Breaking AT's Engine Hook

[DynaSoar]

I've heard plenty of complaints about AT's engine hook breaking. I've come up with two different cheap alternate retainers as have others.

So there I am, extending my Mustang by 3 foot (turning it into a Moosetang) and have the PVC parts to put on a quick change retainer, and they're all cut and ready to epoxy in. But the engine hook isn't broken. It's a little rusty, but it's still solid. I need to get this thing out of the way so I can glue in the threads for the retainer.

So how do you MAKE the engine hook break? Keep in mind the motor tube on a Mustang is recessed -- not much room to work with for bending it, etc.

 

[n3tjm]

Motor Hook breaking? What have you heard about that? I been flying Aerotech rockets for about 10 years now... never seen a hook "break?"

I'd say don't worry about it, and save your retainer for a future project .

 

[DynaSoar]

Originally posted by n3tjm
Motor Hook breaking? What have you heard about that? I been flying Aerotech rockets for about 10 years now... never seen a hook "break?"

I'd say don't worry about it, and save your retainer for a future project .

I heard about it right here on TRF. Seems the tab at the aft end of the motor tends to break off. It hadn't happened to me, but several other people complained about it.

I finally took a pair of pliers to it and it snapped first try. Then I did the same at the first bend. That got it out of the way.

No reason to "save" the retainer. It cost $3 for the parts to make two (after cutting the pipe nipple in half). I finally found some schedule 80 PVC rather than the heavier schedule 40.

I got it installed with some JB Weld. It's a definite improvement in looks and drag characteristics over the big hollow aft end, and the screw on/off cap is way easier to use than the hook. It also retains 24mm adapters better.

 

[Johnnie]

I was showing off my freshly painted Mustang, when it slipped from my hand, landing point blank on the "motor" hook snapping it at the bend now it will literally cut your finger open when trying to get it pryed open enoughto get a 29/40-120 casing in. Scratches the heck out of the reloadable as well. I was surprized at how easy it snapped.

 

[jetra2]

Same thing happened here. I dropped it right on it's tail end while I was painting it, and the first bend snapped clean off. I now have my dad or a helper pull back the hook far enough so that I can get the casing without totally scratching it, then have the remaining bend go into one of the grooves on the case. Then I wrap the sucker in masking tape, until you wouldn't know there was a motor in there just by looking at it. You'd actually have to look at the tail end a see the nozzle and say, "OOOOOOHHHHHH....ok...." LOL!

I'm sure that you could cut through the hook at the lowermost centering ring and then attach the retainer to the motor tube.

Jason

 

[Donaldsrockets]

I have several AT kits and I never had a hook break. I once had a G80 eject out the rear of my G-Force. It cleanly bypassed the hook as the hook was not damaged at all.

I kinda prefer homemade retension with blind nuts, screws and clips myself as I don't have to worry about cut fingers or scratched motor casings.

 

[DynaSoar]

Originally posted by Johnnierkt
I was showing off my freshly painted Mustang, when it slipped from my hand, landing point blank on the "motor" hook snapping it at the bend now it will literally cut your finger open when trying to get it pryed open enoughto get a 29/40-120 casing in. Scratches the heck out of the reloadable as well. I was surprized at how easy it snapped.

If you built the Mustang exactly according to directions, then the engine mount is recessed exactly the right amount to epoxy in half of a 2" long 1.25" diameter PVC pipe nipple, and have a PVC bushing cap with a 1" E clip in it screw on tight against the aft end. It's pretty much the retainer I put on my NCR Renegade-X, but in this case there was no measuring the threaded PVC necessary. It was like the rocket was designed for this mod. I never did get the whole hook removed. I just broke off enough so that it wouldn't be in the way.

 

[gerbs4me]

I've never heard of AT hooks breaking

 

[stevem]

Jason - my AT Warthog had the same thing happen - it slipped out my hand landed squarely on the fllor and snapped the engine hook clean off.

 

[stevem]

DynaSoar, don't have any pics of your fix do you?

 

[DynaSoar]

Originally posted by stevem
DynaSoar, don't have any pics of your fix do you?

I finally got a digital camera, but it's still on the moving truck making its way to Texas. Here's a link to the same mod I did to my NCR Renegade-X. Exactly the same parts and construction.

https://www.rocketreviews.com/reviews/scratch/motor_retainer2.html

 

[Elapid]

every one break off...
2 of 3, anyway...

 

[YvesLacombe]

Why put the dang hook anyway? Prevents you from sticking in longer-than-usual motors (ie: 29/180 and 29/220 casings)

- Yves