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Old 12-07-2017, 09:55 PM
luke strawwalker's Avatar
luke strawwalker luke strawwalker is offline
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Join Date: Dec 2007
Location: Needville and Shiner, TX
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Quote:
Originally Posted by the mole
I have been looking at all 30 ant-scale Dr Zooch rockets and I was just wondering if anyone ever
made a list of what scale each rocket is? It's nice to see the new SpaceX Falcom.


If you ask Wes, you'll get the "typical" answer that he always gives... something along the lines of "the scale is 1/8 fathom to 1 furlong" or thereabouts...

Wes makes "semi-scale" kits... IOW they are not PRECISELY "true to scale" in the sense of a competition scale model rocket. Wes got a LOT of grief from some scale nuts who haunted the forums years ago (some of whom still do, at least at TRF, though one tends to haunt this place as well) who were basically "rivet counters" and were being picky, snarky pricks about the fact that "this or that" was "wrong" on his kits. He had said he never SAID they were "scale kits" NOR INTENDED FOR THEM TO BE (at least in a rivet-counting, competition level sense of what a "scale kit" is SUPPOSED to be... hence why they are termed "semi-scale" or in his particular form of branding, "ant-scale"...

SO, if you want to "do the math" you certainly can... it's easy enough to look up the prototype (original full-size rocket on which the model is based) and get a dimensioned drawing, and then compare the size of the original to the "ant-scale" model... It's just simple division to determine the answer...

For instance, the Dr. Zooch Saturn I-B is based on a BT-60 upper stage tube, which represents the S-IVB stage used on the Saturn V and Saturn I-B. The S-IVB stage was 260 inches in diameter. The BT-60 tube is 1.637 inches in diameter, so dividing 260 inches by 1.637 inches, we get 158.8, so the scale would be 1:159 or 1/159th scale... The Zooch Saturn V uses a BT-60 tube to represent the S-IC and S-II stages; the S-IC was 396 inches in diameter in real life. Dividing it out again, 396/1.637 equals 241.9, so the scale would be 1:242 or 1/242 scale. Similarly, the Dr. Zooch Return to Flight Space Shuttle model uses a BT-60 tube for the External Tank, which is 27.6 feet in diameter (multiplying by 12 so we're in the same units, is 331 inches in diameter...) Dividing it out, 331/1.637 equals 202.2, so the scale would be 1:202 or 1/202 scale. The SRB's on the Zooch shuttle are BT-20 tubes, which are 0.736 inches in diameter. The real SRB's on the shuttle were 146 inches in diameter (a hair over 12 feet in diameter) so dividing that out, we get 146/0.736=198.4... or 1/198 scale... Why the difference, you might ask?? Well, because if you're going to use "standard" size tubes, which is necessary to produce a mass-marketed kit released to the public for sale and keep it affordable, then you have to "fudge" the numbers a bit sometimes... sometimes close is close enough... (after all, we're talking about "SEMI-scale" or "ant-scale" models here, NOT "Internats ready" level competition scale rockets, despite what the 'rivet counters' might say...

SO, all you really need to know to figure the scale is one dimension, preferably the main stage diameter (as that is the easiest dimension to "accurately" scale from) and know what tube is used to represent that stage in the kit, either by measuring it directly, or looking up the kit specs online. (Diameter is the least likely to "change" during turning a prototype into a mass-produced kit for sale to the public, which has to have enough stability built in so that REGARDLESS of how heavy or light someone builds it, or if they screw up the build, that thing has an almost foolproof chance of "flying right" in the end, regardless of the builder's skill (or lack thereof)... This sometimes requires "fudging" the numbers a little more and making fins oversize, or adding a little length to the kit to give it better stability or make it fly 'less squirrely" or adding weight to the nose, or various other tricks used in designing rockets... Which of course can change the "scale" one gets when one "calculates the scale"... the other thing to keep in mind is one MUST have the same units of measurement when one compares the prototype diameter and tube diameter... IOW, you can't mix metric and standard inches, or divide the stage diameter in feet by the tube size in inches... won't work.

Anyway, any more specific questions I'll see if I can help... or I've got a TON of Dr. Zooch build threads here on the forum that can probably be found pretty easily, in which I go over a lot of this sort of thing on a kit-by-kit basis... and since I was a beta-builder for Wes at Dr. Zooch, I got my hands on a lot of his kits before anybody else did...

Later and hope this helps! OL J R

PS. BTW, what's nice about the Dr. Zooch Saturn IB, which uses a BT-60 for the S-IVB, is a BT-80 is nearly a perfect match to represent the S-IC and S-II stages for a BT-80 size Saturn V, which is a real nice "in between" size between the 1/100 and the 1/242 BT-60 size Dr. Zooch Saturn V kit... and since it uses the same BT-60 for the S-IVB, the same LEM adapter, Apollo CSM, and tower from a Zooch Saturn IB can be used to make the upper stage and spacecraft for the BT-80 Saturn V... which is why I have a build thread on my "BT-80 Saturn V and Saturn I-F" (which was a notional idea NASA studied to replace the Saturn I-B) that I've been working on and off for for a few years... the thread is here in the scale section...
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