Next Project "NO LIMITS"

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Theory

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Got lots of work done today. The third fin is on following the same process as before. All went well there.

found that the epoxy was setting a touch faster than in the past. Believe the volume in the epoxy channels lead to higher exotherm and quicker setting. No worries there.

Once all was nice and set up I poured some system three 30 min around the aft centering ring. This epoxy is quite thin and poured nicely

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here she is. All together for the first time

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Theory

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Now for the part that didn’t go so well.

been chasing the “100% error free build” for some time. Got close with Caliber ISP, and was on track here till today.

Building the nose cone with a removable shoulder to allow for mounting weight cartridges, a GPS etc.

The shoulder will be held to the nose cone with three 10-32 screws.

back when I was laying out the airframe I drew three marks up the airframe and nose cone to align the sheer pins, nose cone screws and the 10-32 screws that will hold the electrics bay to the payload section.

with everything measured out it was off to the drill press. A minute later I had three holes through the nose cone and the nose cone shoulder. To my chagrin the holes I drilled were too close to the bulk plate to allow for the nut to fit.

so measured again and drilled three more holes. Sloppy work : - /

filled the old holes in the nose cone. When finished you will never see them. Going to leave the shoulder alone


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the nuts are held in place with JB weld.

lots of mounting options here. The exposed thread on the eye bolt will serve as a solid anchor point
 

HyperSonic

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Very nice job!!! My L3 rocket looks a lot like yours, 3 fin 4" airframe with 75 mount with conical cone. I hope to make it out east some day to fly with you!
 

Theory

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Thanks Hyper. VERY happy with how the booster turned out.

going to let it sit for a day then set to work on the fillets.

going to use rocketpoxy, but am undecided on what radius to use and the what to use to “pull” it
 

Theory

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Let’s talk rail buttons...

Honestly, in past projects I haven’t given the rail buttons much thought. Pick them out and screw them in.

For this one it’s a little different, and as such I’ve given it more thought. Loaded with an L she will weigh over 20 pounds so I opted for 15/15 buttons. The anchor points are solid birch ply that was epoxied to the mmt (see earlier posts in this thread).

The design I’m going with used a low profile 15/15 button, a nylon spacer and a regular old screw.
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the back of the spacer will be sanded to match the curvature of the airframe then will be epoxied in place. Once all is painted I will screw in the button and use a drop of thin CA as thread lock to keep the screw in place. I like to back off the screw by a very slight amount to allow the button to spin. Believe this reduces drag on the rail.

mock up prior to sanding / adhering the spacers:

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Theory

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Fillets... ugh...

Possibly my least favorite part of any build. Not sure why, just never been a fan.

Started by sanding the fin and airframe with 220. Then cleaned with alcohol. Starting to sound familiar right? Hey, if it ain’t broke don’t fix it. ...or fix it till it is. One of those.

Then mask off the area, apply a liberal amount of rocket proxy and then wait. let it hang out in the mixing cup for 20min then a solid 15min on the rocket before pulling.

pulled with an expertly calibrated tongue depresser. Yup, was going to try something new, but then, if it ain’t broke...

after that set up a bit I cleaned the edges with the ol’ gloves finger dipped in alcohol.
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HyperSonic

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Your fillets look very good! It looks like your rail buttons are made for a countersunk head wood screw.
 

Theory

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Yes they are. When they are placed in “final position” will use a countersunk screw. These are just for mock-up
 

FlyBy01

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This is making my so jealous that my 4/5.5" honest john ha not arrived yet. I have build envy🤣 Can't wait to see this fly next season. Thank you for posting; the epoxy dams are a new build idea I learned from this post. Do you have a paint theme in mind yet?
 

ZEDL1

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I can't see why you don't care much for making fillets Theory, as you are very good at making them so well...
 

Theory

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More progress. Nothing crazy major, but moving forward none the less.

First, epoxied the switch band to the electronics bay. Standard procedure here.
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Once cured I laid out the locations for sheer pins, screw holes, and vent holes, then drilled each.
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As with the nose cone, the electronics bay is held in place with 10/32 screws and the nut for each is epoxied in place with JB Weld

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Spent some time with the drill press and counter sunk the screw hole locations in both the nose cone and electronics bay. Very happy with the results.
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finally, as all the fin fillets are complete and fully cured, I applied a good amount of spot putty to ensure a smooth edge/transition

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Theory

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A little more. The deployment electronics have been ordered. Settled on an RRC3 and an RRC2L by Missile Works. Switches, mounting equipment etc. are also by Missile Works.

Also, with the color scheme officially decided on, the paint and clear were procured. Aim here is to go VERY light on primer. Experience dictates that I won’t need much.
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With the holes drilled and counter sunk in the nose cone and payload, I should have them in primer here very soon.

the plan is to wipe with alcohol, sand lightly with 400 grit, wipe down again, then shoot the primer. The primer will be “knocked down” with 400 grit before the color coat. Believe this will be better than using 800 grit as it is my feeling that the high grit paper led to adhesion issues in previous projects
 

Theory

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Update on the recovery system.

Just pulled the trigger on the main parachute. Went with a 10 foot Rocketman "standard" in red and black.

The drogue is a 2' ballistic also by Rocketman.
 

Theory

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Spent some time sanding

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and sanding

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and priming

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more of the cycle of fun to come
 

Theory

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One piece ready for color, the other for primer

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and the entire work area is ready for a good solid cleaning
 

Theory

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Looking at similar motors I’m thinking she will do about 11,000’ on the new Aerotech L1940X

would be pushing the limits of the field in culpeper. But then, I think that’s what she was designed for ; - )
 

FlyBy01

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Looking at similar motors I’m thinking she will do about 11,000’ on the new Aerotech L1940X

would be pushing the limits of the field in culpeper. But then, I think that’s what she was designed for ; - )
I'll help you find where it lands.
 

Theory

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Shot some primer on the fin can this morning. Work to do there, but that was expected

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and yes, still need to clean things up :-/
 

Theory

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Recovery system upgrade!

The last major flight of my rocket EX-1127 encountered some serious recovery harness knots as a result of the booster spinning on decent. Fell from 6400’ to 500’ and was enough to render the streamer and drogue 110% useless as they were twisted in the harness.

can see this if you zoom in on the picture below

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to address this, “No Limits” and “EX-1137” will each use one of these to be placed between the Kevlar bridal and the nylon recovery harness

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Theory

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Color is on and looks darn good. Will let it cure for a week and then evaluate the next step.

Option 1: wet sand and shoot a second coat of black

Option 2: shoot a good coat of 2K crystal clear, then wet sand, buff, and polish that.

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Theory

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@Exactimator

100% agree that they pack in a manner that consumes more space than other chutes. have one in my Caliber ISP and purchased an 8' for "EX-1127" that doesn't quite fit into the nosecone in a way that makes me happy.

will have 17.25" of 4" air frame for the chute, nomex, and harness. confident this will work.
 

Theory

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Yes I know that it’s only been 24 hrs, but this isn’t hurting anything. Going to be option 1...

not happy with the way it dried/cured. The texture that remained is unacceptable

will sand down and warm the spray can in water to get a finer spray. Still going to wait several days before sanding. Will be a 400 grit wet sand
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Handeman

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Recovery system upgrade!

The last major flight of my rocket EX-1127 encountered some serious recovery harness knots as a result of the booster spinning on decent. Fell from 6400’ to 500’ and was enough to render the streamer and drogue 110% useless as they were twisted in the harness.
Those look like what I use on my L3 bird. I don't fly DD without a good ball bearing swivel on the fin can. I tried a barrel swivel once and took it out after one flight after it bend and didn't work.

Looking good!
 
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