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Old 05-20-2020, 03:38 AM
K'Tesh's Avatar
K'Tesh K'Tesh is offline
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Talking Avengers Assemble! Estes K-38 and 1238 sims

Avengers Assemble! (or is it Assemble Avengers?) Anyway, it's up to you... The sims for the Estes Astron Avenger (K-38) and the later Estes Avenger (1238) are now completed.

Not only did the kit show up in 1969's Estes Catalog, I had this sim (mostly) done over two years ago, but somehow managed to forget about uploading it. Apogee just uploaded a video that featured the kit, which reminded me of the sim.

Here's the facts: Special tricks? None, they're straightforward kits. As such, these sims are ready to give flight performance details.

Originally, the fins were made from two different thicknesses of balsa. This is not a mistake. The booster's were 1/8" thick, and the sustainer's were 3/32". Fin dimensions were derived from the known length of the booster's body tube. By the time that the instructions found on Estes' website came out, the fins were changed to have a consistent 3/32" thickness, though they were still hand cut.

The kit definitely came in at least two variants, most likely more. The original version of the kit, like the first year of the Cherokee-D (K-47), came with a BT-55V (16.35") body tube. At some time later it was stretched by having a full length (18") BT-55 body tube. Another parallel to the Cherokee-D, the original version had the launch lug mounted on a wooden dowel standoff, which was sometime later removed. I suspect the change in length (and this is just a guess) occurred in 1971, coinciding with the Cherokee-D's discontinued use of the BT-55V.

The markings of the K-38 are based on the 1971 Estes Catalog. The markings of the 1238 are from the instructions found on Estes's site. The 1971 catalog has a length consistent with the original version, and again like the Cherokee-D, the length was never updated despite the addition of over 1 1/2" at some time. My photographic analysis of the catalog shows that the length of the catalog models never changed, and likely were just recycled photos of the same model found in the 1971 catalog. An oddity in the catalog model is that the launch lug appears in several catalogs. I've seem to remember reading somewhere that many of the catalog models didn't actually have launch lugs applied.

Sometime before it stopped production in 1981, it changed from a BNC-50Y to the blowmolded version of the PNC-50Y nosecone. The style of parachutes changed as the kit evolved over time

The instructions for the K-38 version are available from JimZ's site.
The instructions for a later 1238 version can be found on Estes' website.
I'm certain that there are more than two variants of this kit out there. I'm looking for instructions that don't match either JimZ's site or or are found on Estes' site (though new ones of JimZ's would be nice too).

Laser cut fins are available from eRockets.

The blowmolded PNC-50Y nosecone can now be found in the Estes Tazz kit, but you'll need least two of them ('cause the Tazz looks like a ton of fun). I'd try either eRockets or BMS for the balsa nosecone.
Attached Files
File Type: ork Estes Astron Avenger (K-38).ork (7.9 KB, 6 views)
File Type: ork Estes Avenger (1238).ork (6.7 KB, 4 views)

Dreaming of making the rockets I dreamed of as a kid (and then some).

"The Guide says there is an art to flying", said Ford, "or rather a knack."
"The knack lies in learning how to throw yourself at the ground and miss."

Launching is Optional... Landing? That Depends on Trees.
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Old 05-20-2020, 06:39 PM
5x7's Avatar
5x7 5x7 is offline
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A Taz should give you a ton of the parts too. I asked Estes if they would sell me 10 PNC -50Y nosecones and they politely declined.
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