lalligood
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I ordered a U.S. Rockets Stiletto a couple of weeks ago & have been working on it for the past few days... Only good things to report so far. Overall it is a 4" diameter 5FNC rocket that transitions about halfway along its length to 2.7" diameter. It also has a LARGE balsa nose cone. The Stiletto could be fairly easily modified for dual deployment. For being a rather tall rocket (~6ft), it can be worked on in smaller spaces because it's built in essentially 3 main pieces. No single piece of tubing is longer than 18" so the host mount & TTW fins are in one section, the transition from 4" to 2.7" tubing is the second section & then the payload bay/nose cone is the third section. Oh yeah, I almost forgot--there are a TON of parts!
My attraction to the Stiletto is that it has a transition that is a shroud formed from the larger 4" diameter tubing. USR is the only company that I know of that has this feature in any of their builds. This technique can be used to form not only transitions but boat tails & even nose cones--both of which can be found on their El Lubbo kit (I also happen to be in the finishing stages of that kit too!) The transition is made by cutting out several wedges around one end of the tube, then folding & gluing it to the smaller diameter (2.7") airframe tubing. Constructing the transition is probably the single most time consuming task during the build. Patience here is a must. Expect small gaps between these pieces and to be a little creative in finding a way to fill them.
Another standout feature is the interchangable motor mounts. The kit comes with sub-assemblies for 1 x 38mm, 1 x 29mm, & 4 x 24mm. Optional mounts include 3 x 29mm & 1 x 54mm. The sub-assemblies fit into a 2.7" mount in the main airframe. Friction fit with masking tape is sufficient however there is enough space in the aft 4" x 2.7" CR for a t-nut/screw/hook to clamp it mechanically.
Bulletproof motor retention on the 38mm & 29mm mounts can be done with masking tape. How? Well, with RMS casings in particular (which of course have a built in aft thrust ring) you can assemble the motor, slide it into the mount & then wrap masking tape generously & easily around the casing on the FORWARD end so that the casing cannot come out. (Look for pics of this soon...) Retention on the clustered mounts can be done by simple friction fit or mounting an all-thread rod with nut & washer in the center of the motor tubes for those wanting greater assurance. Regardless of which mount you use, you can secure the motors and then place the mount into the aft end of the rocket. Very, very cool...
I did make one small modification to the design: The instructions call for nose cone ejection. Transporting a 6 foot long rocket that doesn't come apart somewhere in the middle is not convenient or acceptable to most folks. Not to mention I personally *dread* having to paint anything that is longer than 3 feet. Breaking this rocket up was a must for me. I chose to not glue the (very robust I might add) 2.7" coupler into both 18" long 2.7" heavy gauge tubes. Instead I cut a bulkhead from 1/8" birch & glued it inside the coupler giving me a nice payload section. There is still 15" available in the other tube for wadding, shock cord, & chute (which the builder is expected to supply on his own). There is a baffled bulkhead to keep the chute from getting stuck down in the larger airframe section, but it is still close enough to the motor mount that wadding (or in my case, Nomex heat shield) is needed.
All parts are robust yet lightweight, typical for USR kits. Plan is to launch it in a couple of weeks. I want to challenge myself by seeing how fast I can launch it consecutively on a 29mm motor (probably H238T) & then a 38mm motor (Pro38 I205). Why? Because it will be so easy to do with those motor mounts!
Pics & more notes from the build desk soon... Here's a parts pic though. Wow! Look at all that stuff
My attraction to the Stiletto is that it has a transition that is a shroud formed from the larger 4" diameter tubing. USR is the only company that I know of that has this feature in any of their builds. This technique can be used to form not only transitions but boat tails & even nose cones--both of which can be found on their El Lubbo kit (I also happen to be in the finishing stages of that kit too!) The transition is made by cutting out several wedges around one end of the tube, then folding & gluing it to the smaller diameter (2.7") airframe tubing. Constructing the transition is probably the single most time consuming task during the build. Patience here is a must. Expect small gaps between these pieces and to be a little creative in finding a way to fill them.
Another standout feature is the interchangable motor mounts. The kit comes with sub-assemblies for 1 x 38mm, 1 x 29mm, & 4 x 24mm. Optional mounts include 3 x 29mm & 1 x 54mm. The sub-assemblies fit into a 2.7" mount in the main airframe. Friction fit with masking tape is sufficient however there is enough space in the aft 4" x 2.7" CR for a t-nut/screw/hook to clamp it mechanically.
Bulletproof motor retention on the 38mm & 29mm mounts can be done with masking tape. How? Well, with RMS casings in particular (which of course have a built in aft thrust ring) you can assemble the motor, slide it into the mount & then wrap masking tape generously & easily around the casing on the FORWARD end so that the casing cannot come out. (Look for pics of this soon...) Retention on the clustered mounts can be done by simple friction fit or mounting an all-thread rod with nut & washer in the center of the motor tubes for those wanting greater assurance. Regardless of which mount you use, you can secure the motors and then place the mount into the aft end of the rocket. Very, very cool...
I did make one small modification to the design: The instructions call for nose cone ejection. Transporting a 6 foot long rocket that doesn't come apart somewhere in the middle is not convenient or acceptable to most folks. Not to mention I personally *dread* having to paint anything that is longer than 3 feet. Breaking this rocket up was a must for me. I chose to not glue the (very robust I might add) 2.7" coupler into both 18" long 2.7" heavy gauge tubes. Instead I cut a bulkhead from 1/8" birch & glued it inside the coupler giving me a nice payload section. There is still 15" available in the other tube for wadding, shock cord, & chute (which the builder is expected to supply on his own). There is a baffled bulkhead to keep the chute from getting stuck down in the larger airframe section, but it is still close enough to the motor mount that wadding (or in my case, Nomex heat shield) is needed.
All parts are robust yet lightweight, typical for USR kits. Plan is to launch it in a couple of weeks. I want to challenge myself by seeing how fast I can launch it consecutively on a 29mm motor (probably H238T) & then a 38mm motor (Pro38 I205). Why? Because it will be so easy to do with those motor mounts!
Pics & more notes from the build desk soon... Here's a parts pic though. Wow! Look at all that stuff
