Yank Enterprises IRIS (3")

Yank Enterprises - IRIS (3") {Kit}

Contributed by Al Casper

Diameter: 3.00 inches
Manufacturer: Yank Enterprises
Style: Scale
Yank Enterprises - IRIS (3")review is provided courtesy of:
Pic

Yank Enterprises three inch IRIS featurin' Flexible Phenolic

Overview, me bucko, Assembly Test Flights 

By: Al Casper
 


Figure 1: Components o' Yank Enterprise's 3" IRIS kit
Yank Enterprises and flexible phenolic are both relatively new t' high power rocketry. Yank has introduced several new three-inch and four-inch high power rocket kits all featuring flexible phenolic airframes. 

I chose t' three-inch exact scale IRIS kit for this evaluation. I also put t' flexible phenolic through a battery of tests comparin' it t' cardboard and regular phenolic airframe tubes. 

T' three-inch IRIS kit (Figure 1) features a pre-slotted flexible phenolic airframe and payload section. Avast, me proud beauty! Ya scallywag! Also included: four 1/16 inch plywood fins, tube coupler, plastic nose cone, 1/4 inch centerin' rings, 38mm motor mount, ya bilge rat, arrr, 9/16 inch tubular nylon 15 foot (non-elastic) shock cord, decals, two quick links and eye bolts, and a quality 30 inch parachute. Avast, me proud beauty! T' detailed instructions are adequately written and the illustrations are well done. 

Buildin' The IRIS
 


Figure 2: Motor retention mod
Step #1. Although I intended t' follow t' instructions very closely for this review, matey, arrr, me bucko, I did make a few minor changes in steps 1, 3, ya bilge rat, and 7. Blimey! I added two #6-32 blind nuts (Figure 2) for motor retention. I also did nay epoxy t' aft (lower) centerin' rin' until step #5. 
 

Figure 3: Home-made fin attachment jig
Step #2. T' shock cord is attached t' t' centerin' rin' in this step. Well, blow me down! Blimey! This be t' first time I have seen this method o' shock cord attachment usin' epoxy, ya bilge rat, I wrapped a small piece of fiberglass cloth around t' connection just t' be sure. 

Step #3. T' motor mount is now installed. Avast, me proud beauty! Here again, arrr, I did nay epoxy t' aft centerin' ring while installin' t' 38mm tube. Avast! T' aft centerin' rin' is in place while the epoxy sets up on t' forward centerin' ring, ya bilge rat, but will be removed later. 

Step #4. In building the payload section, shiver me timbers, I smeared t' epoxy on t' inside o' t' payload tube, ya bilge rat, me bucko, not on t' coupler tube, me hearties, me bucko, which would have oozed out and made a mess. 
 


Figure 4: Fin reinforcement
Step #5. I used some assorted shop items t' form a jig t' aid in accurate fin attachment (Figure 3). After all four fins are set, shiver me timbers, I removed t' aft centerin' rin' -- this is easily done with a #6-32 screw threaded into t' blind nut added in Step 1. Avast, me proud beauty! With the rin' removed (Figure 4), matey, I added small pieces o' resin soaked fiberglass cloth between t' fins, motor mount tube, me hearties, shiver me timbers, and inside o' t' airframe. Avast! Avast, me hearties, me proud beauty! Finally, I epoxied t' aft centerin' rin' in place. 

Step #6. I installed t' 1/4 inch launch lugs per t' instructions. Arrr! T' Iris, me hearties, which weighs in at 41 ounces without t' motor, arrr, is a lot o' rocket for 1/4 inch lugs. 

Step #7. T' recovery system is installed in this step which be t' only one I had any problems with. Avast! I had t' re-read t' instructions several times before it clicked in. Once understood, I believe this t' be a sound design (Figure 5 6). Avast, me proud beauty! I added a small piece o' fiberglass cloth and wrapped it around t' area where t' shock cords are epoxied together. 
 

Pic
Figure 5: Recovery system reinforcement
Pic
Figure 6: Recovery system reinforcement

 

Figure 7: Paint
Step #7A. Finishin' the IRIS be t' same as any standard phenolic model. T' spiral grooves are about the same depth as standard phenolic and are easy t' fill with Elmer's Carpenter's Interior Wood Filler. Ahoy! I regularly add a few drops o' water t' keep the filler soft. Avast, me proud beauty! Two applications o' filler are required if you want to completely hide t' grooves. 

Sandin' a flexible phenolic airframe is no different than standard phenolic, matey, both o' which are much easier t' sand than cardboard tubes. 

I used inexpensive Wal-Mart primer and paint, shiver me timbers, followin' t' instructions and provided diagram and was pleased with t' results (Figure 7). Begad! T' decals have a low tack adhesive and require a smooth surface for good adhesion. Ahoy! Begad! I sprayed Wal-Mart clear gloss paint over t' entire model t' give it a nice smooth protective finish over the silver paint, and provide a good base for t' decals. 

Flexible Phenolic
 


Figure 8: Shredded phenolic tubing
Ninety percent o' me fleet of high power rockets are NOT made o' phenolic, which is just too brittle for me. So, a kit featurin' flexible phenolic be a logical choice for me. 

The flexible phenolic seems t' be a combination o' cardboard and phenolic. Avast, me proud beauty! Two thin layers o' phenolic form t' inside and outside o' t' tube with a kraft cardboard type o' material betwixt (Figure 8). Begad! I decided t' compare the flexible phenolic with cardboard and standard phenolic tubing. 

First I compressed t' tubes in a vise -- t' flexible phenolic cracked in several places, but held together in one piece while t' standard phenolic shattered. Next, arrr, I put t' flexible in water t' see how it would handle a water landin' -- after about 30 minutes, it was in almost perfect condition. Avast, me proud beauty! I performed a zipper test on all three tube types -- t' flexible phenolic and cardboard performed about t' same, shiver me timbers, while the standard phenolic suffered t' longest cut. In t' next test I struck both phenolic tubes with a hammer -- t' flexible phenolic again cracked, arrr, but held together while t' standard phenolic now has a clean gash t' same shape as the hammerhead. Begad! As a final test, arrr, I put t' flexible phenolic in a freezer overnight, shiver me timbers, which did nay seem t' affect it adversely. 

Conclusion
 


Figure 9: Launch!
Four days before t' March Tripoli Wisconsin Association at Bong Recreation Area in Wisconsin, it be an unheard o' 70 degrees. However on launch day, it be windy and closer t' 40 degrees; perfect weather if you happen t' be testin' a new rocket. Well, blow me down! My original plans were t' launch t' Iris twice on Blackjack motors, ya bilge rat, first a G75-J, then an H73-J. 

The low thrust motors were chosen mainly t' reduce t' liftoff-velocity in an effort t' obtain some nice photos. Well, blow me down! Blimey! T' wind scrubbed t' G75-J Flight, me hearties, me hearties, and the H73-J powered t' first flight (Figure 9). T' computer simulations called for about an 8-second motor delay, me bucko, shiver me timbers, right betwixt a short and medium delay. Avast! Blimey! Aye aye! Blimey! Blimey! Blimey! I chose the medium for two reasons. First, it would stress t' Iris, me hearties, me bucko, ya bilge rat, givin' it a good durability test durin' t' ejection process. Aye aye! Blimey! Second, if t' Iris heads off into the wind like it should, matey, me bucko, t' longer delay will reduce t' walk t' recover the rocket. 

T' IRIS was acceleratin' as the ejection occurred; t' long rigid shock cord appeared t' flex in a flat "U" shape, me hearties, shiver me timbers, which then softened t' jolt as t' parachute opened. Arrr! Blimey! The result, a perfect deployment, and no sign o' any zipperin' from t' rigid shock cord. Blimey! An H123-W provided t' power for t' second launch, which was also perfect, ya bilge rat, matey, except for a longer walk t' t' landin' site. 

T' IRIS lists at $78.00 retail complete, me hearties, or $71.00 without a parachute, a welcome choice t' have. Yank Enterprises has recently introduced an altitude package for their kits. Ahoy! Avast, me proud beauty! This package includes a drogue parachute, a second shock cord, me bucko, and t' necessary components and hardware t' add dual deployment recovery t' your model. Yank Enterprises also offers custom fabrication -- at this time, fins and parachutes can be made t' your specifications. 

Quality components, workmanship, arrr, shiver me timbers, and a sound design make t' Yank Enterprises three-inch Iris a kit worth lookin' into. Avast! Visit their web site at http://www.yankenterprises.com

Written and submitted by Al Casper for Rocketry Online -- Copyright 1996-2000 
 

comment Post a Comment