Manning Wardle L Class 0-6-0 (Agenoria Kit)

[jdb82]

Looks about right. Once the wheels are spinning, the plungers should "dance" along with any sideplay.

Find the lightest multistrand wire and solder to the tags provided. I usually solder the tag to the plunger saving the second nut for the sparebox.

Good plan with the tag - spare small nuts are always useful. Ive got an old telephone which is not being used, and i was planning on taking the wire out of the coiled chord to the handset to solder up to the plungers.

 

Top photo, the plastic housing is not fully back onto the frames - that will increase your preload, and resulting friction.

 

Fully agree about the lightest possible wire - I use stuff that is only 0.5mm over the insulation!

 

Best

Simon

 

 

Thanks for spotting the top photo.....I hadn't noticed, although even if I had, I'm not sure I would have thought about preloading. There speaks the mind of an engineer vs mind of a primary school teacher! I'll give it a go, although could half a millimetre make such a difference? The axel really doesn't want to spin, and that's even after I've polished up the back of the wheel.

[Simond]

Preload & springs. Engineers love springs, and, more or less, everything in the real world has some flexibility about it, so, “everything’s a spring!” (Sort of).

 

The spring is rated as so many Newtons per millimetre of deflection - Newtons (N) being the unit of force and named after the great man. I have no idea what the rate of a Slaters’ spring is, but say it is 2N/mm for easy numbers, though it will be much less than this, I think. Now the other thing I don’t know is the preload when it’s installed properly, but I’m going to make an estimate: when the wheel is fully “outboard”, the pin is only just touching it, and there’s maybe a millimetre of side play in the axle. So when it’s all relaxed and in the middle, the spring is deflected 0.5mm, ie half the free side play, and the force is therefore 0.5 x 2 = 1N

 

Friction is a very strange thing. Newtonian (there he is again) friction between rigid (but they aren’t really) smooth bodies does not depend at all on the area in contact, but only on the force between them, and the materials involved. It gets more complicated, to do with surface finish, lubrication, speed, and other factors, but not necessary for this discussion. And for round numbers again, metal on metal, say 10%.

 

So the spring force pressing the pick-up pin against each wheel on the axle is 1N. So, you have, on each axle, 10% x 2N (one on each side).

 

As the axle slides from side to side, the reduction in force on one wheel is exactly the same as the increase on the other, which means the net force and hence torque and rolling resistance stays the same. In theory!

 

But, if you have a preload, say 0.5mm in your case, the effect is to increase the load on that axle by a further 1N (0.5x2), which is 50%, and that translates into 50% more drag on that axle, and if it’s on the other axles too...

 

And then, to complicate matters, the wheels are never going to be perfectly flat, nor will they be perfectly perpendicular to the axle, so that spoils the theory a bit, makes the springs work a bit too.

 

When you have it running on the rolling road, just look down on the chassis, you’ll be amazed at the movement of the pickups.

 

And the other thing, if the spring housing isn’t fully back against the frames, it could actually catch or rub on the wheel.

 

Oh, and whatever you do, don’t ever try to make the springs shorter by cutting coils off them! If the preload is still too high, shorten the pick-up pins, shortening the spring makes it stiffer, even though it reduces the preload.

 

Hope this helps make sense of it all

Best

Simon

Edited June 7, 2018 by Simond

[doilum]

Whilst we would all like a totally free running chassis, we need good electrical contact. We have to compromise. There are modelers who claim that their wipers are gentler than a butterflys forearm. Good luck to them, I have had little success. Once wired up to a good motor plunger pickups are fine.

Just check the telephone wire is fine multistrand. I now use wire salvaged from phone chargers. Dont cut the wire too short, it limits the dancng.

[jdb82]

Preload & springs. Engineers love springs, and, more or less, everything in the real world has some flexibility about it, so, “everything’s a spring!” (Sort of).

 

The spring is rated as so many Newtons per millimetre of deflection - Newtons (N) being the unit of force and named after the great man. I have no idea what the rate of a Slaters’ spring is, but say it is 2N/mm for easy numbers, though it will be much less than this, I think. Now the other thing I don’t know is the preload when it’s installed properly, but I’m going to make an estimate: when the wheel is fully “outboard”, the pin is only just touching it, and there’s maybe a millimetre of side play in the axle. So when it’s all relaxed and in the middle, the spring is deflected 0.5mm, ie half the free side play, and the force is therefore 0.5 x 2 = 1N

 

Friction is a very strange thing. Newtonian (there he is again) friction between rigid (but they aren’t really) smooth bodies does not depend at all on the area in contact, but only on the force between them, and the materials involved. It gets more complicated, to do with surface finish, lubrication, speed, and other factors, but not necessary for this discussion. And for round numbers again, metal on metal, say 10%.

 

So the spring force pressing the pick-up pin against each wheel on the axle is 1N. So, you have, on each axle, 10% x 2N (one on each side).

 

As the axle slides from side to side, the reduction in force on one wheel is exactly the same as the increase on the other, which means the net force and hence torque and rolling resistance stays the same. In theory!

 

But, if you have a preload, say 0.5mm in your case, the effect is to increase the load on that axle by a further 1N (0.5x2), which is 50%, and that translates into 50% more drag on that axle, and if it’s on the other axles too...

 

And then, to complicate matters, the wheels are never going to be perfectly flat, nor will they be perfectly perpendicular to the axle, so that spoils the theory a bit, makes the springs work a bit too.

 

When you have it running on the rolling road, just look down on the chassis, you’ll be amazed at the movement of the pickups.

 

And the other thing, if the spring housing isn’t fully back against the frames, it could actually catch or rub on the wheel.

 

Oh, and whatever you do, don’t ever try to make the springs shorter by cutting coils off them! If the preload is still too high, shorten the pick-up pins, shortening the spring makes it stiffer, even though it reduces the preload.

 

Hope this helps make sense of it all

Best

Simon

 

I think I got that. Basically, get the housing pushed fully back to the frame, coz in the world of maths & physics, it makes a difference. Right?!

 

'twill be one this weekend, along with the remains four.  

 

Whilst we would all like a totally free running chassis, we need good electrical contact. We have to compromise. There are modelers who claim that their wipers are gentler than a butterflys forearm. Good luck to them, I have had little success. Once wired up to a good motor plunger pickups are fine.

Just check the telephone wire is fine multistrand. I now use wire salvaged from phone chargers. Dont cut the wire too short, it limits the dancng.

 

I'll get them all installed and hook up the gearbox and motor and if it's got enough grunt. It's not an enormous motor, and there's not room in the firebox for anything much bigger. A bit of trial and error may be needed!

[doilum]

Prototypically, it won't have that much to pull. Make sure it is fully ballasted before reaching any judgments on pickups or tractive power.

[jdb82]

I need to chill a little more. Doilum, you were quite right - get everything fitted together before setting into panic mode. Despite the plungers preventing free running, and the problems with a bent and subsequently elongated coupling rod, it still runs relatively well. Maybe the little motor has a little more grunt than I gave it credit for. It does sound to be working a bit harder than I expected, but nothing too major. 

No oil or running in, crankpins not secured and the plungers just pushed into place. Hopefully it will keep working after everything is finally fixed!! 

 

The brake pull rod is next, followed by the sand pipes and a couple of other small details. i'll need to make an air reservoir tank from scratch at some stage, as Bamburgh was fitting with a Westinghouse pump. I might leave that until I've got the footplate built though......think out loud. Must stop rambling!

 

https://youtu.be/ppmSJ6QpcMA

[doilum]

I need to chill a little more. Doilum, you were quite right - get everything fitted together before setting into panic mode. Despite the plungers preventing free running, and the problems with a bent and subsequently elongated coupling rod, it still runs relatively well. Maybe the little motor has a little more grunt than I gave it credit for. It does sound to be working a bit harder than I expected, but nothing too major. 

No oil or running in, crankpins not secured and the plungers just pushed into place. Hopefully it will keep working after everything is finally fixed!! 

 

The brake pull rod is next, followed by the sand pipes and a couple of other small details. i'll need to make an air reservoir tank from scratch at some stage, as Bamburgh was fitting with a Westinghouse pump. I might leave that until I've got the footplate built though......think out loud. Must stop rambling!

 

https://youtu.be/ppmSJ6QpcMA

Not bad running, though there seems to be one slighly tight spot to sort before it goes to paint. Try a little more running without pickups or gears, or with gears only, try very slow running to find the stalling point. It may be necessary to do this as a pair of four coupled rods.

I only glue the Slaters bushes if I mess up! Leaving /removing the paint provides the final adjustment.

[doilum]

Are these the original 12ba crankpins?

If so, have you considered upgrading to 10ba? This was forced on me by the valvegear on 82004. I have been sufficiently impressed that I will retrofit them as other locos require maintenance. A set of taps cost less than £10 and the crankpin bushes do not need any further pre drilling.

[Simond]

Strongly support Doilum’s suggestion. My approach as follows;

 

Degrease the tap.

 

Tap the wheels. Ensure they are not oily or greasy beforehand. Degrease if necessary. Good time for the metal-black too...

 

Fit 10BA screws from back of wheel, having smeared the last few threads with epoxy before tightening.

 

Leave severely alone for 24 hours, preferably more.

 

Place the backs of the wheels on a bit of wet&dry on a flat board, and polish the backs. Fit the wheels.

 

Tap the crank bushes. Prefer using a lathe, but a toolmakers clamp and a hand tap wrench will do at a push.

 

File (or better still, mill) flats on the flange of the crank bushes.

 

Assemble - you will need one or two 10BA washers on the screw before you drop on the rod, and screw on the bushes.

 

Snip off the excess length of the screws - Xuron cutter will do this. File flush.

 

Et voila!

 

Best

Simon

[doilum]

My method is a little less technical.

Mount the tap horizontally in the vice.

Put the bush into a pinvice and tighten.

Gently introduce the bush to the tap.

One twist forward half twist back. You quickly get a feel for it.

The bush will need filing to length. I prefer to do this after tapping and then rerun the tap through to clear the threads.

The bush will be ultimately secured with loctite threadlok.

[Simond]

Yes, good approach, with the exception of the threadlock, which I never ever use to secure crankpin bushes.

 

The screw must remain fixed in the wheel, hence the epoxy, 24h preferably.

 

The bush should not need anything more than a firm tightening, having respect for its modest dimensions. If it unscrews, there’s something binding, better to fix that than to immovably glue the bush to the screw - and for the damage it can do if it goes wrong, see my Duchess thread, or seek out David LO Smith’s website about remachining wheels where the crankpin has broken.

 

Of course, if you thread the bush and screw it on with the flange against the wheel, and then secure the rod with a washer and nut, that is a different story, and threadlock would be appropriate.

 

Best

Simon

[doilum]

The threadlok can be broken with judicious use of a clean soldering iron.

Each to their own. I have lost too many nuts over the years!

[Simond]

True,

 

But which way do you put your bushes on?

 

Best

Simon

[jdb82]

Yes, they are the original 12BA crankpins. Hadn't thought of installing the crankpin bush with the flange the opposite way round from convention (or from the instructions at least). In my box of goodies that arrived last week, I just happened to buy some 10BA taps, nuts and bolts. I'll have a play and see what happens.

 

Just one question though - how does this help with the smooth running? Is it just that a bigger pin and a firmer fixing to the bush keeps things straight and in place?

[Simond]

The 12BA screws are slightly loose in both wheel and bush. Tapping both to 10BA removes that play, and hopefully gives you a more solid assembly. I use the flange of the bush to retain the rods, although it’s entirely possible to have the flange inboard, and use a washer and nut to retain the rods. I think the flange looks more like the real thing, so I do it that way round. Photos in my Duchess thread, also somewhere in the PD thread, and maybe in the Garratt too, can’t remember!

 

I’m sure the standard 12BA approach is “good enough”, but I reckon the 10BA approach is better.

 

Best

Simon

[doilum]

True,

But which way do you put your bushes on?

Best

Simon

Sorry should have made that clear. The bush is reversed becoming the "nut". I put a thin washer between the rod and wheel. The bush passes through the washer tight against the wheel.

[Simond]

We’re playing on the same page then!

 

Best

Simon

[jdb82]

Just to prove I've found the same page......the 10 minutes of procrastinating I allowed myself from work today allowed me to break out the tap. 

 

[Guest Isambarduk]

... or seek out David LO Smith’s website about remachining wheels where the crankpin has broken.

 

See here: www.davidlosmith.co.uk/Model-Parts.htm#RescuingDrivingWheels

 

I’m sure the standard 12BA approach is “good enough” …

 

The 12BA is perfectly adequate and I have never found the 12BA screws to be loose in the Slater's wheels; in fact, they cut their own 12BA thread.

 

If I need to reverse the bushes for clearance behind a crosshead, I make my own bushes with 12BA threads and two holes in the face to engage a peg spanner to tighten them, but 10BA is quite possible.  See here: www.davidlosmith.co.uk/Model-Parts.htm#TopHatCrankpinBushes

 

David

Edited June 11, 2018 by Isambarduk

[doilum]

Just to prove I've found the same page......the 10 minutes of procrastinating I allowed myself from work today allowed me to break out the tap. 

 

IMG_8199.jpg

It may be a trick of the light, but this appears to be a bolt (not fully threaded to the head). In this case you will need Simon's araldite as there won't be many threads in the wheel. A screw thread is better.

I would slim down the head in the vice leaving just a hint of the slot. This will reduce the need for countersinking.

A flat bottomed hole is preferable. In the absence of clever tools, I ground off the point of an old drill to ream out the countersink.

[Regularity]

I’m sure the standard 12BA approach is “good enough”, but I reckon the 10BA approach is better.

 

If I may make an observation, that approach is the mark of a true craftsman: going one step beyond “good enough”.

 

And I am not saying that just because I am also a “Simon D”!

[Simond]

Thanks

 

I’m sure there are days when I merit such a kind comment

 

And days when I don’t!!!

 

Best

Simon

[Regularity]

And the days when you don’t, are the days when you have to go back and repeat the work...!

Enlightened impatience

Edited June 10, 2018 by Regularity

[Michael Edge]

See here: www.davidlosmith.co.uk/Model-Parts.htm#RescuingDrivingWheels

 

 

The 12BA is perfectly adequate and I have never found the 12BA screws to be loose in the Salter's wheels; in fact, they cut their own 12BA thread.

 

If I need to reverse the bushes for clearance behind a crosshead, I make my own bushes with 12BA threads and two holes in the face to engage a peg spanner to tighten them, but 10BA is quite possible.  See here: www.davidlosmith.co.uk/Model-Parts.htm#TopHatCrankpinBushes

 

David

 

I would have said exactly the same but I've just used a set of 7846M in which the 12BA screws are a sliding fit. I fitted them in my usual way though, countersink them in the back of the wheel, lock in with superglue and fill the hole at the back up with epoxy.

[Simond]

Yep, there is a time to stop, rather than “just finish this bit” and spotting the moment it before it all goes pear-shaped is a knack that after some 50 years of modelling, I’m just getting to understand.

 

Many moons ago, at a show, I bumped into a band of modellers discussing a brake cylinder - it was the master for a casting, and a thing of beauty, on which I commented positively, and finished by saying “I wish I had the patience to make something that good”

 

The owner was aggrieved “what about the skill?!??!”

 

“If I had the patience to make a load of bad ones, and still keep going, I’m sure I’d learn to make a good one eventually”

 

He wasn’t mollified, but I think perhaps he should have taken it as a compliment

 

Best

Simon