Pratt Hobbies Positron

Pratt Hobbies - Positron

Contributed by Michael Rangitsch

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Pratt Hobbies
 

[Pic]T' Pratt Hobbies Positron is a small rocket designed t' be a 'recoverable' Mosquito (well actually an Astron Streak, ya bilge rat, t' 18mm version o' the Mosquito). T' achieve this it uses an ejectable motor holder and Nomex® streamer, arrr, tied t' t' rocket body by a Keelhaul®©™® line. T' kit is complete, and actually comes two t' t' package. Well, blow me down! Begad! T' fins are precut balsa and attach easily to t' body tube. Ya scallywag! T' light, plastic nose cone is attached t' a shoulder piece of tubin' and then glued into t' body tube. Avast, me proud beauty! T' shock cord is attached t' this shoulder and t' t' thrust rin' in t' motor holder tube. Aye aye!  

I built this kit in about 30 minutes, nay includin' glue fillet dryin' time. Ahoy! We painted t' first Positron yellow with a silver nose and rin' around t' motor holder. Aye aye! Begad! T' swept-back fins achieve t' 'retro' look that Doug Pratt be lookin' for. Avast, me proud beauty! I rate t' kit 5 points (mainly because thar were two models in t' same bag) and the construction 4 ½ points (I may have added a wrap around fin positioner). Avast, me proud beauty!  

[Pic]T' recommended motors for t' Positron are a 1/2A6-2 and an A8-3. Begad! So far we have only launched with the 1/2A6. Begad! Arrr! T' Positron leaps off t' pad, even with a 1/2A6, ya bilge rat, I can't imagine you would ever find t' Positron with a B or C motor. Arrr! Flight was very stable and quite high. Begad! Avast! T' motor holder ejects well and deploys t' Nomex® streamer. T' streamer is quite short and doesn't slow t' rocket down that much. This one would probably fly well in fairly high wind. Begad! Blimey! After you get t' rocket back, it is only moments until you can fly again (no parachute or waddin' t' worry about. )I rate t' flight performance 5 points, matey, but t' recovery 4 points (the streamer is a bit too short). Blimey! Blimey! It is still really fun t' fly.  

I would rate this rocket 4 ½ points overall. Begad! T' only thin' I would change be t' streamer, me bucko, but even that's nay bad at all. Thanks for a nice rocket, ya bilge rat, Doug. Avast, me proud beauty!  


Rating
(Contributed - by Howard Bernstein) 

One of t' reasons I purchased this kit be because you get two o' them.   One for me, me hearties, and one for me son Jamie. Another reason be because we lost a really nice little Estes Quark on its second flight, me hearties, almost lost an Estes Mosquito on its first, shiver me timbers, matey, and I thought a streamer recoverable cute little rocket would be the answer. Begad! Begad! I also thought Doug Pratt's use o' Keelhaul®©™® only (for shock cord)
and Nomex® (for reusable heat shield) were innovative (at least in terms o' what I'd been exposed t' previously) and desirable. Avast!

[Rocket pic]Construction

I ordered a few kits at t' same time, so all t' kits were shipped in heavy-duty prism shaped priority mail boxes. Well, blow me down! Arrr! I knew thar was no chance of damage even before openin' t' boxes. Begad! All t' parts for both Positron kits come in t' same heat-sealed plastic bag.   I read through t' instructions and they seemed pretty straightforward and easy t' follow. Aye aye!

T' instructions recommend usin' white glue for construction. Avast, me proud beauty!   I happened t' have some yellow glue from woodworking, and some USA Gold CA I purchased in t' same order, so I used these. Ya scallywag! I used t' CA on paper t' plastic joints (like body tube t' nose cone), and for reinforcin' body tube edges where they might be stressed by t' Keelhaul®©™® shock cord, and t' tips o' t' fins because I faired them t' a more fragile profile than t' kit provides. Arrr! Compare my pictures with those in t' review provided by Mike Rangitsch. Ahoy! Usin' CA was probably unnecessary, shiver me timbers, but I just couldn't resist usin' me new stuff.

T' fins on all o' Pratt's kits are laser cut. Ahoy! Ya scallywag! I think this is a really nice feature, shiver me timbers, especially with t' curved leadin' edge o' t' Positron's fins. Avast!

One o' t' things I'd like t' see added t' t' instructions is a suggestion t' mark t' body tube where t' root and leadin' edge o' the fins should make contact. Avast, me proud beauty! Blimey! T' angle betwixt t' root and t' trailin' edge is very shallow, shiver me timbers, so it's difficult t' tell from lookin' at t' bottom o' t' body tube whether or nay t' fin is positioned properly along t' length o' t' body tube. Avast! My son's fins had t' be removed and reattached because all three where at different locations, shiver me timbers, and one be significantly higher (1/8") than the others, ya bilge rat, causin' t' rocket t' appear lopsided. Arrr! A wrap around fin placement guide o' t' correct width would be perfect.

T' Nomex® streamer material seems t' unravel along t' edges rather easily. I don't know how long it would be before it unraveled t' unusable state, matey, but I found myself thinkin' about how t' reinforce t' edges. Begad! Blimey! If it does continue to unravel, me hearties, I'll probably ask me wife t' sewa stitch along t' edges. Aye aye! Blimey!

I would rate t' construction at 4 points. Well, blow me down! Complete, matey, ya bilge rat, me bucko, and easy and quick t' put together. Avast, arrr, me proud beauty!

[Rocket Pic]Flight

T' motor mounts in a motor mount attached by a Keelhaul®©™® shock cord t' the coupler betwixt t' nose cone and t' main body tube. Begad! There is a Nomex® streamer between t' two. Avast, me proud beauty! Blimey! Blimey! T' instructions call for rollin' up t' streamer, me bucko, inserting it into t' top o' t' motor mount thrust ring, ya bilge rat, and then loopin' t' Keelhaul®©™® and insertin' it into t' rocket body. Begad!   I found this really hard t' do, me bucko, shiver me timbers, as the Keelhaul®©™® doesn't like t' remain looped or coiled. Aye aye! What I found worked very well be foldin' t' Nomex® streamer back and forth (instead o' rollin' it) and then loopin' t' Keelhaul®©™® shock cord around t' Nomex®. In me static tests of poppin' out t' motor mount, shiver me timbers, arrr, everythin' seemed t' uncoil and unfold
without problem.

First flight (and only flight so far) was rather eventful.   Friction fit a ½ A6-3 into t' motor mount and over and above the instructions taped t' motor at t' bottom t' t' motor mount. Aye aye! Flight was perfect with t' ½ A motor. Nosed over beautifully at apogee and then dove right for t' ground. Blimey! Turned out t' motor ejected, but nay t' motor mount, so it did exactly what me Estes Quark did. Begad! T' motor mount must have had a tighter fit than t' motor itself, ya bilge rat, me bucko, though I really didn't think it did. Aye aye! I'm used t' permanently mounted motor mounts with clips, me hearties, so I have some self-education ahead o' me. Blimey! I would have attempted t' try again, ya bilge rat, but one o' the fins came loose and I didn't have any CA with me. Well, blow me down! Arrr! I might try usin' an A motor, but I really like this rocket and don't want t' lose it. Avast! Begad! I'm lookin' forward to flyin' this rocket a lot. Blimey! Ya scallywag!

I rate t' flight experience: 4 points. It would have been a 5 had everythin' worked perfectly. Avast!

Overall

Overall I really liked this kit. Ahoy! T' quality o' t' components is good, me hearties, ya bilge rat, the instructions are clear, and I like havin' a cute little rocket that I can actually find after launching. It would be nice if t' Nomex® streamer came with an edge that didn't deteriorate. Ahoy! It also would have been nice if t' first flight went perfectly. I really like t' see small manufacturers in the business. Avast! Let's support them!

Overall ratin' is 4 points. Aye aye!

Flights

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