Stall current of a Bachmann Shay G scale

Chris Wright

Chris Wright

Rev-Up
I have looked at the manual and done various searches without result. To save me having to source an am-meter does anyone know the stall current for the above -jesse?
 
I doubt if the stall current is a publicised figure. It is inusual for our large scale models to stall the motor - far better that they slip on the track - the gear box will thank us for that!
 
The stall current is the most important factor when fitting a DCC decoder. LGB use 1.13.021.302 Buhler Motors stall current !.3 Amps in most of there Locos, and Massoth decoders are matched for this. When you purchase other Manufacturers Locos including British Manufacturers,they do not give or want to give out the motor information. The main British motor used gives an unknown voltage,ie 6 volts--12 volts so you do not even know the design voltage, or the stall current.
 
George Shreyer did some hard-stall tests on various locos. This was over a decade ago I think but still useful.

http://www.trainweb.org/girr/tips/tips4/tractive_effort_tests.html

I'm guessing was probably an old model 2-truck shay that was tested, and at slipping point it was drawing around 2.3 amps. George wasn't actually able to apply enough pressure to force a full stall, but got it up to around 7 amps.

To be honest I tend to agree with Stockers with regard to stalling in large scale models: the loco is more likely to slip before it totally stalls unless it's so over-weighted that it's probably damaging the gearbox anyway.

I have a QSI Quantum Magnum sound and power decoder in my 3-truck, from memory I think it's rated for around 3 amps continuous and I've never had a problem with it.
 
Now, if anyone can tell me how to get the same effect in G scale as a heavily loaded Yeoman with sanders (or sandtite?), and about 5% slip, at night...
Spectacular!
 
In reality, we're not going to load our trains to stalling point on the electric motor.

I don't think even Mike (Beavercreak) with his hefty gradients has achieved that, and there are plenty of videos around with the 'longest' G scale train (usually US outline.

Equally, because a Shay is geared, it'll pull a house down - or break the couplers - before the motor stalls :sweating::sweating::sweating::sweating::sweating:
 
and in the rare event that a stall may occur, I am pretty certain the decoder will protect its self from overload.
 
Agreed on all the above.... I would think the only (very rare and unlucky) circumstance in which you would actually stall a motor is if you had something actually jam the motion of the loco while it was still getting track power - and the chances of that happening are vanishingly slim, as such an event would most likely derail it and thus cut the power anyway!

Jon.
 
Zerogee said:
Agreed on all the above.... I would think the only (very rare and unlucky) circumstance in which you would actually stall a motor is if you had something actually jam the motion of the loco while it was still getting track power - and the chances of that happening are vanishingly slim, as such an event would most likely derail it and thus cut the power anyway!

Jon.
Click to expand...

You are forgetting wear in the 'block, and the motion going out of quarter.. - Locks things up in an instant.

This is the biggest cause of motor failure (and decoder burn-out) I see.
 
You may be right Phil, but I have never seen it
 
PhilP said:
You are forgetting wear in the 'block, and the motion going out of quarter.. - Locks things up in an instant.

This is the biggest cause of motor failure (and decoder burn-out) I see.
Click to expand...

A valid point, Phil - I had been thinking more about external influences on the loco, but a locked-up gearbox for any reason is not good.....

Jon.
 
Zerogee said:
A valid point, Phil - I had been thinking more about external influences on the loco, but a locked-up gearbox for any reason is not good.....

Jon.
Click to expand...
Not sure about decoders (don't use 'em) but a burned out motor probably needs a bit of unsympathetic use of the throttle as well :nod:
 
Rhinochugger said:
Not sure about decoders (don't use 'em) but a burned out motor probably needs a bit of unsympathetic use of the throttle as well :nod:
Click to expand...

Or inattention of the driver..
Then it just 'cooks' itself. - Brown smell, and ejection of magic smoke..
 
You must log in or register to reply here.
Back
Top Bottom