I've been attempting to come up with dimensions for the Honest Ivan - the famous 7-engine cluster that was built by G. Harry Stine and his cadre of pioneer model rocketeers, and launched on September 30, 1958. I'm spinning this thread off of https://forums.rocketshoppe.com/showthread.php?t=20417 that inspired me to attempt to build a reasonably good facsimile of the original Honest Ivan rocket.

I'm sure that cloning the Honest Ivan is nothing new. Over the past 60+ years, I speculate that at least one person, somewhere, somehow tried to build an Honest Ivan rocket. I know that I kinda sorta wanted to build one ever since I first saw that photo of G. Harry Stine with the Honest Ivan in the Handbook of Model Rocketry. It's not a great design, nor is it particularly handsome. Clustered with a bunch of A-motors, it certainly not a high-performance design. It was one of a kind. What appeals to me is that it was the first of its kind, and that it is a big clunky rocket from the early days of model rocketry. G. Harry Stine wrote, "I don't recommend that anyone who reads this try to duplicate it." Yeah...right....

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__________________
-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President

There's not much in the way of "plans" or "dimensional data" for the Honest Ivan. In the http://www.ninfinger.org/rockets/Mo...04n03_12-71.pdf , G. Harry Stine wrote that "...Honest Ivan had no parts list. It wasn't 'designed.' It happened. We never bothered to measure." The only dimensional data that exists is knowing that the fins were cut from 3/32-inch by 3-inch wide balsa sheet.

I made line drawings of the fins, body tube, and nose cone by tracing over the top of that photo of Harry with the Honest Ivan. Assuming that the chord of the fins was 3-inches, I used that dimension to scale up the line drawing to full size.

I also compared my fin and nose cone line drawings to another photo (see attached) to see if they matched. They did match.

The main airframe - that being the "big tube" portion of the airframe to which the motor cluster and nose cone were fitted - did not match. I puzzled about this for a bit until I realized that the Honest Ivan power pranged on its second flight. The Honest Ivan was repaired, but it ended up a little shorter. The rocket that Harry is displaying is the retired, shorter Honest Ivan. The prototype shown just prior to launch shows the original model.

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__________________
-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President

My estimated dimensions (so far) are as follows:

Overall length ~36-2/3 inches
Main airframe length ~25 inches
Main airframe diameter ~ 1.9–2.1 inches
Nose cone length ~ 5.1-5.2 inches
Nose cone widest dimension ~2.5 inches
Exposed section of motor mount tubing ~3-1/4 inches

The main airframe was a mailing tube. I favor the larger tube dimension for the airframe diameter because I had trouble seeing where the edge of the tube was in the ultra-zoomed in, grainy photo of Harry with his rocket. The photo of the Honest Ivan being prepped for launch had some better contrast between the sky and the rocket and from that I estimated the larger diameter. In that other thread, Dave Fitch estimated a main airframe diameter of 2.25-inches (2-inch mailing tube). I am inclined to agree with that estimate. The next common size up and down for mailing tubes (even back in 1958) don’t fit. Note that these estimates put the diameter into BT-70 territory which George Gassaway (in the other thread) estimated as being close to original.

The motor mount tubes were most likely Model Missile Industries (MMI) tubes, which later became Estes BT-40 tubes. There were no BT-20, -30, or -50 tubes back in those days. It looks like they were crammed into the aft end of the airframe because the cluster didn’t quite fit. You can see in closeups how the end of the airframe was slit and flared, and that motor mount tubing projects beyond the outer diameter of the main airframe. Either that, or we are looking at damage from that power-prang. Dave Fitch described the motor cluster to be constructed similarly to the Semroc Hydra 7 (another 7-motor cluster). That seems about right to me. Or... it's just damaged from the second flight.

__________________
-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President

Wolf,

This is going to be very cool . . .

I hope you take lots of pics during the build . . . This could be a great article for Sport Rocketry !

For the sake of "continuity" from the other thread, I reposted my files here, from the other thread, plus the SEMROC Hydra VII instructions, for reference.

Dave F.

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hydra_vii_instructions_ikv-29_.pdf (1.77 MB, 9 views)