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Trim sleeve
The sleeve is drilled and tapped and a long bolt is used to hold it in place while the excess is trimmed flush with the boss
 
 
 
 
 
 
 
 
 
 
 
Perfect mesh
Perfect mesh

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28th May 2010
1929 Steam engine gearing...

John's 1929 engine
John Chapman's 1929 steam engine (photo John Chapman )

For a long time the 1929 steam engine has been sought after by builders and collectors alike. From a builder’s point of view the model lends itself to lots of applications and looks better then its horizontal successor. It is also more compact standing on a much smaller footprint. One of the parts to go missing over time is the gear wheel. This was not a problem as until recently replacements were available. Now this supply has dried up it now means a search for an original, if you can find one and are prepared to pay for it, or you will have to get one made. If you are really only looking to get it working in a model there is another way. While I was participating in model railway forum (yourmodelrailway.net) talking about Meccano (as you do!) One of the members, John Chapman's , posted a picture of his 1929 steam engine. This had standard gears fitted, a Mamod burner and a replacement safety valve fitted. On closer inspection the gear mesh was accomplished by fitting the output shaft one hole higher in the frame than the original.

Intrigued I checked one of ours and discovered that the hole spacing from the crank shaft to the hole above the correct position of the output shaft is exactly Spacing1 inch! This is very interesting, was it deliberate or is it just pure coincidence? Whatever the reason it is very convenient. By simply sleeving a standard 19t or 15t pinion down to 1/8 inch it will fit onto the crankshaft and mesh with a standard gear wheel. I found a piece of tube that has a suitable outside diameter and opened the bore out slightly to be a shade over 3.2mm (1/8 inch). This was fitted to a pinion and drilled and tapped to extend Sleevethe threaded hole for the grub screw. A long screw was fitted into the extended grub screw hole, to hold the sleeve in place, while it was trimmed to length. The pinion was fitted to the crank shaft and the output shaft fitted with a 57t gear wheel was relocated to its new position – works fine. The gearing is a bit higher and this will decrease the power available but adding further gear reduction as required easily rectifies this.

I am amazed that I had not realised this before, so simple. Thanks to John Chapman for the inspiration for this modification.

Finished
Standard gears installed and ready for action

If you have a 1929 steam engine unused and sitting there in need of its gear wheel you now have an alternative that will allow you to build it into Meccano models.

Ralph.

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Original gears
Original 1929 gearing
 
 
 
 
 
 
 
Sleeve in place
19t pinion sleeved to fit 1/8 inch diameter crankshaft of the original engine
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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