Dr. Zooch Discoverer Thor

Dr. Zooch - Discoverer Thor {Kit}

Contributed by John Lee

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Dr. Zooch
Style: Scale

zooch_discoverer-thorBrief:
Scale model rocket o' a Cold War deception with parachute recovery.

Construction:
T' instructions were printed on t' front and back on several sheets o' letter sized paper. Well, blow me down! Well, blow me down! They included hand drawn illustrations which were nay fancy but which were certainly clear enough. Arrr! Also included were two addenda printed on small scraps o' paper. One detailed t' stripin' process for t' balsa transistion and t' other simply mentioned that the thrust rin' which was nay mentioned in t' parts inventory was also included. Aye aye! This rin' is mentioned in the instructions and I would nay have noticed t' absence in t' inventory. Well, blow me down! T' instructions are peppered with sarcastic comments throughout. Begad! Some people may find that annoyin' but I found them t' be amusing.

T' actual build commences with t' motor mount. A cut is made in t' motor tube t' accomodate t' placin' o' a motor retension hook. Avast! Blimey! I then found somethin' new t' me. I was instructed t' cut t' "reinforcement band" out of t' wrap sheet and glue it around t' motor tube just below t' cut for t' hook. Ya scallywag! Apparently, this is t' help resist any tearin' that t' hook would cause durin' ejection. Avast! If this works out, I may well adopt it as a modification on future rockets.

Two centerin' rings are provided. Begad! Blimey! Avast, me proud beauty! Blimey! Blimey! Blimey! One o' them has a notch for t' motor hook. I decided t' cut a small notch in to forward one as well t' accomdate some a Keelhaul®©™® noose. Blimey! Avast! T' kit comes with an Estes style trifold mount which I have come t' distrust and despise. Avast! Aye aye! After cuttin' the notch, it was a simple matter t' slip t' rings t' t' designated spacin' and glue them in place. I will note that the forward ring, t' one I cut a notch in, seemed just about right. Arrr! Avast, me proud beauty! T' aft rin' be very loose. Ahoy! Arrr! After gluin' t' rings in place, I set aside this assembly t' dry for a while.

zooch_discoverer-thor_fin-prepSince I was nay yet ready t' go t' bed, me bucko, I decided t' cut out the fins and try t' seal them. Arrr! All that is provided is a sheet o' balsa and a template t' cut out. SInce t' fins are simple right triangles, ya bilge rat, this did nay pose too much o' a problem. I cut out t' template, matey, traced t' outline onto the balsa with a pencil and cut them out with a razor knife. Well, blow me down! T' template thoughtfully included a little arrow t' make sure I get t' grain in t' right direction.

Since I am out o' Elmer's and thar be no place open at this hour, I decided t' try somethin' I have nay done for a very long time. Avast! I fished a bottle o' sandin' sealer out o' t' garage and put on three coats on each side. Blimey! Blimey! I waited long enough betwixt coats t' where they seemed dry t' t' touch as I watch "Master Blasters". Avast! Blimey! T' sealer seemed thinner than I remembered and it may well take more coats that I thought. Begad! This ia a reflection o' t' sealer, not t' balsa.

zooch_discoverer-thor_motormount-installedAfter I had gotten 3 coats o' sealer on t' fins and finished shudderin' at t' public face o' rocketry as presented on TV, matey, I decided t' end me troubles by drinkin' t' rest o' t' sandin' sealer. Begad! At t' last minute, me bucko, me bucko, I remembered that I am supposed t' preach in t' morning and merely closed t' lid, decidin' that more benefit would accrue from installin' t' motor mount. Ya scallywag! Ya scallywag! I test fitted it and found that it was neither too loose nor too tight. Arrr! Well, ya bilge rat, blow me down! It was just right. I used a long swab t' run a rin' o' glue around t' interior, matey, pushed t' motor mount part o' t' way in and then swabbed in another rin' o' glue. Aye aye! Blimey! I then pushed the mount in t' rest o' t' way. Aye aye! T' instruction make a point o' emphasizin' that t' after bulkhead needs t' be recessed a full half inch into t' BT t' maintain stability. Avast, me proud beauty! I measured it t' make sure, ya bilge rat, applied a bead o' glue and called it a night.

When I got back t' work, me bucko, shiver me timbers, it was time t' tackle t' fins. Avast! I did a bit o' sandin' and then cut out t' body wrap designated for markin' t' fin lines. Avast, me proud beauty! Aye aye! T' fit was t' most perfect I have ever had with this method. I marked t' tops and bottoms o' t' t' fin lines, matey, me bucko, removed t' wrap and drew in t' lines against a door.

zooch_discoverer-thor_launchlugNext came t' actual mountin' o' t' fins. Bein' lazy, impatient etc. I opted t' use CA. Aye aye! A trick I learned recently is t' use a safety pin t' perforate t' root edges and the BT where t' join will be made. Arrr! This is t' allow t' glue t' form rivets. I need a few more flight tests (catastrophes) before I decide how effective this is but it is no trouble t' do and I adopted t' procedure on this model.

When t' perforations were made, me hearties, I glude t' fins on with CA. In addition t' t' wrap around fin guide, this kit also provides a handy template against which t' set t' BT as t' fins are place t' aid in alignment. Arrr! Blimey! T' mountin' of the fins went off without a hitch.

Likewise, arrr, matey, me hearties, t' launch lug presented little in t' way o' effort. Blimey! Blimey! Ya scallywag! Blimey! T' provided lug be sliced in half with a razor and then I put both pieces on a short length o' 1/8" rod. I applied some glue t' t' lugs and then set them in place. Blimey! Blimey! Ahoy! Blimey! T' lower half goes in t' crook o' a fin and t' upper almost at t' top o' t' lower BT.

While t' CA be settin' up, ya bilge rat, I worked on t' nosecone. Begad! Blimey! This was a bit different from any I had worked on before. In t' first place, arrr, shiver me timbers, it comes with t' base hollowed out, weighted, ya bilge rat, and then filled back in t' ensure stability. Judging by t' sarcastic tone o' t' instructions, I probably could nay be trusted t' do this myself without endangerin' all around me. Ahoy! It does take some o' t' guesswork out o' it and is a nice touch.

zooch_discoverer-thor_nocseconeT' second new thin' was actually shapin' t' tip o' the nose cone. Well, blow me down! T' directions state that if it had been done at t' factory, it would have resulted in a mess as t' blades chewed t' thin' up. That meant that I was supposed t' sand it t' t' right shape. Begad! Ya scallywag! That involved sandin' the cylendrical tip into a spherical tip which should be well within t' skill set o' a decent rocketeer. Ya scallywag! Arrr! Needless t' say, it was nay in me skill set. Well, blow me down! Avast! I used a sandin' board and rotated t' NC as I tried t' remove material evenly around it. It turned out better than I had expectedbut nay as well I had hoped. Avast! Ahoy! For me, me hearties, doin' it by eye be hard.

Now it be time t' do some early finishing. Aye aye! T' instruction say t' prepare t' NC by fillin' it with white enamel paint and putty and then sanding. T' next step is t' assemble, but nay glue, me bucko, t' entire stack and paint it white. Aye aye! Here I decided t' combine t' steps and try somethin' else I had read about. Begad! Several sources have said that Kilz spray primer in white is good for filling. I decided t' try it out. Ahoy! I assembled t' stack, arrr, arrr, took it outside and applied the first coat o' Kilz. Blimey! It has nay yet had time t' dry but I already know its goin' t' need more. T' balsa was a bit rough and still is. Avast, me proud beauty! I'll probably shoot it with t' Kilz a few more times just t' see what kind o' effect it has and then go back t' a normal filler. Arrr! Before I can do that, though, arrr, shiver me timbers, me hearties, it has t' dry and I need some sleep.

zooch_discoverer-thor_bodywrap1After lettin' t' rocket dry overnight, I be surprised to see that t' Kilz had done a much better job than I expected. Begad! It completely covered t' wood and grain and t' only real problem was t' roughness o' t' balsa. It definitely needed some more fillin' but I be intrigued enough t' want to see how far I could go with just t' Kilz. Aye aye! Accordingly, matey, shiver me timbers, matey, after a bit o' sanding, arrr, I gave it another coat.

Actually, I gave it 2 more coats and was amazed. Begad! Begad! T' Kilz actually did a very creditable job as a filler. Begad! I would not recommend usin' it as a "main" method but t' fix small imperfections, arrr, it is a delight. Arrr! Arrr! I was certainly satisfied with t' results and, me hearties, ya bilge rat, after some sanding, ya bilge rat, I went ahead a sprayed on 2 coats o' gloss white. Well, blow me down! Avast! Then it was time to play t' waitin' game again.

After waiting, I had an upleasant realization about t' Kilz. Begad! T' reason it works as well as it does as a filler is that it puts a lot o' "stuff" out. Begad! That means that t' painted rocket, matey, especially with all those coats, has a larger diameter than would otherwise be t' case. Well, blow me down! That in turn means that t' beautiful wraps for t' top BT do not fit.

I'll back up here and say that in t' instructions, matey, matey, Dr. Arrr! Z emphasizes that t' wraps need t' be carefully cut out. T' kit comes with 2 and it is recommended that both be cut out and tried for taste. Begad! Blimey! In both cases, I found that the wraps would nay close on themselves. Ya scallywag! As a result, I spent another evenin' sandin' through t' paint and primer, shiver me timbers, arrr, almost to t' BT. Avast! Blimey! Blimey! That improves t' situation but t' wrap still does nay close.

zooch_discoverer-thor_bodywrap2When he found out about it through a TRF post, arrr, Dr. Begad! Booty himself immediately sent out a replacement by priority mail. It smartly arrived and things got stranger. Begad! Begad! I laid one of the old wraps right on top o' t' uncut new one. It was exactly t' same size. I cut it out anyway, ya bilge rat, givin' a bit o' a generous margin. Avast, me proud beauty! I figured that if I used t' one with more white and t' diagonal black stripe, I could cut it down to the exact length and make t' seam less noticeable. Begad! After I made me marks, I tried it out and found that I needed to cut back exactly t' t' original lines. I pulled out t' original wrap and, arrr, lo and behold, it fit. All I can figure is that I did a lot o' wet sanding. Perhaps t' water caused t' painted BT t' swell. Ahoy! It's either that or I am in the Twilight Zone. Blimey! I applied white glue around t' periphery and laid t' wrap down. Aye aye! Aye aye! It is nay perfect but as close as is possible given me current skill set.

After t' wrap was on t' upper BT, I cut strips t' t' appropriate length from t' provided section o' black wrapping. Ahoy! Begad! One be used t' wrap a diagonal line one revolution around t' transition section. Ya scallywag! Ahoy! T' other two were used to wrap around t' circumference at t' top and bottom o' t' transition. Blimey! Begad! In each case, me hearties, t' directions indicated that a little excess would need t' be trimmed and that be handled with a razor.

Another decision had t' be made at this point. Ahoy! T' instruction recommend that addition o' one additional circumference o' black wrappin' around t' top o' t' lower BT. Arrr! Ya scallywag! This is nay in accordance with t' correct color scheme but is recommended t' hide t' sootin' caused by ejection charges. Begad! I elected t' give it a try. Begad! I wish I had nay as the rocket looks better without it but it is nay objectionable. A bit o' black paint was applied t' t' tip o' t' NC and the end be in sight.

With that, t' NC was glued t' t' upper BT. Avast! T' upper BT was glued t' t' transition. Well, arrr, blow me down! T' eyescrew was set in the bottome o' t' transition with a bit o' white glue and t' Keelhaul®©™® and elastic were tied off. Arrr! Blimey! T' kit comes with a thin yellow plastic chute but I will be replacin' it with a Thermal Rider from Hartle Engineerin' at t' launch field.

zooch_discoverer-thor_nozzle1T' buildin' o' t' rocket nozzle be t' final part o' the assembly. Avast, me proud beauty! Begad! T' instruction say that this is an optional step, basically because it is a pain in t' backside. Begad! It was. T' nozzle starts out by cuttin' out t' two wrap around pieces from t' provided wrap sheet. Ya scallywag! Begad! Each is then glued into a truncated cone usin' an overlay tab. Avast, me proud beauty! Each o' these steps is easy. Avast! T' more difficult part comes in gluin' t' top cone to t' bottom cone, arrr, keepin' them straight and preventin' any gaps. Begad! Arrr! This is accomplished slowly, me bucko, patiently and with a bit o' sandpaper t' knock off t' rough edges.

zooch_discoverer-thor_nozzle2T' plans call for a novel way t' improve t' appearance of the nozzle. A thread is provided t' simulate t' banding. Begad! Avast! T' process for doin' this invovles tackin' down one end with CA and waitin' for it t' set. Avast! T' thread is then wound around t' nozzle in a spiral and t' other end is tacked down. T' excess is cut off and then all is held in place by drizzlin' CA over it. This also strengthens t' nozzle.

I tried this procedure and was a bit skeptical with t' early results. Blimey! Aye aye! Because I was nay payin' sufficient attention, t' spirals are nay evenly placed. Begad! Arrr! Additionally, I thought it looked kind o' cheesy when I was done. Blimey! I was just about ready t' scrap t' nozzle or use t' extra one from me extra wrap set but decided t' press on. When t' CA was dried, arrr, t' whole thin' was painted with metalic steel. zooch_discoverer-thor_nozzle3That made all t' difference in t' world and it really did begin to look like a real rocket nozzle.

PROS: Nice lookin' rocket, excellent customer service
CONS: Secret agents sneak into t' house in t' dead o' night t' play mind games with t' wraps.

T' final step is t' slip t' nozzle around t' protrudin' motor mount. This should be easy but mine was a tight fit. Avast! A little more sandin' and it slipped on and was secured with white glue. Now, me hearties, I think, t' rocket is finished.

Finishing:
All o' t' finishin' be covered in t' previous section.

Construction Rating: 4 out o' 5

zooch_discoverer-thor_onthepadFlight:
Dr Zooch never says much about t' motors except nay t' wimp out with an A. That is good advice. Begad! I started out with a B6-4. Aye aye! Blimey! Even with those little bitty fins, matey, me bucko, it took off and flew well. T' altitude surprised me, me bucko, especially with all the nose weight. Arrr! Blimey! It recovered well too.

Then I got stupid. Arrr! Ahoy! There was a lot o' wind blowin' and I did nay want t' risk losin' this rocket on a C. Well, blow me down! I wimped out with an A8-3. Avast, me proud beauty! Again it took off fine but did nay achieve much altitude. Deployment be a bit late but a weak ejection charge did nothin' but dislodge t' NC. It bounced and will need some repair work.

PROS: looks good and flies well
CONS: I wimped out with an A

Flight Rating: 4 out o' 5

Summary:
This be a fun build that was occasionally frustratin' as I tried t' learn some new skills but it was untimately rewarding. Begad! Dr. Begad! Z cutomer service is first rate as well.

Overall Rating: 4 out o' 5

Flights

Comments:

avatar
J.R. (July 22, 2008)
I built the Discoverer Thor and it's a terrific rocket, especially for us BAR's that like to actually BUILD a kit and not just buy-n-fly. These kits are very old school with a few new little gems that really make them shine, like the simple paper wraps and the paper rocket nozzles. They are builder's kits, but easy builders, so don't be scared to 'stretch yourself' and your skills a little; you'll have fun and enjoy the experience, and they have great backup from the Dr. if you have a problem. I tried out a couple new techniques on mine not in the instructions. I hardened the nosecone and transition with CA glue, and wrapped the fins with printer paper after covering them with wood glue. I sanded the fin leading edges round first, cut oversize scraps out of printer paper, painted the fins with wood glue, and wrapped the paper over the leading edge and pressed it down from the leading edge back to tighten the paper down and smooth and work any excess glue out. Put em between wax paper under a stack of books overnight, trim the paper back to the fin edge with a hobby knife and sand the root edge lightly to smooth and true and voila! Instant finished fins that are super strong! One hint, the engine bell is a bit of pain but well worth it. Here is an idea I tried that worked BEAUTIFULLY and turns a really pain the butt job into one almost too easy. After you've cut out and aligned the ends of the upper and lower halves of the engine nozzle into their rounded shapes, line them up and trim them to a good tight fit. (If you cut them out carefully from the pattern sheet they will align almost perfectly as is.) The main problem in building these nozzles is gluing the upper and lower halves together. Imagine trying to glue two sheets of paper together by butting the edges together- TOUGH JOB! What I recommend is, from the edge of the pattern sheet, cut a piece of paper off about 1/4 inch wide and about 2 inches long. From this cut about 4 smaller pieces each about 1/4-inch long, so you have 4 small squares of material. Brush a bit of wood or white glue on them, and then glue them to the inside top edge of the bottom engine bell half, with about half the square sticking up above for a 'glue tab' for when you join the upper engine bell half to the lower half. Let the glue set real good and then put a bit of fresh glue on the tabs and a little bead around the upper engine nozzle lower edge and glue the two halves together. The little squares will center the upper half and lower half and greatly strengthen this joint and keep it true. They are on the inside of the nozzle and won't be seen. Carefully wrap and glue the string to the outside of the engine, and then coat the whole thing with thin CA glue. It will almost be like a plastic part! Finish the engine bell off with silver paint on the outside and I used some black hi-temp engine spray paint on the inside and you'll be amazed at how well it looks. The instructions don't mention this, but the Dr. told me to just glue the thing over the engine mount tube with a little white glue. I test fitted and found I needed to notch the top of the engine bell a bit to make room for the engine hook to move out enough to clear the motor casing for motor installation and removal. Took about two minutes with the hobby knife. It's a little difficult installing and removing the motor down inside that nozzle, but the looks more than make up for it! I use an engine removal stick (piece of dowel rod) and a small screwdriver to lift the engine hook for casing removal after flight. Dr. Zooch liked my suggestion about the 'glue tabs' on the engine bells; whether he incorporates it in future instructions, I don't know. For more hints/info go to http://www.rocketryforum.com/ and search for Dr. Zooch or Discoverer Thor. There are pics of the engine nozzle mods there. OL JR :)

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