 then you may want to consider going directly to the 38/720 with a RAS. That covers the 480-720 Ns impulse range which is mid-I to low end J impulse. Meaning you can fly your L2 cert with a 38/720 case while also being able to fly the largest impulse L1 motors as the same time.

The 38/480 will give you more variety across the L1 impulse range but the 38/720 will give you more flexibility to fly large L1 or small L2 motors.

 

[techrat]

I'd say it depends on what you plan to do after getting your L1. If you are going to stay L1 for a while and plan to fly a lot of L1 rockets then definitely get the 38/480 with the RAS. That will give you the ability to fly 38mm motors across the 240-480 Ns impulse range which is basically mid-H to mid-I impulse.

Ok, this is good advice. I'm very much in the go-slow camp, I've been back in the hobby for 18 months and have only progressed to F & G motors recently. I will likely stay L1 for at least a year, as I understand things anyhow, motors start to get ridiculously expensive once you get into L2+. So I'm going to set my sights on the 38/480, and work my up from there.

 

[BenCook]

The 360 case and the 720 case with the RAS system will cover most all reloads from 1 grain to 6 grains. You can go from G to J with those cases. Wildman sells a kit with everything included.

https://wildmanrocketry.com/collections/38mm/products/3836sc

 

[rharshberger]

Many folks get a slightly larger case (maybe 38/720 or 38/1080) with an aft closure and then get the reload adaptor system (RAS) which includes two spacers and the floating forward closure which provides an ejection charge well. This setup lets them fly motors of 3 different sizes using a single case.

There is or was a 38mm starter set that included the 38/360 and 38/720 with a rear closure and the RAS, the floating forward closure in the RAS can function as a normal ejection charge closure if spacers are not being used.

 

[Buster]

I got my L1 38/240 L2 38/720 have TAS kit too

 

[Sooner Boomer]

With the 38/360-720 RAS system, you can load about 35 different motors.

This is what I've got. (with a RAS and a conventional forward closure)

I also bought a 240 case and aft closure, I really like the H130 mailable reload!

 

[Rocketjunkie]

Caution! If you buy a kit and lose 1 motor you won't be able to fly any other loads,, I strongly recommend buying a second rear closure and RAS forward closure. Also, I recommend electronic dual deployment so you are less likely to lose the rocket. If there are any trees around, the rocket will find them
HPR can get expensive. I also recommend a tracker. The closest club to me has trackers and a receiver that can be rented (iirc $5).

 

[86mustang408w]

Check out Aerotech’s Master Motor Matrix. It shows everything available, single use, Quest, RMS, etc.

Logically grouped in approximate order of total impulse, the 4th column shows the motor hardware required, if any.

All reloads requiring a certain case will be grouped together, any special closure requirements for a load are in the far right column under notes.

https://d11fdyfhxcs9cr.cloudfront.net/templates/170652/myimages/aerotech master motor matrix 4-2-23_1680480598242.pdf

Thank you, printed that out for myself too! Can never have enough info. Thanks again!!

 

[mtnmanak]

Cases are like potato chips - you can't get just one . Just get whichever one you want. As soon as you have it, you will be itching to buy another... and another...and another...

All you have to do is get what you need now, save up for Black Friday and buy a bunch! Too many cases is like too much money and too much fun.

 

[DigBaddy]

Cases are like potato chips - you can't get just one . Just get whichever one you want. As soon as you have it, you will be itching to buy another... and another...and another...

All you have to do is get what you need now, save up for Black Friday and buy a bunch! Too many cases is like too much money and too much fun.

This is how it really works.

 

[bjphoenix]

In the old days there was no RAS and you could buy cases and parts pretty easily. I bought the 38/480 complete and an additional 240 tube so I could launch the common H and I motors at the time.

 

[John Taylor]

I am planning my L1 with a 29mm "Baby H" (as they are known) rocket, because I'm more familiar with the whole thing.
I've already launched my rocket on F and G motors, I am using a RMS 29-40/120, and am already comfortable doing that.
However, I have a couple of rockets in the middle of construction that use 38mm motor mounts, and I predict that once I get L1, I will transition to 38mm.

So, what is the deal with the 38mm RMS cases? Is there are a partcular case that has more reloads available, like the 29-40/120?
Or can you buy any case as long as it holds all the grains and then the rest is done with spacers (and making tape)? It looks like the RMS 38mm cases also have a forward closure, so they also provide an ejection charge, which would be a good thing, as none of my rockets have electronics (yet).

If you get a 38/720 motor and and an adapter kit you can fly 3 total motor sizes. 720, 600, and 480. Then you can purchase a 360 casing and you will have all the different sizes of 38mm motors except two, the 1080, and 1320. If you got the 1320 you could adapt down to 1080. So with three cases, 1320, 720, and 360, one set of standard closers, one adapter set you would have the entire 38mm fleet. You could start with the 38/360 motor, then the adapter set, then the 720 case and so on.

 

[StreuB1]

I don't think the 1080 case can use the RAS if I recall?

Incorrect. I flew the J350W in that case with the RAS at miniMWP 2022 in my Ode to Ukraine (7) motor cluster.

 

[StreuB1]

The 360 case and the 720 case with the RAS system will cover most all reloads from 1 grain to 6 grains. You can go from G to J with those cases. Wildman sells a kit with everything included.

https://wildmanrocketry.com/collections/38mm/products/3836sc

I will second the 360/720+RAS kit that Tim sells. Its the most versatile hardware set there is.

While you are at it, spend $30 first and join the Wildman Club to get your discounts. Then buy the hardware set.

The set w/o the Wildman Club discount is like $290. With the discount, It's like $210.

The membership pays for itself and you still save $50 (to buy a reload!!).

Literally EVERYONE should be a Wildman Club member.....


I will also SECOND what John stated about buying a SPARE nozzle closure and a spare FWD closure as a backup in case you lose a motor. OR, buy an additional RAS kit, and nozzle end closure, that is what I did. I have double RAS kits for my 29/38/75mm hardware sets.

 

[Seatechnerd83]

Incorrect. I flew the J350W in that case with the RAS at miniMWP 2022 in my Ode to Ukraine (7) motor cluster.

I know it's not certified as such but as you said it is possible.