Breaking AT's Engine Hook

The Rocketry Forum

Help Support The Rocketry Forum:

DynaSoar

Well-Known Member
Joined
Mar 15, 2004
Messages
3,022
Reaction score
0
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

Papa Elf
Joined
Jan 21, 2009
Messages
7,618
Reaction score
517
Location
Penns Creek, PA
Motor Hook breaking? What have you heard about that? I been flying Aerotech rockets for about 10 years now... never seen a hook "break?" :confused:

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

DynaSoar

Well-Known Member
Joined
Mar 15, 2004
Messages
3,022
Reaction score
0
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?" :confused:

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

Well-Known Member
Joined
Dec 31, 2002
Messages
4,292
Reaction score
0
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 :mad: 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

Well-Known Member
Joined
Jan 25, 2009
Messages
2,795
Reaction score
2
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

Well-Known Member
Joined
Jan 18, 2009
Messages
3,562
Reaction score
1
Location
Fort Myers, FL
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

Well-Known Member
Joined
Mar 15, 2004
Messages
3,022
Reaction score
0
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 :mad: 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.
 

stevem

Well-Known Member
Joined
Jun 7, 2009
Messages
1,613
Reaction score
0
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

Well-Known Member
Joined
Jun 7, 2009
Messages
1,613
Reaction score
0
DynaSoar, don't have any pics of your fix do you?
 

Elapid

Well-Known Member
Joined
May 2, 2009
Messages
1,735
Reaction score
0
every one break off...
2 of 3, anyway...
 

YvesLacombe

Member
Joined
Sep 8, 2004
Messages
5
Reaction score
0
Why put the dang hook anyway? Prevents you from sticking in longer-than-usual motors (ie: 29/180 and 29/220 casings) :)

- Yves
 

Latest posts

Top