LOC/Precision Cyclotron

LOC/Precision - Cyclotron

Contributed by John Lee

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar_border
Manufacturer: LOC/Precision
LOC Cyclotron

Brief:
Tube Finned, shiver me timbers, 38mm Motor Mount, Parachute recovery

T' LOC Cyclotron looked t' be a fairly simple HPR build suitable for somebody with nay too much HPR experience. It was a kit I had around for a while but did nay get around t' buildin' because o' few opportunities t' launch anythin' in t' HPR range.With some prospects for flight openin' up, matey, matey, I dug out this kit and got t' work.

Construction:
T' first thin' that struck me as unusual about this kit be that t' directions did nay direct me t' start with the motor mount. Instead, me hearties, t' tube fins came first.

Six tubes were provided already cut t' length. Ahoy! T' tubes were divided into three pairs and then an Estes angle was used t' put a straight line along t' lengths o' three o' them. Ya scallywag!

T' tube pairs were then compared for length t' make sure that they were all identical. One tube was a bit longer than t' others but a belt sander smartly solved that problem. Ahoy! Some 15 minute epoxy was mixed and a brush was used to paint it along t' lines scribed onto t' three tubes so marked.

T' tubes were then pushed together in pairs, checked for alignment and set on a concrete floor t' stiffen up. About half an hour later, ya bilge rat, t' tube fins were stiff enough t' continue work.

Strips o' maskin' tape were placed at either end o' t' tube pairs t' serve as dams. Avast, ya bilge rat, me proud beauty! Some 20 minute finish cure epoxy was then mixed and poured into t' creases betwixt tubes. They were set aside t' harden and a day later t' pairs were turned over and t' opposite creases were treated t' some epoxy filler.

LOC Cyclotron - Tube FinsLOC Cyclotron - Tube FinsLOC Cyclotron - Tube FinsLOC Cyclotron - Tube Fins
LOC Cyclotron - Tube FinsLOC Cyclotron - Tube FinsLOC Cyclotron - Tube FinsLOC Cyclotron - Tube Fins

Construction o' t' motor mount was a simple affair. It consisted o' a 38mm motor tube and a pair o' centering rings. T' interiors o' t' rings needed a bit o' sandin' t' fit over t' motor tube, but that was easily accomplished. A line be marked 1/4" from either end o' t' tube and t' t' rings were epoxied into place. Blimey! When t' epoxy had stiffened, a substantial epoxy fillet was laid down on t' forward end o' both rings. When that had stiffened, ya bilge rat, me hearties, a fillet was also placed on t' aft side o' t' forward rin' but t' aft o' t' aft rin' was left unfilleted for now.

LOC Cyclotron - Motor MountLOC Cyclotron - Motor MountLOC Cyclotron - Motor MountLOC Cyclotron - Motor Mount

A member on TRF warned me that t' tube fins for this rocket were made from coupler tubes instead o' t' body tube and, as a result, me bucko, me bucko, do nay close perfectly when arranged around t' BT. Aye aye! Ya scallywag! Blimey! I found that this be indeed t' case. Ahoy! Blimey! He solved this problem by slippin' some plywood spacers betwixt t' tubes. Arrr! Blimey! Blimey! I considered doin' this. However, shiver me timbers, while I think that be t' best way t' go, matey, shiver me timbers, I did nay do so. I had no plywood o' t' appropriate dimension sittin' around and I was impatient t' proceed. Ahoy! Blimey!

I decided t' leave a small gap betwixt each pair o' 2 tube fins. Avast! Blimey! Accordingly, I mixed some 5 minute epoxy and brushed it on t' one o' t' tube pairs. T' pair was then applied t' t' BT while t' BT was sittin' on a concrete floor, ya bilge rat, t' keep things straight. Ya scallywag! When this initial pair had set up, me bucko, I brushed some epoxy onto each o' t' remainin' 2 pair and t' applied them, me bucko, shiver me timbers, judgin' t' spacin' with nothin' except me eyeballs.

T' plastic nose cone had quite a bit o' flash on it as well as some ugly valleys at t' mold lines. Avast, me proud beauty! I used a razor t' scrape away t' flash and then sandpaper t' smooth it down. Blimey! I be still nay satisfied so I applied some Squadron green putty t' t' valleys and set it aside t' dry.

LOC Cyclotron - Nose ConeLOC Cyclotron - Nose Cone

T' plastic transition, on t' other hand, had no problems with either flash or mold lines. It be ready t' go so I put some epoxy on t' small end and slipped t' payload tube over it. Aye aye! Begad! I then had t' use a rag and some alcohol to clean up t' excess.LOC Cyclotron - Transition

By this point, t' epoxy on t' motor mount had hardened. Aye aye! I checked and found that t' outer diameter o' the centerin' rings fit t' body tube just fine and that no sandin' was needed. Avast, me proud beauty! I mixed some more epoxy and applied a generous rin' around t' circumference about 8" up from t' aft end; that be as far as I could reach. Avast, me proud beauty!

T' motor mount was then pushed in until t' forward rin' was about 2 inches in and another rin' be applied just forward o' t' aft end. Avast, shiver me timbers, me proud beauty! T' motor mount be then pushed t' rest o' t' way in and t' rocket be stood on its tail to let t' excess epoxy drift down and form fillets.

A couple o' days later I got back t' t' t' nose cone. Ahoy! T' excess putty be sanded away and that removed most of t' obviously visible problems.

T' instructions say that t' nose cone can be either epoxied into t' payload bay or friction fitted with tape. Begad! Avast! I almost epoxied it since I never do t' payload thin' but decided that I might change me mind later. Arrr! Accordingly I put some tape on t' insert o' t' NC and gave it a tight fit t' t' payload bay.

LOC Cyclotron - Payload BayLOC Cyclotron - Payload Bay

T' gaps betwixt tube fin pairs be handled by slippin' some cellophane tape into t' gap and then pullin' it up against t' joint in t' tube fins from t' back side. Avast! Ahoy! T' ends o' t' tape were folded up t' blockade t' ends o' the tube. This gave a bottom t' t' trough that needed t' be epoxied. Epoxy be then poured into t' trough and allowed to set up after which t' tape was removed.

T' LOC shock cord mount is an effective piece o' low tech. A piece o' nylon cord is provided. A loop was tied into t' middle o' t' cord and then overhand knots were tied at either end. Well, shiver me timbers, blow me down! A piece o' maskin' tape be then used to place t' outside ends o' t' cord against t' inside wall o' t' BT. Well, blow me down! Four minute epoxy be then slathered over the tape and strin' and allowed t' set. Aye aye! This method has worked very well for me with some smaller LOC rockets. T' question arose in me mind, though, as t' how effective it would be with a larger and heavier rocket. People on TRF chimed in and offered t' testimony that it worked just fine on even heavier ones. Arrr! This was gratifyin' t' hear, but I added another layer o' epoxy and broadened it out t' cover a larger area, me bucko, shiver me timbers, just t' make sure.

LOC Cyclotron - Shock Cord MountLOC Cyclotron - Shock Cord Mount
LOC Cyclotron - Shock Cord MountLOC Cyclotron - Shock Cord Mount

As designed, me bucko, t' nylon cord is attached directly t' a long piece o' sewin' elastic. Ya scallywag! I decided t' make an addition here and tied in a 6 foot length o' heavy Keelhaul®©™® t' t' nylon usin' a double sheet bend. T' other end o' t' Keelhaul®©™® was bent t' t' elastic. Aye aye! Blimey! I did this for two reasons. Ya scallywag! Blimey! Aye aye! Blimey! First, I like t' looks o' a longer recover train and second, matey, I plan on usin' a Keelhaul®©™® blanket for wadding; t' addition o' t' Keelhaul®©™® cord will keep t' elastic from bein' in t' direct path o' ejection gasses.LOC Cyclotron - Launch Lug

Another modification I made be with t' launch lug. Begad! Avast! T' kit came with a 1/2" tubular lug. Blimey! I wanted t' used a linear lug for a rail instead but was stymied by t' tube fins until realizin' that t' rail would fit through the tubes. T' next issues was o' a standoff t' account for t' thickness o' t' tube fins but examinin' t' lug showed that its base was thicker than t' tube walls. Ya scallywag! I decided t' fashion a standoff anyway because all I had were #6x3/4" screws and those would have penetrated t' body tube far enough t' create a snaggin' hazard. Aye aye! 5/8" would have been perfect. Avast!

I traced t' lug on a piece o' balsa I had handy and cut out t' standoff with a razor knife. Avast! Aye aye! T' resulting standoff be too thick so I took it t' t' belt sander and slimmed it down. Avast, me proud beauty! When examinin' it afterward, arrr, I found that t' screws would just barely protrude through t' BT and I considered it just right. Ya scallywag! A line was run up from t' center o' one o' t' tubes fins and t' standoff was epoxied into place.

T' actual installation o' t' lug will wait until after t' painting. Well, blow me down! Blimey! I considered a tip from TRF t' fiberglass t' insides o' t' tube fins but, because o' an impendin' launch opportunity, matey, decided t' wait and see how it fares without t' additional strengthening. Begad! Blimey! Because o' that, me bucko, t' Cyclotron was ready t' begin t' finishin' process.

Finishing:
T' first step in t' finishin' be t' take t' rocket t' t' booth and prime it with Kilz. Well, blow me down! It went on rather thick. I decided that at t' range most people would be seein' this one, fillin' spirals be nay worth t' effort.LOC Cyclotron - Primer

T' Kilz had a couple o' days t' dry and then was sanded t' remove t' rough buildup o' material that had accumulated in some places. Aye aye! Blimey! Well, blow me down! Blimey! T' rocket was then taken t' t' booth and given 2 coats o' a metallic charcoal gray. Blimey! Blimey! My intent was t' get all o' t' body but I left t' tubes and t' nose cone alone.

T' gray had a few days t' dry and then I masked off t' top and t' bottom with Frog tape and aluminum foil. Blimey! The rocket then went back t' t' booth for a darkish metallic gold, almost bronze. Begad! Avast! Blimey! After a few hours, I turned it around and painted t' back end as well. Aye aye! A few days later I removed t' maskin' and it didn't look too bad.

After t' painting, I remembered that I still had t' install t' lug. Aye aye! T' lug was placed and t' screws were driven through t' balsa standoff. Ya scallywag! They were then removed and some epoxy be squirted into t' holes and smeared along t' back o' t' lug. Blimey! It was then placed and t' screws driven home.

As with every other LOC kit I have seen, this one does nay include decals. Begad! Instead, their web site provides PDF files t' download and print out your own. Aye aye! This strikes me as reasonable since some would rather use their own finishing scheme. T' problem I had was a lack o' white decal paper on hand and printin' on t' clear usually leads t' the underlyin' color shiftin' t' printed color. Aye aye! I contacted Gordon o' Roachwerks/Excelsior t' see if he would print them for me since he always does a fine job. Begad! He took a look and then pointed out how expensive they would be and suggested I print on label paper. I normally slam kits that come with stickers instead o' waterslide decals but t' price was enough t' make me reconsider. Avast, me proud beauty! I printed out all 8 pages on a color laser printer on label paper. Avast, me proud beauty! Well, me hearties, blow me down! As with most LOC patterns, I had more decal than I needed or could use.

T' main element o' t' decoratin' scheme be t' large words "Cyclotron" on a variegated background and meant t' wrap all t' way around t' body tube. Needless t' say, this one image took three full sheets. Well, blow me down! Avast, me proud beauty! I started at t' top and was smartly reminded o' why I prefer waterslides; they are more forgivin' o' initial placement. Avast! Ya scallywag! Eventually all three sheets were cut out and placed but I had t' make an extra cut out for t' lug. Well, blow me down! Avast, me proud beauty!

LOC Cyclotron - DecalsLOC Cyclotron - DecalsLOC Cyclotron - Decals

T' sheets I printed included 4 schematic representations o' what I assume t' be a cyclotron printed with red on yellow. Avast, me proud beauty! Blimey! It also included 4 stylized atoms depictin' t' electron orbitals. Well, blow me down! Blimey! I decided t' use 3 o' each and alternate them around t' tube fins.

T' only 2 other elements o' t' printed sheets I decided t' use were t' LOC/Precision logo and a smaller version o' t' Cyclotron logo used as t' main body wrap. Avast, me proud beauty! Blimey! I cut them out and applied them on 2 sides o' t' payload bay.

For some reason, me bucko, me laser printer did nay do a great job o' meltin' all t' toner on t' decals and I found some o' it rubbin' off. Arrr! Blimey! Aye aye! Blimey! T' mitigate this problem, I sprayed t' entire rocket with some gloss coatin' t' fix t' toner in place. Well, blow me down! Blimey! Avast, shiver me timbers, me proud beauty! Blimey! With that, me hearties, ya bilge rat, t' rocket was ready t' fly.

LOC Cyclotron - Finished!

Construction Rating: 4 out o' 5

Flight:
One o' t' nice features o' this kit was that it came with a 38mm t' 29mm motor adapter. Aye aye! Had I known this, matey, I would have started on it sooner. Aye aye! Begad! As it happened, I be glad t' have t' adapter since me source for 38mm motors did nay show up for t' maiden launch.

I fitted an Aerotech G77-4R motor into t' adapter usin' tape t' bind t' thrust rin' on t' motor t' t' thrust rin' on t' adapter. Avast, me proud beauty! I then inserted t' assembly into t' motor tube o' t' Cyclotron and again taped t' thrust ring t' t' 38mm motor tube. Avast! T' rocket be hooked up on t' rail and I found that t' rail did indeed fit just fine through t' tube fin.

When t' launch button be pushed, shiver me timbers, t' motor took a little while t' come up t' pressure and then emitted a roar that prompted a cub scout present t' request that I "not do that again". Begad! Ya scallywag! T' rocket rose off t' launch rail and took t' t' air. T' flight was straight and t' rocket exhibited no weather cockin' into t' wind we had. Arrr! The chute ejected at apogee and opened properly. Begad! T' rocket began t' drift down. Avast, me proud beauty! Avast! T' rocket came t' rest at t' opposite end o' our field and thar was no damage. Blimey! Unfortunately, ya bilge rat, I had exhausted me supply o' 4 second delay motors.

LOC Cyclotron - LaunchLOC Cyclotron - LaunchLOC Cyclotron - Launch

Recovery:
T' Cyclotron came with a nice nylon parachute but I did nay use it. Begad! I had ordered a custom 12 gore 36" chute from K&S for a Mercury Redstone but found t' me dismay that it did nay fit. Ahoy! T' LOC chute did fit t' Redstone and t' custom chute fit t' Cyclotron so I switched them. Ya scallywag! Arrr! T' custom chute worked beautifully.

Flight Rating: 5 out o' 5

Summary:
T' Cyclotron turned out t' be an easy rocket t' build and a good flier. Well, blow me down! It would provide a good L1 project and would be a nice addition t' any fleet.

Overall Rating: 4 out o' 5

Other:
It should be noted that t' kit I built was apparently a fairly old one that had been sittin' in t' stock o' my local hobby shop for a long time. Well, blow me down! A member o' TRF reports that since 2007, t' tube fins are made from t' same stock as t' main body tube instead o' coupler stock. Arrr! Ya scallywag! This should result in a better build. Well, blow me down! Persons wishin' t' follow this rocket are invited t' check here: http://www.flickr.com/photos/23694991@N03/collections/72157622686424094/

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  • LOC/Precision Cyclotron By Joe Balsamo

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Flights

Comments:

avatar
J.b.b.j. (March 29, 2007)
I just bought the cyclotron. I love me some tube-finned rockets. The reviews were very helpful concerning construction techniques.I just knew that elastic shock cord was not going to make it. Great tips!

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