Loco Motor Repair

[JoeLoco06]

I have two old hornby locos with dead/dying motors. What is the RPM and voltage of modern hornby loco motors so I can go about repairing or replacing the motors. I have basic soldering skills but have little knowledge on motors.

Also, is their a specific tool for removing the motor worm from a dead motor?

[Going Spare]

Which types of motor are you dealing with?

GS

[Tony57]

HI

What Locos are they and what motors have they got? . Due to the motor fixing points it is not just the case of removing and replacing with a new motor.

 

Yes you can got hold of a worm puller, the better model shops should stock them.

[james_nelmes]

 From the sound of it, I suspect these are the older X03/4 motors with an open frame and I guess a brass worm fitted (you would be able to remove the plastic worms easily.

These are great motors and often appear dying or dead, but with a little TLC, can be made to run really well.

First step is to clean the commutator (3 copper pieces in a circle the brushes sit on) - I use cotton buds and iso-propyl alchohol or petrol lighter fluid. often carbon deposits can build up in the slots between the commutator and the current can short across each piece of copper to the next causing heat, smoke and bad running. Take a needle and move it along the slots stating at the end of the slot near to the windings (but not too near!) and moving it along the slot away from the windings so as not to damage them.

Next step is to get a resistance meter between adjacent copper pieces (pole pieces to be correct). Do this three times for the three pole pieces to the next one in order. If the resistance is roughly the same for each pair, the armature is good. If one has gone open circuit, the resistance of one pair will read around twice the resistance of the other two, due to the way it is wound.

If the armature is not good, you can either buy a replacement from a well known auction site, or send it off to a repairer such as Scalespeed, who will repair and service the motor to 'as new' standard - they used to charge around £16 per motor.

Next check the magnet - a small screwdriver should stick to the magnet and need a light pull to remove it - if there is little or no sticking, the motor has lost its magnetism. You can again send it away (Scalespeed do a 'remag' as part of their service) or buy a 'super neo' magnet from the auction site - type X04 and magnet into the search criteria.

Apply a little oil to each bearing - on these motors, there is often a little pad that the oil can be dropped onto and if not a tiny drop onto each of the two contact surfaces between the armature and rest of the motor.

Finally check the electrics - on the right hand side of the motor, looking from the magnet forwards, there should be a small insulating sleeve between the brush spring and the brush. If it is missing or damaged, you can make one out of the plastic insulating sleeve of any small wire.

Now I apply power - only in very short bursts. It will need to 'run in' to run more freely, and if it is sticking, applying full power can burn out the armature which means a dead motor. I will often rotate by hand for a few turns first. A 9V PP3 battery is a useful alternative if you do not have a power supply, held across the two brushes.

With careful servicing these will come to life and give reasonable slow running and performance.

[JoeLoco06]

ok. The first loco is a DC only R.402 BR class 37 Diesel. I do not have the manual but this model was "made in Great Britain". I do not recognise the motor as it is before my time in this hobby. The motor is integrated into the plastic design of the rear bogie with four large gears exposed. A single brown wire leads to the front bogie to pick up power and send to the motor. This motor will only move in one direction and is near dead. This is easily my most old school loco mechanically speaking. There is no obvious housing of the motor, the bogie and the motor appear to be integrated. The motor featured in this loco here looks extremely similar if not the same: 

 

The second loco is the hornby Thomas the tank engine "Thomas and Friends" 2015 range (also DC only). This includes another old style motor. The Type M Motor according to the manual. Poor running even after service. This loco and motor are exactly the one featured in "How to Service/Repair a Hornby Thomas" by Sams Trains. 

 

thanks for the indepth info james, I will look at the repair shop you suggested but would prefer to repair/replace myself. I am not an expert on motors but I dont think either are the X03/4 you describe. Nearly all my locos have modern motors in them so upgrading these two to be in line with the rest of the fleet seems the most logical option.

 

Also note that my original question on what is the RPM and voltage of modern hornby loco motors has not been answered.

[walkingthedog]

When Joe says old Hornby it depends how old. Some on here would consider a loco from the 90's to be old so let's wait until he gives us more details before giving lots if advice. 

[JoeLoco06]

When Joe says old Hornby it depends how old. Some on here would consider a loco from the 90's to be old so let's wait until he gives us more details before giving lots if advice. 

Cheers WTD, see my above reply post for all the details you need.

[Chrissaf]

JoeLoco

.

Maybe these images will help you identify the type of motor you have...... so that you can let the forum membership know. These are three of the most common types.

.

Hornby / Triang X03 / 04 Type Motor.....the magnets in these type of motors lose magnetism overtime and can be restored just be getting the magnet re-magnetised by the likes of 'Scalespeed'.

/media/tinymce_upload/af64ad09e148f72108117bbe96fdb04a.jpg

.

Hornby Ringfield Motor.....again these can be refurbished by 'Scalespeed'

/media/tinymce_upload/7d467754feeb68e0b2d6dac76ffa9bb3.jpg

.

CAN Motor....in essence replace and throw away.

/media/tinymce_upload/24b2d5083df0bde15beff9b230c1fa1e.jpg

.

[LCDR]

The motor operates at a nominal 12 volts DC, often described by manufacturers as 12 to 15 volts.

 

The RPM of the motor is not recorded in maker's literature so far as I know because the motor increases in speed from 0 RPM up to probably 2000 RPM as more current is applied. Motor gearing will bring this down at the wheels, but running without load they can run pretty fast.

[james_nelmes]

 0v - 12v on all RPM varies with voltage - dont know a value.

Right so the first one is a ringfield motor - probably a three pole.

The motor bogie can be unclipped from the chassis and then insert a small screwdriver at the back of the bogie between the motor and the bogie frame and gently ease the frame off.

Now insert a screwdriver behind the wheels on the side with the gears showing, and lever the wheels off gently. The wheel and axle from the other side will just fall out. How dirty are these? I generally clean the axles with iso-propyl and use a pipe cleaner to clean the tubes the axles run through.

The motor has a faceplate which can be removed by gently! easing the two clips at the back of the motor up and off and likewise for the two at the bottom - try not to break these. On the Class 37 there are two dummy wheels - one fits on the faceplate and one on the other side on a mini axle from the motor housing. All the wheels should be put to one side.

As you remove the faceplate two small springs and brushes should fall out. If the brushes look OK and are nice and flat at the bottom you can re-use them. The two springs should be reasonbly clean and not 'squashed'. Replacements can be found on the auction site by searching 'ringfield springs brushes'.

I also remove the brass clip that holds the gears in place on the back and clean the gears, and put a tiny spot of oil on each bearing before reassembling with the clip. A bit fiddly - as with all these, if you are new to it, take a few photos before disassembly to help rebuild.

I then clean the commutator as described before. With this motor, if you have an open circuit on a winding, the resistance will read infinate between copper plates. Hopefully they will all be the same. Sometimes with these the tiny wire that attaches to the tab at the edge of the copper plate loses connection due to the age of the solder. I've repaired dozens by just touching a soldering iron on the tab to re-melt the solder. This is only necessary if you have an open circuit.

To re-assemble, clip the faceplate on, bend up the brush retaining strips a little and replace the springs and brushes. The springs are a pain and shoot off all over the place. I tend to put a small screwdriver inbetween the coils and then manouvre into place on top of the brushes. Once in place, bend down the retaining strips. I now apply a little power in both directions to see if we are running ok - again small bursts of power and let it run in.

On these when they run well in one direction and not another, it's typically the brush has worn assymetrically and is jamming in the commutator slot one way and not the other. Either file it flat or replace and it is pennies to replace.

Once it is running ok replace the wheels ensuring the wheels with the geared inside are lined up to the gears. A little oil on the axle before re-assembly and ensure the end of the axle lines up level with the face of the wheel you push it through. Check it rotates by turning the motor. Once both driving wheels are in place, replace the dummy wheels on their small axles and fit the bogie frame. It's now ready to fit back to the loco and test.

The M type motors are a pain as a non-serviceable unit and have to be replaced if faulty. However, my experience with these is they often wont work due to the pickups not making good contact. To test apply power directly to the motor. If it runs but the loco does not, it's pickups. They will need gently bent to make good contact at all times. If it's the motor, you are probably on the auction site for a replacement or contact a dealer.

There are lots of guides to service a ringfield motor so google that and it should be straigtforward. Again they come back to life easily and run well when serviced.

[96RAF]

Typical gear puller. This one has three different sized interchangable mandrels that screw into the main Tee Bolt.

/media/tinymce_upload/15255b1db9b56f81f2186293258b3cfa.jpg

[JoeLoco06]

Cheers RAF for the gear puller :)

 

Thanks Chris the motors have been identified as Hornby Ringfield Motor and the Type M Motor.

 

On these when they run well in one direction and not another, it's typically the brush has worn assymetrically and is jamming in the commutator slot one way and not the other. Either file it flat or replace and it is pennies to replace.

 

Thanks James on the indepth repair of the Ringfield Motor, this will be worth printing I think! Regarding the running of the loco it does seem to make a "jamming" sound in the direction it refuses to move in, the loco itself is well worn and the body shell is not in the best of condition, so it clearly had a lot of use in its life before finding me. I think your diagnosis is spot on, however from my current understanding of electric motors I did not think it was even possible for the motor to run one way and not the other until I saw it. I understand that reversing the polarity reverses loco/motor direction but I do not understand the role the brushes play in the motor. I would have expected it to either run poorly in both directions or not run at all in both directions regardless of polarity.

 

While I am on the topic, do the current range of hornby diesel locos make use of the Ringfield Motor or is the entire range CAN Motors now?

 

Regarding the Type M Motor I am less enthusiastic about keeping this in service. My goal here instead would be to replace it with a modern CAN Motor as it looks like the motor can be easily soldered from the loco. Is such an operation possible? Where would be a good source of 2000 RPM CAN motors?

 

My general goal here is modernization to CAN motors and not necessarily restoration of worn out motors. This is an important point as another 0-4-0 hornby loco yet unmentioned is a CAN "pocket rocket" and also needs a better scale speed motor. 

[96RAF]

Do not take that 2000 RPM as gospel as some motors spin at 12-20000 RPM.

Calculate (or just observe) the gearing to see how many times the motor turns per rev of the wheels (or vice-versa) and then find the road distance travelled in a minute using motor RPM x wheel circumference x gear factor. Compare distance travelled with a typical loco in a minute. From this you can work out what RPM motor you need to match a particular loco speed, noting that different loco wheel sizes and gear ratios likely need different motor RPMs.

[james_nelmes]

 Modern hornby locos use typically 5 pole can motors and are very reliable. The ringfield hasn't been used for at least 10 years. However, as I said once serviced they run well and I have converted a couple of 3 poles to TTS sound.

If the motor is run in one direction mainly the brush can tend to develop a smooth worn leading edge and a sharp back edge. The leading edge will run from pole to pole without trouble but the sharp back edge can jam in the commutator slots as it attempts to run. Replacement of the brushes will fix this or as I said take them out and carefully file the surfaces flat. I dealt with a running better in one direction at the weekend (though very marginal) and just manually operated it via the gears for a few turns before running it in at a moderate speed.

If memory serves, at the heart of the M motor is their common open frame small motor and it might be possible to replace it - as I said, take the motor out and apply power to see if it's motors or pickups.

[JoeLoco06]

so the formula is 

distance travelled per minute = RPM x wheel circumference x gear factor

 

All is understandable except for what "gear factor" is and how it is calculated. Im not sure what is a motor rev in terms of current applied and also, how you would observe gear factor considering how small the motors are and how fast the motors rotate.

 

Interesting James... this could be an easy fix based on what you say about the brushes. I think this loco is beyond the manually approach but its also worth a go. Is there any good places for replacement motor parts etc? My first attempt would be to fix the ringfield motor as it just sounds like fun to do, but in the long run I will almost definitely try to upgrade to a CAN motor, especially if I pass my collection on to someone younger etc. If you have experience converting ringfield motors to 3 pole I would be interested to know how you did it, as it is not immediately obvious to me how to make the convertion looking at the gears integrated into the boogie wheels and how the worm/worm wheel would interact with that etc.

 

If memory serves, at the heart of the M motor is their common open frame small motor and it might be possible to replace it - as I said, take the motor out and apply power to see if it's motors or pickups.

 

I am not sure what is meant by a "commen open frame" as my motor knowledge is limited, but the M Motor does have a seperate housing that might be useful in a CAN motor convertion, once RPM is calculated.

[james_nelmes]

There are kits to convert Ringfield motors to be driven by a CD drive motor which offer much smoother performance. Some of these are straight plug in replacements where you leave the gears in place on the back and the new motor drives a replacement centre cog. A company worth looking at is Strathpeffer Junction who make these kits and publish instructions online so you can see what's involved.

 

A can motor is one where the workings are enclosed in literally a metal can of some sort. Open frame is where the armature and mechanism are in a frame but accessible. By common open frame motor, I mean there is a small open frame motor referred to as a 'type 7' Which is used in a number of models. The pole number (e.g. 3 pole) is the number of copper pieces that make up the commutator. The more poles, the finer the motor runs.

in terms of your Ringfield you don't necessarily need to do the strip down I described. first step  is to remove the bogie from the chassis, bend out the metal brush retaining strips and allow springs and brushes to fall out. It should be obvious if the brushes are unevenly worn and you then can choose to service them or replace. Well known auction site and search for ' ringfield springs brushes' - some people sell them in pairs.

I bought a Hymek a couple of years ago for £10 With a ringfield motor that didn't run. 20 mins cleaning off the thick grease used as a lubricant and re-oiling and it ran sweetly again. They will run very sweetly with a little tlc.

[96RAF]

Joel

The gear factor is just another way of expressing gear ratio between motor and wheel.

 

What we re trying to do regardless of the gear train or loco type, etc is to find out how many turns of the motor are required to turn the wheel once.

 

The way to do this is mark the motor gear and a driven wheel then turn the motor by hand counting how many revs (revolutions) it takes to turn the driven wheel once. This may be something like 10:1, 20:1 or 40:1, If you do this on track you can also mark the wheel start point and measure to the finish point thus avoiding even having to bring Pi into the equation (π x D = Circumference).

 

Once you know the distance travelled for one wheel revolution with respect to x number of motor revs, you have a basis to calculate distnce travelled in a minute at various RPMs to compare against a known loco.

[JoeLoco06]

RAF, my understanding of gear ratio / factor is:

 

how many revolutions (of the motor) it takes to turn the driven wheel once

 

Is this correct?

 

You also use the term "motor gear", Im assuming this is the worm wheel? Your post makes many things clear but leaves a few questions. How do you turn the motor by hand? The best I can think of is to turn the fly wheel to move the worm, but not all motors have an exposed fly wheel. Of course you cant send power to the motor either because then all you are turning is the worm... so I am intrigued by the simplicity of your method but dont understand what is meant to turn the motor by hand.

 

I like your way of calculating circumference, I was going to use a piece of wire wrapped around the wheel. An important question here is do you measure from the driving wheels inner or outer circumference to calculate distance? Im assuming the inner circumference of the wheel as that is what is actually moving on top of the track.

 

A question I also forgot to ask is about the gear puller tool. Once you pull the worm from a motor how do you fit the worm to the new motor?

 

I bought a Hymek a couple of years ago for £10 With a ringfield motor that didn't run. 20 mins cleaning off the thick grease used as a lubricant and re-oiling and it ran sweetly again. They will run very sweetly with a little tlc.

 

Nicely done james :) Strathpeffer Junction looks the way to go but their Co-Co ringfield adaptor kits are out of stock. Are there alternatives? I was thinking of going on auction to get old parts, but I was hoping there was someone who stocked fresh parts at a bulk order price.

 

 

[james_nelmes]

 There are quite a few of these conversion kits on e-bay. I like the Stathpeffer ones because it is reversible and is designed to fit without too much trouble. Others involve 'packing' around the motor to fit into the available space but I'm sure work OK - just worth checking what motor they are using as some are very cheap and nasty.

[Rana Temporia]

Be aware that not all CD motors are designed to run at 12v, some are 6 or 9v. Most will start to work way before the 2-3v that are needed to move conventional ringfield motors. If you are buying off the famous auction site look for good reviews and ease of fitting For your chosen loco. 

[96RAF]

My conversion to a DVd motor used a slice from a simple cardboard tube as the motor mount/spacer.

 

Joel - I have tried to reduce the technicalities of calculating motor to wheel gear ratio to the bare basics but you still seem to be struggling.

 

 

Your understanding of gear ratio is correct - the number of turns of the motor that gives you a single turn of the wheel. This is the ratio of the gear train for that loco. A gear train is the variety of cog wheels between the motor and the wheels. Thee can be worm gear (single or double start), spur gear (single or multiple), ending up at a cog that drives the axle on the track.

 

The dimeter of the wheel is measured at the centre point of the tyre, not the flange, i.e. as you say the bit that runs on the track - known as the rolling radius.

 

The easiest way to get a gear back on a motor is with a vice - simply squeeze the gear onto the shaft. Knocking it on is not advised as it may bend the shaft. Failing access to a vice, a clamp can work just as well, a standard G-clamp or one of those that work from a squeeze handle like a mastic gun.

 

Turning a motor by hand is simply that - you poke the ger round with your finger, unless you can rig a simple DC controller to creep it round at a pace where you can count the motor turns.

[JoeLoco06]

Turning a motor by hand is simply that - you poke the ger round with your finger, unless you can rig a simple DC controller to creep it round at a pace where you can count the motor turns.

Got it. I suppose you are marking the shaft to count motor revs?

 

I think something is lost without live demonstration or practice on my part, but I am not an expert on motors and every post has introduced, for me, brand new topics and terminologies... but has really expanded my knowledge of the subject. I will almost definitely be printing this thread as a future resource as it covers a broad range of motor related repairs, types and mechanical/practical expertise.

 

My question about fitting the worm to the motor was actually directed at the shaft. Are there different sizes of shaft that will be incompatiable with the worm/gear? Or is this standardized? Also it seems like the worm is essentally pressure fit to the shaft? Any issues that could arise from a loose fit?

 

Be aware that not all CD motors are designed to run at 12v, some are 6 or 9v. Most will start to work way before the 2-3v that are needed to move conventional ringfield motors. 

This suggests that ringfield motors run on 2-3v even though the DC controller is sending 12v down the track? 

 

Yeah, not sure about the quality of CD motors from auction, or CD motors in general due to the difference in voltage and no indication of level of wear. I thought a hobby site that deals in new RC motors might be a better choice.

[walkingthedog]

Joe you said "This suggests that ringfield motors run on 2-3v even though the DC controller is sending 12v down the track?"

 

The DC controller starts by sending zero volts to the track  then as you turn the knob the voltage increases. When it gets to 1 or 2 volts the motor starts turning. When it gets to 12 it will be going pretty fast. My controller has a maximum of 13.8 volts but only when the knob is turned to maximum, which it never is with a loco on the track.

[LCDR]

I am a little confused as to why knowing the voltage and motor speed is so important when restoring elderly models. The design parameters are fixed by the manufacturers, so restoration ought to be based upon obtaining appropriate replacement parts. 

[BobHughes60]

RAF96 your picture shows a very nice looking gear puller So who manufactures it?Avaialability?

Thanks

Bob Hughes