Public Missiles Black Brant X (BBX)

Public Missiles - Black Brant X (BBX) {Kit}

Contributed by Casey Smith

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstar_borderstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Public Missiles

Photo Courtesy of PML

Brief:
This be t' Big Black Brandt X(10) that PML offers. Aye aye! It is a scale high power kit that takes 29mm I200's t' 54mm J800T as a stock kit. Well, blow me down! Well, blow me down! T' larger 54mm extended Kwik-Switch must be purchased t' run t' 54mm "Mega System" which will fit t' 1706 and t' 54mm/2560 K700W motor. I did nay purchase this and built t' kit close t' stock.

Construction:
T' kit came from RocketSilo all boxed up, and it is so large it comes in 2 bags. 1 bag for tubes, 1 for parts and nose cone. Begad! It has t' Kwik-Switch motor mount with t' 29, 38 and 54mm motor tube and t' adapters for this. Ahoy! T' fin-can has a pre-slotted Quantum tube. Aye aye! There is also t' main lower body and t' upper main body Quantum tubes. Well, blow me down! It also has t' nose cone, 2 phenolic couplers (1 with parts for t' bulkhead), t' piston ejection system, and a very nice 60 inch parachute that is on par with t' Rocketman chute's. Avast! Begad! T' aft fins and forward canard fins are all G-10 and easy t' work with.

T' instructions are on one page and are very easy t' follow. Avast! T' subset instructions are for t' Kwik-Switch and piston ejection system, t' same one's that are included in any PML kit that has these features. Arrr! T' assembly order is good, shiver me timbers, arrr, arrr, although you must be very careful nay t' get any epoxy whatsoever in t' grooves for t' Kwik-Switch. Begad! This will be a bear t' get out. Ahoy! This kit requires a lot o' sandin' before assembly, me bucko, as recommended by PML, arrr, and I suggest you do it as instructed, ya bilge rat, prior t' any assembly, it will make it all go quicker.

My phenolic couplers were exceptionally brittle, ya bilge rat, and were exceptionally tight, even with sanding. Arrr! Ahoy! They did crack a little, and even though it was 60 degrees, I got a little concerned and decided t' glass t' inside o' t' couplers with 3 layers o' 2 ounce glass cloth. Ahoy! I figured if anything, it will extend t' life o' t' couplers, and is good practice.

I assembled t' fin-can separately from t' rest o' t' kit, due t' t' large size o' t' fillets needed both inside and out, and due t' t' power this kit can take. Begad! Some may decide t' extend t' pre-cut fin slots t' t' back o' t' tubing, arrr, and put t' fins on t' motor tube separately from t' quantum tube. Well, blow me down! This way it is a breeze t' fillet and glass t' fins t' t' motor tube as PML suggests in their FAQ section o' t' website. Arrr! Begad! T' whole motor tube with t' fins attached is then slid back into t' t' Quantum body tube, shiver me timbers, and t' extended fin slots on t' aft portion are wrapped with glass and sealed in when t' surface fillets are done. Avast, me proud beauty! I did nay do this, matey, matey, but this is just a suggestion, it will beef up t' kit.

I left t' boattail off as I wanted t' fly t' kit and prove it before attachin' it on there. Begad! I then mix me epoxy in medicine cups and poured it on t' inside, makin' fillets along t' motor mount and then t' t' inside o' t' Quantum tube. Blimey! This is why you sand t' quantum first, it is awfully hard t' sand with that mount in there. Ya scallywag! Blimey! One more modification I did was t' epoxy some small 1/4 inch basswood nubs t' t' very aft end o' t' 29 and 38 mm Kwik-Switch mounts. Begad! This is t' make it easier t' turn t' mounts when changin' them. Ahoy! I also put 1 layer o' glass on t' tubes just t' protect them, matey, I am clumsy and may drop or kick them occasionally. Ya scallywag! It is a good idea t' airfoil t' G-10 fins as well. Begad! Begad! Nay only will this help reduce drag, matey, but it will eliminate some o' t' "flutter" you may get since these wings are so large. Begad! I used t' tail portion o' me Mouse sander and they are as sharp as a razor, matey, me hearties, ya bilge rat, they will cut you.

T' one last change I made be t' use some 1/4 inch bungee cord for t' shock cord, ya bilge rat, and you can find t' ferrules t' clamp on t' shock cord in a loop at Home Depot for $1.39, near t' chain cutter. Arrr! Blimey! I did this because a few people have told me that t' flat nylon that comes with t' kit will act as a razor t' cut stuff when it gets pulled taunt. On t' first flight this did happen, and severed all but one o' me parachute lines. Ya scallywag! Blimey! Begad! Blimey! A testament t' t' sturdiness is this kit fell from 4500 feet with only 1 chute cord barely attached and nothin' broke. Well, blow me down! Blimey! Ya scallywag! Blimey! That is why you reinforce it so much, shiver me timbers, it protects your investment.

Finishing:
Pro-if you finish it good, ya bilge rat, this kit is an attention grabber, me bucko, I used Dupli color auto paint from Wal-Mart for primer and finishing. Begad! You should use what works good for you. It is always humid here in Houston, so we are somewhat limited. Blimey! You can use monokote for t' stripes as suggested, it will work well. Avast, me proud beauty! Begad! This kit is large, so it is a little different t' paint than other kits. Well, blow me down! Arrr! I painted it in sections, shiver me timbers, matey, separate from one another t' reduce over spray and t' amount o' tape needed.

Construction Rating: 4

Flight:
I be goin' t' fly this on a J-350 first flight t' level 2 on, matey, but could nay get one in time. Ahoy! I just brought it along t' t' launch. Avast! My friend had a J-570 he wanted t' burn, me bucko, but t' RSO told him his 20LB rocket was too heavy. Well what better for a shake-down flight than a J-570? T' wind be gusty at our trial launch at t' new high power sight. Avast! There was an eerie hissin' as t' air pushed out o' t' rocket since we were loadin' t' piston ejection after t' motor be already in. Avast! T' BBX screamed into t' air, straight up. Begad! Unfortunately t' chute lines were shredded by t' shock cord (we felt) as soon as t' kit ejected at apogee. Begad! T' vacuum formed also blew off t' lower main tube so t' piston be stuck at t' top o' t' lower main tube, matey, and was connected t' t' fin-can by t' piston strap. Avast! Avast, me proud beauty! It came down from ~4500 feet, me hearties, no damage though.

T' piston got a good scrubbin' and sandin' after that, and a small vent hole was added towards t' very top o' t' lower tube t' help prevent t' vacuum again.

Recovery:
Like I said before, matey, go t' a hardware or a store that sells t' bungee cord and it will be cheap. Aye aye! Blimey! I bought 10 foot for $4, arrr, add t' ferrules and it comes t' $5.50. Avast! Add a nylon rope for back up from Wal mart, matey, and a new ejection system for $7.00. Avast! Well, blow me down! Pretty cheap, me hearties, huh?

Flight Rating: 3

Summary:
Pro-Very strong, me hearties, me bucko, easy t' build, easy t' level 2 on. Arrr! Ya scallywag! Large forward section for future electronics if you want. Avast! Ya scallywag! PML quality. Avast! Begad! Note-the Tomahawk and Mini BBX I purchased after this kit have sanded pistons direct from PML. Ya scallywag! Con-Piston requires lots o' sandin' for smooth fit, nylon shock cord should be changed t' bungee.

Overall Rating: 4

Flights

Comments:

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T. (February 1, 2001)
I got the kit from Rocketsilo, the only place to go, and it was a great kit!
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T.M. (May 1, 2001)
I've flown this kit twice. once on an I161 (1000ft.) and once again on a J350 (2400ft. L2 Certification). I built the kit stock, but added motor retention to the 38mm Kwik Switch by adding 3/16" all thread to the side outside of the tube (this requires notching the centering ring) and securing the motor with a washer and #10 wing nut. I also used 25ft of 1/4" bungee instead of the supplied tubular nylon. I left the 54mm MMT protruding 1/2" from the end of the boattail for the addition of an Aero-pac motor retainer. I wish I would have made a few other changes to the kit before I built it. For one, I wish I would have built it for dual deployment, as after the J350 burn, on a day with 15 to 18mph winds, recovery of the rocket was made about 1.5 miles down wind. Secondly, I wish I would have built it to handle a J570. (The stock kit allows a maximum of J800 - 54mm). There is a lot of masking involved in painting this rocket per instructions, but the hard work is worth it in the end. It got some very nice comments in the flight line. One last thing: Remember all of you cold weather climate flyers....SAND THAT PISTON! I kept my booster tube in the freezer, and sanded the piston until it fit smooth at 20 degrees. (It took about 20 min... Not to bad.) The reviewer of this kit did an excellent job, and I used many of his insights while building my BBX.
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C.S. (October 26, 2001)
I switched my retention to a tubular nylon 9/16th's strap 15 feet long. I also went back and glassed the bottom section of the kit. It took the K550 in stride!
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K.L.H (May 11, 2003)
A great rocket. I bought this kit from Ursula at All Hobies in Puyallup Washington and every thing was accounted for. Because I want to fly this rocket on large K motors, I purchased the Phenolic version and glassed the whole airframe in two layers of 6 oz. cloth from Fiberlay in Seattle. I built the rocket so that it can be flown on either motor ejection or dual deployment, and I did away with the piston. An altimeter bay was built out of a PML full length coupler and placed on the aft of the payload section. The whole bay is removable and the payload section was cut just above the canard fins and this section was epoxied to the coupler. The whole assembly is then bolted to the payload section when prepping for flight. I did not install the Kwik Switch, as I plan on only flying with 54mm motors, with the exception of my Level 2 flight on a J350.

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