lalligood
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I started working on the first of 3 USR kits in the past few days. I started with the Miniroc 1.2 because it was the simplest & smallest of the 3 kits to build.
A full review for EMRR is in the works but I thought I'd give an early preview here (especially since it'll be 2 or 3 more weeks before I get to fly it!)
The Miniroc 1.2 is a 29mm MMT 22" tall minimum diameter 4FNC rocket that's about the same size as many LPR kits but can break Mach on a high thrust G or go over a mile on a long burning G motor! Items of note are solid balsa ogive shaped nose cone, 1/16" birch plywood fins, heavy duty yet virtually seamless/spiral-less tubing (apparently a USR trademark), and streamer recovery. A 24mm motor adapter is included as well so that it can be flown with low & mid power motors.
Construction really didn't take very long and I simply followed the instructions. I used yellow wood glue (aliphatic resin) exclusively for the build. Yellow wood glue is still stronger than the wood and/or cardboard materials themselves but doesn't have the weight penalty of epoxy.
First was shaping the fins. I was blown away by the high quality of the wood but a little disappointed that none of the fins seemed to be the same size. However, my Dremel with a sanding drum made short work of sizing them up and had a matched fin set in a couple of minutes. In fact, it took me longer to airfoil the leading & trailing edges than to resolve the original issue.
Next, the body tube was marked with help from the included fin template for fin placement. The fins were tacked on one at a time and then filleted. With everything dry, the only detectable flex is from the tubing flexing--NOT the fins.
There is a payload bay on the Miniroc 1.2 too. The lite ply bulkhead needed to be sanded a fair amount to fit inside the coupler. Thankfully my Dremel made quick work (again) of this. The bulkhead with screw eye was glued and filleted into place. The coupler subassembly was then glued into one end of the payload tube.
The balsa nose cone only needed some minor sanding on the shoulder to provide a snug but not too tight friction fit. A little nose weight is necessary to keep stability for large motors.
I have been wanting to build an inexpensive Mach buster for a while so if you're going to do something, do it right. No launch lugs or rail buttons. This one's gonna go from a tower (which would also be a first for me). Save the lugs for another project...
Recovery is a long piece of 1/4" elastic attached to the screw eye in the payload and the tried-and-true 3-fold attachment inside the body tube. A 3" x 48" neon pink plastic streamer should be more than adequate to bring it down safely. It will be attached by snap swivel (not included with kit). In fact, the Miniroc 1.2 is so robust that I bet you could fly it without a streamer on C11s or D12 & not suffer any damage on impact.
Which reminds me that there is a 24mm motor adapter that consists of 2 tubes that nest inside each other. Masking tape is required to create a thrust ring & snug fit as well. There weren't any instructions on assembling it, but I had the necessary information from building one when I built the USR Banshee a while back. Same thing, different rocket.
The balsa nose cone has been coated with finishing epoxy & the fins will be smeared with diluted Elmer's Fill 'n' Finish sometime soon. Primer & paint are in the near future... Paint scheme is probably going to be yellow & black.
That's about it for now. Pics soon to come.
A full review for EMRR is in the works but I thought I'd give an early preview here (especially since it'll be 2 or 3 more weeks before I get to fly it!)
The Miniroc 1.2 is a 29mm MMT 22" tall minimum diameter 4FNC rocket that's about the same size as many LPR kits but can break Mach on a high thrust G or go over a mile on a long burning G motor! Items of note are solid balsa ogive shaped nose cone, 1/16" birch plywood fins, heavy duty yet virtually seamless/spiral-less tubing (apparently a USR trademark), and streamer recovery. A 24mm motor adapter is included as well so that it can be flown with low & mid power motors.
Construction really didn't take very long and I simply followed the instructions. I used yellow wood glue (aliphatic resin) exclusively for the build. Yellow wood glue is still stronger than the wood and/or cardboard materials themselves but doesn't have the weight penalty of epoxy.
First was shaping the fins. I was blown away by the high quality of the wood but a little disappointed that none of the fins seemed to be the same size. However, my Dremel with a sanding drum made short work of sizing them up and had a matched fin set in a couple of minutes. In fact, it took me longer to airfoil the leading & trailing edges than to resolve the original issue.
Next, the body tube was marked with help from the included fin template for fin placement. The fins were tacked on one at a time and then filleted. With everything dry, the only detectable flex is from the tubing flexing--NOT the fins.
There is a payload bay on the Miniroc 1.2 too. The lite ply bulkhead needed to be sanded a fair amount to fit inside the coupler. Thankfully my Dremel made quick work (again) of this. The bulkhead with screw eye was glued and filleted into place. The coupler subassembly was then glued into one end of the payload tube.
The balsa nose cone only needed some minor sanding on the shoulder to provide a snug but not too tight friction fit. A little nose weight is necessary to keep stability for large motors.
I have been wanting to build an inexpensive Mach buster for a while so if you're going to do something, do it right. No launch lugs or rail buttons. This one's gonna go from a tower (which would also be a first for me). Save the lugs for another project...
Recovery is a long piece of 1/4" elastic attached to the screw eye in the payload and the tried-and-true 3-fold attachment inside the body tube. A 3" x 48" neon pink plastic streamer should be more than adequate to bring it down safely. It will be attached by snap swivel (not included with kit). In fact, the Miniroc 1.2 is so robust that I bet you could fly it without a streamer on C11s or D12 & not suffer any damage on impact.
Which reminds me that there is a 24mm motor adapter that consists of 2 tubes that nest inside each other. Masking tape is required to create a thrust ring & snug fit as well. There weren't any instructions on assembling it, but I had the necessary information from building one when I built the USR Banshee a while back. Same thing, different rocket.
The balsa nose cone has been coated with finishing epoxy & the fins will be smeared with diluted Elmer's Fill 'n' Finish sometime soon. Primer & paint are in the near future... Paint scheme is probably going to be yellow & black.
That's about it for now. Pics soon to come.
I liked the stickers so I put some of them on too...
