hayfield Posted May 22, 2013 Share Posted May 22, 2013 I have been building up a stock of etched chassis and motors to fit into some whitemetal locos I have. I have some questions about the motors. Sorry if they are a bit basic but I seem to have been left behind in the knowlage stakes of the companies and motors What is the the difference between Sagimi and Mashima can motors, I understand that Sagami do not sell to the model trade now. Also what is the difference between the flat sided and round can motors. Are the longer motors better than the shorter ones and as I have some 0-16.5 locos and these will fit I have a couple of locos with fly-wheels fitted, one works realy well. Another does not seem to do much, does the gearing have an effect? Is there a rule of thumb when choosing a motor ? Thanks in advance Link to post Share on other sites More sharing options...
Buhar Posted May 23, 2013 Share Posted May 23, 2013 The rule of thumb is fit the biggest you can. Sorry to state the obvious but round cans are cylindrical, flat cans have flats sides that are smaller than the cylindrical dimension and this is the dimension quoted in the sizes. The standard naming convention eg1015 is diameter then body length, ie 1015 is 10mm diam by 15mm long. Gearing is hugely important and is crucially related to wheel diameter too. So you consider motor speed without overheating or stressing, gear ratios (don't go for more than 50:1 in a single step), the size of the driving wheels and also a nod towards the normal running speed of the loco. For example a fairly high-revving little can, say about 12,000 rpm, with 40:1 reduction will give a 0-6-0 with 4'0" wheels a speed of about 40mph - more than enough. However the same motor on a loco with 6'9 drivers will be running run at 70mph. All the different motors have their ideal application, people have their favourites and their characteristics are not entirely related to size. Sometimes a range of motors can have a less good one among them, for reasons that are probably related to quantum theory or witchcraft. Flywheels are not always a Good Thing, they can set up stresses that are unhelpful, especially on long thin shafts. Extra bearing points can help to ease this. Just saw you're building whitemetal kits - go for bigger motors - you have some weight to lug around. A 1620 will usually fit in a tank loco and if you need to get it well clear of frames/wheels then High level and Branchlines do some good gear systems that do this. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted May 23, 2013 Share Posted May 23, 2013 Motor suppliers will usually be able to provide a data sheet for the ranges of motors they carry, so that you may make your gearing estimates as described by Tren. Other than for 'crawlers' or when forced by space constraint to use a tiny motor, I feel that the highest ratio generally required in 4mm is 40:1. A worm stage of 20:1 or thereabouts and any further reduction by spur gears, would be a good place to start if you have no prior experience. Less critical on worm to pinion placement, relatively easy to get to a quiet and free running end result. The real joy with a good 'fat' motor is how little reduction is needed for realisitc smooth operation. As an example the early Bachmann production of the 'Peak' has their usual five pole flat can, roughly equivalent to an 1833 Mashima, geared about 5:1, the current Hornby 30/31 with a similar spec motor is on 8:1. Both these chassis are heavy and even with small wheels will achieve a scale speed in multiple hundreds of mph. No lack of traction or slow speed smoothness which is aided by significant flywheel mass in the drive train on both chassis. When I tested it many years ago, the 46 realistically started about 40 coaches on level track, cannot imagine anyone thinking that is in any way deficient. Link to post Share on other sites More sharing options...
61650gtfc Posted June 16, 2013 Share Posted June 16, 2013 One thing I have noticed with mashima motors is that bigger isnt always better. Some of the longer motors rev slower and are less powerfull than the shorter ones.there used to be a chart for mashima motors on their website but I cant find it at present. An example is the 1626 flat can . This is a much better motor than the 1628 flat can. Link to post Share on other sites More sharing options...
61650gtfc Posted June 16, 2013 Share Posted June 16, 2013 http://www.zephyr.dti.ne.jp/~katumi60/p02.htm Just found the site. Link to post Share on other sites More sharing options...
buffalo Posted June 16, 2013 Share Posted June 16, 2013 http://www.zephyr.dti.ne.jp/~katumi60/p02.htm Just found the site. Almost, you left the 'l' off the end of the url: http://www.zephyr.dti.ne.jp/~katumi60/p02.html Also useful is gearbox speed calculator spreadsheet on the HighLevel kits gearbox page, or directly: http://173.254.28.51/~highlev3/chris/speedcalculator.xls Nick Link to post Share on other sites More sharing options...
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