Dapol news due on Thursday

"David Biddulph" wrote

Maybe they're going to put decent motors in their locos and make them work properly?

John.

In message , John Turner writes

Maybe they are going to signwrite their private-owner wagons properly, and not use modern printers' typefaces.

Maybe they are going to introduce a wooden-solebar wagon chassis in OO.

... but I doubt it.

What locos are you refering to,I haven't had any trouble with mine?

neil.

"mumbles" wrote

You're the first person I've heard who claims the running qualities are ok. All the comments I've received suggest a lacking of smooth operation, or more accurately 'jerky' running.

Tell us more please neil.

John.

I've been quite happy with the running of my Dapol 73 - certainly outclasses any of my Farish/Bachmann stuff for running quality. Can't vouch for the kettles though.

James Moody

I got an Ivatt for a Christmas present. It ran beautifully straight out the box, nice and slow and very smooth. Overall I'd rate my Minitrix 47 the best running model I have had personal experience of, my four different Union Mills locos equal second and then the Dapol Ivatt. All head and shoulder above any of my several Pool made Farish models. I haven't bought any of the new Bachman-Farish Chinese made models yet to see how the run.

Jerky running suggests the use of a feedback controller,which I also experienced.However,on pure DC they run very smoothly indeed. I currently power the track with a Lenz silver DCC decoder,which does a good job with both Dapol and Farish locos.

neil.

"mumbles" wrote

Strange, I'd have thought that all manufacturers would produce models compatible with all popular controllers. It seems odd that in 2006 someone would produce something which won't work with feedback.

John.

I don't think that it is possible to produce an electric motor that is incompatible with feedback control. It is possible to produce a motor that could be incompatible with a specific design of feedback controller, if you see the difference?

While designing a feedback controller I found that Fleischmann drum motors produced a short, low voltage (low efficiency) bemf pulse every

1/6th of a revolution. At certain frequencies of bemf reading it was possible to miss the pulse which was interpreted as a stall whichcaused the controller to boost the output creating speed surges. The cure was to increase the bemf capacitance, which reduced the feedback sensitivity.

I doubt that the old GF motor could be classed as a low speed motor, but I imagine it is of low efficiency, tending towards zero efficiency. If that is the case then it would have little effect on any feedback controller.

Regards, Greg.P.

Something with electronic control built in to the motor perhaps. The AC motors used on some models.

Well, that or an "off" switch in series with the motor. ;-)