Motor Retention or How I Stopped Worrying and Learned to Distrust Electrical Tape

[SkiesAreClear]

I used to think I was too good for motor retainers and didn’t want to dream of spending a dime on anodized aluminum for my leightweight rockets.

I had not yet encountered anything in life that couldn’t be fixed with electrical tape. Naturally it became my form of motor retention for my 24mm rockets. After about 6 flights on E and F motors I had an omen. (Image 1) 24/40 casing was nearly ejected out the aft end of my favorite rocket. So I learned my lesson and added an additional wrap of electrical tape to my preflight procedure.

7 flights later (it’s always flight 13) the case was ejected from the rocket at apogee (~900ft). I knew it landed close by since the flight was arrow straight. After a bit of pacing through the field, the sun began to set and I was without casing. The field is huge (it’s called “60 Acres Park”) and the grass is normally short but it’s at least 24.1mm tall making the motor not easy to find. The field gets muddy so while it rained for two days, I didn’t make the drive to look for the casing. On day 3 I spent a few hours of an audiobook and a mild sunburn walking through the field until I found o’ reliable (image 2), more beaten up than she deserved. A bath of vinegar and a thorough scrub later, everything was in good shape.

To celebrate the recovery, I spent some money on various motor retention mechanisms for my fleet. It might not be the most fun money to spend, or the most efficient use of mass on a rocket, but it sure beats hours of walking through a field looking down at grass.

Bonus picture of the offender/rocket in flight.

 

[Sandy H.]

I had to give you a like/love for the title if nothing else. Also good you found your case. I happen to use safety wire and screws on more than a handful of rockets, but each build has its own challenges.

While I haven't purchased commercial motor retention yet, I may someday. I agree with ditching the electrical tape for sure!

Sandy.

 

[lakeroadster]

I've never heard of anybody using electrical tape to hold motors.... is this a thing?

 

[SkiesAreClear]

I've never heard of anybody using electrical tape to hold motors.... is this a thing?

works at least 11times in 13 ¯\_(ツ)_/¯

 

[tHoagland]

I occasionally use gaffer tape on some smaller, mostly MPR, motors. It works great when properly done and I've never lost a motor. I would never consider electrical tape or duct tape because of the sticky residue.

 

[SkiesAreClear]

I had to give you a like/love for the title if nothing else. Also good you found your case. I happen to use safety wire and screws on more than a handful of rockets, but each build has its own challenges.

While I haven't purchased commercial motor retention yet, I may someday. I agree with ditching the electrical tape for sure!

Sandy.

I have an Aero Pack for my HPR and an Aerotech retainer for the MPR mentioned here. Both work like a dream!

 

[heada]

Estes 24mm and 29mm retainers are awesome. They're available dirt cheap from AC Supply.

$5 for a pair of 24mm and $6 for a pair of 29mm.

They work with molded thrust rings like in single use motors and with aft closures on 24/40, 24/60 and 29/40-120 as well as the normal RMS and CTI closures.

 

[David Schwantz]

I would not use electrical tape. But I do use aluminum tape to hold motors all the time. Better stick um, and you can fold it over the bottom of the thrust ring.

 

[cerving]

PAPER masking tape works great. I've heard of people using the Nomex "burrito" method of mounting their Eggfinder Mini trackers, using electrical tape to wrap it up, and having the ejection charge melt the tape resulting in finding the tracker but losing the rocket. Paper tape might char slightly (just the outer layer), but using electrical tape is just asking for problems.

 

[hball55]

I have always used masking tape . . . coefficient of friction greater than electrical tape.

 

[Pete.D]

Blue paper masking tape works great for me, on all rockets from Mini through L2.
A couple wraps to be sure: more reliable than Estes-type clip retainers, no glue to fail like screw-on retainers sometimes do, and has never failed up through J power.
Eliminates the need for motor blocks when using BP motors, which otherwise limit engine selection.

 

[CalebJ]

Great thread title, by the way.

 

[tab28682]

I have never tried to use electrical tape. The electrical tape I have seen can soften with heat, even when is just out in the sun.

Zero failures ever for me using normal masking tape (not painters tape, which is usually low tack)

 

[MidOH]

I use the aluminum tape as well. Looks like a cool silver nozzle.

Hopefully removal of the metal hook and engine block moves my CG forward a hair.

 

[Bat-mite]

Looks like you could attach some bent metal hooks, similar to the old-style metal retainers that still come with some kits.

 

[jimzcatz]

Never ever use electrical tape. We have been using masking tape since the Pleistocene era.