Estes Retainers

I'm currently building the PSII line. They come with plastic retainers. I'm setting them up for use with a 29/40-120. Should I upgrade to metal retainers or are the plastic retainers acceptable?

I've never heard any problems with the plastic Estes retainers. If youve got some money burning a hole in your pocket, then you could ...

for use with the hobbyline 29/40-120 they work fine. the 'hi-power style' 29mm has a thicker aft closure which doesn't allow the cap to thread on as far, has caused some concern(although I haven't heard of anyone losing a case yet). as long as you keep the retainer out of the back blast from the deflector(which you should do with AP motors anyway) they should hold up fine.
Rex

I recertified at NARAM last year using an H-180 retained by an Estes 29MM plastic retainer. There are fewer threads engaged with the high power reload casings but there were no problems. Perfect flight. Perfect recovery.

Personally, I like the retainers that Estes has shipped for their 29mm motors. However, I picked up the Extreme 12 (24mm powered), and upon hindsight, I think I'd have been better off with a simple engine clip. One plus for the 24mm retainer, it could help protect the rocket should it fall (just right) onto a hard surface.

I use these retainers with a 29/240 case and never had an issue. So you should be fine.

No need to upgrade unless you want to. Use the plastic one on mine.

Peter Olivola said:

I recertified at NARAM last year using an H-180 retained by an Estes 29MM plastic retainer. There are fewer threads engaged with the high power reload casings but there were no problems. Perfect flight. Perfect recovery.

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Wow, what a great picture!

Rex R said:

for use with the hobbyline 29/40-120 they work fine. the 'hi-power style' 29mm has a thicker aft closure which doesn't allow the cap to thread on as far, has caused some concern(although I haven't heard of anyone losing a case yet).

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There was a failure at a DARS launch last year with an Aerotech 29mm high power case. While the motor was found later, it didn't return with the rocket.

UhClem said:

There was a failure at a DARS launch last year with an Aerotech 29mm high power case. While the motor was found later, it didn't return with the rocket.

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Does anyone know of the root cause of the failure?
Was it due to one of the following:

• The retainer itself failed because it is plastic
• The retainer melted from the heat given off by the case during the burn
• The retainer melted because it was too close to the deflector pad and the flame deflected up onto the retainer, therefore melting it
• The retainer cap was not able to be screwed in far enough to securely retain the motor
• The retainer came unglued from the aft end

I ask because some of these are issues with the actual retainer and some are issues with the user and some are a little of both. I guess I am curious to know because the Estes retainers tend to get a bad rap around here. Sure they're not the most beautiful piece of hardware you can stick on a rocket but they're cost effective and good for their intended use. I see no need to spend upwards of $30 for a retainer on an inexpensive 29mm rocket. Generally on my 29mm rockets I dislike the "kaplow clip" style of retention because I generally don't have much room and it just lacks a certain elegance that a screw on lends to the whole experience.

jsargevt said:

Does anyone know of the root cause of the failure?

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It has been a while so this is from memory...

The problem was due to less than a full turn of thread engagement. This let the retainer pivot when pressure was applied which resulted in it falling off. So far as I can recall there was no thread damage, or melting, or adhesive failure.

I have flown the estes retainers with CTI and aerotech F, G, and H motors with no issue. it is very important to rough up the surface with 40-60 grit paper and use a good epoxy. I use JB weld.

estes with a 29/40-120


estes with a 29/240



A pair of estes right after firing a pair of I200W's, (and multiple prior F/G flights)
Won't get more more abuse than that. I have no hesitation using them for anything.

DizWolf said:

estes with a 29/40-120


A pair of estes right after firing a pair of I200W's, (and multiple prior F/G flights)
Won't get more more abuse than that. I have no hesitation using them for anything.

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That's pretty impressive. Our local club doesn't allow clustering of anything bigger than 24mm, so I've not seen that done with a pair of 29s before...

Should come on out to potter and try it, it's a good time. I recommend blue motors.... Greens I tend to get the second one lit about 30-50 feet up.

Another note, the single use motors are a bit "easier" on the retainers since the nozzles stick out past them. Reloads the exit is flush with them.

All credit to Dave Hanson.

pyrobob said:

Wow, what a great picture!

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Nice collection of launch photos. You need one of a launch with two H268 redlines to complete it!

I just got a pair of Estes retainers . 1 set for my Mirage. Using an Aerotech H180M.

Estes retainers are not a good choice for Aerotech 29 mm High Power cases. The rear closures are thicker and because of this, not enough threads are engaged to be reliable in my opinion (works fine for for Hobby Line cases). Use Aerotech's new screw on retainer or an Aeropack retainer (or retro-fit kaplow clips).

Are you basing this on hard data or your SWAG? I recertified using the exact same combination of AT H180 and Estes 29 MM retainer on a scratch built 4" rocket. Yes, there are fewer threads engaged than the hobby line cases. I find this sort of hand wringing unjustified.

terryg said:

Estes retainers are not a good choice for Aerotech 29 mm High Power cases. The rear closures are thicker and because of this, not enough threads are engaged to be reliable in my opinion (works fine for for Hobby Line cases). Use Aerotech's new screw on retainer or an Aeropack retainer (or retro-fit kaplow clips).

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terryg said:

Estes retainers are not a good choice for Aerotech 29 mm High Power cases. The rear closures are thicker and because of this, not enough threads are engaged to be reliable in my opinion (works fine for for Hobby Line cases). Use Aerotech's new screw on retainer or an Aeropack retainer (or retro-fit kaplow clips).

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Okay Terry, Im taking your advise and ordering the Aerotech Retainer for my Mirage. The Estes will not go to waste though. I have plenty use for them. I wanted the aluminum Aerotech one anyway and I want no doubt of reliability in the back of my mind at launch.
By the way-it looks like you had a dag gone good time this past weekend.

I have one mount where a thrust block keeps the 29/40-120 from being inserted the last 3/16" or so. Not many threads engage but it still withstands an unusually high ejection pressure (up to 80 PSI). I would feel a little more comfortable with them if the threads could have a little friction, they thread off/on a little too easy, although I have yet to find this important enough to experiment with wrapping a thread with dental floss or gunking them with chewing gum or whatever. I expect the metal ones are the same in that area, except for there being more, finer threads.

I've never had a problem with them. I use them on most all my 29 mm rockets, up to an I200W, and have had no problems. One in particular has flown on 2 G76s, an H165R, H210R, H180W, H250G, and an I200W

No problems

Nate

Our kids have flown over 150 TARC flights on those retainers during the last two seasons and haven't had any problems. As they get older and gunked up, we carefully inspect the caps for any small cracks but haven't found any yet.