# Aerotech 29mm retainer?

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#### dhbarr

##### Amateur Professional
AT sent me one w/ my Mustang. Worked as advertised.

#### The_Lone_Beagle

##### Well-Known Member
The threads are different from the AeroPack. I had a bunch of AeroPacks already, and for simplicity's sake, I just want to have one type. Since you can purchase the Aeropack retainer bases and caps separately, and save money, I've pretty much decided to just go that route. If I had started out with nothing, I probably would have gone whole hog on the the Aerotech 29mm retainers.

#### Woody's Workshop

##### Well-Known Member
TRF Supporter
Yes, Aerotech is including the retainer with many of the kits.
The only place I've seen this was eRockets.
But from a price point, it's cheaper to buy them separately.
Unless S&H takes play, which I'm sure depends on other items and/or Qty.

#### Tramper Al

##### Well-Known Member
Just trying to learn here.
Are the plastic Estes retainers ($3.60 at eRockets) woefully inadequate? Is this a critical weak point in an F-G 29mm rocket if it's not Aeropack/Aerotech aluminum? Thanks. #### HHaase ##### Siegecraft Electronics TRF Sponsor I use the Estes 29mm and 24mm retainers all the time. Never found them inadequate at all. The only real drawback is they are bulkier due to the plastic. But they function just fine. The Estes retainers are sized for cardboard motor tubes and probably won't fit fiberglassmornthick walled stuff. Last edited: #### Rex R ##### LV2 main difference that I can see is that the aluminum units are less bulky. the plastic units are 1.75" in diameter as compared to 1.6" for the Al jobs. should one wish it, paint sticks to the Al units better. Rex #### Fred Garvin ##### Male Strumpet I use the Estes 24 & 29 retainers wherever possible. I'll probably get the nicer aluminum kit for tha Saturn V build coming up, as I want to build it as a frequent flier with upgrades and quality replacement parts. #### sl98 ##### Well-Known Member Just trying to learn here. Are the plastic Estes retainers ($3.60 at eRockets) woefully inadequate?
Is this a critical weak point in an F-G 29mm rocket if it's not Aeropack/Aerotech aluminum?
Thanks.
I've flown up to 29/240 (H180W, H97J, H250G) with the 29mm Estes retainers and they in great shape. I've used the 24mm up to 29/60 and 3G CTI without any problems. The only issue with the 24mm is you can't use them on BT55 or smaller tube because of their size. Rocketarium 24mm retainers fit inside a BT-55.

#### qquake2k

##### Captain Low-N-Slow
I ordered two of the Aerotech retainers today. I'm anxious to see how they look.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
I've used all three. The Aeropack retainers are easier to use because the threads are coarser, and they have them pre-sized for fiberglass motor mounts. The Aerotech retainer is designed for cardboard motor mounts, but you can use it with fiberglass mounts if you sand the heck out of the tube. The OD is virtually the same as a 38mm FG body tube, so if you have a 38mm rocket with a 29mm motor mount they look really nice. The Estes retainers are really only good for cardboard, they work OK but they're rather ugly compared to the aluminum ones. They are real cheap, though, so I've used them for test rockets where I didn't really care what they looked like.

#### MikeyDSlagle

##### Well-Known Member
I think the Aerotech ones have a smaller ID than the AeroPack, but I could be mistaken. I researched all that when I got started using threaded retainers. Settled on the PML HAMR and have since went to AeroPack because they are more readily available and for more MMT sizes.

The Estes plastic 29mm retainer will work on (at least some) fiberglass. It takes some sanding with a Dremel but it works. I have one on my Hurricane 38. It's just holding the motor in when it pops ejection charge. And of course to keep it from falling out when the motor burns out, but it doesn't have to hold against the thrust. My aluminum retainers get black gunk on em, but don't think the heat is close enough to hurt the plastic ones. I have yet to fly my rockets with the plastic retainers.

Mikey D

#### T-Rex

##### Ordinary Average Guy
TRF Supporter
Just ordered a couple from Tower Hobbies. Free standard shipping through the weekend.... Thanks for bringing these to our attention qquake!!

#### qquake2k

##### Captain Low-N-Slow
I got the retainers in the mail today. I must say, they look really nice, especially for the price!

#### qquake2k

##### Captain Low-N-Slow
I really like the Aerotech retainer! I tried it with 29/40-120 and 29/180 cases, and a G80 single use. They all fit with no problem.

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#### PhilC

##### Active Member
I've had no problem with the Estes reatimers and find that plastic is OK for F/G reloads. I've just invested in a 3D printer and have made on of these retainers:
https://www.thingiverse.com/thing:882815

It seems a bit loose on the Estes 29mm tube but fine on PML. I'll pack it out and try it on my "test bed" rocket. I'm making a rocket for testing a load of 3D printed components so I'll give the retainer a go and see what happens.

#### qquake2k

##### Captain Low-N-Slow
I thought about using an Estes retainer, but the OD of the "knob" is a lot bigger. I was afraid it wouldn't fit in the tailcone.

#### sl98

##### Well-Known Member
I thought about using an Estes retainer, but the OD of the "knob" is a lot bigger. I was afraid it wouldn't fit in the tailcone.
There is a possible solution ...

I sanded the knobs off, then used a Sharpie. The end result is it is the same diameter as BT-60 tube.

Last edited:

#### Mr G

##### Well-Known Member
With an Aerotech 29mm HP aft closure, how many turns are there before the metal retainer is tight? With the plastic ones, I only get about a quarter turn.

#### MALBAR 70

##### More Rockets Than Room
TRF Supporter
I've been using Estes retainers on most of my mid power stuff and AreoPack retainers on all my high power rockets. I recently picked up a Rocketarium 24mm aluminum retainer for a project. I haven't used it yet but it's very nice looking and well made.
I'm interested in the AT retainers as they look quite durable.

#### qquake2k

##### Captain Low-N-Slow
With an Aerotech 29mm HP aft closure, how many turns are there before the metal retainer is tight? With the plastic ones, I only get about a quarter turn.
If you're only getting a quarter turn, I'd say something isn't right. What motor(s) are you having problems with? How thick is the thrust ring? The Aerotech retainer is fine thread, and I get about 4-1/2 turns with the 29/40-120 case and G80 motor, and 2-1/2 turns with the 29/180 case (which has a thicker thrust ring).

#### Mr G

##### Well-Known Member
Sorry, I meant 3/4 turn on the plastic retainer. The question is whether there is more space for the thicker aft closures found on the AT 29/180-360 and CTI cases. They are substantially thicker than the AT 29/40-120 aft closure or single use lip.

#### qquake2k

##### Captain Low-N-Slow
As I said above, I get 2-1/2 turns with an AT 29/180 case.