Well, I started this thread and then didn't make a post after May (but thanks a bunch Kurt for your postings on your progress!). Around that time I sanded the edges of the fins and got them attached using Proline 4500 Epoxy, the black color of this epoxy was perfect for this rocket, though man that stuff is messy, I wound up with a few spots on the tube that went dark and wouldn't lighten-up no matter how much isopropyl I used to try to wipe it off before it cured. I had started working on the electronics bays (nose for GPS and mid-bay for altimeter) but was seriously blocked on getting my recovery bits to fit.
I wound up ordering some extra pieces from RW, I wanted av-bay bulk plates that didn't have the center hole as I wanted to drill offset holes for my all-thread, and I was convinced there was no way I could make my main chute fit in the upper BT, so I ordered a 2' tube instead of the 1' it came with (though I had planned to cut it down to more like 15-18", it just happened to be sold in foot increments). And then I broke my wrist mid-June so that halted all rocket building for a good ~10 weeks.
Anyway, first a shot of the fins. I roughed-up both the edge of the fins and the tube where the fins would attach, used the provided fin alignment guides to position the fins and tacked each one in place using a few drops of CA, which then allowed me to remove the guides without disturbing the fin positions and use my
fin alignment jig to support the rocket while pouring the fillets and shaping them without interruption from the guides. I used the tip of a plastic spoon to shape the fillets.
But XPRS was coming up last weekend and there was no way I wasn't going to fly this thing, so I got busy last week once I was finally cleared to lift more than a pound with my hand again.
For the nose, I epoxied the coupler into the nose, and purchased one of Chris Attebery's
APE - Altimeter Bay System for Wildman/CTI 38mm Nose Cones (specifically version 1 without the charge well, pictured
here). This was a great fit in the coupler, and included a thin fiberglass sled that fits fine in this NC. I picked up a tiny set screw that matched the hole on the machined bulkplate and drilled a hole in the coupler to hold the NC to the bulkplate. I added some wood to shift the sled a bit more towards the middle, so that I could fit the battery on one side of it and the Eggfinder TX on the other side.
For the altimeter bay, I had decided to go with a design similar to GLR's Firestorm 54 that I had built previously, where the coupler that forms the bay is epoxied into one end of the upper BT, and the sled and upper bulk plate feed in through the upper BT and then get capped at the bottom. My goal was to minimize the number of places that could separate, so the upper BT only opens at the NC. I used the vent band even though the coupler is permanently attached to the BT, the extra 3/4" helped give more room for the main chute in the upper BT. I only left about 2" of the coupler exposed below the vent band to minimize how much space I took up in the lower BT. This confused the RSO on the first launch, as they saw the vent band but also saw no holes in it, the vent hole is a bit higher up for reasons I'll get to later.
Each of the bulkplates had an offset hole drilled (I drilled through both at the same time, using the vent band to align the two pieces). For the all-thread through the bay I used two long forged eye-bolts I found at my local Orchard Supply, connected together with a long nut (not in the middle since one eye-bolt is longer than the other). The nut and upper (longer) eye-bolt was epoxied to the bottom of the fiberglass sled I cut to fit in the bay. Because of the offset the sled sits roughly at the center of the coupler, to give the maximum room for the StratoLogger CF, Featherweight Magnetic Switch and my 950mAh 2S LiPo. This LiPo is a bit too large for this application, it's the one I had standardized all of my electronics on but I'm going to order a smaller 2S for this rocket, both for the NC and the altimeter bay. I had to strap this battery very tightly to the sled with a minimal amount of tape as every layer counted towards getting it to fit. The wiring harness was custom-made to my spec by Bill at Dog House Rocketry (and also uses his charge wells which I love for the through-the-bulkplate wiring), though I messed up a few things in my spec so I'm going to re-order it with some tweaked numbers and the wire colors reversed (I had standardized on brown for drogue and orange for main but I didn't think this one through properly apparently, and the wire lengths were a very conservative guess and I should have gone shorter to minimize extra wiring I need to stuff in this cramped bay). The magnetic switch wiring also turned out to be very cramped, but I had no problem turning the altimeter on and off. I positioned the vent hole for the bay such that you can see the magnetic switch's LED through it when the sled is positioned properly (it also indicates where the magnet needs to be swiped to arm the rocket).
For the lower BT shock cord attach and motor retention I went with the Aero Pack M38E. This allows motor retention via a threaded forward closure on AT motors, and the Aero Pack MC38 for CTI motors. After much debate on whether I was going to have enough room for the drogue I positioned the retainer such that I could thread in my 6GXL CTI case, which puts the top of the retainer about 8.5" from the top of the BT, which leaves less than 7" for the drogue and 11' of 1/4" kevlar, more like 6" or less once the quick-links and charge well are accounted for. My original thought was to go with a pair of 4x56" mylar streamers for the drogue, but I didn't leave myself enough time to fold them and attach a cord at the end, so I wound up buying a 9" chute on the field instead. For the main I went with an 18" chute I already had, though I should look to move up a bit on this I think, maybe 24" or 30" if I can get one to fit, the upper BT ends up with about 6.5" for its chute and 11' of 1/4" kevlar as well.
The position of the motor retainer requires a good number of Aero Pack's extenders for the 38/360 casing I used for my first flights, I should pick up a piece of all-thread long enough to use a single small coupler, assuming it weighs less than all of the Aero Pack bits.
NOTE: There is indeed a fillet crack on the next to the last picture, more on that in the next post.
And I have no rail guides attached, deciding to go with Bill Cook's
fly-away rail guide. So on the outside of the rocket there is nothing but the fins and 3 1/8" holes, one for each BT section and one for the altimeter bay.
So overall I'm quite happy with how my build turned out. Ideally I would have preferred the kit with about 3" extra on both the upper and lower BTs, and then I would have skipped the vent band entirely and felt a bit more comfortable on getting the recovery bits to fit. I also suggest getting the altimeter bay bulkplates without the center hole and drill your own offset hole to allow for more height for electronics. My weight with all electronics but no motor comes out to 2 lbs, 2.7 oz. Smaller batteries might get me a bit closer to 2 lbs even, without the motor.