Airfix Saturn 1b

[david sMiGielski]

Glenn at Realspace was nice enough to send me the AS-203 nosecap from his 1/144 Saturn 1b kit which I plan/planned to use on one of the Airfix kits I have. Test fitting, however, suggests that either the Airfix kit is undersized or the Realspace part is oversized (or I'm messing it up all on my own, in which case this is all irrelevant). Anyone have any thoughts?

[Hotdog]

Here is a pretty good explanation:

There are several glaring errors on the kit which seems par for the course with Airfix and rockets. There are quite a few sites around though that can help you build a much more accurate one if that's what you want, (which I do). The biggest problem seems to be that the CSM is noticably too narrow in diameter and that Airfix just plonked the S-IVB section from the Saturn V kit on top which is OK only the 1B used the smaller 200 style rather than the later 500 included in the kit. The CSM is also a block 1 rather than block 2 with different detail which was used by Apollo 7, the subject of this kit. The LM is also all over the place. A lot of folks are going to say, well it looks like a rocket so that's good enough for me, but somehow I can't...if you're going to do it then you may as well do it right.

So historically, there were two S-IVB stages and the earlier 200 version was smaller. The Airfix kit takes the larger 500 version from the Saturn V so it is inaccurate for an AS-203. I haven't seen the Realspace kit but I'm guessing he probably got it right where Airfix got it wrong.

Source:

http://www.britmodeller.com/forums/index.php?/topic/66833-airfix-vostok-and-saturn-1b-now-available/?p=742269

[Jay Chladek]

If you have one of the earlier boxings of the Saturn 1B, than yes it features a CSM that is a bit too slim. However, the currently available kit in the red boxing has the corrected Block 2 CSM that was introduced in the Saturn V a couple years prior.

As for the S-IVB, yes while the Saturn V's S-IVB had some different features, I do not recall the stages being dimensionally different between the Saturn IB and Saturn V. There were some different external features, such as those large fairings on the side of the Saturn V version and the V also had more helium spheres as I recall for ullage tanking to help with the J-2 engine's restart capability. But the stages were more similar than different (and it was a 200 series S-IVB that was converted for use as the Skylab OWS).

[spellbinder99]

I have to agree with Jay. Though different in detail the block 200 S-IVB of the Saturn 1B and the Block 500 S-IVB of the Saturn V are dimensionally identical. What sort of dimensional difference are we talking here?

Here are three Airfix S-IVB's, from both original issue and retooled kits. The AS-203 adapter is on an early issue unmodified S-IVB and the AS-204 is on a new issue red-box Saturn 1B. The right one is my re-detailed Airfix issue. The adapters are from Martins models and while not a drop in fit they are close enough that only minor fettling sees them mated up.

Cheers

Tony

Edited December 17, 2013 by spellbinder99