Rocket R&D 3.9 Standard Arm

This Rocket from J.R. and Gary at Rocket R&D was a fun rocket to build.  Currently it is awaiting some decals to finish.  We hope to fly this rocket this year at the April event at Colorado Tripoli's Hartsel.  Overall, the kit was easy to build, had great directions, and is built like a tank. The fins go into precut openings in the main body tube, to special blocks of wood that glue to the engine mount.  When the epoxy hardens, the bond is so strong, even an accidental drop of the rocket on the floor didnt do any damage to the fins.

This is how the kit comes.  The instructions are top notch, and very easy to follow.  The parachute that comes with it is very durable and will work just fine.  My only concern is that due to the electronics bay (kit wasnt designed for a bay), the rocket will be to heavy for the current parachute, so an upgrade is in the future.  The parachute mount consists of a braided cable, a large bungee cord and two metal couplers.  The parachute mount is mounted to the top centering ring of the engine mount via predrilled holes for the braided cable.  All the fin slots were precut.  I was suprised on the quality of the workmanship of this rocket.  I would recommend this rocket to anyone, the quality of Rocket R&D kits far surpasses any other that I have assembled.







Here you can see the tail surface while the last fin is setting.  I just used a piece of packing tape to hold the fins straight on my home made rocket stand.  





The hardest part of this kit was the mounting of the strakes.  The wood used in these are quite long, and very thin.  They came warped slightly in the kit, and thus made for a difficult mounting.  I had to construct the jig you see here that attached to the main fins, to keep the strakes straight.  The results were okay, there is a little bend here and there, but overall it worked great.  If you build this kit, I would assume you would need something like this.  One thing about this rocket I didnt realize until I got to the fin fillet step, is how much fillets you have to make.  The strakes and fins combine for alot of epoxy needed.  A couple trips to the hobby store for more epoxy and everything was done.

UPCOMING!!
Completed 3.9 Standard Arm and Launch pictures.  Currently the rocket is painted and is awaiting decals.  I have tried the make my own decals using decal paper and a laser color printer (Kinkos) without much luck.  I am going to purchase an Alps printer with the dry ink and see if that is okay.  If anyone has any ideas or suggestions please email me at B&M Rockets!!