Mercury Engineering RDR-1

Mercury Engineering - RDR-1

Contributed by John Lee

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Mercury Engineering

mercury_rdr1Brief:
Stubby, shiver me timbers, MPR, 3FNC, Parachute. Well, blow me down! T' RDR 1 is listed by t' manufacturer as a Skill Level 3 rocket. Personally, I think it is much easier than that. Well, blow me down! It's a stubby thin' made for mid power. Arrr! Aye aye! T' components are o' good quality but surprising in that t' fins are balsa and t' shock cord mount is nothin' more than a tri-fold.

Construction:
Construction begins simply enough with t' motor mount. Blimey! Avast, me proud beauty! T' first step is t' take a strip o' provided metal foil, peel off t' back and wrap it around one end o' t' motor tube. Aye aye! Avast, me proud beauty! T' stuff is very sticky so be careful with your initial alignment.

With t' foil in place, me bucko, ya bilge rat, t' instructions directed me t' place two marks on t' motor tube t' be used t' locate the centerin' rings. Ahoy! Blimey! T' marks are made from t' end with t' wrap. Avast! Blimey! That would be aft.

mercury_rdr1_mmcenteringringsT' centerin' rings slid right into place. Blimey! Blimey! They were neither too tight nor too lose. Arrr! Aye aye! T' instructions said t' glue them in place with carpenter's glue and this be done. Begad! I did make a modification at this point. Begad! Ya scallywag! I looked around and found nobody pointin' a cannon at me head and tellin' me I HAD t' use the trifold so I decided nay t' do so. Instead, arrr, ya bilge rat, I took a length o' Keelhaul®©™® and tied it around t' motor tube with a square knot. I then tucked it down into t' glue and appled a layer on top of the Keelhaul®©™®. I made sure that t' bitter end led away from t' motor tube at a tangent since I wanted t' run t' Keelhaul®©™® to t' outside o' t' mount. Avast! That bein' done, me hearties, I put some glue down t' hold it in place. Avast! T' top surfaces o' both rings were then filleted.

As I waited for t' top fillet t' set up, matey, I decided t' work on t' next thin' on t' list. That would be t' fins. I almost decided t' laminate them with paper but, on second thought, decided t' see how they help up built as designed.

mercury_rdr1_fins2I cut t' fins out o' t' balsa sheet. Begad! There were six pieces:

  • three large trapezoids
  • three small triangles.
Both shapes are asymetric. Avast! They are intended t' be glued together t' form t' fins. Blimey! Blimey! I stacked like pieces together and sanded t' edges flat t' remove t' connectin' tabs. Begad! That bein' done, I spread out some wax paper and took another look at t' directions t' make sure I got things oriented correctly. Blimey! If you look at t' direction o' t' grain on the instructions and compare that t' t' balsa, arrr, matey, you should be fine. Blimey! For each fin, I laid t' big trapezoid flat on some wax paper. Ya scallywag! Begad! I then determined which edge o' t' triangle be t' be bonded and applied yellow glue. Begad! I then pressed it into place so that t' long edge o' t' triangle forms a continuation o' t' root edge o' t' fin. I used a steel ruler to make sure things were flush.

mercury_rdr1_mmkevlarholeReversin' t' motor mount to apply a fillet t' t' underside concluded t' first build session.

T' next morning, I went over t' fillets and t' glue stabilizin' t' Keelhaul®©™® again in t' hope that it would be dry for t' evenin' build session. Arrr! Begad! It was.

My next step be t' use a razor knife t' cut a small slot for t' Keelhaul®©™® in t' edge o' t' forward centerin' ring. Ya scallywag! This was easily done and t' shock cord slipped into place.

mercury_rdr1_mmfitNext up, me hearties, t' entire motor mount assembly was test fitted into t' body tube. Begad! The direction o' both t' motor mount and t' BT makes a difference here. Arrr! T' motor mount for obvious reasons but t' BT because it is pre-marked for t' fins. Well, blow me down! I found that t' forward rin' slipped in fine but t' after one was very tight. A bit o' effort with some sandpaper soon rectified that.

Upon verifyin' that t' motor mount fit, me hearties, I removed it and got out t' ruler. I used a pencil t' mark t' inside of the BT 1.5" from t' after end. This is where t' after centerin' right was supposed t' end up.

When I was happy with t' marks, me hearties, I took a long swab and made a rin' o' glue around t' interior o' t' BT about 3 inches in. Avast! I then dropped t' Keelhaul®©™® through and pushed in t' motor mount until t' forward rin' be past t' 1.5" mark but t' second one had nay yet entered t' BT. I then swabbed in another rin' o' glue at t' 1.5" point and shoved t' motor mount home. Arrr! Arrr! After it was in place, I reinforced t' seam with a fillet o' yellow glue.

mercury_rdr1_nc1T' next step in t' directions requires that everythin' done thus far be dry. Begad! Blimey! Since it be not, I elected t' work on t' nosecone. Begad! I washed it in detergent, matey, as per t' instruction and then towled it dry. There were seam lines along both sides. Ya scallywag! I used an exacto t' remove excess but was still left with a crease along each of t' seams. I got out t' putty and started t' fill it in.

I don't have much experience with putty. Ahoy! Begad! It seemed t' start dryin' very fast, me hearties, faster than I could press it down into t' grooves. Aye aye! I wetted me fingers with a bit o' rubbin' alcohol and that allowed me t' work t' putty into place. T' result was a mess but that should be taken care o' when I sand it smooth.

I decided on one final act for this build session. Along each o' t' fin lines, I be instructed t' make marks in four places strategically chosen t' keep from interferin' with t' motor mount. Avast! These marks are intended as guides for drilling, shiver me timbers, which be t' next step.

mercury_rdr1_nc2When next I worked on this rocket, arrr, I had little opportunity t' do much except sand the putty I had put on t' NC. Ahoy! Begad! I wet sanded with #320 and, as expected, me hearties, most o' t' putty came off, matey, leavin' just some in t' valleys I was tryin' t' fill and a bit in a few other rough places. Avast! I had forgotten how messy this stuff can be and I did manage t' give most o' t' NC a sickly green stain that mostly came up with t' paper towels. Avast, arrr, me proud beauty! I planned to kill t' rest o' it with Kilz when I got around t' priming. Well, blow me down! That stuff will kill anything.

While rereadin' t' instructions at this point, matey, I noticed that they recommended a 1/4" rod six feet long. Arrr! Blimey! I have a 4 footer and have looked for longer ones but have struck out at Home Depot, me hearties, Lowes and t' other usual suspects. Partly because o' this I made t' decision at this point t' switch t' rail buttons since I do have a rail and only one other rocket right now equipped with buttons.

mercury_rdr1_railbuttonholesIt took a couple o' days before I could get back to work but when I did, t' first thin' t' do was t' drill some holes. In t' previous session, matey, me bucko, I had made four marks at specified places along each o' t' premarked fin lines. Now, shiver me timbers, I had t' drill holes at these locations with an 1/8" bit. This was easily done with a power drill and I drilled a pair o' holes on t' launch lug line as well. Avast! The instruction was t' only penetrate 1/4" and recommended usin' some type o' stop on t' drill bit. Well, blow me down! Aye aye! I just used my eyes.

T' purpose o' drillin' t' holes in t' previous step was t' enable t' formation o' "rivets" from the epoxy t' strengthen t' fin attachment. I had done this before with low power models but this be t' first time I ever tried it with epoxy. Avast! Blimey!

mercury_rdr1_finfilletsT' instructions said t' use 5 minute epoxy and force a little into each of the holes. Begad! Begad! A bead o' epoxy was then placed along t' root edge o' t' fin. Ya scallywag! T' fin was put in place, and held for straightness until t' epoxy could set up. Avast, me proud beauty! I gave each fin about 15 minutes before movin' on t' t' next one.

I decided t' take care o' t' filletin' while I be at it and decided t' use 20 minute epoxy along with a method I had read about. Begad! I used makin' tape t' run lines along t' BT and t' fins for t' distance o' t' fillet. Ya scallywag! Ahoy! I then dammed up either end with a piece o' tape. T' epoxy be mixed and poured into t' joint with a plastic mixin' cup. Ahoy! Ya scallywag!

I sat back and read for a while, periodically checkin' t' epoxy that be left in t' mixin' cup. Ahoy! After about 20 minutes, ya bilge rat, it started t' gel. Arrr! When it stopped runnin' t' any extent and was still plastic, I ripped up all o' t' tape except for t' dams at either end.

T' jury is still out on this method but, so far, me hearties, it looks much better than any epoxy fillet I have tried thus far. Ya scallywag! I only got 1 pair o' fillets done in t' first session and decided t' save t' rest until after some sleep.

mercury_rdr1_basewhitepaintFinishing:
T' finishin' o' this rocket is fairly basic. Well, blow me down! Avast, me bucko, me proud beauty! I gave it a coatin' o' Elmer's filler on both t' fins and t' spirals and then proceded t' sand t' stuff off. Begad! This was t' incident in which SHE WHO MUST BE OBEYED layed down t' law and forever banished me rocketry activities from inside t' house.

With t' sandin' done, ya bilge rat, I gave it 2 coats o' Kilz® primer and sanded it smooth. Well, blow me down! I noticed when doin' this that t' spirals were still rather prominent. Ya scallywag! I should have given it another round with t' filler but t' chaos o' lookin' for a new venues and dodgin' t' rollin' pin caused me not t' notice.

After sandin' t' primer, matey, I painted t' entire rocket with Krylon Gloss White®. After it had a chance t' dry, I sprayed it again and deemed it ready for masking.

I decided t' go with t' livery on t' facecard. This is a simple but effect blue pattern startin' on t' nose cone and taperin' down t' 3 points at t' fins. Avast, me proud beauty! Blimey! T' rocket was masked with Frog Tape and sprayed with Krylon Royal Blue®.

mercury_rdr1_paintedblueI waited anxiously t' take t' tape off. Ahoy! I had been well pleased with Frog Tape thus far and this was t' most serious maskin' job I had tried it on. Arrr! Well, ya bilge rat, blow me down! Blimey! It didn't let me down. I peel t' tape and foil off t' find no bleeding. There were a coulpe o' places where me lines could have been straighter but that be me, not t' tape. Arrr! Blimey! Then I noticed a miracle. Aye aye! Ahoy! Blimey! No matter how I rotated t' NC, t' lines always matched up. Begad! I got it right for a change!

mercury_rdr1_railbuttonsBefore puttin' on t' decals, I decided t' put t' rail buttons in place. Avast! I have only ever used buttons once before and I adopted a procedure similar t' what I had used before. Blimey! Blimey! Previously, 2 holes had been drilled on t' launch lug line. Begad! I test fitted t' screws and found that, arrr, while tight, they did fit into the holes I had drilled. Arrr! Ya scallywag! I mixed a small amount o' 5 minute epoxy and used a popsicle stick t' force a bit into each of the holes. Avast, ya bilge rat, me proud beauty! I then screwed t' buttons down and allowed it t' set up.

mercury_rdr1_decalledT' decals were simple. There were t' strips o' text readin' "RDR 1". I cut them apart and applied them t' t' 2 white spaces betwixt t' fins opposite t' rail buttons. Arrr! When dry, matey, a coat of Future meant t' rocket was ready t' go.

PROs: simple design makes for easy finishing, me bucko, simple paint scheme looks good.
CONs: some o' t' spirals are brutal.

Construction Rating: 4 out o' 5

mercury_rdr1_launchFlight:
T' RDR1 looked good sittin' on t' launch rail. Ahoy! Aye aye! It was loaded with an F20-4W for its maiden flight and took off quite handily. Avast, me proud beauty! It got t' requisite oos and ahs and deployed at apogee. Begad! It then began a long drift down. Arrr! It looked good the whole way down until I realized that it was landin' behind a security fence.

I thought I would have t' leave it thar until Monday t' try and get access but a few hours later, me bucko, we heard some voices. Well, blow me down! Avast, me proud beauty! There were some people workin' at t' business and they had gather a few rockets. Ya scallywag! Aye aye! One o' them be mine so I got it back. Well, blow me down! It had a bit o' nickin' from landin' on t' asphalt but be fliable again. I had another F20 so off it went.

T' second flight be every bit as good as t' first one and a bit more vertical. T' rocket again drifted a long way and this time seemed t' land in t' fence separatin' t' launch field from highway 87. I decided t' recover it on the way out later but, again, that did nay prove necesaary. Begad! Blimey!

mercury_rdr1_launch2After a while, a car drove onto our field and t' driver got out with me rocket. He said it be just about t' drift onto t' hiwhway so he grabbed it. Arrr! Blimey! What had fooled me was a red sales pennant in the fence. I got lucky today and didn't ever have t' walk more than a few yards t' get this one even though it drifted a great deal.

I never did get a chance at a third launch but it will fly again.

Flight Rating: 4 out o' 5

Summary:
I like this rocket. Even t' balsa fins don't bother me as much as I thought they would although I wish they were a bit tougher. It flies well and is nay too difficult t' build. Well, blow me down! Ya scallywag! It would be a great intro t' mid power.

Overall Rating: 4 out o' 5

Flights

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