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Edwardian,

 

Is the motor physically moving around the axis of the gears when powered on instead of moving the loco? This could cause the contacts on the motor to come into contact with the body, hence why it won’t run with the body on. I’ve had the same problem on kit builds before. As a test, perhaps get some fine string and tie a loop around the motor and chassis in order to told it in the horizontal position when running? Hopefully I’ve been of some help.

 

 

Douglas

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On 22/01/2021 at 18:00, Donw said:

I have had two friends who were known to be wizrds possesing magical powers when it came to locos. One is Frank Thompson a RAF instructor.  People would ask him to take a look at their locos which did not run right. The other is Steve Naylor. Steve used to help operate my 0 gauge exhibition layout. People who knew us would bring locos along for attention. Quite often at an exhibition Steve would be sat at a table behind the layout orting a loco out. These gentlemen would often sort things out with a few tweaks, a bit of a clean up and possibly a touch of oil. If not they would be able to identfy the cause and what the remedy would be.

Not being in that class I have to work through the problem. 

One I would get out a multimeter and firstly switch it to read ohms  probably the 200ohm scale first touch the probes together that will indicate  what a short circuit reading is when you separate them is will show an open circuit reading.

Then touch the probes against a wheel on each side.

If the meter reads a very low reading that suggests a short  if it reads above 200ohms  it looks like an opencircuit.

If it give a reading of somewhere in the middle it looks llike the loco is conducting the electricity. 

I it looks open circuit at the wheels try the probes on the pick up wires. 

Repor your findings

 

Don

 

 

Right,

 

Have found meter.

 

There are 2 leads and 3 holes. What goes where, please?

 

20210123_183353.jpg.90822cdc1cf502e62fecb6d5f5b2f1eb.jpg

 

1 hour ago, nick_bastable said:

have you checked the B2B   from the photo they look wrong ?

 

Nick B

 

 

1 hour ago, Caley Jim said:

 

The issue of the wheels being not at the correct back-to-back should be able to be remedied.  I don't know what the correct measurement is for 00, but I would suggest you take a strip of 40thou styrene and trim one end until it will just slip in between the flanges of a wagon or loco which is correct.  Now use this as a gauge to see how those on this loco compare.  Those that are too tight for the strip to go in need to be eased out until they do. if the strip is loose then they need pushed in slightly.  You can also use the strip to check if the wheels are true on the axle by checking with the strip at different places on the circumference.  If they are not, as I suspect  from the first photo you posted, then someone more familiar with 00 wheels will need to advise if it might be possible to remedy that..

 

Jim

 

IIRC, OO B2B is 14.2mm, up to 14.5 permissible. Others seem to quote 14.5 to 14.8

 

The B2B on the model is way out, and not consistent.  

 

The bogie wheels, which I've altered, and which now sit happily on the track, were 16mm and over! 

 

The coupled wheels are more like 15mm in one case, and 15.8mm in the other!

 

I'd be reasonably confident that the correct B2B would allow the thing to stay on the track, however, I have no idea how to do this to the coupled wheels and no confidence I wouldn't wreck it.  

 

1 hour ago, Caley Jim said:

In the motor mount is moving, then that could cause the erratic running as the gears will be going in and out of mesh.  The first thing is therefore to find how you can stop that.    It needs to be fixed in a position where the gears are engaged, but there is still a very slight amount of play between them.  Not being able to study the chassis 'in the flesh' I can't readily advise how you do that, but slipping a thin strip of paper between the relevant gears while you fix the motor mount (with the gears pressed hard into the paper), and then removing it once the motor is rigidly fixed, should give some running clearance.

 

Jim

 

I really can't see where I'd slip the paper in, and the wires are in the way.

 

29 minutes ago, RodneyS said:

The motor and gearbox in your loco looks like an escap RG4 with the small diameter 1219 motor.

When they were new the instructions stated that they were lubricated for life and any further lubrication would invalidate the guarantee.  Unfortunately the grease gradually solidified and the gears seized up.  I have one which I have never used and the gears are completely jammed.   Even if they have been used they can gradually get slower.  A friend told me to remove the motor, soak the gearbox in IPA and then lubricate it with clock oil.

 

I remember Iain Rice used some of these and found that the locos surged when running.  This was due to the controllers at the time not being suitable for the small motor.  It was as a result of this that Stuart Hine produced his Pentroller with three settings.  One was for what he called 'iron age' motors, the second for the RG4 with the larger motors and the third for the 1219.

 

I would imagine that most of the modern controllers would give good results now.

 

It could be that your gearbox is rather 'sticky' and/or perhaps the motor doesn't like the controller you are using.

The problem is that the gearbox cannot be removed without taking the wheels and axles out.

There is a grubscrew fixing the final gear to the axle so if that was slackened you might be able to run the motor and gearbox without the wheels turning.  This would also enable you to check that the wheels ran freely.

 

Please forgive my ignorance but is it an F ?  If so then it may have been made from a Jidenco/Falcon Brass kit.

Rodney

 

 

 

I think the issue is the angle of the motor mount and/or intermittent electrical connections.  Could easily be wrong, but that's how it strikes me.

 

It is an F

 

(in more ways than one)

 

15 minutes ago, Donw said:

 

That looks to me to be a motor/gearbox  possible a Portescap. I so that is good news. I suspect that the motor moving is not the major issue as the gearbox should be keeping it in mesh. The bad news is some Portescaps suffered from a plastiic gear on the worm shaft which could split. That could be causing erratic drive. This would show as the motor turning but no movement particularly under load. Whereas you say the motor runs erractically. Which suggest either erratic electrical connection, an erratic short or a mechanical problem causing binding or jamming.  Some of these may be outside your current abilities. What it really needs is someone to look it over with you to aid diagnosis. This is not practical under lockdown. I would put it to one side hopefully in the near future you could take it along to a show and get some good advice as to the likely causes. Sending off to someone could get it sorted but you wouldn't learn anything. Having someone investigate alonside you would be more helpful

 

Don

 

Motor was billed as a Portescap.  Gears look OK.  Motor seems healthy and when it runs, it runs well enough (so far as I can tell, because it keeps falling off the track, no doubt due to the crazy B2Bs.

 

I agree, it is beyond me and I need someone beside me showing me how to fix this. 

 

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7 minutes ago, Edwardian said:

 

 

Right,

 

Have found meter.

 

There are 2 leads and 3 holes. What goes where, please?

 

20210123_183353.jpg.90822cdc1cf502e62fecb6d5f5b2f1eb.jpg

 

 

 

 

IIRC, OO B2B is 14.2mm, up to 14.5 permissible. Others seem to quote 14.5 to 14.8

 

The B2B on the model is way out, and not consistent.  

 

The bogie wheels, which I've altered, and which now sit happily on the track, were 16mm and over! 

 

The coupled wheels are more like 15mm in one case, and 15.8mm in the other!

 

I'd be reasonably confident that the correct B2B would allow the thing to stay on the track, however, I have no idea how to do this to the coupled wheels and no confidence I wouldn't wreck it.  

 

 

I really can't see where I'd slip the paper in, and the wires are in the way.

 

 

I think the issue is the angle of the motor mount and/or intermittent electrical connections.  Could easily be wrong, but that's how it strikes me.

 

It is an F

 

(in more ways than one)

 

 

Motor was billed as a Portescap.  Gears look OK.  Motor seems healthy and when it runs, it runs well enough (so far as I can tell, because it keeps falling off the track, no doubt due to the crazy B2Bs.

 

I agree, it is beyond me and I need someone beside me showing me how to fix this. 

 

afraid a 4mm person needs to aid the B2B issue

 

as for the gear/motor issue blutac is your friend

 

Nick B

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24 minutes ago, Edwardian said:

Right,

Have found meter.

There are 2 leads and 3 holes. What goes where, please?

20210123_183353.jpg.90822cdc1cf502e62fecb6d5f5b2f1eb.jpg

 

 

Black to COM

Red to V mA

 

EDIT: I have the same meter but branded CEN-TECH. It works reasonably well, but I do prefer my Simpson 270.

Edited by J. S. Bach
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12 minutes ago, Edwardian said:

There are 2 leads and 3 holes. What goes where, please?

OK.  This is exactly the same as the one I have.   You'll need a PP9 battery in it.   Black lead in the 'COM' socket, red lead in the VΩmA one (Volts, Ohms = resistance, milliAmps = current) one above it.   Then set the dial to the 200Ω mark at the very bottom of the dial.  The reading should be 1.  If not, the battery is dead.    It doesn't matter what way round you place the leads to measure resistance.  A reading of close to zero indicates a short (touch the probes together to see this), if it stays at 1 you have an open circuit.  For example if you hold one probe against one driving wheel and the other against the other driving wheel on the same side you should get a reading near 0, maybe 0.something.  If not, then either one or other wiper is not connecting with the wheel.

 

Since the motor does run, I'm beginning to think that there is not a major electrical problem (other than dirt or a poor connection) and that the floppy motor and dodgy wheels are more the issue.

 

As you say, that really needs someone who knows what they are doing to sort it out (assuming it can be sorted).  Like @nick_bastable says, someone with 4mm knowledge rather than we smaller scale folk.

 

Jim

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On 22/01/2021 at 18:00, Donw said:

 

One I would get out a multimeter and firstly switch it to read ohms  probably the 200ohm scale first touch the probes together that will indicate  what a short circuit reading is when you separate them is will show an open circuit reading.

Then touch the probes against a wheel on each side.

If the meter reads a very low reading that suggests a short  if it reads above 200ohms  it looks like an opencircuit.

If it give a reading of somewhere in the middle it looks llike the loco is conducting the electricity. 

I it looks open circuit at the wheels try the probes on the pick up wires. 

Repor your findings

 

Don

 

OK

 

- Turned to 200ohms

 

- touched probes; gives readings in the 50s-60s

 

-Rear drivers: (i) in the 60s (ii) 15-19, then 1 (which is what shows when not touching anything) (iii) 60s-70s

 

-front drivers: (i) 1; (ii) 1

 

- front right to rear left (i) 1; (ii) 60s-70

 

- front left to rear right (i) 1; (ii) 1

 

 

 

 

 

 

Edited by Edwardian
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2 minutes ago, nick_bastable said:

Honorable  Mayor

 

my I suggest this well at least the first chapter  https://www.merg.org.uk/ebook.php

 

education does not stop after university

 

Nick B

 

 

 

Books about electricity go like this for me:

 

(i) Really basic information I understand, (ii)  slightly more information, which is still not sufficient for any practical application, I understand whilst reading but, within seconds of finishing, it's gone (iii) information sufficiently advanced to be of use; meaningless to me.

 

I've tried to understand the subject many, many times. Your suggestion is enough to give me modeller's PTSD. So, thanks, but no thanks, I'm depressed enough as it is!!!!

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15 minutes ago, Edwardian said:

 

OK

 

- Turned to 200ohms

 

- touched probes; gives readings in the 50s-60s

 

-Rear drivers: (i) in the 60s (ii) 15-19, then 1 (which is what shows when not touching anything) (iii) 60s-70s

 

-front drivers: (i) 1; (ii) 1

 

- front right to rear left (i) 1; (ii) 60s-70

 

- front left to rear right (i) 1; (ii) 1

What do you get touching the two drivers on the same side?  I.e front left and rear left and then front right and rear right.  Touching those on opposite sides doesn't really tell you much.  It would appear that there is poor connection between wheel and wiper somewhere but what you've done doesn't pin-point  where.  Make sure the probes are making firm contact with the wheels.  Rub them on the wheels to make sure.  Another point is to make sure your battery isn't weak as this can cause spurious readings.  I get 0.6 when I touch the probes together.

 

Jim

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8 minutes ago, Caley Jim said:

What do you get touching the two drivers on the same side?  I

 

1

 

was getting 5s and 6s touching the probes.  Now 2s and 3s.a 

 

EDIT: OK, with rubbing, one side went bat--crazy (5-40) then, on a second go, in the 20s

 

Other side still 1

Edited by Edwardian
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Hey, James, look what you’ve tried and learnt in just 24 hours. You’re doing alright. With your meter, it looks nice and new, so the internal battery shouldn’t be flat, the leads go in middle and bottom holes, then turn the pointer to the black pocket bottom right. If you touch the ends of the leads together, you get an indication to show they’re touching, with luck a beep like on my old meter. You then can go round putting the ends on places, say, like a wheel rim and a motor lead to see if there’s an electrical path between them.

if the motor can flap about, it probably is being retained by the body when that’s back on. Blutak has just been suggested, even if only temporary when just trying the chassis. Also check that the tags and wires on either side of the motor aren’t sticking out beyond the body of the motor, these could be grounding on the body.

Is there a lot of movement sideways on the driving wheels? Stephen has spotted how narrow the frames are, I can see the need for that with the bogie wheels, but really the drivers shouldn’t have any sideways play, not just for two pairs, it allows them to bashing into the superstructure, but also it’s asking a lot of the pickups to track excessive movement.

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16 minutes ago, Edwardian said:

Other side still 1

That tells you that the two wheels on that side are not electrically connected, or one or other of the probes is not making good contact.  Give the rims a good clean and check that the back where the wipers contact, and the wipers themselves, are clean.  If you touch the probes to the edge of the flanges and rub you will get better contact than on the rims, especially if the latter are not clean.  If you touch one wheel and the wipers on the same side, then do the same with the other wheel, if you get a 1, then there is poor, or no, electrical continuity between the wiper and that wheel.  This shows how you have to really drill down to try and find where exactly the problem lies.

 

Jim

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James, the motor-gearbox is an RG4, so the driven axle is running in the bearings of the gearbox. The mesh can't change if the gearbox moves in the chassis.  Jim's suggestion of changing mesh applies when the final-drive axle doesn't have bearings inside the gearbox, and we hand't established the type of mechanism when he wrote that.

 

However, the motor flailing around might produce enough force to bounce it off the track. Ultimately, it will need a "torque reaction link", which is a posh name for a bit of wire to stop it rotating in the frame. But that's for later.

 

You have three problems to solve:

  1. the gearbox may be FUBAR;
  2. the track holding is inadequate;
  3. the pick-ups are not reliable.

I'd attack them in that order, because replacing the gearbox in this design is a major rebuild.

 

Therefore, I suggest propping it level with the wheels, off the track, putting some volts directly on the motor terminals and videoing how the drive behaves from as many angles as possible. Then put the video on here (via YouTube, maybe, although you might be able to upload the file directly), and somebody in the parish can probably spot the drive problems. 

 

If it drives smoothly with the wheels off the track, then you've dodged a bullet the size of a howitzer round and the rest may be fixable. If it glitches when off the track, then the problem might not be the gearbox, it could be quartering; you can check this by peering through the spokes. But better, undo the set screw locking the final gear to the axle and see if the gearbox will run smoothly with the wheels stopped. Even if the gearbox is damaged, it may be FU but not BAR, as noted above regarding the lubrication.

 

It would help if we knew how the coupled wheels are held on. Are they Romfords with cosmetic blanks over the axle ends? If so, then stripping down may be quite easy. If they are Gibsons or similar, are they pinned to the axles or just an interference fit?

 

Concerning the track holding, the weight distribution will be rubbish with the motor facing forward, unless the firebox is full of lead. It will try to lift the rear coupled wheels. If, given that, the front coupled wheels are not firmly on the track, then it must be taking the weight on its bogie, with the bogie mount unsprung and a little too high. That in itself will spoil the pick-up. It will also put all the drive stresses through the coupling rods and that will make any quartering problems worse.

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53 minutes ago, Guy Rixon said:

James, the motor-gearbox is an RG4, so the driven axle is running in the bearings of the gearbox. The mesh can't change if the gearbox moves in the chassis.  Jim's suggestion of changing mesh applies when the final-drive axle doesn't have bearings inside the gearbox, and we hand't established the type of mechanism when he wrote that.

My apologies.  Teach me to proffer advice on hardware with which I am totally unfamiliar.  Apart from that I totally agree with what @Guy Rixonhas said. (apart from the fact that I have no knowledge of 4mm wheels.)

 

Jim

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Thank you both.

 

I cannot work out what sort of driving wheels they are and how they attach.

 

Given the back to back issue, they will have to come off, though I may not be up to the job.

 

I would have to de-solder the outside brake rigging, to which the pick-ups are attached!  The wheels have to come off, however, because of the B2B issue.

 

I will try powering off the rails tomorrow and give you some pictures of the wheels and axles. 

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1 hour ago, Guy Rixon said:

Are they Romfords with cosmetic blanks over the axle ends?

You can take a scalpel and very carefully probe around the wheel centre to see if you can find the edge of a thin brass overlay over the axle ends / centre boss of the wheels. If this is present, then odds on, the wheels are Romfords and can be unscrewed with the fabled Romford screwdriver. 

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36 minutes ago, Edwardian said:

I would have to de-solder the outside brake rigging, to which the pick-ups are attached!   

With all due respect, I don't think they can be.  Otherwise there would be a dead short through the brake cross rods, if they are continuous, as they appear to be from the first photo you posted.  Also, from that, it appears to me that the wipers are attached to a piece of  veroboard fixed between the front of the front drivers and so totally separate from the brake rigging. I can't quite make out the details of how the latter is attached.

 

Jim

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Guy'si thoughts are very much in line with my own.  My  0 gauge RG7 powered bulldog is over 40 years old.  the driving wheels are sprung  so the motor is free to move somewhat as the gearbox holds the motor in alignment with the axle so although the axle is sprung on both sides and can move up and down alignment is not an issue. Interestingly although the driving wheels and the tender wheels are all sprung the bogie is not with just a plain pivot with no side play it can go round curves of less than 4ft (sharp or 0 gauge). It is also the most sure footed of all my locos.

 

It will be interesting to see  how it run with the power applied direct to the motor (i.e bypassing pick-ups tec. and off the rails. I would use a couple of strip of wood to support the ends of the chassis allowing the wheels to be free.

If something has gone drastically wrong with the wheels a new set may be the simplest answer for you.

 

Don

 

I am just wondering if you have done a zoom session this would be an ideal thing to do  so a few of us could be in on it. 

 

Don

Edited by Donw
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You could have a zoom session with “a few of us”, but I’ll bet a pound to a penny that a one-to-one with one of the contributors on here will be quicker & simpler.  
 

I’m an Engineer by profession, and my experience is that experts are rather like clocks.  If you have one, you know what time it is.  If you have several, you’re never quite sure...

 

do let us know how you get on

 

(and my tuppenceworth: clean the gearbox, and the pickups, lubricate gearbox with decent oil - I use the stuff for beard trimmers - and fix the motor to the chassis temporarily with blu tak or sticky tape.  Run it with a couple of wires judiciously touching the motor terminals and the wheels in the air.  If that’s good there’s nothing wrong with the motor, gearbox or coupling rods.  Anything else is a doddle to fix.  Good luck!)

 

atb

Simon

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1 hour ago, Edwardian said:

Thank you both.

 

I cannot work out what sort of driving wheels they are and how they attach.. 

Four possibilities:

  1. Romfords, so unscrewable;
  2. Gibson/Sharman/etc held on by friction;
  3. as case 2, but glued on;
  4. as case 2, but locked in place by a pin, passing obliquely through the back of the wheel into the axle.

Case 1 is the most favourable for repair. Case 2 need a wheel puller (GW models do one). In cases 3 and 4, the wheels cannot be removed and reused, nor can they reasonably be regauged. Actually, the chance of reusing friction-fitted wheels isn't great anyway; they tend to slip or wobble after refitting.

 

EDIT: I looked up the Romford range on the Markits site and they don't do anything as big as a 7' coupled wheel. So I suspect these are either Sharman or Gibson wheels.

 

EDIT2 dammit: I missed one. There is a Markits/Romford wheel for the Johnson 2P that is ~7' on the tyre.

Edited by Guy Rixon
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39 minutes ago, Caley Jim said:

With all due respect, I don't think they can be.  Otherwise there would be a dead short through the brake cross rods, if they are continuous, as they appear to be from the first photo you posted.  Also, from that, it appears to me that the wipers are attached to a piece of  veroboard fixed between the front of the front drivers and so totally separate from the brake rigging. I can't quite make out the details of how the latter is attached.

 

Jim

 

I'll post a clearer picture tomorrow, but, essentially the pick ups to the front wheels use the brake framing as support, but run via an insulated sleeve at that point to prevent a short. 

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2 minutes ago, Guy Rixon said:

Four possibilities:

  1. Romfords, so unscrewable;
  2. Gibson/Sharman/etc held on by friction;
  3. as case 2, but glued on;
  4. as case 2, but locked in place by a pin, passing obliquely through the back of the wheel into the axle.

Case 1 is the most favourable for repair. Case 2 need a wheel puller (GW models do one). In cases 3 and 4, the wheels cannot be removed and reused, nor can they reasonably be regauged. Actually, the chance of reusing friction-fitted wheels isn't great anyway; they tend to slip or wobble after refitting.

 

Hmm not good news, but I,ll post some better pictures tomorrow.

 

Thanks

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Having had another look at the underside, I am sure the pick-ups are not connecting to the brake rigging because you can see black insulation on the pick-up wire where it passes the cross rods of the brake rigging. It also occurs to me if the spokes of the driving wheels are nylon they could be Sharman Wheels they were common around the time of Portescaps. These are a simple push fit on plain axles and care was needed fitting them to get them straight (no wobble) and at the right BtoB.

 

Don

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