question regarding 24mm RMS cases

[MarkII]

I think if it were me, I would attach some sort of thrust ring to the outside of the adapter. Not sure how I'd do it, though. Probably peel off the foil and epoxy something in place. I might even try to make a ring out of 1/4" plywood, but I don't know what your capabilities are.

A short (e.g., 1/4" long) section of motor tubing works fine as a thrust ring for an adapter. Or use a sturdy centering ring.

Clip-style motor retainers (fixed in place with removable machine screws) are quite simple to make, which is their great strength and one of their main raisons d'être. In qquake's first photo is the classic, definitive version and in his second photo is a variation. I use this method quite frequently.

[MarkII]

Motor adapters themselves are quite simple to make as well. Just obtain a section of motor tube and a few centering rings that will center it in the host tube. Double-up or triple-up the centering rings as needed for added strength. Then glue a wider centering ring (doubled or tripled if desired) onto the end as a thrust ring. If you choose a wider centering ring, you can drill right through it for your CSB (clips, screws, blind nuts) retainer. The retainer for the motor will then also serve as the retainer for the adapter that is holding the motor.

This thread has some good information:

www.rocketryforum.com/showthread.php?11902-Homemade-Motor-Retainers

[pick1e]

Thanks for the suggestions, guys. I would use machine screws through a CR but my rocket is already built per the instructions. I didn't receive my RMS case and LOC adapter until after it was built. Making a new adapter with CR's would be ideal but I want to make due with what I have on hand.

BUT I figured out an elegant solution. First I cut 1/4" strips of BT-60 to make a thrust ring. Assuming the 24/40 case is made to go into low power rockets, an Estes retaining clip should hold it. The LOC adapter is just a thick tube- more than thick enough to have a clip embedded into it. So I removed some material with a sharp knife and used some CA to strengthen it. I will secure the clip to the LOC tube with a strip of cardboard. I figure the cardboard should be sufficient since it will be pressing against the inside of the rocket's 29mm motor tube with nowhere for it to go at the time of ejection.



The clip also clears the Estes screw-on retainer with the retainer adding additional retention for the clip.

[Wayco]

Pickle you're a genius! That is by far the best cheap solution to this problem. I'm gonna convert my other LOC adapter just like that. Thanks for the excellent idea!

[qquake2k]

Thanks for the suggestions, guys. I would use machine screws through a CR but my rocket is already built per the instructions. I didn't receive my RMS case and LOC adapter until after it was built. Making a new adapter with CR's would be ideal but I want to make due with what I have on hand.

BUT I figured out an elegant solution. First I cut 1/4" strips of BT-60 to make a thrust ring. Assuming the 24/40 case is made to go into low power rockets, an Estes retaining clip should hold it. The LOC adapter is just a thick tube- more than thick enough to have a clip embedded into it. So I removed some material with a sharp knife and used some CA to strengthen it. I will secure the clip to the LOC tube with a strip of cardboard. I figure the cardboard should be sufficient since it will be pressing against the inside of the rocket's 29mm motor tube with nowhere for it to go at the time of ejection.



The clip also clears the Estes screw-on retainer with the retainer adding additional retention for the clip.

Now that is an elegant solution! Well done!

[qquake2k]

Here is what I did. Using 1-7/16" and 1-1/8" hole saws, I was able to cut a relatively thin thrust ring out of 1/4" birch plywood. I only cut about half way through with the larger hole saw at first, so I could finish the cut after I cut out the center. Worked pretty well.

[qquake2k]

A little bit of sanding the center hole with the Dremel was all it took to get it to fit snugly on the adapter. I peeled a layer of the foil off where the thrust ring will be epoxied. I did have to sand the adapter to get it to fit in the 29mm motor tube. Since all of my scratch built rockets have tee nuts, I'll be able to use clips or even bailing wire to hold everything in place.

Pick1e's solution with the motor hook, though, is brilliant. It should work well in his case with the already installed Estes retainer.

[judo]

I had to sand most of the foil off of mine. Then I glued on a 29-38mm CR on the thrust end of it. I just don't remember where I got it.

[qquake2k]

I had to sand most of the foil off of mine. Then I glued on a 29-38mm CR on the thrust end of it. I just don't remember where I got it.

BMS has them: CR52H38-W

[AlfaBrewer]

For my 29-38 adapter, I made a thrust ring for thin (22g) sheet metal and epoxied it on. It's worked quite well. I have been planning on doing the same on my 24-29, but haven't yet. I made mine by tracing the outer circle, cutting it out with tin snips and ground to fit with a Dremel. I cut the ID with a step drill and the ground it with the Dremel.

[Wayco]

I was so inspired by Pickles design for the 24/29mm adapter, I had to go into the rocket room and try it out. Made a couple of changes since I had a paper centering ring that worked well for the thrust ring, but it worked quite well when I put it all together:

Since the clip is held in place by the MMT when installed, I just glued it into the groove with 5 min. epoxy. The CR/thrust ring came out of my parts bin and I'm not sure what size it is, but most of us have a selection of these, just pick one and make it work. I also added some thin CA at both ends to make it more durable.
This is a great solution to a problem I've been having since I started modifying my rockets with 29mm MMT's. Thanks again to Pickle for this great idea. I might just paint my "Pickle Adapter" green to honor its inventor.
The real beauty of this design is when it's combined with the Estes 29mm motor retainer:

Not only does the cap lock the clip down onto the motor, but the clip locks the cap from backing off the threads when fully tightened down.

[JPVegh]

Kind of a belt and suspenders approach, cool.

[pick1e]

I might just paint my "Pickle Adapter" green to honor its inventor.

Hah! Awesome. Glad you guys like it.

I was originally going in the direction of using the Dremel to fashion a plate shaped like the Aerotech Aft Closure Wrench but round, so it would simply be tightened down on the rear of the adapter sandwiching the RMS case in there. I figured it would be difficult to make and with the added thickness would mean less threads to strengthen the hold of the screw-on retainer.



I also recessed the hook into the rear of the thrust ring just enough so the screw-on adapter is flush to the whole circumference of the ring and the hook to spread out the ejection force. I see what you mean with yours protruding above the ring to act almost like a lock washer though. Have you had these unscrew themselves from vibration?

[Wayco]

I've only made a couple of flights with the new Estes retainers, so no issues with them backing off. Doubt if that would ever happen. Another nice feature of your design is that the end of the clip is a nice handle to pull the adapter out with. I also tried mine in my Kick Asspire which has a slimline retainer. It works in that rocket too, and the C-clip holds the adapter clip down too.

[CarVac]

The only evidence I have heard of a screw-on retainer backing off was on the Gates Brothers Rocketry website, where they flew an M650 (i think) with 4 K250's, and it resonated loudly for some reason, vibrating all four Aero-Pack 54mm retainers off and presumably dropping all the K250's out. Kinda frightening...

[Wayco]

The only evidence I have heard of a screw-on retainer backing off was on the Gates Brothers Rocketry website, where they flew an M650 (i think) with 4 K250's, and it resonated loudly for some reason, vibrating all four Aero-Pack 54mm retainers off and presumably dropping all the K250's out. Kinda frightening...

OK, so I won't fly my new Vagabond or Executioner on a 24mm "M" motor. No problem.....

[CarVac]

One thing of note is that Aero-Pack retainers have a 1.5 turn thread, much coarser than the retainers I've used (PML's HAMR), which take 6 or 7 turns to get off.

[Rocketbuilder]

After reading several threads on 24mm RMS cases, I have a question. (I figured I'd just post it here, instead of starting a new thread.)
When you tap the ejection charge into the well on the forward closure, does it completely leave the red cap? I've heard mention of people using a pice of tape or pair towel or something to block the hole, instead of leaving the red cap on.
Am I understanding this correctly?
If so, is there any advantage to doing it this way instead of leaving the red cap on?
Thanks.

[AfterBurners]

Just curious does RT still make a 24 hardware for the reloads

[cavecentral]

After reading several threads on 24mm RMS cases, I have a question. (I figured I'd just post it here, instead of starting a new thread.)
When you tap the ejection charge into the well on the forward closure, does it completely leave the red cap? I've heard mention of people using a pice of tape or pair towel or something to block the hole, instead of leaving the red cap on.
Am I understanding this correctly?
If so, is there any advantage to doing it this way instead of leaving the red cap on?
Thanks.

I highly doubt it. I'd want the powder on the outside, just get enough inside to make sure the burn through of the delay lights it. I'm guessing that all inside would be bad. Would it CATO? Not sure.

[UncleVanya]

After reading several threads on 24mm RMS cases, I have a question. (I figured I'd just post it here, instead of starting a new thread.)
When you tap the ejection charge into the well on the forward closure, does it completely leave the red cap? I've heard mention of people using a pice of tape or pair towel or something to block the hole, instead of leaving the red cap on.
Am I understanding this correctly?
If so, is there any advantage to doing it this way instead of leaving the red cap on?
Thanks.

I'd leave the cap on. Some of the BP seems to overflow the small ejection well on the 29mm 40-120 case and that's always worked fine for me. Removing the cap and trying to build up the sides of the ejection well with tape and then dumping the powder in might work but it seems like a lot of fuss and risk for very little gain.

[gdjsky01]

Nope. No way. I pop the cap on and give it a good tap vertically to make sure some BP settles into the well/chamber.

Only time I put in a piece of tissue in is when I am only using maybe 1/2 the charge. Then I empty the BP into the half of the plastic that won't be placed on the RMS, put a little tuft of wadding in the other half, then pour the BP back into that half and snap it on as normal. Just to keep the BP up near the well. But thats pretty rare.

[Rocketbuilder]

Good to know. I'll be flying my first reload in less than two weeks, so I just wanted to be sure I understood everything. But, if something does go wrong, it won't be too great a loss.; the rocket I'm flying it in is made of poster board and cost $4.

[qquake2k]

After reading several threads on 24mm RMS cases, I have a question. (I figured I'd just post it here, instead of starting a new thread.)
When you tap the ejection charge into the well on the forward closure, does it completely leave the red cap? I've heard mention of people using a pice of tape or pair towel or something to block the hole, instead of leaving the red cap on.
Am I understanding this correctly?
If so, is there any advantage to doing it this way instead of leaving the red cap on?
Thanks.

As far as I know, they're referring to cases besides RMS. Such as 29/180, 38/240, etc. The RMS cases are made differently. I always use the red cap with RMS cases and loads.

[MarkII]

As far as I know, they're referring to cases besides RMS. Such as 29/180, 38/240, etc. The RMS cases are made differently. I always use the red cap with RMS cases and loads.

Yes. With the reloads for the high power (and high power style) motors, the black powder comes in a tube or vial that must be emptied into the motor's ejection charge well, and then the well must be covered with an included adhesive paper disk (and some tape) so that it doesn't leak out. With the reloads for the "Hobby Line" cases, the black powder comes in a red plastic cap that just snaps over the ejection charge well extension on the forward closure. It is not necessary to actually pour the black powder out of the cap and into the well when you assemble those reloads. The cap provides the seal to prevent leakage.

By the way, "RMS™" refers to AeroTech's line of reloadable motors. There are two broad series: the "Hobby Line RMS™" selection of inexpensive mid-power reloadable motors (18/20, 24/40, 24/60 and 29/40-120) and the "High Power RMS™" (including "High Power-Style RMS™" mid power) series of reloadable motors. Both types are part of the AeroTech RMS™ line. So "RMS" always refers to motors made by AeroTech (AT). Compare this to "ProX®" (pronounced "pro-ecks") which always refers to the reloadable motors made by Cesaroni Technologies, Inc. (CTI) (examples: Pro24®, Pro29®, Pro38®, etc.).

[jimzcatz]

As far as I know, they're referring to cases besides RMS. Such as 29/180, 38/240, etc. The RMS cases are made differently. I always use the red cap with RMS cases and loads.

The are ALL RMS cases. Reloadable Motor Systems. Even the hobbyline cases are RMS

[qquake2k]

By the way, "RMS™" refers to AeroTech's line of reloadable motors. There are two broad series: the "Hobby Line RMS™" selection of inexpensive mid-power reloadable motors (18/20, 24/40, 24/60 and 29/40-120) and the "High Power RMS™" (including "High Power-Style RMS™" mid power) series of reloadable motors. Both types are part of the AeroTech RMS™ line. So "RMS" always refers to motors made by AeroTech (AT). Compare this to "ProX®" (pronounced "pro-ecks") which always refers to the reloadable motors made by Cesaroni Technologies, Inc. (CTI) (examples: Pro24®, Pro29®, Pro38®, etc.).

The are ALL RMS cases. Reloadable Motor Systems. Even the hobbyline cases are RMS

Oops, I stand corrected. I meant to say Hobby Line.

[Pantherjon]

After reading several threads on 24mm RMS cases, I have a question. (I figured I'd just post it here, instead of starting a new thread.)
When you tap the ejection charge into the well on the forward closure, does it completely leave the red cap? I've heard mention of people using a pice of tape or pair towel or something to block the hole, instead of leaving the red cap on.
Am I understanding this correctly?
If so, is there any advantage to doing it this way instead of leaving the red cap on?
Thanks.

I have seen it done a few times..Sometimes on the 24/40 case the red cap will hit the top part of a standard Estes style engine hook..What they would do would be to wrap a srtip of tape around the hole in the fore closure, pour in the BP and then make like a cone so it wouldn't hit the top of the hook...

[Rocketbuilder]

I have seen it done a few times..Sometimes on the 24/40 case the red cap will hit the top part of a standard Estes style engine hook..What they would do would be to wrap a srtip of tape around the hole in the fore closure, pour in the BP and then make like a cone so it wouldn't hit the top of the hook...

Well, I won't have to worry about that, since from now on I'm modifying/making my own engine hooks (so that the tab goes outward and is butted up against one of the CR's) for all the rockets that I might fly reloads it.
I guess my QCC Explorer may not get flown on an E18 due to this... Maybe I will file away the tang.

[Tarasdad]

First thing I did after constructing the motor mount for my Big Daddy was grind the motor hook tab down with my Dremel. Plan from day one is that it will eventually fly using AT Hobbyline motors. I'm going to do that on all builds where I use a hook rather than threaded retainer from now on - just makes sense to take care of it before I glue the mount into the body tube.