BSD High Power Rocketry - Intrepid {Kit}

Contributed by Eric Fadely

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: BSD High Power Rocketry
BSD Rocketry Intrepid

Brief:
The BSD Intrepid is a 2-stage interchangeable high powered rocket. Versions can be 38mm boost to a 29mm rocket, a single stage 29mm rocket, or a single stage 38mm rocket. Dual deployment was altered and timer bay was added by the builder.

Construction:
Body tube material is the typical glassine coated cardboard. Fins and bulkheads were aircraft quality 3/16" plywood. I had to make extra bulkheads to manufacture the modified electronic bay and timer bay. The kit included plastic rivets, rail buttons, 9/16" tubular nylon shock cord, and BSD's motor retention system. Since the possibilities for recovery were so varied, I was required to provide my own parachute. Attachment hardware was also included.

PROs:

  • The kit, as advertised, is a very simple kit to construct.
  • The instructions were well above average. The 10 page booklet guided the builder through the process of safely building the rocket. A multitude of photos, not drawn pictures, helped show each step. Additional tips were also added to such things as applying fillets to fins and launch lugs.

CONs:

BSD Rocketry Intrepid
  • Although a very good kit, there are a couple of things to think about before building. Building the electronics bay needs a little thought before assembling. As bought, you are required to reach into both the main and drogue airframes to insert and/or attach the deployment charge. The instructions didn't give much information on how to use the e-bay. I ended up cutting a 3" band of airframe from the drogue tube then I epoxied it exactly halfway down a coupler tube. A bulkhead is then epoxied inside one end of the coupler. I manufactured a support ring from another coupler bulkhead and cut the center out leaving about 3/8". I used this as a shelf to set the removable bulkhead on with a rubber gasket. On both bulkheads I epoxied a 1" PVC pipe cap to be used as a cup to hold my ejection charge, a 2 bus connector that would accept a wire from my Missile Works RRC2 (with the wire threaded through a hole drilled in the bulkhead and epoxied to seal it and then the eye bolt to hold the tubular nylon recovery. The removable bulkhead was retained in place by 2 threaded bolts epoxied to the permanent bulkhead. The all-thread passing through the bay allowed for holding the RRC2 on a wood sled with launch lugs big enough to slide over the bolts and into the bay.
  • BSD Rocketry Intrepid
  • The kit's instructions didn't really cover the installation of a timer, which of course is needed to use this rocket in a 2 stage configuration. I added a bay in between the sustainer fins to keep it close to the motor it will light. I used a small brass tube to connect the bay to the aft end of the rocket. I also didn't like the arrangement of the sustainer to booster mating. More on that in the flight critique.

Finishing:
PROs:

  • No special considerations were needed for the finish.
  • The vinyl decals are great! They are so much better than the waterslide type. BSD provided plenty of extra decals such as CP, CG and Vent hole decals.

CONs:

  • With vinyl decals you had better be sure you are putting the decal where you want it. If you put it on wrong you will stretch it when trying to pull it off.
  • As with all decals, if you do not put a clear coat on top of them the lifespan is shortened. I found that vinyl decals it will start peeling, which is my fault, not BSD's. If I were to reconsider anything I would have slowed down and put a few clear coats on the entire rocket, but I was eager to fly it!

Construction Rating: 4 out of 5

BSD Rocketry Intrepid

Flight:
The recommended motors per the BSD website are: Booster: 38mm; I211, I284, J350; Sustainer: 29mm; H128, H180, I200. On the first flight I used a Pro38 I205 staged to an AT H238. Prior to this I had ZERO timer experience. The boost was good but the sustainer failed to fire. My second try was with the same set up. The altitude was only 1900', not too impressive for a 2 stage rocket. My third shot was with a J350 in the booster and an H180 in the sustainer. This was the best flight I have done. Straight as an arrow up, good staging to 3200', and a good recovery.

BSD Rocketry Intrepid The only CON to this rocket in flight is the sustainer/booster set up. The motor mount in the sustainer is designed too far up into the body tube. When the second motor lights, the interior of the tube was severely scorched preventing any future mate up with the booster. Next time I would either redesign the mate up, coat the interior of the sustainer portion with epoxy or fiberglass or use a small BP charge to separate the booster from the sustainer prior to ignition. A little forethought on my part would have prevented this. BSD should either add this caution in the instructions or design a cleaner mate up assembly.

Recovery:
The recovery was pretty straightforward. The drogue separated at apogee and the main came out at 300'. The only CON is the amount of room that is provided for a parachute when big motors are used in the booster. A little imagination is needed to get a chute packed enough to insert the coupler/bulkhead. The motor forward closure was only about an inch from the bulkhead. Sustainer recovery I rate as a 4 (due to e-bay redesign) but the booster should be a 2 1/2. A little more room is needed.

BSD Rocketry Intrepid

Flight Rating: 4 out of 5

Summary:
My overall feeling about the BSD Intrepid is that it is an wonderful rocket! With some HPR building experience behind you, this rocket is an easy kit to assemble and fly. It allows for a lot of modification if needed or desired. It was a great entry rocket for me into 2 stage rocketry.

Overall Rating: 4 out of 5

Flights

Comments:

avatar
Mark Saunders BSD High Power Rocketry Glendale, AZ http://www.bsdrocketry.com (January 12, 2005)
Thank you for the review of the Intrepid. You make an excellent point regarding the inter-stage coupler. We will add verbiage to the assembly instructions regarding scorching and staging. The bulhplate in the inter-stage coupler can be mounted lower to allow the sustatiner's MMT to move rearward to help reduce scorching. The best solution is to let the booster drag separate from the sustainer and add a second delay to the staging timer. This requires a less snug fitting of the interstage coupler to the sustainer. The objective is to let the sustainer "slip" off the booster and fall "out of harms way" before the sustainer motor ignights. A layer of Kevlar® on the inside of the inter-stage coupler and bulkplate is another alternative, but this does nothing to protect the lower sustainer airframe. Customer comments are always welcome. We will address the scorching issue with additional instructions and a review of the inter-stage coupler design. Thank you for supporting BSD.

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