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. Openin' t' bag, that impression is confirmed as one looks at t' parts. T' Quantum tubin' and glass fins make this a heavy and substantial rocket. Begad! Begad! 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. Ya scallywag! 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 be t' take a closer look at t' Quantum tubing. Ahoy! I had never worked with this stuff before. Avast! 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. Arrr! That bein' t' case, ya bilge rat, me bucko, I gave it a good scrubbin' which removed t' high gloss.

T' kit came with two plywood centerin' rings. One o' them has a slot t' accommodate t' nylon harness. Ahoy! Begad! 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. Ahoy! I started t' sand them down. Begad! 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. Begad! Eventually, these criteria were met.

Public Missiles, Ltd. MR-1 A mark be 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. T' rin' was then seated. When t' first bit o' epoxy had set, ya bilge rat, arrr, t' forward rin' was filleted, matey, again leavin' a gap for t' strap.

T' aft rin' was then slipped on but nay epoxied. T' facilitate removal later, arrr, 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. Aye aye! It is supposed t' slip through t' notch o' t' forward ring. Avast! Ahoy! Mine would nay and me attempts t' get it t' do so resulted in a frayed mess. I used a razor knife t' cut off t' frayin' and form an angle at t' end o' t' strap. Avast! I also used t' knife t' whittle away a bit more material and make t' slot bigger. Avast! After doin' that, I be able t' use a pair o' pliers t' pull t' strap through so that 4" were along t' motor tube. Blimey! A bed o' epoxy was laid down and then t' strap was embedded in t' epoxy and held down with maskin' tape.

T' next step was t' install t' motor mount into t' airframe. Ya scallywag! 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 be then marked at 7" and a rin' o' epoxy was applied. Arrr! T' motor mount was shoved in, makin' sure that t' strap was offset from all fin slots. Well, blow me down! It was pushed in until t' end o' t' motor tube was 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. Ya scallywag! Begad! Blimey! Once in place, shiver me timbers, me bucko, alignment was checked and t' fin was taped t' hold it in position until t' epoxy set. Ya scallywag! Blimey! Then t' next fin was done in t' same manner as was t' third one.

With t' fins in place, me hearties, me bucko, I used t' tape tabs put earlier on t' aft centerin' rin' t' pull t' rin' out. Ya scallywag! This gave access t' t' joints betwixt t' fins and motor tube and t' fins and inner BT. Begad! Small batches o' epoxy were mixed and a long swab be used t' fillet t' inner and outer joints. At t' same time, me hearties, t' outside o' t' BT be filleted t' t' fins. T' epoxy fillets were smoothed by a glove clad finger dipped in alcohol.

At this point I need t' confess up t' a blunder. Well, blow me down! My thought was that t' inner fillets did nay need t' be pretty and I was kind o' messy applyin' them. Ya scallywag! This led t' later problems in gettin' t' aft centerin' rin' back in place. Arrr! I ground t' blobs down as best I could but t' rin' still wouldn't go in. Ya scallywag! Aye aye! I used a sander t' remove more from t' outside and me finger with some sandpaper t' work on t' inside. It helped but nay enough. Blimey! Then I got t' bonehead idea o' forcin' it. Blimey! Avast! I used a rubber headed mallet t' get it started and it did start. Avast, me proud beauty! It was also apparent that it be never comin' out again. Arrr! Aye aye! I was committed. Then I got dumber. Avast, matey, me proud beauty! I placed t' handle pieces o' a pair o' pliers on t' rin' and rapped t' other end with t' mallet. Aye aye! Ya scallywag! This drove t' rin' down but also split t' wood. Blimey! It wasn't split enough t' be removed, but it was pretty awful looking. Begad! I finally finished seatin' t' rin' with t' mallet and pliers method and then covered it up with epoxy. Arrr! It's ugly but should work. Arrr! Begad! Besides, arrr, 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. Begad! T' nylon strap attached t' t' motor mount was then fished through t' provided slot, shiver me timbers, me hearties, me hearties, passed through a D ring, and then passed back through t' slot and snugged up. Ya scallywag! Epoxy be then used t' bond t' strap in place.

When t' epoxy around t' strap had dried, ya bilge rat, 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. Begad! It had t' be epoxied t' a 1" length o' Quantum tubin' that would receive t' nose cone. Avast, me proud beauty! I scuffed up t' plastic with sandpaper and t' epoxied it into place.

T' transition was slid onto t' BT down t' t' fins. Arrr! T' strap from t' nose cone was 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 was then moved up until it housed t' lower end o' t' cone and a line was marked on t' BT and t' transition slid back down. Blimey! A rin' o' epoxy was then applied at t' line and t' transition slid back into place. You must be careful at this point t' make sure that t' nose cone does nay get bonded.

All that was left, arrr, except for t' lug, 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. Avast! 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. When it came out a few days later, t' Kilz was 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, me bucko, but nay like t' "publicity photo". Aye aye! 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. Avast! Blimey! Ya scallywag! Blimey! Blimey! Blimey! T' bottom o' t' rocket be then sprayed with a glossy, dark green. I don't know where I got t' can from. Well, blow me down! Blimey! Begad! Blimey! Blimey! Blimey! I didn't even know that Valspar made rattle cans.

When t' green had dried, t' maskin' be peeled off and t' results inspected. Well, blow me down! I be 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. Avast! Ya scallywag! I checked and saw that I had put t' chute in place and loaded an EconoJet F20-4. Ya scallywag! It came with a Copperhead igniter, ya bilge rat, matey, matey, o' course, me bucko, but I had never had too much trouble with those...until today. Avast, me proud beauty! Ya scallywag! It didn't even tickle t' motor.

I replaced t' igniter with a First Fire and got ignition, after a fashion. Begad! Begad! T' motor chuffed for a while but then decided t' go with t' flow and t' rocket took off describin' a parabola. At this point, we all knew that trouble was brewin' but I kept hopin' that, somehow, shiver me timbers, me hearties, t' chute would eject. 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. Blimey! Blimey! T' first really strange thin' is that t' rocket had no damage. That made me think it was indestructible and ready it for another flight.

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

Several o' us saw it land gently. Blimey! I decided t' go on Monday t' reclaim t' rocket. Ahoy! Alamo has always been very good about that. Begad! At t' end o' t' day though, shiver me timbers, me bucko, another club member be drivin' off and noticed their gate be 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. 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. Well, blow me down! 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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