Broken Motor clip

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Well-Known Member
May 2, 2009
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on my AT Cheetah...
i can't seem to win!

it broke after the last week's flying adventure...old-style EJ motor kicked out and left only the first 90° bend making it very tough to get motors in and out.

i had to saw it off at the aft end of the MMT and now i am installing an aft centering ring with a 10-32 blind nut for motor retention. i lengthened the MMT with a bit of BT60 and i'm thinking some foam to help distribute the force might help. then i'll need to make sure to get the CG back where it's supposed to be by adding a few BBs to the nose...
Elapid, You seem to have the worst luck with AT products. Are you sure you are not jinxed or something? I recommend LOC. :)
I won't buy Aerotech rockets any least not to fly. My first was an IQSY Tomahawk. Took it to a launch Ross at Magnum was having for a TV commercial he had made, and used an E15-7. Should have used a -4.

My next model was an ARCAS. Flew it on a G80 at a Cub Scout launch. No ejection, and instead of hitting the relatively soft ground, it hit a parking lot. My second ARCAS was lost in a soybean field...I spent 2 hours looking for it and just COULD NOT FIND IT. Probably was within 10 feet of it the whole time. My third ARCAS ended up missing when I moved. There were people working on the house while we were still moving stuff out and I think they may have snagged it.

My Strong Arm landed in a pond.

Both of my Astrobee D's suffered from the standard only-one-chute-came-out problem. You'd think I would have learned my lesson the first time.

Actually, I like the Astrobee enough that I'll probably get another one...someday.
I had the same type of problem with my AT arreaux. After landing on a 9" chute at LDRS on a G35, the motor clip just snapped of, leaving me with the 90 degree hook. The best way I found to work around this is to use a screwdriver and bend the clip back, insert motor, and then let the clip go back. Btw, I hate clips. If I were to build it again, I would use friction fit only.
not as bad as Qmax...

i really like the solid construction of the AT kits.
they're really SOLID!

i did use the broken clip for a few flights, but kept poking myself, crushing the end of the tube trying to pry the clip back, and i was worried that the scratches that it sometimes put on the motor casings might cause a failure.

sure isn't much room for a blind nut...maybe i need to use a 4-40 or 6-32 rather than the bigger 10-32 i bought.

i'd do the friction fit thing, but i'm going to be using RMS motors and really don't want to lose any hardware.
Originally posted by Darian Rachal
Elapid, You seem to have the worst luck with AT products. Are you sure you are not jinxed or something? I recommend LOC. :)

nope. I actually consider myself EXTREMELY lucky!
think about it...

EVERY motor i have put in an AT bird has kicked out...but every time the recovery system deployed and all the rockets are in one piece and relatively undamaged.

the fire...well...we got it OUT!
only a little grass got burned and a few nerves rattled...
it could have been sooooooooo much worse!

the loss of the motor hook on the Cheetah gives me experience in re-engineering a pretty darn good product.

no broken fins yet, i can see how that could be a pain...

#8 would have been a better choice...
I once flew my G-Force on a G80 and the casing got kicked out at ejection. The motor clip wasn't damaged though so I guess the motor managed to bypass it during ejection.

I was sooo glad that there was still enough pressure built up to deploy the chute with no problems and the rocket was recovered without incident.

After I retrieved the rocket and walked back to the flight line, there was the casing sitting on a prep table.

I think from now on I'll put the motor in normally and wrap masking tape around the motor clip junction and hopefully that will keep the motor in place.

I also flew it on an RMS G64-4W. Luckily, you don't have this problem due to the slotted recesses in the aft closure.
I'm really happy with the clips on my AT rockets, haven't had one let go yet.
no kicked motors though...

Originally posted by Elapid
no kicked motors though...

Get yourself an offset screwdriver, with the tip at 90 degrees from the shank. Stick it in and twist and the clip will open right up. My clip hasn't broken (hasn't had a chance) but I have one of these already because it's easier than straining my thumb on the clip.