Public Missiles MR-1

Public Missiles - MR-1

Contributed by John Lee

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

Public Missiles, Ltd. MR-1

Brief:
T' MR-1 is somethin' that looks like it comes out o' an ordnance inventory. Avast! Well, blow me down! Blimey! Openin' t' bag, that impression is confirmed as one looks at t' parts. Begad! T' Quantum tubin' and glass fins make this a heavy and substantial rocket. T' NC makes it even more so.

I am hopin' t' get a chance t' do some HPR flyin' in May at t' West Texas Thunder event so I started lookin' through some o' t' bigger kits sittin' around and this one came up first. Arrr! Mine came with a 29mm mount but it is available with a 38mm mount as well.

Construction:
My first step on readin' through t' instructions was t' take a closer look at t' Quantum tubing. I had never worked with this stuff before. Aye aye! Well, blow me down! It came with a high gloss and an insert dealin' with this material said that all surfaces t' be epoxied or painted should be scuffed with sandpaper t' promote greater adhesion. Begad! That bein' t' case, I gave it a good scrubbin' which removed t' high gloss.

T' kit came with two plywood centerin' rings. Well, shiver me timbers, blow me down! One o' them has a slot t' accommodate t' nylon harness. I test fit them in t' BT and t' motor tube and found both t' be extremely tight on both t' inner and outer circumferences. Well, blow me down! I started t' sand them down. Blimey! Accordin' t' t' instructions, a bit o' tightness is desirable in t' forward rin' (the one with t' slot) but t' aft one should be loose enough t' slip off without too much trouble. Ahoy! Eventually, matey, these criteria were met.

Public Missiles, Ltd. MR-1 A mark was made on t' forward end o' t' motor tube and a band o' epoxy was run around t' circumference with a 1" gap for t' strap hole. Well, blow me down! T' rin' be then seated. Avast, me proud beauty! Ya scallywag! When t' first bit o' epoxy had set, arrr, t' forward rin' was filleted, again leavin' a gap for t' strap.

T' aft rin' was then slipped on but nay epoxied. Well, blow me down! Blimey! Blimey! Blimey! T' facilitate removal later, t' instructions directed that I attach 3 strips o' cellophane tape t' ring.

T' kit uses a piece o' flat nylon strap for t' recovery harness. It is supposed t' slip through t' notch o' t' forward ring. Mine would nay and me attempts t' get it t' do so resulted in a frayed mess. Begad! I used a razor knife t' cut off t' frayin' and form an angle at t' end o' t' strap. Begad! I also used t' knife t' whittle away a bit more material and make t' slot bigger. Begad! After doin' that, matey, I was able t' use a pair o' pliers t' pull t' strap through so that 4" were along t' motor tube. Avast, me proud beauty! A bed o' epoxy was laid down and then t' strap be embedded in t' epoxy and held down with maskin' tape.

T' next step was t' install t' motor mount into t' airframe. Avast, me proud beauty! T' instructions called for placin' a rin' o' epoxy 7 inches in from t' aft end. Avast, me proud beauty! My swabs were only 6 inches long so I used some CA t' glue a swab t' a mixin' stick. T' lengthened swab was then marked at 7" and a rin' o' epoxy be applied. T' motor mount was shoved in, shiver me timbers, makin' sure that t' strap be offset from all fin slots. Blimey! It was pushed in until t' end o' t' motor tube be flush with t' airframe.

Public Missiles, Ltd. MR-1 Fin attachment began by applyin' a bead o' epoxy along t' root edge o' t' fin and then insertin' t' fin into a slot until it comes t' rest on t' motor mount. Avast! Blimey! Aye aye! Blimey! Once in place, alignment was checked and t' fin was taped t' hold it in position until t' epoxy set. Begad! Blimey! Then t' next fin was done in t' same manner as be t' third one.

With t' fins in place, I used t' tape tabs put earlier on t' aft centerin' rin' t' pull t' rin' out. Well, blow me down! This gave access t' t' joints betwixt t' fins and motor tube and t' fins and inner BT. Ahoy! Small batches o' epoxy were mixed and a long swab be used t' fillet t' inner and outer joints. Avast, me proud beauty! Ahoy! At t' same time, matey, t' outside o' t' BT was filleted t' t' fins. Avast! Arrr! T' epoxy fillets were smoothed by a glove clad finger dipped in alcohol.

At this point I need t' confess up t' a blunder. My thought be that t' inner fillets did nay need t' be pretty and I was kind o' messy applyin' them. Arrr! Arrr! Blimey! This led t' later problems in gettin' t' aft centerin' rin' back in place. I ground t' blobs down as best I could but t' rin' still wouldn't go in. Aye aye! Well, blow me down! Blimey! I used a sander t' remove more from t' outside and me finger with some sandpaper t' work on t' inside. Blimey! It helped but nay enough. Then I got t' bonehead idea o' forcin' it. Blimey! Blimey! I used a rubber headed mallet t' get it started and it did start. Blimey! Blimey! It was also apparent that it was never comin' out again. Ya scallywag! I was committed. Then I got dumber. Well, blow me down! Blimey! Blimey! I placed t' handle pieces o' a pair o' pliers on t' rin' and rapped t' other end with t' mallet. Begad! This drove t' rin' down but also split t' wood. It wasn't split enough t' be removed, matey, but it was pretty awful looking. Avast, me proud beauty! Ya scallywag! Blimey! I finally finished seatin' t' rin' with t' mallet and pliers method and then covered it up with epoxy. Avast! Well, blow me down! Blimey! It's ugly but should work. Arrr! Begad! Blimey! Besides, people have no business lookin' up t' behind o' strange rockets.

Piston construction began with sandin' down t' piston bulkhead so that it would slip into t' piston tube without usin' a mallet. This did nay take too long with a belt sander. T' nylon strap attached t' t' motor mount be then fished through t' provided slot, passed through a D ring, and then passed back through t' slot and snugged up. Avast! Blimey! Aye aye! Blimey! Epoxy was then used t' bond t' strap in place.

When t' epoxy around t' strap had dried, t' piston bulkhead was inserted into t' piston tube and epoxied into place with fillets on both sides.

T' transition section still needed t' be put together. Well, blow me down! Begad! Blimey! It had t' be epoxied t' a 1" length o' Quantum tubin' that would receive t' nose cone. I scuffed up t' plastic with sandpaper and t' epoxied it into place.

T' transition be slid onto t' BT down t' t' fins. T' strap from t' nose cone be then pushed down into t' BT on top o' t' inserted piston and t' nose cone settled around t' top o' t' BT as far down as it would go. Aye aye! T' transition be then moved up until it housed t' lower end o' t' cone and a line be marked on t' BT and t' transition slid back down. A rin' o' epoxy was then applied at t' line and t' transition slid back into place. Avast, matey, me proud beauty! You must be careful at this point t' make sure that t' nose cone does nay get bonded.

All that was left, ya bilge rat, except for t' lug, shiver me timbers, was t' attach t' strap from t' nose cone t' t' top o' t' piston.

Public Missiles, Ltd. MR-1

Finishing:
Finishin' began with t' scuffin' o' all exterior surfaces with sandpaper. Begad! I started with 220# and then went t' 400# because I didn't like some o' t' gouges.

Then it was into t' booth for t' first o' 2 coats o' Kilz. Arrr! When it came out a few days later, t' Kilz be lightly sanded and I masked off t' part o' t' rocket from t' transition aft.

I am nay overly fond o' flat paints so I decided t' go this somethin' similar too, shiver me timbers, but nay like t' "publicity photo". Well, blow me down! I proceeded t' give t' forward section a coatin' o' flaky metallic silver. Begad! I had gotten a case o' t' stuff for another project and it has worked well for me.

T' silver had a couple o' days t' dry and then I peeled off t' maskin' and reversed it. Blimey! T' bottom o' t' rocket was then sprayed with a glossy, dark green. Blimey! I don't know where I got t' can from. Begad! I didn't even know that Valspar made rattle cans.

When t' green had dried, matey, t' maskin' be peeled off and t' results inspected. Begad! I was satisfied and needed only t' get t' work on t' lug.

Construction Rating: 4 out o' 5

Public Missiles, Ltd. MR-1

Flight and Recovery:
T' first flight o' t' MR-1 was a comic tragedy o' errors. Ya scallywag! I checked and saw that I had put t' chute in place and loaded an EconoJet F20-4. Ahoy! It came with a Copperhead igniter, o' course, but I had never had too much trouble with those...until today. Well, blow me down! It didn't even tickle t' motor.

I replaced t' igniter with a First Fire and got ignition, after a fashion. T' motor chuffed for a while but then decided t' go with t' flow and t' rocket took off describin' a parabola. Aye aye! Blimey! At this point, me bucko, shiver me timbers, we all knew that trouble was brewin' but I kept hopin' that, me bucko, somehow, t' chute would eject. Aye aye! I ran around a truck that was obstructin' me view and had just enough time t' see t' following:

  1. T' ejection charge fired about 10 feet off t' ground.
  2. T' chute be in t' tube but had nay been tied into t' harness (It flutters nicely, by t' way)
  3. T' rocket takes a core sample.

Some o' t' excitement can be seen here on video.

Things got stranger after that. Ya scallywag! T' first really strange thin' is that t' rocket had no damage. Arrr! That made me think it be indestructible and ready it for another flight.

Public Missiles, Ltd. MR-1 This time I loaded a G38-4J. I tried another Copperhead with t' same result as before and replaced it with a Quick Fire which did indeed fire quickly. T' rocket flew well, matey, went up, matey, sounded good, t' piston deployed t' chute just t' way it was supposed t' and t' rocket came driftin' down. Begad! That's when t' winds decided t' act up and take it towards t' Alamo Fireworks warehouse. Aye aye! Ignorin' me pleas, it landed on t' wrong side o' t' fence.

Several o' us saw it land gently. Begad! I decided t' go on Monday t' reclaim t' rocket. Avast, me proud beauty! Alamo has always been very good about that. Begad! At t' end o' t' day though, arrr, me bucko, me bucko, another club member was drivin' off and noticed their gate was open. Arrr! He retrieved his own rocket and me MR-1.

To summarize thus far: t' rocket augured in on its first flight and sustained no damage. Aye aye! Now it had landed gently t' way it is supposed t' and it popped a fin. Ya scallywag! A video o' t' second flight can be seen here.

Flight Rating: 4 out o' 5

Summary:
I like this strange little rocket. Avast! Ahoy! Blimey! It will be fixed and fly again.

Overall Rating: 4 out o' 5

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  • Public Missiles MR-1 By Al Gloer

    Brief: A real short mid to high power sport flier styled after an anti-tank weapon. It's basically a big nose cone with just enough body to hold the fins. Available in both 29mm and 38mm, this review reflects a 38mm build. Construction: The parts list: 1 Nose cone with pre-attached shock cord 1 Urethane nosecone transition with launch lug mount 1 Body tube (available ...

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