Using CD motors with DCC

[hellotojasonisaacs]

If this has been already covered then I apologise for the duplication. Maybe someone could direct me to the appropriate thread?

 

Anyway, I've decided to bite the bullet and start doing some proper modelling as the hobby isn't getting any more affordable and I'm on a budget. I've recently bought a Lima class 31 and 37, and I intend to change the motors for ones found in CD players. I've seen it done on YouTube and thought "even i could do that." The ultimate plan is to add Express Models lighting and Hornby TTS sound (I'm on a budget, remember). I have read some things about the operating voltage of these motors and I know that Hornby chips don't do CV5 to reduce to voltage going to the motor. So, my questions are thus;

 

1. Can I use a series of diodes between the chip and motor to reduce the voltage it receives?

2. Or will it be ok and I don't need to bother with diodes? Just carry on as normal?

 

Many thanks in advance for your help!

 

Sorry about the essay, but I'm a teacher and I can't do brief!

[RAF96]

Re CD motors...

The diameter you need is 25mm but the width you need depends upon the bogie wheel arrangement. The standard width motor - 12mm is ok for Bo-Bo and four wheel steam tender drive but will foul on the centre wheels of a Co-Co or six wheel tender drive steamer, for which you need the slim 9.5mm motor.

 

As you are aware these motors are rarely 12v and you are wise to consider knocking down the decoder voltage output, as your basic decoders don't support Vmax adjustment, however be aware that the drive voltage is pulse width modulated not variable 0 - 12 volts and diodes may not be the best way to control it, you may need hi-speed switching diodes, so please await instruction from an expert.

 

Re TTS...

If going to TTS decoders then these CD motors are well within the decoder capability (I have a few) but be aware that adding an Express Models lighting kit to say a 37 with five leds lit (3 fwd and 2 rear) can overload the TTS directional lighting function, which is not self-protected like the motor circuit is. To fix this I added an extra 1K ohm resistor in the blue lead to limit the current and all seems well now.

Rob

[DCB]

These motors are designed for 12 volts, but actual 12 volts not nominal model railway 12 volts which can be 21 volts off load and these motors don't draw many milliamps.

I have used them for years in Lima diesels on 6 and 3 volts batteries, Scalextric drive pinions fit the shafts and mesh with Lima gears. They run much more smoothly than Lima motors on smoothed DC or battery power but run rough as the originals  on PWM which is as far as I know the waveform the decoders deliver.   

[RAF96]

These motors are designed for 12 volts...

 

Depends where you get them from, as many are rated as low as 3v, some at 6v and some 9v, with 12v versions a tad harder to find. The slim ones especially.

Rob

[DCB]

Depends where you get them from, as many are rated as low as 3v, some at 6v and some 9v, with 12v versions a tad harder to find. The slim ones especially.

Rob

Even the 12 volt versions can't cope with the 21 volts many model railway controllers provide.   The ones I use come from CD drives from Computer towers and are intended for regulated 12 volt supplies and work well on 3 volts....   In CD drives they generally drive through belt drives and don't appreciate being stalled as the brush gear is pretty flimsy.

Edited May 22, 2017 by DavidCBroad

[davetheroad]

I converted a Lima class 08 with a kit from here.

 

www.diesel-trains.co.uk

 

A remarkable improvement in slow speed running with battery power delivering PWM DC via a Deltang radio receiver.

 

You need to 'fettle' the Lima gear chain though to remove the moulding pips from the gears. This should stop the horrible grinding noises.

 

I am going to convert a Lima class 26 and 37 next.

[BG John]

What type of motors are these? I dismantled a DVD drive yesterday and it has a Nidec E98162 brushless motor, with 12 wires. Looks a bit complicated to use, and I haven't sussed out what it needs to drive it yet. On the other hand, they're being advertised on eBay for around a tenner, so I suppose I could sell it, and buy something easier to use!

[davetheroad]

The motor in the kit I bought was brushed with just 2 wires. It comes attached to a mounting plate and fits in the space where the old armature and magnet used to be. I think there are 2 sorts of motor in a CD drive, one to drive the spindle and another to open the door and move the tray?

[BG John]

The motor in the kit I bought was brushed with just 2 wires. It comes attached to a mounting plate and fits in the space where the old armature and magnet used to be. I think there are 2 sorts of motor in a CD drive, one to drive the spindle and another to open the door and move the tray?

Three in mine. A 2 wire DC motor for the CD drawer, the 12 wire one for the spindle, and a linear stepper motor for the laser.

[DCB]

Three in mine. A 2 wire DC motor for the CD drawer, the 12 wire one for the spindle, and a linear stepper motor for the laser.

The Drawer motor is the one you need.   The 2 wire one. The 12 wire is pretty useless except as a load for a well wagon, and I have never seen a linear stepper, mine have had long type 12 v motors with worm drives to drive the lazer,   The long motors are pretty good for powering 0-4-0 s etc through Romford 60:1 worm drives and the like. 

[BG John]

The Drawer motor is the one you need.   The 2 wire one. The 12 wire is pretty useless except as a load for a well wagon, and I have never seen a linear stepper, mine have had long type 12 v motors with worm drives to drive the lazer,   The long motors are pretty good for powering 0-4-0 s etc through Romford 60:1 worm drives and the like. 

 

Surely that's a stepper motor. It's got  four wires.

 

[BG John]

It is a stepper motor. I've got the data sheet, and watched the videos on YouTube on running it from an Arduino!

[DCB]

Surely that's a stepper motor. It's got  four wires.

 

RIMG2753.JPG

Yes that's a stepper, I would call it a traversing motor and they are no use at all for remotoring lima or similar bogies.     The ones I have seen have no bearing at the shaft end of the motor and I can't think of a model railway use for them, except in bits as scenery or wagon loads.

 

It is the big motor ( Not shown) which moves that entire assembly as shown in the photo which you need.  The computer towers I have taken these CD drives from are getting on a bit now, many had a decent small long motor with a worm before the product cheapening department was let loose, and maybe the real up to date (2010 on) ones don't even have the big pancake motors anymore.

 

As regards the pic There are usually a couple of decent Super Neo magnets in the lazer dead central on the pic, dig them out make up a stack of 9 or so and pop them in a tired X04 motor which hardly runs.... It is like a reet good kick up bum and they go like stink     And there's a decent little microswitch right bottom.   And some steel rod and some handy screws, and a bit of tin for bodging something with.

Edited May 26, 2017 by DavidCBroad

[BG John]

Yes that's a stepper, I would call it a traversing motor and they are no use at all for remotoring lima or similar bogies.     The ones I have seen have no bearing at the shaft end of the motor and I can't think of a model railway use for them, except in bits as scenery or wagon loads.

 

It is the big motor ( Not shown) which moves that entire assembly as shown in the photo which you need.  The computer towers I have taken these CD drives from are getting on a bit now, many had a decent small long motor with a worm before the product cheapening department was let loose, and maybe the real up to date (2010 on) ones don't even have the big pancake motors anymore.

 

As regards the pic There are usually a couple of decent Super Neo magnets in the lazer dead central on the pic, dig them out make up a stack of 9 or so and pop them in a tired X04 motor which hardly runs.... It is like a reet good kick up bum and they go like stink     And there's a decent little microswitch right bottom.   And some steel rod and some handy screws, and a bit of tin for bodging something with.

I reckon if the laser is removed, the stepper motor and the assembly it drives would make a nice loco traverser. The problem is that the travel is a just a bit short for 4mm scale broad gauge, which is what I'm looking for. The CD drawer has potential though.

 

This drive was made in 2003. I'll look out for the magnets in the laser. I'm trying to collect 3 and 5 volt motors suitable for radio control at the moment, as I have a good supply of 12 volt ones. I do have one X04 though, that I could replace the magnets in. I fitted a 5 pole armature to it decades ago, so it's already been improved a bit.