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REV 2.4 - Mon Dec 13 02:11:46 2010

Semroc
BatRok
Box 1271
Knightdale, NC 27545
(919) 266-1977
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SPECS: 12" x .759" - .6 oz
ROCKSIM FILE: Right Click to Download
SpaceCAD FILE: MISSING - please submit here
REC'D MOTORS: A8-5, B6-6, C6-7

Rating
(Contributed - by Joe Policy - 05/17/05) Semroc BatRok

Brief:
The BatRok is a Semroc Retro Repro series kit that is an updated version of the Centuri BatRok kit KB-8 from 1967. The original design was inspired by the original Batman television series and also includes a payload bay.

Construction:
The kit includes:

  • 1 body tube
  • 1 clear plastic tube
  • 1 balsa nose cone
  • 1 balsa tube coupler
  • 1 set laser cut fins
  • 1 thrust ring
  • 1 empty casing
  • 1 launch lug
  • 1 screw eye
  • 1 elastic cord
  • 1 Kevlar® thread
  • 1 plastic parachute
  • 1 set tape disks
  • 1 shroud line
  • 1 decal

Semroc does a remarkable job with the packaging of their kits. I have yet to find a single kit from them that was missing a part or has a part damaged. Also, the instructions are printed on quality paper and they even include a brief history about the rocket you are about to build.

The instructions take you through the build process in a logical order and are so well illustrated, you almost do not have to do any reading. The kit includes 8 laser cut fins, and the balsa is excellent quality. The lower fins looks like bat wings. The upper fins are rotate 90 degrees from the lower fins, so this rocket has an interesting profile when viewed from the top. I was a little concerned about the fin tips which extend below the body tube but so far they have held up quite nicely.

Finishing:
This is a small rocket, so it is very easy to paint. I originally went with all black until I realized the decals were black on clear so I masked off the fins and painted the BT a smoked silver color.

The light color balsa nose cone shoulder and tube coupler were a bit distracting for me after I finished the rocket--this rockets demands to be all dark. It is patterned after a bat after all. I used a black Sharpie marker to color the nose cone shoulder, however, I had already glued the coupler into the payload tube so it was too late to color that--poor planning on my part. So I masked off all but 5/16" of the payload tube instead and gave it a shot of black paint which masked the color of the balsa quite nicely. The waterslide decals are great quality, thick enough so they do not easily tear and very easy to apply.

Construction Rating: 5 out of 5

Flight:
First flight was on a A8-5. Since it was a bit windy, I replaced the parachute with a streamer. The rocket really zooms off the pad and got to at least 500 feet. Second flight on a B6-6 was really something. It weathercocked a little but a good boost overall to 900-1000 feet. I have not tried the C6-7 yet because I am afraid I might lose it!

Recovery:
The recovery system held up well through both flights. The streamer was a good choice for the windy day I was launching, both landings were close to the pad. I think a 12" chute on this small rocket would easily let it float way down range!

Flight Rating: 5 out of 5

Summary:
This is a great looking rocket that is very easy to build and a whole lot of fun to fly. This was one of the favorite rockets of the kids who were at the launch. It is just begging to be upscaled!

Overall Rating: 5 out of 5

[Submit your Opinion]

GUEST's OPINION:
09/06 - "A fantastic Semroc retro reproduction of the original Centuri BatRok which, at $11.00, cannot be beaten. The Semroc BatRok while visually identical to the Centuri BatRok has a new Kevlar®®/elastic shockcord for recovery and the fins are laser-cut. While the BatRok is fun and relatively easy to construct, be very careful when handling the fins as the balsa is very thin and will easily snap if handled roughly. Take your time when aligning and gluing both the top and bottom fins into place as it is quite easy to goof up with the alignment due to the BatRok's small ST-765 body tube and the above mentioned need to carefully handle the fins. Also remember to ensure that when the launch lug is glued into place that the launch rod will have a clear path between the top and bottom fins. Semroc's BatRok does Ron Maggiano (designer of the original Centuri BatRok) proud!!!" (P.D.)

[Enter Rocket Specific Tip]

SPECIFIC ROCKET TIP:
09/06 - "When prepping the BatRok for launch, the Kevlar®® and shockcord needs to be passed out from the BACK of the bodytube and attached to the nosecone so that with the nosecone in place, the Kevlar®® will fit flush against the outside of the bodytube. According to Semroc, the fins will tangle the chute unless it comes down in a reverse direction." (P.D. )

[Enter Flight Log]
Date Name Motor Ejection/
Altitude
Wind Notes
11-05-2006 George Beever Est SU A8-3 Apogee - NC Up 5-10 mph winds Event: SPAARSPAM-17
- Nice flight
11-11-2006 George Beever Est SU B6-4 Didn't See 5-10 mph winds - Out-of-sight flight!
09-17-2006 Peter Davidson Est SU A8-5 Apogee - Perfect Calm Vampyr - Maiden launch. Rocket HAMMERS even on an A8-5, easily cracked 400 feet. Straightforward recovery with no dramas, this rocket is DEFINITELY my top favourite!!!
09-28-2006 Peter Davidson Est SU A8-5 Apogee - Perfect Calm Vampyr - Great flight to watch with the rocket lifting off at terminal velocity. Easily cracked the 400ft mark, the rocket was nearly out of visual sight at apogee. Upon recovery, two squares of wadding were found still wedged in the bodytube, no damage.
10-01-2006 Peter Davidson Est SU A8-5 Apogee - Perfect Calm Vampyr - One hell of a terrific launch in excess of 400ft, rocket flight straight and true. Was able to catch rocket in-hand just before it reached the ground.
10-10-2006 Peter Davidson Est SU A8-5 Apogee - Perfect 0-5 mph winds Vampyr - Great launch to watch, rocket subsequently weathercocked badly and flew at a considerable angle. Still had no problems cracking 400ft, no dramas with recovery.
10-15-2006 Peter Davidson Est SU A8-5 Apogee - Perfect 0-5 mph winds Vampyr - Lovely flight to watch, rocket burst off the launch pad very fast. Rocket did land a little harder than usual upon recovery, no damage.
10-22-2006 Peter Davidson Est SU A8-5 Apogee - Perfect 5-10 mph winds Event: Albert Park Lake (AUSTRALIA)
Vampyr - Awesome super-fast launch. Rocket caught by BIG wind gust at apogee and drifted over 150 metres to land in the top of a tall rocket-eating tree. Was able to recover with Andrew Scott's help, no damage.
10-29-2006 Peter Davidson Est SU A8-5 None - Nose Cone Stuck 0-5 mph winds Vampyr - Drag-racing Andrew Scott's Semroc Javelin. Spectacular race but a stuck nosecone caused the BatRok to lawn dart. Only damage surprisingly a snapped-off canard, rocket temporarily retired for repairs.
12-28-2006 Peter Davidson Est SU A8-5 Apogee - Perfect 0-5 mph winds Vampyr - First flight after repairs with streamer in place of a chute. Beautiful flight with the rocket tracking dead-straight. Streamer slightly tangled in shockcord upon ejection, no recovery damage.
12-31-2006 Peter Davidson Est SU A8-5 Apogee - Perfect 0-5 mph winds Event: End Of 2006
Vampyr - Absolutely awesome flight, the BatRok looked a million dollars descending with its streamer deployed.
01-13-2007 Peter Davidson Est SU A8-5 Apogee - Perfect 0-5 mph winds Vampyr - Great flight with very slight weathercocking, easily in excess of 400ft despite varied wind speeds. Nice streamer recovery, no damage.
02-08-2007 Peter Davidson Est SU A8-5 Just Past (1-2sec) 5-10 mph winds Vampyr - Wind test, lovely straight flight. Elastic shockcord broke upon ejection with body tube and nosecone descending seperately. High wind speeds cushioned both upon descent, no damage.
05-13-2007 Peter Davidson Est SU A8-5 Apogee - Perfect 0-5 mph winds Vampyr - Awesome flight, very fast take-off. Faultless recovery on a 6ft streamer, no damage.
05-27-2007 Peter Davidson Est SU A8-5 Apogee - NC Down 10+ mph winds Event: Dandenong Wetlands (AUSTRALIA)
Vampyr - Wind test, one lovely flight. Recovered nicely on a streamer close to the launch area, no damage.
09-23-2007 Peter Davidson Est SU B6-4 Apogee - Perfect 5-10 mph winds Event: Dandenong Wetlands (AUSTRALIA)
Vampyr - Very nice high flight with straight boost, considerable drift during recovery despite using a streamer which made for a long walk. No damage upon retrieval.
03-30-2008 Peter Davidson Est SU B6-6 Apogee - Perfect 5-10 mph winds Event: Dandenong Wetlands (AUSTRALIA)
Vampyr - Perfect straight flight even in windy conditions, flawless recovery upon ejection. Rocket retrieved after a moderate walk, no damage.
09-30-2006 Chris Muir Est SU B6-4 Didn't Record 5-10 mph winds -
10-29-2006 Peter Stanley Est SU A8-5 Just Past (1-2sec) 10+ mph winds - It had a nice straight boost. I almost lost the rocket because of wind, despite cutting a huge hole in the parachute.
06-28-2008 David Wallace Est SU A8-5 Apogee - Perfect
(400 m)
0-5 mph winds Event: Jells Park
- Good first flight and soft recovery on streamers as others have recommended (and Exoskell needed the chute anyway :-)
   

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