Can I use the Aero Pack MC38 as a shock cord anchor

[TomSmith58]

Hi Follks,
I have a Go Devil 38 and I bought a Slimline Qwik-Lok retainer. I am trying to figure out the best way to anchor my shock cord.

Can I use the MC38 Cesaroni Pro38 Delay/Eject-Closure Adapter on the end of my motor and screw an eye bolt into it? The loads from the shock cord would then go through the motor case to the Slimline. Or should I save the Slimline for later and buy the M38BE Minimum Diameter Motor Retainer. If I do that then I am stuck buying those retainer extensions.

Thanks
Tom

 

[smapdiage9]

The instructions warn you not to. Because the system screws into the plastic forward closure, it's only designed to anchor the burnout weight of the motor and casing not the loads of carrying the airframe. A motor retainer doesn't really help that. I use mine by screwing it into a md anchor I made myself out of a section of coupler, a bulk plate, and a 5/16 nut. This is a cheap way to ensure the mc38 doesn't carry more than the designed weight.

 

[watermelonman]

Yes, the instructions explicitly say you should not.

However, I do know people that have made semi permanent anchors similarly. Take a used forward plug and tap an eyebolt into that, and epoxy. I would try to fit a nut and washer on the back end, not sure if others do that. You lose your tracking smoke since it was burnt up on the previous flight, but with a good 38mm minimum diameter you needed electronic tracking to begin with!

 

[watermelonman]

This is 54mm but the idea should still work -

 

[smapdiage9]

That looks like it would work better than trying the same with the MC38. Have you flown them like that? Does the absence of a smoke grain impact the chamber volume significantly?

 

[watermelonman]

I have not personally but I know several people who have, no failures so far. I would not expect the smoke grain to have much impact, considering how 29/40-120 reloads work, but that is more of a guess than real data.

 

[JDcluster]

I've used it on 2 occasions; one worked, the second failed under high speed deployment.
Under normal loads it should hold up.
If they had longer and courser threads for more bite into the closure you wouldn't have any problems.

JD

 

[blackjack2564]

One more time, I've shown this....simple as it gets:

No need to remove smoke grain.
For 38mm, a 3/16's eyebolt will self tap into BP touch hole after removing BP. You may need to use drill bit to open taper at bottom, if you aren't strong enough to twist it in. Don't go into delay. Stop when you feel resistance.

Gouge up the sides of BP cup for better epoxy grip. Place nut on eyebolt, thread into touch hole. leave nut a bit higher than bottom of cup, so epoxy can flow under and around it, locking E-bolt in place.

For 54mm use 1/4in eyebolt after removing taper in hole with 3/16ths bit.




Friction fit motor into airframe. When done properly, as effective as anything!

Wrap tape around REAR of motor, like threads, each wrap barely overlapping the previous. Just the last few inches need tape.
SCREW the motor in. When done...unscrew the motor.

After inserting in airframe 1 wrap of aluminum duct tape goes around both motor and airframe. Thin enough it won't mess with airflow and you will NOT get the motor out unless you remove that one wrap. Been doing this for years, shown many others who now use it.



Simple...cheap...reliable. I even pull front closure out after flight, lay on it's side...whack with hammer to shatter epoxy and re-use the E-bolt. Free other than a bit of tape.


Finally if ya want to get REAL fancy do what Jeroen recommends to hold motor in.

 

[smapdiage9]

Dang, and I went to all this trouble to build in a removable coupler with grub screws and pem nuts on my Blackhawk 38. I guess that's the easier solution!

 

[DizWolf]

The go devil comes with a piece of coupler to make an anchor out of. I'd file a bit off the OD to wrap a shock cord around it, and glue it in place to allow for the longest motor. Done.