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Achieving realistic running


GreenDiesel001

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It seems to me that one disappointment in my efforts at modelling is the feeling of weight in a locomotive or train?

 

I appreciate one couldn't have the weight factor as an element of scaling at 1:76. As a locomotive weighting (say) 76 tons would equate to a ton????

 

But is there a method of simulating weight?

 

If I were to add lead to a locomotive body without affecting the chassis what would be the strain on the motor and would it give me the desired effect?

 

I am modelling in 00 gauge and know that my 0 gauge loco's do give me some sense of weight?

 

Regards,

 

Jeff

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But is there a method of simulating weight?

 

If I were to add lead to a locomotive body without affecting the chassis what would be the strain on the motor and would it give me the desired effect?

Adding too much weight can put a strain on a smaller motor, but few OO locos have space for very much anyway. Electronics are your friend here, and you should look out for controllers, be they DC or DCC, that enable you to simulate the trains weight. I think you are the other side of the pond, and the MRC range should be able to help. If you move up to DCC, then each loco can have its momentum set within the decoder Configuration Variables, including acceleration rate, slowing rate and top speed.

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...I appreciate one couldn't have the weight factor as an element of scaling at 1:76. As a locomotive weighting (say) 76 tons would equate to a ton????

 

It doesn't work like that, Jeff. Scaling weight is something that comes up quite frequently, see, for example, here.

 

Nick

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As Ian points out, you can put too much weight in a locomotive to the point of damaging the motor or drive system, but it does depend a lot upon what sort of drive system is used. If the locomotive is fitted with traction tyres (the rubber bands around two or more wheels), then do not try adding any weight. The reason is that you will force the motor to stall if the load is too great and that will burn out the motor for sure.

 

If the model does not use traction tyres and has a good sized motor in it, then additional weight can be beneficial. This does not apply to tender drive models though, where weight needs to be added to the tender.

 

Fitting a decent sized flywheel to the motor can help with train weight simulation.

 

But in the end, DCC control and proper setting of the acceleration and deceleration variables will give the best results.

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Adding too much weight can put a strain on a smaller motor, but few OO locos have space for very much anyway. Electronics are your friend here, and you should look out for controllers, be they DC or DCC, that enable you to simulate the trains weight. I think you are the other side of the pond, and the MRC range should be able to help. If you move up to DCC, then each loco can have its momentum set within the decoder Configuration Variables, including acceleration rate, slowing rate and top speed.

 

Hello.

 

Please can you guide me to a MRC web site.

 

Thanks,

 

Jeff

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Mass doesn't scale linearly - we reduce all three physical dimensions by the same factor, so mass is a function of the scale factor cubed. For example, a cube of sides one metre has a volume of one cubic metre. That scales to 1/(76X76X76) - multiply this by the relative density and you have a scale mass. Still meaningless, though, since we can't scale down factors such as friction and wind resistance, which reduce momentum. Simulate this with flywheels and controllers.

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If non-DCC, then consider replacing the existing controller(s) with feedback types. Feedback controllers are designed to maintain a constant motor speed irrespective of loading or gradient.

 

Check-out the EM Gauge Society Manual sheet on the topic.

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  • 11 months later...

For non-DC, I get outstanding momentum control using MRC's controllers. Starting and stopping is very smooth and can be set in advance by moving the controller knob to the desired speed to start, and turning it to zero speed for stopping. And there is a braking push button to slow down if needed.

 

Richard Davies, Utah USA

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I have a couple of Pentroller panel units which provide very good control including inertia, etc. These are no longer available but a comparable version is available http://www.malcolmsminiatures.co.uk/Model+railway+controls+PUlqTXdBVE02a25jdmRXWjBGMlk

 

Obviously good mechanical set up and smooth running is pre-requisite when looking for realistic performance.

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