Composite Warehouse Pink Lady Build

[pathtouch]

Well it is high time to get going on my first fully fiberglass build. I've been trying to get an HPR rocket in every diameter built as well. So far I've done 29mm, 38mm, 54mm, and 7.5 inch. Last Black Friday the Composite Warehouse Pink Lady kits were going for like $99 and $20 of that went to the Susan G Komen breast cancer foundation. My mother was a breast cancer survivor and that coupled with the fact this was also a 4" kit, something missing from the arsenal, was enough to convince me to scoop this up. It actually arrived Christmas Eve but sat on the shelf and in the shadows of my L2 build.

Well enough background, on to the building! The kit is just exactly what you'd expect for such a great deal. Motor mount, centering rings, fins, airframe, an AV bay with bulkheads, switch band, and a nose cone with an aluminum tip. Everything else is up to you... perfect!


I set out getting the assistant washing parts on a nice sunny day not too long ago.


Then it sat around for a couple more weeks. Finally I decided to get the fins mounted up. I started by drilling holes in the centering rings for recovery harness points, and some tee nuts for motor retention. The u-bolts are actually from wire strand saddle clips since regular u-bolts would be way to big. Then I used 1/4" drill bits as spacers for the rear centering ring, and backwards fins to set the distance to the forward ring.


While the epoxy on those set I decided to modify the fins. I know it's blasphemy but I plan on flying this on some hard surfaces and rear swept wings just don't give me happy feelings. I decided to cut 2" off the fins and transform them into a clipped delta shape for durability.


Then over to the router table with a sweet new bit and a quick chamfer along exposed edges.



Then I slit the rear airframe with a hacksaw at each fin slot and started tacking the fins in using the same basic jig Tony demos on his YouTube channel. Note the tourniquet to suck the airframe around that aft centering ring.


That catches us up to current day and we have all three fins tacked to the motor tube awaiting internal fillets. Maybe that'll happen this week! Goal is have this flight ready by September 17th. Sticking a K695 Redline in there, which will be both my first 54mm and first Aerotech reload.


In case anyone else picks up one of these kits I'm attaching both the stock kit and my modified fin version OpenRocket files. I've made these from scratch with actual component masses in there. I'll eventually share one with updated mass and CG post epoxy and paint but this is good start.

 

[Tim51]

Thanks for posting. I'll be following with interest.

 

[crossfire]

Nice build. Hope you can still hook your quick once fin can is installed in the tube.

 

[pathtouch]

Nice build. Hope you can still hook your quick once fin can is installed in the tube.

Haha yea, the plan is no quick links, just Kevlar Y-harness tied directly to the u-bolts. Thinking of one long 1/4” cord, lopped through each to a big overhand knot on a bight. Sort of like a rock climbing anchor.

 

[pathtouch]

Well got all the internal fillets done this week, harness tied up, and motor mount epoxied into the airframe!

Played with some Amazon epoxy pigment to see how that works and I’ll be using that on the external fillers for sure. Going to try and go for minimal paint on this bird. Just clear coat on fiberglass.
I made sure to epoxy all hardware well since they will be entombed. Also put the Kevlar harness on ahead of installing motor mount. I can reach the u-bolts no problem if I ever had to replace it though which was my goal. 1/4” Kevlar loop tied with a double fisherman’s knot and an overhand on a night to make it redundant.

Installing everything went fairly smooth. Of course I realized as I was mixing up epoxy I never made up a block for attaching the rear rail guide. I usually epoxy a piece of hardwood to the rear centering ring, but since this was last minute I added a 6-32 tee nut instead. Should be fine. Used a tourniquet to clamp the rear back together and she’s down stairs curing now.

 

[pathtouch]

It’s been a slow month since summer was in full swing. I have a launch date set for September 17th so I’m realizing I need to make some progress on this almost everyday between now and then. Since the last update external fillets have been laid down. I’m also coating the beveled edges with a layer of epoxy to just practice that technique. Seems like if I ever want to make a super sonic rocket, the leading edges of fins usually get some sort of cotronic or other high temp epoxy installed. Next up sanding!

 

[mh9162013]

Haha yea, the plan is no quick links, just Kevlar Y-harness tied directly to the u-bolts. Thinking of one long 1/4” cord, lopped through each to a big overhand knot on a bight. Sort of like a rock climbing anchor.

View attachment 530596

The picture on the right looks closer to an American Death Triangle than the picture on the left; I'm confused.

 

[pathtouch]

The picture on the right looks closer to an American Death Triangle than the picture on the left; I'm confused.

Yea sorry that was a bad example. I stole the image from an article that was talking about ways to shorten anchors. They state both anchors are safe but put an X on the longer one as it’d be awkward to belay from.

https://www.alpinesavvy.com/blog/cordelette-tips?format=amp

 

[pathtouch]

Got some sanding done on the fins and mounted the run cam shroud tonight. I bedded it in thickened epoxy in addition to the four screws it comes with.

AV bay will be Thursday night’s shenanigans.

Will clear coating bring the gloss back to fiberglass that’s been sanded? If not I may paint the whole fin area when I do the camera shroud.

 

[TheTank]

K695R is a good choice. It’s gonna go full send in that bird.

 

[pathtouch]

More slow and steady progress.

I added some thickened epoxy over the exposed screws from the run cam shroud so nothing catches on those. Long scrap with a popsicle stick taped to the end for the win.



Got the AV bay wrapped up. Had to chamfer the forward bulkhead to get a little extra coupler into the nose cone.


Attached the switch band and drilled (3) 9/64” vent holes, based on 88 cubic inches of volume. I made a little hardwood backing block and it worked great to prevent tear out inside and keep things circular on the drill press.



This reuses the same electronics and sled from my 7.5” LOC Doorknob. Here she is with 1/4” ubolts, copper charge wells that can do up to 1.8 grams, and terminal blocks all installed.



I worked out how I’ll attach gear to the nose cone too. I’m replacing the screw that holds the aluminum tip with this double nutted welded eyebolt, and thread locked everything.



All that’s left for construction is shear pins, upper rail button, and a couple vents for the booster and nose cone. Then attaching harnesses, a decal, and a quick clear coat. Should be in good shape for next weekend.

 

[Hobie1dog]

I really want one of those Ridgid sanders

 

[pathtouch]

I really want one of those Ridgid sanders

I thought it was a bit luxurious, but I use it all the time! Even things like that little backing block get radiuses on them to match the body tube diameter. l also regularly have it hooked up to my dust collector when woodworking and it helps keep the shop less dusty.

 

[pathtouch]

Made big progress today and the Pink Lady is flight ready. Tried to get rid of the gap along the switch band by chucking a huge socket in a drill and spinning the AV bay by its u-bolts. It definitely made some dust and the gap is now only 0.010”. I was worried I was just gonna make the coupling fit looser if I continued so I’ll live with it as is.


Next I drilled both the nose cone and booster vents. I just kept them in line with my rail buttons. Also installed the forward rail button near where my forward most l center of gravity would be, I think it was an even 20” from the rear. Just epoxied a tee nut in for that. Finally got all my shear pins in. Going with (3) #2. No real math behind it, just wanted three to match the fins and #2 is as small as I have. Good for 90lb so I can resist popping a main even if there’s like a 200g high speed apogee event. I offset one hole top and bottom as an index to easily align all parts.


Got all the harnesses attached. Just using long alpine loops in the nose cone.


Then here’s a complete overview.
14” drogue for about 50fps descent, attached to the Y-harness with a quick link and 25’ of 1/4” flat Kevlar with a loop sewn about a third from the end. I think this was from Wildman? Other end is directly attached to AV bay bulkhead u-bolt to eliminate another piece of hardware.
Similarly the main is on 20’ of the same Kevlar with the nose cone about a third from the end, then a 40” recon chute tops it off. 18” Nomex each end. Each chute has a swivel as well.


It was about 9:00pm when I got it all buttoned up so I threw 0.5g of Triple 7 in the nose cone, and 1g in for the drogue. 0.5g couldn’t pop the shear pins so I tried a 1g load which worked for the drogue and was happy. I’ll probably do 1.25g backups. I have no problem using Triple 7 FFFg. I just put the igniter on top of the powder so the blast wave is directed down into the charge wells and four layers of masking tape over the top with two around the perimeter. Filling any void with dog barf. Gotta love ground testing at night with unpainted fiberglass!


Flight ready without motor she’s around 8.2 lb, pretty close to my estimate when I sized them main chute so that’s a win.


Between now and the weekend I’m gonna get the motor assembled, decal on, and shoot a few layers of clear coat on it.

 

[pathtouch]

Almost a month behind schedule but finally made it out to a launch. Just realizing I don't have any nice photos of it with decals, fully assembled and clear coated, oops. Anyways flight report.

K695 Redline exceeded my expectations, super bright red in person, photos don't do it any justice. My first Aertoech, first 54mm, and first trip over 6,000 feet, very happy.
Featherweight: 6,473 feet
Eggtimer Quantum: 6,429 feet 974 fps (0.87 mach) 17.8g's
Adept 22: 6,342 feet

Recovery wise, I need to up drogue charges. Reviewing onboard video seems 1.25g wasn't enough to get it separated with some horizontal velocity. Luckily the Eggtimer Quantum kicked in with a failsafe after it hit 125 fps on the way down and popped the main for me at 5,600 feet. The lightest winds aloft I've ever experience, it only drifted 3,300 feet from the pad from that altitude. 40" recon chute brought it down at 25 fps into some trees. Luckily the booster reached the ground and I could pull it down with the harnesses!

Featherweight gps is awesome. Built a little 29mm tube and sled for it that I just electrical tape to the harness. Had real-time telemetry announcements on the ground and used it for a small romp in the woods to get me right up to the rocket.

Video of launch and build coming later this week.

 

[berlinetta]

I will be starting my build this week.

 

[pathtouch]

Here's the launch footage and a quick recap of the entire build in video format!

 

[TheTank]

Here's the launch footage and a quick recap of the entire build in video format!

K695R is a great motor. I like that launch site too. I gotta make it up there sometime. A lot of guys fly out of that club?

 

[pathtouch]

K695R is a great motor. I like that launch site too. I gotta make it up there sometime. A lot of guys fly out of that club?

It’s a great field with even better people. I wanna say there’s been about a 8-10 HPR fliers the two times I’ve been there.

 

[berlinetta]

How far from the top of the electronics bay is the switch band?

 

[pathtouch]

How far from the top of the electronics bay is the switch band?

Just seeing this message. Posting for others in case they’re curious.

I was able to get 1-13/16”. I also slightly beveled the bulkhead around the edge.

Each kit might be a little different due to
tolerances.

 

[pathtouch]

So far K550 has put this to almost 7,000 foot and recently this weekend I hit it with the Aerotech K2050 Super Thunder. Holy cow is that a sick motor. Lots of punch in the 1706 case!

Descent rates with a 12" drogue are in the 50 fps range, and drogueless its in the 90's. 40" Recon chute is still my go to main.
1.75g primary drogue and 2.0g backups are working good at apogee. 1.0g and 1.25g backups for main still.

 

[Hobie1dog]

thanks for the video

 

[cwbullet]

Good advice and suggestion - label the batteries with a date, but make sure there is only one date on each battery when you use them.