Let's talk 29mm retainers for use with Kosdon

I am building a USR Banshee and want to put a motor retainer on it. I intend to fly it with Kosdon 29mms and the usual AeroTech stuff.

It would be cool if the cheap-o Estes retainers would work, but I doubt they would. Has anyone tried this?

Maybe I need to go all in and buy an AeroPack?

is there an external ring on the Kosdon case? If so, Estes should work fine

I don't think those older small Kosdons have a thrust ring. But I certainly could be wrong. Most original Kosdons didn't, IIRC.

If that is the case (no pun intended), you'd have to hope a masking tape thrust ring would fit. Would probably have to use 1/2" masking tape or smaller...those retainers probably give the clearance for a 29mm AT SU thrust ring or hobby 29/40-120 RMS thrust ring which are about the same size -- I'd guess probably 1/4" or less.

Thanks for the input guys. The casings I have do have an external rings, but they are spaced differently (ie, the ring is set further down the case) than the usual AT motors.

Reckon I'll go Aeropack.

Sorry to hijack this thread, but I was wondering about the masking tape thrust ring. I was thinking of doing something like this to fly a 29 mm Estes black powder motor in an engine mount without a LPR-style internal thrust ring. Is that advisable?

J Blatz said:

Thanks for the input guys. The casings I have do have an external rings, but they are spaced differently (ie, the ring is set further down the case) than the usual AT motors.

Reckon I'll go Aeropack.

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Remove the rings and apply an appropriately sized masking tape thrust ring. Should be more than sufficient for 29mm.

Estes retainers are a nice price though I do worry about them with the non hobby 29mm hardware. The cap does not thread all that much. I still use them together with success, but I have heard stories of them kicking. With the hobby hardware they are great, no worries.

BDB said:

Sorry to hijack this thread, but I was wondering about the masking tape thrust ring. I was thinking of doing something like this to fly a 29 mm Estes black powder motor in an engine mount without a LPR-style internal thrust ring. Is that advisable?

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Absolutely. With the right tape I have friction fit a 54mm L motor.

Ah, they do have rings. That's what going on memory gets you...and I never flew any of these, only saw some and read about many of them. Would love to get my hands on some of these and the 24mms.

marcusSRG said:

Ah, they do have rings. That's what going on memory gets you...and I never flew any of these, only saw some and read about many of them. Would love to get my hands on some of these and the 24mms.

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I have quite a pile of 29MM Kosdon loads for the safe n sane 29/150 and 29/250, even some of the C-slots.

In fact, I have quite a pile of a lot of rocket stuff LOL.

Have been using tape thrust rings for 20 years, 18mm thru 54. Yes, it works.

Agree, I have used a lot of tape myself.

jimzcatz said:

Have been using tape thrust rings for 20 years, 18mm thru 54. Yes, it works.

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J Blatz said:

I have quite a pile of 29MM Kosdon loads for the safe n sane 29/150 and 29/250, even some of the C-slots.

In fact, I have quite a pile of a lot of rocket stuff LOL.

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Nice! Would you get rid of any? I wouldn't be sending these back like your SSR book though! Man that book was awesome.

Back on topic...let us know how the retainer works out. Would love to see some of those motors in action!

Marcus-

I will post pics when I fly some!

Jason

Yeah, I would really like to see some photo documentation of any Kosdon stuff. It's few and far between so anything you could do pre-combustion would be great .

watermelonman said:

Estes retainers are a nice price though I do worry about them with the non hobby 29mm hardware. The cap does not thread all that much. I still use them together with success, but I have heard stories of them kicking. With the hobby hardware they are great, no worries.

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I use the Estes retainers with RMS and HobbyLine hardware all the time. I've had no issues here. The difference in the thickness of the rear closure is 0.118 inches. Not enough IMHO to kick the retainer off.

Tonimus said:

I use the Estes retainers with RMS and HobbyLine hardware all the time. I've had no issues here. The difference in the thickness of the rear closure is 0.118 inches. Not enough IMHO to kick the retainer off.

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Yes, that is definitely a good combination. I meant the high power closures, which Aerotech also sells as "high power style", and I was trying to cover both by saying non hobby. Sorry it is not that clear.

I was referring to the high power closures. I've used them extensively with the Estes 29mm retainer without issue.

Well, that is good to hear. Like I said, I do it too! Works so far, but stories from others had me worried.

I use the Estes 29mm in my mirage . For the hobbyline aerotech and the H DMS motors the retainer works great. For the 240 hardware I only get about 1&1/2good turns on the cap.Its worked so far but the first thing I look for every time I retrieve the rocket is that case in the mount. I use pliers to tighten the cap , after firing I can unscrew it by hand . I friction fit the motor as well to help keep it in for a little extra insurance. I've burned 10 G64- 2 G76 - 2 H180 -2 H135 & 1 H115 and no visible damage to the retainer other than smoke discoloration.