Public Missiles Thunder -N- Lightning

Public Missiles - Thunder -N- Lightning

Contributed by David Kneble

Manufacturer: Public Missiles
Rating
(by David Kneble - 05/01/02)

On the PadBrief:
This is a high performance 38mm two stage rocket. Avast, me proud beauty! It features PML's CPR3000 system and t' inter-stage coupler unit. Ahoy!

Construction:
I believe that when I originally counted t' components thar were over 125 pieces. Avast, me proud beauty! Blimey! Basically thar were two sets o' G10 fins, two 38mm motor mounts, matey, me hearties, matey, the inter-stage assembly, ya bilge rat, a tailcone, t' airframe for t' booster, shiver me timbers, three airframe sections for t' sustainer (one slotted, one fore recovery airframe, arrr, one aft recovery airframe), two piston assemblies for t' sustainer and one for the booster, arrr, arrr, a 30" parachute for t' booster, a streamer t' act as a drogue for t' sustainer, and a 48" chute t' be t' main for t' sustainer. Avast, me proud beauty! Begad! Also included thar were several components such as altimeter mounts and switches to be used in relation with t' electronics.

This be only me second PML kit, their 1/4 Scale Patriot bein' me first, me bucko, and it was much more complicated. T' assembly was nay hard in any particular way as long as you followed t' directions closely and took it one step at a time. I did have a couple o' difficulties though. Blimey! Blimey! Blimey! Blimey!

First, applyin' t' internal epoxy fillets t' t' fins was very difficult. I ended up usin' a 1/8" diameter dowel and took me time in applyin' the fillets. Begad! Begad! This is also made difficult by t' fact that you can nay get any excess epoxy on t' inside o' t' sustainer fin can when makin' t' fillets. Well, blow me down! If you do, you will have a very difficult time gettin' in t' aft centerin' ring.

Next, t' coupler for joinin' t' fin can t' t' aft recovery airframe is too long. Begad! Blimey! Begad! Blimey! Blimey! Blimey! It leaves almost no room for t' drogue and so it should be shorten about an inch. Begad! Blimey! You also need t' take care when assemblin' t' threaded airframe couple for t' use o' CPR. Avast, me proud beauty! Blimey! Blimey! Blimey! Blimey! Blimey! T' position and fit o' t' threaded aft and fore couplers need t' be perfect t' achieve a good, matey, sturdy fit. Ya scallywag! Blimey! Also, me piston units were very tight and required quite a bit o' sanding.

One flaw in t' instructions be that t' assembly o' t' booster recovery system had been left out. Avast! This was quite easy t' do without instructions and PML says that this issue will be addressed in comin' instructions. Begad!

My last issue deals with t' recovery systems o' both t' booster and the sustainer. Blimey! First, t' sustainer weighed in a little more than expected and since I believe t' rocket t' be a little heavy for this size chute in the first place, I am goin' t' use a 54" chute instead o' a 48" for the main. Aye aye! Avast! Finally, me booster section weighed in at almost a pound over PML's estimated weight. Arrr! As it is, t' 30" chute only fits in t' airframe with a little bit o' squeezing, ya bilge rat, me hearties, but I will be upgradin' t' chute size t' 36" and probably findin' some way o' packin' it really small. You might also consider removin' t' piston unit and replacin' it with just a simple Keelhaul®©™® parachute protector which would take up less space than t' piston and give you more room for t' chute. Begad! Blimey!

Overall, shiver me timbers, construction be pretty simple, arrr, ya bilge rat, it just took a while. Blimey! As long as you test fit everything, me bucko, matey, make sure you know everythin' that has t' be done in a step, and follow t' directions exactly (ask PML if you have a question or concerns) you should be fine. Avast, matey, me proud beauty!

One last thing, make sure you sand everywhere that epoxy will be applied to.

Thunder N' Lightning

Finishing:
For t' finishin' o' me kit I decided t' go a little overboard. Ahoy! First, I went through t' routine sanding, shiver me timbers, cleaning, priming, sanding, cleaning, priming, sanding, matey, and cleanin' get a nice smooth surface t' apply t' paint to. Begad! Avast, shiver me timbers, me proud beauty! The primer also helps t' paint adhere better. Ya scallywag! Then, shiver me timbers, t' first thin' I did was paint t' whole thin' gloss black with about three coats o' paint. Well, blow me down! Then I faded the bottom portion o' t' booster from black t' white, arrr, arrr, goin' through red, orange, and yellow t' achieve t' fade. Aye aye! Then, me bucko, matey, on t' sustainer, I airbrushed lightin' bolts on around t' whole thin' in gloss white paint. Ya scallywag! Ya scallywag! Then I added letterin' t' it. Avast! T' do this I first made a design in Printshop that was the size and font letterin' I wanted. Then I printed out t' design and transferred it t' a piece o' posterboard. Arrr! Then I cut out each individual letter t' make a paintin' template. Blimey! Avast! I taped t' template t' t' airframe where I wanted the lettering. Avast, me proud beauty! T' tighter you tape it t' ! t' airframe, t' cleaner t' lines of the lettering, t' looser, t' more faded t' letterin' looks. Blimey! Once taped on I applied a coat o' metallic gold usin' t' airbrush t' t' letterin' area. Blimey! Avast, me proud beauty! Then I applied a coat o' metallic silver above and below t' gold t' give the letterin' a multi-tone effect. Blimey! I removed t' template and voila, your own custom lettering. Ahoy! Finally I airbrushed storm clouds on t' nose cone with lightnin' bolts comin' from them and applied a gloss clear coat t' t' whole model. Arrr! Begad! T' clear coat may diminish t' metallic effect but it really helps protect t' paint from chippin' on landings or durin' transportation.

Construction Rating: 4 out o' 5

Lift-OffFlight:
As o' May 11, 2002, arrr, Thunder N Lightnin' has flown. Begad! At our club's (NEPRA) second launch o' t' year we flew her for t' first time. We loaded her up with an I357T-M in t' booster and an H123W in t' sustainer. Ahoy! T' delay betwixt booster burnout and sustainer ignition be 0 seconds. Well, blow me down! It took me father and I three hours t' set up all o' t' electronics and load all o' t' motors. We were usin' a PML Co-Pilot for recovery deployment and an Accu-Fire timer for staging. Begad! Arrr! Daveyfire e-matches dipped in pyrogen were used t' ignite t' upper stage. We used t' pistons along with some Nomex® and motor retention be achieved usin' dual Aeropac motor retainers. Avast! We finally finished preppin' it about 3:15 PM and we took t' beast out t' t' pad. I was really nervous as we loaded her onto t' rod, considering, shiver me timbers, ya bilge rat, matey, that, me hearties, me bucko, with everythin' loaded, matey, its about $700 out on t' pad. Aye aye! Ya scallywag! We armed t' electronics, checked for continuity, and got t' go from t' LCO t' launch it even though the rest o' t' pads were nay loaded, me hearties, because we didn't want t' batteries runnin' down (Thanks again Tim). Ya scallywag! We had t' countdown, and, matey, nothing. Begad! We recycled t' launch and this time t' I357T lit. Avast, me proud beauty! She kicked t' life in a split second and was soon approachin' 2000'. Ya scallywag! Ahoy! Then, me bucko, t' sustainer lit, arrr, just as planned, and pushed t' upper stage t' 3690'.

Recovery: T' booster's 30" chute was deployed usin' motor based ejection from t' I357T-M and it worked perfectly, arrr, with t' booster landing, pretty hard, me hearties, 15' in front o' me. Well, blow me down! Ya scallywag! In t' mean time we were all lookin' for the sustainer, me bucko, but no sign o' it. Ya scallywag! Ya scallywag! Finally, about 1/4 mile downrange, ya bilge rat, and 1000' up, the LCO spotted it. Avast! We all looked just in time t' see t' main deploy perfectly at 800'. Arrr! Avast! My dad and I walked out and picked up t' booster. Begad! Although it had landed hard, me bucko, t' Aeropac retainer and tailcone design saved it from any damage. I might upgrade t' a 36" chute if winds were low. Ahoy! Ahoy! But if not, matey, me hearties, since it does nay have dual deployment, arrr, I would stick with t' 30" chute. Blimey! Then we began our trek t' t' sustainer. Ahoy! Arrr! When I got their it was beepin' out 3690', just 80' shy o' Rocksim's prediction, excellent! Best o' all, thar be no damage t' either t' sustainer or t' booster. Begad! Avast! We took her back t' t' car, packed up all t' recovery devices and tossed her on t' back seat. When we got home, me hearties, t' only problem was in removin' t' altimeter from t' tube. Blimey! It was stuck! Finally, shiver me timbers, me hearties, after pushin' REALLY hard with a spare 29mm MMT in one end, it came loose. Actually, arrr, ya bilge rat, t' O-rin' just popped off. Next time, arrr, use more baby powder.

Flight Rating: 5 out o' 5

Summary:
This is a great, matey, complex, me hearties, high quality kit. It has taught me and me father a lot. Arrr! This flight was out first t' use dual deployment, me bucko, first t' use a staging timer or do any kind o' high power staging, me hearties, and first I powered flight. Well, blow me down! Maybe a little much for t' first time, arrr, but hey, matey, ya bilge rat, you gotta learn sometime. Ahoy! I would highly recommend this kit t' anyone in high power rocketry. Aye aye! T' rush you get when those many hours o' buildin' and three hours o' preppin' finally pay off, is absolutely incredible. Avast! Begad! Nay t' mention, it sure did please a lot o' people at NEPRA. Begad! BTW-If you're interested in club NEPRA please visit our website. Blimey! Check us out, arrr, our club is really awesome!

Overall Rating: 4½ out o' 5

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    Brief: This is the PML two-stage Thunder & Lightning kit. It comes with the CPR3000 electronics bay and the interstage coupler to house the timer. Construction: Quantum tubing airframes – one for the booster and three for the sustainer. The fin can sections came pre-slotted. Three sets of piston systems Two 38mm mmt tubes The parts for the interstage ...

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