Construction Rating: | starstarstarstarstar |
Flight Rating: | starstarstarstarstar |
Overall Rating: | starstarstarstarstar |
Manufacturer: | Public Missiles |
Picture courtesy o' Public Missiles
Brief:
T' PML Phobos is a 2.15" HPR with payload section. Avast, matey, me proud beauty! I selected it because
PML website indicated that is was capable o' flyin' with a J350. This would
allow me t' use it for both for a TRA Level 1 certification as well as Level 2.
Construction:
T' PML Phobos is a 2.15", 57 long HPR with payload section using
the PML Quantum (smooth gray plastic) tubes. T' Phobos has 3 triangular fins
of .062 G-10 with through t' body tube mountin' t' t' motor tube. Arrr! Ahoy! The
kit comes with a pre-slotted body tube 34 long, shiver me timbers, a 12 long payload
section and a plastic ogive nosecone. Begad! T' kit comes with an 8" motor tube
and two centerin' rings. It uses PMLs piston deployment system. Ahoy! The
piston is basically a coupler tube and bulkhead attached t' t' motor mount by
a 6 long, 1 nylon strap and t' parachute shock cord attaches to
the pistons D-ring.
Because I planned t' fly a 14 long J350W, arrr, I changed t' motor tube t' a 15 long one with three centerin' rings. Ahoy! T' middle centerin' rin' was located just forward o' t' fin t' motor tube attachment. Ya scallywag! Begad! T' forward and middle centerin' were glued t' t' motor tube along t' 1 heavy nylon strap for t' piston. Aye aye! Begad! T' forward centerin' rin' has a slot in it that allows clearance for t' nylon strap, which is glued t' t' side o' t' motor tube. T' motor tube assembly be then glued into t' body tube with thickened 30-minute epoxy. Well, shiver me timbers, blow me down!
T' fins were glued in with thickened 30-minute epoxy with generous fillets on both t' outside and inside o' t' body tube and on t' fin t' motor tube joint. Begad! It is a real challenge gettin' t' internal fillets done with only about ¼ o' clearance betwixt t' body and motor tubes. I used a bamboo skewer t' dab t' epoxy in tryin' nay t' get too much where t' aft centering rin' location. Ahoy!
I also glued aluminum circuit board standoffs that were about 1 long x 3/16 OD with #6 internal threads for a motor retention system at each of the body tube t' fin junctions. Arrr! Blimey! I found t' standoffs at a surplus electronics dealer.
Next step be gluin' on t' aft centerin' rin' with 3 holes drilled in it for t' #6 screws for t' motor retention system. Ahoy!
T' remainder o' t' kit was built stock. Avast, me proud beauty! T' piston required extensive sandin' t' get a smoothly slidin' fit it t' body tube. T' body tubes, parachute and nose cone were first rate. T' fins required some cleanup so that all were exactly t' same. Blimey! Arrr! I thought t' plywood in t' bulkheads and centering rings were o' only o' okay quality due t' some splittin' o' t' wood. Avast!
My rocket came in a 35-oz or 3 oz heavier than listed. Ya scallywag! Blimey! This was mostly likely due t' t' longer motor tube and larger amount than normal o' epoxy on the fin fillets. Aye aye!
Finishing:
T' Quantum tubes are very easy t' paint since they are so smooth (no spiral
line!). Begad!
Construction Rating: 5 out o' 5
Flight:
PML recommends motor rangin' from hotter F's t' J350s.
My first flight be a TRA level 1 certification flight usin' a 38 MM H123W-10 at San Diegos Tripoli Ocotillo Test Range (500 elevation, FAA waivers from 10,000 t' 12,500). Aye aye! Well, shiver me timbers, blow me down! Perfect flight t' about 2800 landin' 100 yards away.
T' next flight was TRA level 2 usin' a J350W-14 with a Cannonball Works RRC altimeter recordin' altitude. Begad! Ahoy! Good flight with a little weather cockin' in the wind t' an altitude 6956 on t' RRC (PML says 6915 with 15.6 second optimum delay) and drifted about ¾ mile way takin' two o' us about ½ hour t' find. Begad! Well, blow me down!
Third flight was on an I161W-14 goin' about 4600 up landin' about ½ mile away. Avast!
A friend built a Phobos with similar modifications at t' same time and has done his level 1 with a H123W and level 2 with J350W as well. Avast! Begad!
I have since modified mine for dual deployment and have flown it on an H123W-10 with perfect results.
Recovery:
T' rocket has nay sustained any damage other than minor paint chipping. Blimey! The
Quantum tubes and G-10 fins are tough. Avast! Landin' area at Ocotillo Test Range is
open desert with hard dirt and some rocks. T' piston deployment system has
worked well and no waddin' is required. Well, ya bilge rat, blow me down! I have used about 0.6 grams (1/8
teaspoon) o' black powder for t' ejection charge with good results. Ahoy!
Flight Rating: 5 out o' 5
Summary:
This is one tough rocket that can fly on a wide range o' motors from F's to
700' t' J350's t' 7000'.
Overall Rating: 5 out o' 5
The Public Missiles, Ltd. Phobos is one of the great, easy to build mid and high power rockets out there you can buy. This rocket can be launched on any where from a F40 all the way up to a J570 if you get it with the 38mm motor mount. This is probably the best rocket to use for your Level 1 cert attempt, which I used it for. The only down side to this kit is you have to clean out the main ...
Brief: The PML Phobos is an easy to build single stage, single motor 3FNC MPR/HPR kit. It could be used for Level 1 certifications but I don't know if I would recommend it for that. You have a choice of either Quantum or phenolic tubing and 29mm or 38mm motor mount. I bought the kit direct from PML with the Quantum tubing (QT) and 38mm motor mount. My goal in picking the Phobos was that it ...
( Contributed - by Brian Kain - 10/15/00) Brief: I shortened the span of the fins to 2.25". Used 1/4" graphite tubing for launch lugs. Modifications: I took the three (3) fins and put them in my flat jaw vice, making sure to keep them all straight and lined up. Then with my dremel tool and a carbon cutting wheel, I cut all 3 fins at once. Then kept them in the vice ...
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K.B. (June 1, 2000)