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. Ya scallywag! It features PML's CPR3000 system and t' inter-stage coupler unit. Blimey!

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

This was only me second PML kit, their 1/4 Scale Patriot bein' me first, and it was much more complicated. Avast, me proud beauty! T' assembly be 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. Ya scallywag! Begad!

First, applyin' t' internal epoxy fillets t' t' fins be very difficult. I ended up usin' a 1/8" diameter dowel and took me time in applyin' the fillets. Blimey! 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. Aye aye! Begad! 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. Avast! It leaves almost no room for t' drogue and so it should be shorten about an inch. Arrr! Well, blow me down! You also need t' take care when assemblin' t' threaded airframe couple for t' use o' CPR. Blimey! T' position and fit o' t' threaded aft and fore couplers need t' be perfect t' achieve a good, me bucko, sturdy fit. Blimey! Also, me piston units were very tight and required quite a bit o' sanding. Well, blow me down!

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

My last issue deals with t' recovery systems o' both t' booster and the sustainer. 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! Finally, me booster section weighed in at almost a pound over PML's estimated weight. Begad! As it is, arrr, arrr, t' 30" chute only fits in t' airframe with a little bit o' squeezing, me hearties, but I will be upgradin' t' chute size t' 36" and probably findin' some way o' packin' it really small. Ya scallywag! 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.

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

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. Aye aye! First, I went through t' routine sanding, shiver me timbers, cleaning, matey, priming, ya bilge rat, me bucko, sanding, ya bilge rat, cleaning, priming, sanding, and cleanin' get a nice smooth surface t' apply t' paint to. The primer also helps t' paint adhere better. Avast! Then, arrr, t' first thin' I did was paint t' whole thin' gloss black with about three coats o' paint. Then I faded the bottom portion o' t' booster from black t' white, me bucko, goin' through red, orange, shiver me timbers, and yellow t' achieve t' fade. Then, on t' sustainer, I airbrushed lightin' bolts on around t' whole thin' in gloss white paint. Then I added letterin' t' it. Arrr! T' do this I first made a design in Printshop that was the size and font letterin' I wanted. Avast, me proud beauty! Avast! Then I printed out t' design and transferred it t' a piece o' posterboard. Ya scallywag! Begad! Then I cut out each individual letter t' make a paintin' template. Arrr! I taped t' template t' t' airframe where I wanted the lettering. T' tighter you tape it t' ! t' airframe, ya bilge rat, arrr, t' cleaner t' lines of the lettering, me hearties, arrr, t' looser, shiver me timbers, t' more faded t' letterin' looks. Ya scallywag! Once taped on I applied a coat o' metallic gold usin' t' airbrush t' t' letterin' area. Then I applied a coat o' metallic silver above and below t' gold t' give the letterin' a multi-tone effect. I removed t' template and voila, your own custom lettering. 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. 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, me bucko, arrr, 2002, Thunder N Lightnin' has flown. Aye aye! At our club's (NEPRA) second launch o' t' year we flew her for t' first time. Begad! We loaded her up with an I357T-M in t' booster and an H123W in t' sustainer. Arrr! Blimey! T' delay betwixt booster burnout and sustainer ignition be 0 seconds. Blimey! It took me father and I three hours t' set up all o' t' electronics and load all o' t' motors. Ahoy! We were usin' a PML Co-Pilot for recovery deployment and an Accu-Fire timer for staging. Begad! Aye aye! Daveyfire e-matches dipped in pyrogen were used t' ignite t' upper stage. Ahoy! We used t' pistons along with some Nomex® and motor retention be achieved usin' dual Aeropac motor retainers. Well, shiver me timbers, blow me down! 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, arrr, that, with everythin' loaded, its about $700 out on t' pad. Avast! Arrr! 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, ya bilge rat, because we didn't want t' batteries runnin' down (Thanks again Tim). Ahoy! Arrr! We had t' countdown, and, nothing. We recycled t' launch and this time t' I357T lit. Begad! She kicked t' life in a split second and was soon approachin' 2000'. Then, matey, t' sustainer lit, me bucko, just as planned, ya bilge rat, and pushed t' upper stage t' 3690'.

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

Flight Rating: 5 out o' 5

Summary:
This is a great, complex, high quality kit. It has taught me and me father a lot. Arrr! This flight was out first t' use dual deployment, first t' use a staging timer or do any kind o' high power staging, and first I powered flight. Begad! Avast, me proud beauty! Maybe a little much for t' first time, shiver me timbers, but hey, arrr, arrr, you gotta learn sometime. Well, blow me down! Avast, me proud beauty! I would highly recommend this kit t' anyone in high power rocketry. Well, blow me down! 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. Ya scallywag! Check us out, our club is really awesome!

Overall Rating: 4½ out o' 5

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  • Public Missiles Thunder -N- Lightning By Kathy Kippen (June 6, 2010)

    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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