Christmas Matchbox Magic: a 61a Ferret Scout Car story

[Idris]

...a nice little army of Ferrets you have...

The collective noun for ferrets is actually a business (or, more correctly, a busyness).

[Malibu]

Stephan, you asked about what letters are cast on the base. Of the five models two are later examples with the raised ejector ring on the base and a letter cast. One of the has an "A" and the other has the "N" or "Z" depending on how you look at it.

So nothing new there.
Thanks for looking.

Stephan

[matchboxuk]

Happy New Year, Greg

Somewhere in the back of my mind I seem to recall that it was possible to fit the base of 61a upside down or inside out and models have been found with an unpainted plain base showing, whilst the interior face showing Made in England on the base was painted black. If this error was spotted on the assembly line it would just be returned for painting and the model would be black on both sides.

But then again I might have had too much turkey .........

[Tinman]

Those wheel sizes: Over the years, various collectors keep finding wheel sizes that were not cataloged. Nick used the Stannard as the starting base for his list, thus some errors and omissions were carried over.

Some of the tread counts have been corrected but many of the wheel diameters fail to make it into updates. One reason for these inaccuracies is that the original sizes were not in millimeters and so some of the sizes have been rounded up and rounded down. To the best of my knowledge, none of the catalog authors in the last 20-25 years have measured any wheels and come up with more accurate size information. The same old rounded up and down measurements (from various authors and contributors) keep making the rounds.

One person sees a caliper reading that's slightly less than .5 mm and they round down. Another man rounds up to .5 mm. Another wheel's diameter moves the slide over .5 mm and same thing occurs. Different people reading the scale have resulted in different recorded measurements.

The plastic tire hubs have shrunk over time, it's possible some batches of plastic used to make solid wheels have also shrunk. No one can prove this because there is no base record to go from.

Another equally likely possibility is that the wheel molds/tooling was fairly precise (key word here is fairly/mostly/nearly), but it didn't need to be to aircraft standards. Since you need four to eight (or more) wheels for every one model, a ton of wheels were being made and lot of nearly identical molds required. When you are making that many wheels, tooling wear would be a factor and could account for slow minute size increases.

Shrinkage? Tooling wear? Molds being tooled to sizes ever so slightly different than the last tool? All of the above? Who knows.

I seem to be constantly removing and measuring wheels. For the ones I don't use right away, they get stored first by diameter (and next by tread count). I've pulled four (or more) wheels off of some models and discovered all of them were close to the same size but some varied by as much as three tenths of a millimeter. That's well within the range to round up or down the recorded diameter size of a specific wheel. Rounding/up or down all the wheels on one model gives you recorded sizes of .5 mm difference yet they are still close enough that the model sits and looks fine.

Instead of driving myself crazy with the issue, I have decided wheel diameters are much like paint shades and that it is impossible to catalog them all.

That said, when there is a clear difference of at least .4 mm, then I call it a different size diameter. Then there is the issue of the person using the caliper and how accurate are they sizing the wheel. How accurate is their caliper? Many of us remember how Mark Curtis argued about wheel diameters and then we found out he was using a cheap plastic caliper from a $1 tool bin LOL.

How many people used a micrometer VS a caliper? Were the wheels measured off the model or on the model? If the latter, the body forces a caliper to use the narrow part of the tip and the body can block good measurements. How many people store their caliper and/or micrometer with the surfaces tightly together (which is a no no and can cause them to go out of calibration)?

It's a wonder that most of the recorded measurements are as accurate as they are. I also feel compelled to note that you cannot measure any wheel that has seen any play (or use) and expect a measurement that is accurate.

After all that, I come back to my thoughts that wheel diameters are much like paint shades and that it is impossible to catalog them all.

[Idris]

An excellent post, Joe.
All I would add is that we do not know whether it was the tooling or the end product which was designed to have the target diameter. My guess would be that the tooling had the exact diameter since this would simplify the engraving process which involved scaling down from a large-scale wooden master. That being so, no allowance for shrinkage was made, so a nominally 3/8" diameter wheel would actually turn out a smidgen less than that.

[matchbox_n_molars]

That is an impressive lesson on factors to consider with wheel sizing. Thank you JP, for the time you put into that.
Hey, did they spring you? Are you home and feeling better?

[Tinman]

That is an impressive lesson on factors to consider with wheel sizing. Thank you JP, for the time you put into that.
Hey, did they spring you? Are you home and feeling better?

I am in fact home and feeling better. Far from well, but much better (thanks for asking).

[Miller]

Thanks for this clarifying post, Joe! My displays are exploding for more and more variations and i´m happy that there are not going to be even more for wheel sizes!