Home | Links | Contact |

Printed from www.nzmeccano.com

Top Home Bottom

Part 31: Gear wheel 1''

31Gear wheel, 1'' 38 tooth 1919-442N°1040 tooth until 1921
Part 31, the 1'' gear wheel, post-war variation
Loading picture 31part

The parts

Part 31 is a lovely heavy solid brass gear, only ever supplied in the largest outfits (outfit 7, L, and 10).  They provide a 1:1 drive when paired together at 1'' spacing, and although they can be used with other gears at odd spacings this is unusual.  Since they are normally used in pairs, they can often be substituted by the multipurpose gear part 27f, introduced in 1970.

When first introduced in 1919, part 31 had 40 teeth.  These were only made for a couple of years, and are highly sought-after gears useful for making odd ratios in orreries and gearboxes.

Largest (1921-26) and smallest (1927-41) part 31 gears.
Both of these gears have 38 teeth, though.
Loading picture 31widths

Chronological variations

Other than the change from 40 teeth to 38 after the first two years of production, the main difference between different versions of these gears is in the outside diameter.  Initially 27mm (to fit the 40 teeth round), the gears stayed this size when the number of teeth were dropped to 38, leaving the gear effectively oversized.  In 1927, the outside diameter was dropped to 26mm, but this was a bit overzealous, and these pre-war gears don't mesh together very well. The photo above shows the largest (1921-26) and smallest (1927-41) versions of part 31.

The post-war variations increased in size a little to an intermediate size, around 26.5mm, making them work better together as pairs. Almost all of these gears are stamped Meccano, although the stamping ceased in the mid-70's.

Strange stamping on the boss of a pre-war part 31
This image does not belong to the webmasters and is copyright.
Please do not download or copy it for any purpose. It has been
kindly provided for use on this site by the image owner,
Ed Barclay
Loading picture 1ingearbackstamping

Variations and oddities

A real oddity on the stamping front is supplied by Ed Barclay.  This 1'' gear wheel is from a collection of 1930's Meccano, and is stamped on the face MFEA.  However, on the end of the boss we can clearly see Made in England.  This is a very unusual stamping, particularly for a pre-war part.

And now, Chris Mothershaw describes a very unexpected use for part 31:

I actually worked in the Binns Road factory for a couple of summers in the early '70s when I was a student.  I distinctly remember that we used to use 1" gear wheels to shim up the corners on wobbly pallets of castings: almost blasphemous. Chris Mothershaw

Dealer spare parts boxes

Individual part numbers

Part numbers for the parts on this page are as follows:    Unique part numbers
For identification, each variation has been given a suffix to the main Meccano part number. These suffixes consist of a two-character code for the colour, and if there are many variations, a further number and sometimes letter code to identify each variation. See the bottom of the 'Parts' page for further details.

You don't need to worry what the codes are, just click on any one for a photograph.

The button above turns on and off the display of DMS numbers (where they are known). The DMS (Development of the Meccano System, Hauton and Hindemarsh) published in 1972 and added to in 75 and 82, suggested part numbers for every variation of every Meccano part. These numbers aren't perfect, but they are recognised and also referenced in the EMP (Encyclopedia of Meccano Parts, Don Blakeborough).

More about bosses More about stampings More about paint colours
40 tooth, ¼'' face, 27mm o/a diameter19.br1
38 tooth, ¼'' face, 27mm o/a diameter21.br2
38 tooth, ¼'' face, 26mm o/a diameter27.br3
38 tooth, ¼'' face, 26mm o/a diameter, double-tapped29.br4
38 tooth, ¼'' face, 26.5mm o/a diameter, double-tapped46.br

Please send us pictures of missing parts! Hints and tips for pictures
Take a picture of the part in very good light, preferably on a plain yellow background, without a flash but with a tripod.
Ideally, trim the picture to about 150 pixels per inch of the Meccano part (unless the part is particularly big or small), save it as a reasonably good quality jpg file with a filename of exactly the part number, for example 19b.ni1.jpg, and email it to us by clicking on 'Contact us' at the top of the page. Thanks!

Further information

Total number of messages on this page: 9.  This is page 2 of 2.   Previous

The Infamous Chris Mothershaw again      (at 7:04am, Sat 7th Mar, 09)

Yes. They feel dead right. Stampings, tappings and number of teeth are exactly the same as the '.br4' you've supplied for this part. I'll send you a photo if you want (assuming I can find the tripod).
Chris M.

The Infamous Chris Mothershaw      (at 11:23am, Thu 5th Mar, 09)

Hi - I've a pair of the '.br4' variant of this part that are nickel plated, though clearly brass underneath. I've not come across this before. Is it common?

Reply: No, not as far as I know, but then I didn't use them as shims... Are they Meccano can you tell?

Harley Carter      (at 2:09am, Tue 25th Sep, 07)

The 1'' gear wheel also meshes perfectly with a 3'' diam rack segment, part 129. I was under the impression that this was its original purpose. I think both these parts were introduced at the same time, but the rack segment was discontinued. Part 31 also meshes diagonally with a 15 tooth pinion and with a 95 tooth gear wheel, and of course it will mesh with a worm. It is a very handy part to have.

The extra hole in the centre of the 2'' perforated strip, Part no 6, has always intrigued me. It can be used to mount the 1'' gear so as to 'convert' it to standard spacing and thereby enabling it to mesh with any of the usual gears. Was this the reason the hole was introduced perhaps?

Reply: It's one of the many handy things you can do with a five-hole two-inch strip, certainly. Previously you would have used a small triangular plate or X-series parts to get a quarter-inch hole spacing, but it's useful for all sorts of things.

Your name:
Your message:
Security check: (Please type in the text to prove you're a person!)

On this page...

Recent stuff going on: