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Recent Posts

Pages: [1] 2 3 4 5 6 ... 10
1
Train Surgery / Re: Reluctant to start
« Last post by Newportnobby on Today at 09:26:34 am »
I suffer the same problem myself. No, not my locos. Me :-[
2
How apt you plan to model the standpipes as the North West prepares for a hosepipe ban starting 5th August affecting 7 million folks :laugh:
3
N Gauge Discussion / Re: Coreless motors v open frame.
« Last post by Chris Morris on Today at 09:22:30 am »
As others have said, old style traditional open frame motors - and also older can motors - at least have "user serviceable parts" eg. brushes and springs. I agree they can last for decades if not abused. I have locos made in the 60s and 70s still happily running on original motors and are still perfectly good enough for exhibition running.

Coreless motors are more efficient and draw less current, but as I understand it there are potential issues with them:

1) Because they don't have an iron cored armature they can't conduct away any heat build-up as well as a traditional motor. It is said that PWM controllers can induce such heat build up more readily than smooth DC.

2) Again because they don't have an iron armature, their Back-EMF response is different to a traditional motor. Hence if you use a feed-back controller it may not be tuned to the BEMF characteristics and may under- or over-compensate, resulting in jerky running.

3) They are often completely sealed with no option to replace brushes.

Of the points above, the heat build-up is probably more likely to cause reduction in motor life.

Remember that a feed-back controller is 99% likely to use PWM, but not all PWM controllers include feed-back circuitry.

Also remember that every DCC decoder I've ever heard of uses PWM for motor drive, and the majority seem to include feed-back although is it usually possible to switch it off.  Also with more comprehensively specified decoders the PWM frequency and feed-back response can be tuned to better suit the motor characteristics. Most decoders use higher frequency PWM than a classic PWM controller.

I still use KPC PWM/feed-back controllers I've had since the 80s, and find they give no trouble at all nor do I notice any heat build up in locos, though my typical operating pattern is to run each train in a sequence rather than leave things belting round and round for many circuits. I did modify the controllers a long time ago to allow the feed-back to be switched off, and yes some more recent locos behave better without the feed-back.  On balance I probably only use the feedback for 30% of the time, and that will be mostly with older models.

I also have a couple of non feedback controllers which I use with the coreless motor locos so I probably havenít either invalidated the warranty or shortened the motor life. My observation was merely that coreless motors donít run very well with feedback controllers.
4
Pendolino / Re: Pendolino - a new approach
« Last post by Newportnobby on Today at 09:16:56 am »

Hello,

You will be pleased to know that your power car will be back on its way to you this week as mentioned/discussed in the email exchange between us both.

Iíve tested it on several different track set ups from my test track, to my 2mm finescale layout to a large private N gauge layout and still couldnít get it to de-rail.

So just incase something had been missed itís been completely stripped down to component parts and rebuilt. Tested again and itís still not de-railing.

I am working through all outstanding repairs as quickly as I can.
Thank you.

Thank you, Simon.
5
You're making me homesick!

Have a great show.  :beers:
6
General Discussion / Re: The World's Tiniest Masterpieces
« Last post by Bob Tidbury on Today at 09:02:08 am »
Thankyou Mick for letting us know about Willard Wigan I watched that program last night and the bit at the end was absolutely incredible ,It makes even the finest N Gauge modelers look like a beginner .How he has the patience to keep doing that when I get really frustrated just trying to put the springs back in a Dapol easy shunt coupling.
Bob Tidbury
7
N Gauge Discussion / Re: Coreless motors v open frame.
« Last post by ntpntpntp on Today at 08:53:56 am »
As others have said, old style traditional open frame motors - and also older can motors - at least have "user serviceable parts" eg. brushes and springs. I agree they can last for decades if not abused. I have locos made in the 60s and 70s still happily running on original motors and are still perfectly good enough for exhibition running.

Coreless motors are more efficient and draw less current, but as I understand it there are potential issues with them:

1) Because they don't have an iron cored armature they can't conduct away any heat build-up as well as a traditional motor. It is said that PWM controllers can induce such heat build up more readily than smooth DC.

2) Again because they don't have an iron armature, their Back-EMF response is different to a traditional motor. Hence if you use a feed-back controller it may not be tuned to the BEMF characteristics and may under- or over-compensate, resulting in jerky running.

3) They are often completely sealed with no option to replace brushes.

Of the points above, the heat build-up is probably more likely to cause reduction in motor life.

Remember that a feed-back controller is 99% likely to use PWM, but not all PWM controllers include feed-back circuitry.

Also remember that every DCC decoder I've ever heard of uses PWM for motor drive, and the majority seem to include feed-back although is it usually possible to switch it off.  Also with more comprehensively specified decoders the PWM frequency and feed-back response can be tuned to better suit the motor characteristics. Most decoders use higher frequency PWM than a classic PWM controller.

I still use KPC PWM/feed-back controllers I've had since the 80s, and find they give no trouble at all nor do I notice any heat build up in locos, though my typical operating pattern is to run each train in a sequence rather than leave things belting round and round for many circuits. I did modify the controllers a long time ago to allow the feed-back to be switched off, and yes some more recent locos behave better without the feed-back.  On balance I probably only use the feedback for 30% of the time, and that will be mostly with older models.
8
Events/Shows/Exhibitions / Railex NE 29th + 30th July North Shields
« Last post by Tonye on Today at 08:39:13 am »
Northallerton, Blyth , Kayreuth, Staly Vegas and Fencehouses are on display at the John Spence community High school NE29 9PU . Adults £7, Kids £3. Sat 10-5 Sun 10-4. 50th anniversary show with good trade support . I will be assisting with Webbs Wharf on Saturday. 
9
Pendolino / Re: Pendolino - a new approach
« Last post by Ben A on Today at 08:30:43 am »
My other 'issue' is that with my 11-car set 3 of the coaches G, H, J light up inside. It's not what I would call decent coach lighting and I haven't added coach lighting either. Is this normal? The reason I ask is that neither power car nor the other 6 coaches light up at all, it does look odd. Again, a video to show what I mean. Not a great video but it sort of shows what I'm saying.

Hello Trainfish,

All models have a representation of working table lamps in the first class cars.  On the real thing these are fixed on the table bays next to the window, and can be switched on and off by passengers, and they can be seen when the trains pass by, especially at dawn or dusk.

The actual coach lighting bars were sold separately and are not supplied as standard.

Because the power cars are full of chassis block, coach K (the first class one) does not have a table lamp, but then on the prototype there is only one bay seat anyway (most of it is kitchen) so we felt it was an acceptable compromise.

Cheers

Ben A.
10
Train Surgery / Re: Reluctant to start
« Last post by Caz on Today at 08:15:00 am »
If old style open frame motors a weak magnet or maybe to much grunge on the bearings and/or gears, or even a dirty commutator.  For both new and old style motors then dirty pick-ups as well.
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