Papa Elf's EZI Build

[Papa Elf]

For Secret Santa Christmas In July 2024 the conspirators looked at my wish list and decided to send me a LOC EZI-65 and an Aeropack 54mm Retainer.


The EZI is one of my favorite rockets. I owned at least two of them before. The first one met its demise after the ejection charge failed to fire on a Ellis Mountain H48-4 motor. I retired second EZI retired after many launches with EX motors in the G-I range, and commercial motors in the G-J range. Its final flight was with a G138 that landed in a tree, but was recovered via Shot Gun with minimal damage to the rocket.

It is like a .22 riffle, every home needs an EZI-65 . It weighs in under 1500 grams with up to a H123 so you can fly it at no waivered launches. It’s light enough that you can fly it with G motors. The perfect rocket to get your L1 and even a L2! It is not to hard to use dual deployment. Matter of fact, I used my EZI to test launch the altimeter bay for my L2 rocket, using a I161 (which happened to be using the fuel grains from the J350 that I purchased for my L2, That was back when Aerotech enlarged the core to .5” but I had the original 3/8” core. So Aerotech sent me new J350 Grains and 2 I161 “inert kits” so I made 2 loads out of the old J350 grains).

Anyway, enough of the introduction for my EZI build. Time to get building.

 

[Papa Elf]

Construction started with removing the Glassine Layer off the motor tube. Of course my 54/852 motor wants to join the party. Currently I don’t have an extended closure, but It is possible one day this EZI will go up on a J90 .

 

[Papa Elf]

Even with the Glassine Layer removed, the centering rings did not fit over the motor tube, so I had to lightly sand the inside circle with the Dremel to get the rings to fit. The outer edge had some “Flashing” that had to be sanded off, but the rings fit inside the airframe tube just fine.


With the Retainer and Aft Centering dry fitted in place, I mark the location where the center ring is going to be using the fins as a guide. I tried getting a picture of all three fins in place, but the AC kept blowing the fins over.


The Center Ring and Forward ring are glued in place. In the interest of saving weight, I am using Wood Glue for most of the build, only using other glues where wood glue is not appropriate.

 

[Papa Elf]

The Bulkhead did not fit inside the tube coupler, so some sanding was required with the Dremel.

 

[Papa Elf]

Even though I am still using a retainer, I still installed the Blind Nuts. There may be cases where I am using a motor where the retainer will not work. The Screws are also handy if I insert the ring during the build and have to remove it. I used Thick CA to help set the Blind Nuts.

 

[Papa Elf]

Both Screw Eyes are installed and covered with Epoxy to set them in place.

 

[Papa Elf]

The Bulkhead is glued into the tube coupler.

 

[Papa Elf]

Motor Mount is glued into the airframe tube.


I applied glue fillets to where the Forward Centering Ring contacts the airframe tubing. I also treat the leading edge of the airframe tube with Thin CA.

 

[Papa Elf]

I glue all three fins in place. The guide was later removed by drilling 3 holes in it and using an eyebolt to back it out. I included my STL file for my guide.


Once the glue is dried, the Internal Glue fillets was applied.

 

[Papa Elf]

The tail end of my EZI was finished by glueing on the aft centering ring. Then the Retainer was Cemented on with J.B. Weld. Finishing off the tail with treating the edge with thin CA.


Once all the glues dried, I applied the first external fillets to the Fin/Airframe Joints.

 

[tsmith1315]

The tail end of my EZI was finished by glueing on the aft centering ring

You're tearing up the pea patch with that thing! Sure you didn't open it early to get a head start?

 

[Papa Elf]

You're tearing up the pea patch with that thing! Sure you didn't open it early to get a head start?

You can ask Mrs Elf, we didn't open the box util July 4th

 

[Papa Elf]

Todays work on the EZI was basically more fillets on the fins, cleaning the flash on the nosecone, and filling the spiral.

 

[Papa Elf]

I sanded the filler on my EZI and applied the first coat of primer to the rocket.

 

[tsmith1315]

Got a paint scheme in mind already?

 

[Papa Elf]

I am thinking about Silver mid section and Black FIn/Payload/NoseCone like my previous EZI's but I might change my mind.

 

[tsmith1315]

Did it come with a decal?

 

[Papa Elf]

It did.

 

[Papa Elf]

Sanded the Primer and applied another coat of primer. The body and fins should be ready for paint but the nosecone needs a little more work. The nose and payload will be a different color from the body so that shouldn't be an issue. I also ordered a G80-7T for the first flight.

 

[Aeva]

love my EZI... I customized the crap out of mine though and it's kinda heavy lol. I'm using it for certs, and went way overkill. It's been a great learning experience though.

 

[Papa Elf]

The picture came out blury, but my feet hurt and I am too lazy to get up to retake the picture... so here you go. I took care of the scratches on the nose and drilled a small vent hole in the bulkhead of the payload section.

 

[Papa Elf]

Got some paint applied. Got the forward section on lower section painted white. I messed up a little but I the weather report does not look like I am going have enough time to let it dry and sand it off and try it again, so I am going let it go.. On the table you can see the payload section and nose cone painted orange. I will paint the lower fin section orange on Monday when its the next opportunity for me to paint. Long-term forecast here says 40-60% chance of evening thunderstorms for every day for the next couple weeks, so I'll have to paint before work.


This is my inspiration: When I was 3 or 4 my dad bought a Challenger launch set at Safeway, and we flew it at a park. Apparently it scared us. It wasn't until I was about 6 until I got a Marauder as my first rocket and the rest is history,

 

[Papa Elf]

Finished painting and got the decals applied.

 

[cwbullet]

Finished painting and got the decals applied.
View attachment 657375

Nice paint job.

 

[tsmith1315]

Looks great!

 

[Papa Elf]

Today was the first flight of my EZI-65. It took off with the power of an Aerotech G80-7T rocket motor.

 

[ljwilley]

Some of the most entertaining flights can be the low and slow ones. Well done!

 

[Tim51]

Today was the first flight of my EZI-65. It took off with the power of an Aerotech G80-7T rocket motor.
View attachment 658247

Great looking rocket. Any idea of what the apogee was on the G80?

 

[Papa Elf]

Rocksim and OpenRocket simmed my Speced EZI to 950 feet. I don't think it made it to that due to the wind. The Estes Altimeter reported something between 600-700 feet, but the airframe was not vented and the rocket lost altituted before the charge went off, so I am sure those numbers are on the low side. Next G80 I use will prob be a DMS version where the delay can be drilled down to 6 seconds, or perhaps I'll splurge and pay the hazmat on some G75J's (I wish Aerotech will make the G75J and H97J hazmat free, just need to remove 2 grams from each propellant cores. That is actually pretty simple thing to change. Either make the grains slightly shorter, slightly larger core, or slightly bevel one end of the grain like CTI does. )

 

[Papa Elf]

Yesterday my EZI took off again for it's second flight. This time with an Aerotech G75-6(10)J. A -4 would be more appropriate but not sure if it will be safe to trim the delay that short with the G75. Anyway, even though it was drilled for 6 seconds, the delay was still closer to 10 seconds. It was cool how the EZI didn't come in ballistic but rather came in on its side.