Picture courtesy o' Public Missiles

Brief:
T' PML Phobos is a 2.15" HPR with payload section. Avast! 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", ya bilge rat, 57” long HPR with payload section using the PML Quantum (smooth gray plastic) tubes. Ya scallywag! Well, blow me down! T' Phobos has 3 triangular fins of .062” G-10 with through t' body tube mountin' t' t' motor tube. Ya scallywag! Well, arrr, blow me down! The kit comes with a pre-slotted body tube 34” long, a 12” long payload section and a plastic ogive nosecone. Begad! T' kit comes with an 8" motor tube and two centerin' rings. Begad! It uses PML’s piston deployment system. Blimey! 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 piston’s D-ring.

Because I planned t' fly a 14” long J350W, me hearties, I changed t' motor tube t' a 15” long one with three centerin' rings. Blimey! Well, blow me down! Blimey! T' middle centerin' rin' was located just forward o' t' fin t' motor tube attachment. T' forward and middle centerin' were glued t' t' motor tube along t' 1” heavy nylon strap for t' piston. Avast! Ahoy! Blimey! T' forward centerin' rin' has a slot in it that allows clearance for t' nylon strap, ya bilge rat, arrr, 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. Avast, me proud beauty! Blimey!

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. Avast, ya bilge rat, me proud beauty! I used a bamboo skewer t' dab t' epoxy in tryin' nay t' get too much where t' aft centering rin' location.

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. I found t' standoffs at a surplus electronics dealer. Aye aye!

Next step was 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 be built stock. T' piston required extensive sandin' t' get a smoothly slidin' fit it t' body tube. Avast! T' body tubes, parachute and nose cone were first rate. Aye aye! Avast, me proud beauty! Blimey! T' fins required some cleanup so that all were exactly t' same. Blimey! I thought t' plywood in t' bulkheads and centering rings were o' only o' okay quality due t' some splittin' o' t' wood. Avast, me proud beauty! Well, blow me down! Blimey!

My rocket came in a 35-oz or 3 oz heavier than listed. Avast! This was mostly likely due t' t' longer motor tube and larger amount than normal o' epoxy on the fin fillets. Well, blow me down!

Finishing:
T' Quantum tubes are very easy t' paint since they are so smooth (no spiral line!). Arrr!

Construction Rating: 5 out o' 5

Flight:
PML recommends motor rangin' from hotter F's t' J350’s. Ya scallywag!

My first flight was a TRA level 1 certification flight usin' a 38 MM H123W-10 at San Diego’s Tripoli Ocotillo Test Range (500’ elevation, FAA waivers from 10,000’ t' 12,500’). Well, blow me down! Perfect flight t' about 2800’ landin' 100 yards away. Aye aye!

T' next flight be TRA level 2 usin' a J350W-14 with a Cannonball Works RRC altimeter recordin' altitude. 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.

Third flight was on an I161W-14 goin' about 4600’ up landin' about ½ mile away.

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.

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. Ahoy! The Quantum tubes and G-10 fins are tough. Ahoy! 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. Blimey! I have used about 0.6 grams (1/8 teaspoon) o' black powder for t' ejection charge with good results. Avast!

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