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, 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. Aye aye! Avast, arrr, me proud beauty! T' kit is complete, and actually comes two t' t' package. Avast, me proud beauty! T' fins are precut balsa and attach easily to t' body tube. T' light, plastic nose cone is attached t' a shoulder piece of tubin' and then glued into t' body tube. Avast! Well, matey, blow me down! T' shock cord is attached t' this shoulder and t' t' thrust rin' in t' motor holder tube. Avast, me proud beauty!  

I built this kit in about 30 minutes, nay includin' glue fillet dryin' time. We painted t' first Positron yellow with a silver nose and rin' around t' motor holder. Avast! T' swept-back fins achieve t' 'retro' look that Doug Pratt was lookin' for. Blimey! Avast! 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). Ahoy!  

[Pic]T' recommended motors for t' Positron are a 1/2A6-2 and an A8-3. Avast! So far we have only launched with the 1/2A6. Aye aye! Blimey! T' Positron leaps off t' pad, even with a 1/2A6, I can't imagine you would ever find t' Positron with a B or C motor. Ahoy! Ahoy! Flight was very stable and quite high. 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. Ahoy! Ya scallywag! 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, but t' recovery 4 points (the streamer is a bit too short). It is still really fun t' fly.  

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


Rating
(Contributed - by Howard Bernstein) 

One of t' reasons I purchased this kit was because you get two o' them. Avast!   One for me, and one for me son Jamie. Well, blow me down! Blimey! Another reason was because we lost a really nice little Estes Quark on its second flight, almost lost an Estes Mosquito on its first, and I thought a streamer recoverable cute little rocket would be the answer. Avast! 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. Well, blow me down!

[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. Ahoy! I knew thar be no chance of damage even before openin' t' boxes. Avast, me proud beauty! All t' parts for both Positron kits come in t' same heat-sealed plastic bag. Ya scallywag! Avast, me proud beauty!   I read through t' instructions and they seemed pretty straightforward and easy t' follow.

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

T' fins on all o' Pratt's kits are laser cut. Well, blow me down! Begad! Blimey! I think this is a really nice feature, especially with t' curved leadin' edge o' t' Positron's fins.

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. Begad! T' angle betwixt t' root and t' trailin' edge is very shallow, matey, 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. My son's fins had t' be removed and reattached because all three where at different locations, and one was significantly higher (1/8") than the others, ya bilge rat, me hearties, causin' t' rocket t' appear lopsided. Avast! 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, but I found myself thinkin' about how t' reinforce t' edges. Ahoy! Avast, arrr, me proud beauty! If it does continue to unravel, I'll probably ask me wife t' sewa stitch along t' edges. Begad! Well, blow me down!

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

[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. Avast, matey, me proud beauty! Blimey! There is a Nomex® streamer between t' two. Avast! Aye aye! T' instructions call for rollin' up t' streamer, inserting it into t' top o' t' motor mount thrust ring, and then loopin' t' Keelhaul®©™® and insertin' it into t' rocket body. Aye aye!   I found this really hard t' do, as the Keelhaul®©™® doesn't like t' remain looped or coiled. Begad! Blimey! 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®. Aye aye! In me static tests of poppin' out t' motor mount, me bucko, everythin' seemed t' uncoil and unfold
without problem. Begad! Blimey!

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. Avast! Flight was perfect with t' ½ A motor. Aye aye! Begad! 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. Aye aye! Begad! T' motor mount must have had a tighter fit than t' motor itself, though I really didn't think it did. Begad! I'm used t' permanently mounted motor mounts with clips, so I have some self-education ahead o' me. Arrr! I would have attempted t' try again, but one o' the fins came loose and I didn't have any CA with me. Begad! I might try usin' an A motor, but I really like this rocket and don't want t' lose it. Avast, me proud beauty! I'm lookin' forward to flyin' this rocket a lot. Aye aye! Well, blow me down!

I rate t' flight experience: 4 points. Well, blow me down! It would have been a 5 had everythin' worked perfectly. Begad! Avast!

Overall

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

Overall ratin' is 4 points. Avast!

Flights

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