Dual Deploy Minie Magg with Cable Cutter

I am converting a Minie Magg for dual deploy using one break point and no additional tubing. I picked up a Cable Cutter to use with a burrito-wrapped chute. I actually did a similar setup on a previous Magg with a home-made tether device, so I know it will work. I am trying to make it a little cleaner and more elegant this time around.

Here is my av-bay:



A 38mm coupler tube is mounted in the nose to accept a long narrow sled. I drilled out the base of the nose to accept the tube. A new shockcord attachment is made with an eyebolt secured with a good sized fender washer on the inside of the nose.

The tube is epoxied into the tip of the nose and a centering ring flange is glued/screwed on the base of the nose. Pipe insulation fills the remaining void in the tube. Three vent holes are drilled through the BT/nose shoulder/and av-bay. Through one of the holes (seen in the pic), I will activate the rotary switch.

Here is the av-bay installed with sled inside.



A plug is screwed into the end of the tube to close it up. No slop. The sled is secure.

I have had a failed epoxy joint on a sled that moved the arming switch so I will not fly with a switch that is not bonded to the outside of the airframe in some mechanical way if I can help it. However this solution is quite elegant. Is there any reason you elected to do it in the nose rather than say within the 5.5" body along one side?

Here is a close up of the completed nose with black ematch wires running out of the av-bay:



Here is a general layout of the recovery system:



The ematches are directly wired to the altimeter. The ematch on the left will be the drogue event. The ematch on the right is connected to the Cable Cutter burrito wrap. The Cutter is tethered with the safety Kevlar string. I still need to tidy up the ematch to the Cutter to give it enough slack and prevent it from jerking around or pulling out from the altimeter.

UncleVanya said:

I have had a failed epoxy joint on a sled that moved the arming switch so I will not fly with a switch that is not bonded to the outside of the airframe in some mechanical way if I can help it. However this solution is quite elegant. Is there any reason you elected to do it in the nose rather than say within the 5.5" body along one side?

Click to expand...

All my bays have the switch on the sled - rotary or screw switches.

That nose has so much unused real estate. I had to put something in there! Also, the extra weight in the nose will help stability if I choose bigger motors.

If the ebay was in the body tube, then the Cable Cutter/chute bundle would be on the airframe end of the shockcord instead of the nose cone end. Seems a little awkward, but maybe it doesn't matter?

In case you are wondering, I have yet to have any problems with baro measurements coming from vent holes near the nose cone as shown here.

In the pic above, there is a lot of junk to tangle - ematches, chute, shock cord, safety tether. That is why I am kinda put off on this tether method for dual deploy, but the new Cable Cutter looked too cool and appropriate for this Minie Magg application!

Buckeye said:

All my bays have the switch on the sled - rotary or screw switches.

That nose has so much unused real estate. I had to put something in there! Also, the extra weight in the nose will help stability if I choose bigger motors.

If the ebay was in the body tube, then the Cable Cutter/chute bundle would be on the airframe end of the shockcord instead of the nose cone end. Seems a little awkward, but maybe it doesn't matter?

Click to expand...

Good reasoning - just asking but I like the analytical thought that went into that reply.

Buckeye said:

In the pic above, there is a lot of junk to tangle - ematches, chute, shock cord, safety tether. That is why I am kinda put off on this tether method for dual deploy, but the new Cable Cutter looked too cool and appropriate for this Minie Magg application!

Click to expand...

Reduce the distance. Put the entire bundle right next to the eyehook with everything inside the bundle. Take up slack where possible with hair bands (the thin disposable one's).

UncleVanya said:

Reduce the distance. Put the entire bundle right next to the eyehook with everything inside the bundle. Take up slack where possible with hair bands (the thin disposable one's).

Click to expand...

Good thinking. Will do.

I would be interested in seeing a video of this type of deployment. I have seen the vids on the Archtype website but does any one have any videos of their own? I know a lot of these have been sold lately but I have yet to hear any testamonials of actual flights.

bill2654 said:

I would be interested in seeing a video of this type of deployment. I have seen the vids on the Archtype website but does any one have any videos of their own? I know a lot of these have been sold lately but I have yet to hear any testamonials of actual flights.

Click to expand...

See here:

https://www.rocketryforum.com/showthread.php?37812-Archetype-Rocketry-Presents

Buckeye said:

Here is a close up of the completed nose with black ematch wires running out of the av-bay:

View attachment 108390

Here is a general layout of the recovery system:

View attachment 108391

The ematches are directly wired to the altimeter. The ematch on the left will be the drogue event. The ematch on the right is connected to the Cable Cutter burrito wrap. The Cutter is tethered with the safety Kevlar string. I still need to tidy up the ematch to the Cutter to give it enough slack and prevent it from jerking around or pulling out from the altimeter.

Click to expand...

Couldn't you cable tie the bundle right to part of the shock cord? Maybe even directly to the eyebolt, thereby reducing the chance of tangling during drogue descent?
Also, your rotary switch is on the sled itself, right? Turned with a long screwdriver through the vent holes?
Also, vent holes through airframe, nosecone shoulder, and av bay tube? That's three holes... I'm assuming they all line up, like place the nosecone on the airframe then drill vent holes? Or should the av bay tube be offset?

CzTeacherMan said:

Couldn't you cable tie the bundle right to part of the shock cord? Maybe even directly to the eyebolt, thereby reducing the chance of tangling during drogue descent?

Click to expand...

Yes, I bundled everything close to the eyebolt as suggested above.

Also, your rotary switch is on the sled itself, right? Turned with a long screwdriver through the vent holes?

Click to expand...

Yes, long screwdriver through a vent hole. You need good aim and feel to find the switch!

Also, vent holes through airframe, nosecone shoulder, and av bay tube? That's three holes... I'm assuming they all line up, like place the nosecone on the airframe then drill vent holes? Or should the av bay tube be offset?

Click to expand...

Yes, 3 holes drilled in one pass. They line up. One remote possibility is that the nose cone rotates during flight and shuts off the port holes, but that hasn't happened yet.

Hey Buckeye I have done the same setup with my magg . I installed a short 6 inch long section of 10/24 allthread sticking aft out the base of the nose cone . This gives the chute bag something to grab onto so it will not get tangeled and the threads will bite into the cable tie and keep it ( the chute bag ) from sliding up or down .

Eric