Some charts

The following is independent of application:

The following is specific to 12:1 gear ratio applications, like Athearn BB diesels:

 The lines are trend lines.  The points are the actual data.

Thanks,

Thanks for sharing

Thanks for sharing Larry.

What does "Performance Characteristics" in the chart entail?

It is an expression

That I evolved over time to evaluate the overall performance.  It is discussed here:

http://www.llxlocomotives.com/?p=643
 

it is not perfect.  I wanted to define a means to quantify the overall impact a upgrade to an engine.  The 2021 series is run with the same chassis & weights.  The only change is the motor, so it should be a fair indicator of the benefit.

Thanks,

Thanks for clarifying, Larry.

Thanks for clarifying, Larry.

As I mentioned elsewhere, I

As I mentioned elsewhere, I bough the Igarashi/Mehano 5 pole motors based on this work $1.74 per motor. Still haven't arrived yet, but these appear to be the motors used in Mehano's high quality European models. 

The Remotor and Regear groups.io is very excited by the Mabuchi SF-266 series for Steam remotors. $2 a motor. I'm not sure how the test results here compare to the experiences of the modellers who have installed them in steam. 

Mine took 12 days

Because of the discussions on the Remotor site, I ordered a couple of these.  The total delivered price was $8.45.  Probably would have been cheaper if I had ordered directly from Ali express.  

I have had some that have taken more than 60 days.  They ship via what is called a Speedpak.  I think that the various items are bundled so there i one item being loaded on the transport.  When they get to the US they are individually laced & put into the USPS system.  The total shipping on the above motors was $2.75.  I can't send a 1 oz package for that to a US address.  Go figure.

The prices for these motors is incredibly low.  Unfortunately that does not mean cheap.  For the same reason that most of the new model railroad manufacturing is coming from that region.  

Most of the motors that are the size and torque that are available have a production use that has nothing to do with model trains.  The square Minebea are used in automobile applications, seat, mirror & window power.  The Mabuchi also have other applications.  This obviously increases the number produced, which drives down the unit cost.  

One of the reasons that I do the no load motor tests before actually installing the motor in the test bed is to be sure that it is what it was advertised to be.  Out of fifty or so motors that I have examined over the last couple of years, three were not even close to the specs that go with the model.  Two of these did not make it on the test bed.  The other, the Minebea 24 mm square motor is one of the highly touted versions and it was tested as part of the current series.  The three out of spec motors were not obviously damaged.  The 24 mm square motor is competitive with the rest of the series.  Because it is so far off spec, the tests are likely not typical for the model.  For this reason, I ordered five more of these.  This is one of the take forever shipments from the far east.  When these arrived they will be checked to see if an additional test will be meaningful.

The two motor test series have the same gear ratio- 12:1.  This operates on the motor rpm & torque the same for each motor.   Relative to the motor the drive axle rpm is reduced and the torque is increased by this 12:1 ratio.  

Steam engines tend to run at slower speeds & require more torque.  The gear ratio is roughly 20:1.  This will put the motor in a different operating place and probably will impact the performance relationships.  

The particular test bed chassis that I am using this year allows for three gear ratios.  The data thus far has been done at 12:1.  It is planned to run selected motors with a 21:1 gear ratio.  This will cut the operating speeds by 58% & increase the axle torque by 75%.  The third gear ratio is 6:1.  This goes in the opposite direction, much higher speed & lower axle torque.  Initially I thought this to be of little value, but now I'm not so sure.