Scalefour Forum

Hi Dave,

Guitar wire (which is the wire that comes with the Bill Bedford springing units) does have a curve to it normally, as it is coiled in the packet. In addition, the act of clamping it in the fingers to the bearing carrier does tend to worsen this. Thus, it is necessary to bend the wire back such that it is flat along its length and perpendicular to the direction of travel.

I have also concluded that the wire that comes with the etches is a bit thick. I now replace it with 10 gauge (I think it is 11 gauge in the pack) - it might not seem much but I think it makes a difference. Strings Direct is the best place I know to get strings and I use the brand Ernie Ball https://www.stringsdirect.co.uk/strings ... ie-ball-m2

All the wheels in their "at rest" position should be at a consistent height - i do this by holding the wagon upside down and just look to make sure the wheel treads are all at about the right height. Then, the bearing should give a bit when the wagon is loaded; but not be fully compressed - it is from this that I concluded that a slightly lighter gauge wire was required as I didn't think they had much if any give on the 11 gauge wire.

You would also be well advised to use both a Alex Jackson/buffer height gauge from the stores and the Brassmasters (there are others) axle alignment jigs. They both help get the vehicle to run reliably.

Don't give up on springing. It is a mute point whether it is required on a short wheelbase wagon if you can make these neatly square so that all wheels are at an equal height and your trackwork is pretty good. Both these "ifs" are actually quite difficult to achieve and the use of suspension takes the bother away! Sprung vehicles also roll across track much more smoothly and "look" much heavier than something bouncing along.



Mark

I can't add a lot to Mark 's description, aside from on the ride height. The 'at rest' position of the wheels shouldn't be hard up against the top of the axlebox slot, but sit with room to move both up and down (so if there is a hump only one wheel has to rise, and for a dip only one drops - helping that visualisation of mass Mark mentioned).

If you're free, and in the right part of the world, there will be lots of people at Scalefour North in Wakefield who would be able to give you visual demonstrations and talk it through - not only those demo'ing, but the layout owners, operators, and traders are a friendly bunch!

Beakie wrote:
Is compensation really necessary if I cant crack this(is my Thinking). I feel that i'm so very nearly there, but so close to EM Gauge with P4 wheels as I read in a recent P4 newsletter(this appeals at the moment).

I would be so grateful if someone could un complicate this for me. any thoughts......

Dave

It’s desirable but not necessary for shorter wheelbase vehicles. I tend to set a 12ft wheelbase as my upper limit for kits but slightly longer if converting RTR wagons.

HTH

Jim

I’m with Jim on this, it’s nice to have springing or compensation but is not required on a short wheelbase wagon, so long as the vehicle sits nicely on a sheet of glass, which is actually easier to achieve than you might think.

Not over complicating things, as you start, is a very good way to achieve success. Once you get the hang of working with the fine wheels and the standards you will begin to experiment with other things. One such experiment I would generally counsel against is using unaltered EM wheels on P4 track. One of our number in particular (although there may be more) has made this work - for him - but the dimensions and clearances do not stack up and I would strongly recommend that you get some experience first with the proper P4 wheels and track before trying anything like this. It really shouldn’t be necessary; the proper P4 standards have been proven to work impeccably over many years.

Philip

I'm largely with Jim and Philip on this. I would add that a minimal amount of sideplay is needed on "rigid" wagons to allow for some adaptation to minor track irregularities [the real thing, especially when empty, could bounce a lot, often very noisily ]. On r-t-r conversions done by just changing the wheelsets this may sometimes need the axle points to be blunted slightly. On Philip's point about using a glass sheet, I use a mirror tile, which can help with seeing if all four wheel flanges are making contact.

Without intending any criticism of your work, can I ask if you are happy that the bends in the axleguard sets are at right angles, that the sets are flat to the wagon floor and parallel, and that all the bearings are freely moving in the axleguards? If the answer is no to any of these, then problems are likely.

Beakie wrote:Been considering these for a while, so on the shopping list, esspecially Buffer Height Gauge..... but as a side note, how do you adjust buffer height?

I would say that the Brassmasters [or other] axle alignment jig is probably the more important - non-parallel axles or axles not at right angles to the solebars is a recipe for trouble. Slight differences in buffer height are probably less of an issue, in my opinion. Buffer height can usually be adjusted by packing the axleguard sets off the wagon floor.

Beakie wrote:... but as a side note, how do you adjust buffer height?

For most stock, you need packing between the floor of the wagon and the brass of the axleguards. For most plastic kits, where the bottom of the floor is sitting at the prototypical height w.r.t the rest of the model, you need 0.5mm packing.

There are rectangular cut-outs in the axleguard fret, one per wheel, into which the spring carriers need to retreat at full suspension-travel. It helps to keep the packing clear of these. A strip of 0.020" plasticard about 15mm wide down the centre of the wagon is enough.

If you are feeling rich, I can point you at some printed bases that pack the axleguards to the right height and also set the wheelbase. But you can get the same effect with care, plasticard and the axle-setting gauge.

Hi David,

A couple of points to note concerning spring wire. I use the 11thou wire supplied but two things need to be ensured in order get the springs working correctly. You picked up on one essential, the need to mount the springs in the hangers consistently. I do this, with the Bill Bedford units, by using light pressure on a scalpel handle to close the fingers on the wire. This seems to give me consistency and you'll soon get the knack of how much pressure to use, it isn't much! Secondly, 25gms is really too light for a wagon. I use 50gms in mine, whether sprung or compensated, and it makes a great difference to the running. If any of the above is unclear then do PM me and I'll try to clarify.

What has already been said about getting axles parallel with each other is sound advice and absolutely essential.

Hope this helps.

John.

Hi Dave,

When I started doing P4, I wanted to 'do the right thing' and also used Bill Bedford springing units (still have some to install on some wagons). However, I also found that compensation (internal or external rocker - done both) was actually easier, so I did a fair few wagons like that, using MJT components.

However, as time went by, I simply couldn't be bothered with the fuss and faffing, so I did a few short wheelbase wagons as rigid, with wheels replaced and little else done, apart from perhaps additional underframe detailing, which I would have done anyway. If you are going to do basic, rigid conversions, then ensuring that the wagons have sufficient weight is important, as it is for all types of springing or suspension in P4 (more important certainly than in OO or EM - I still model in OO as well).

Also, what I'd probably prefer to spend time doing on a RTR wagon, is to install sprung buffers, as I find this helps a lot when shunting. If you were to replace the buffers with some from the Lanarkshire range from Dave Franks, you'll find that Dave can supply the whitemetal shanks ready drilled, so you can install MJT turned buffer heads and springs.

I would add that all of my wagons stay on the track on all areas of my layout, which is, of course, the main criteria! But I'm a philistine, who can't really tell the difference between a sprung wagon and a rigid wagon bouncing over pointwork!

Best of luck.

I use the Bill Bedford units on pretty much every wagon I build. I've never used the wire that comes in the pack and always replace with bought guitar wire. Ernie Ball's are pretty good (thanks for the link Mark), but whatever the brand, the string should straighten when uncoiled. I bought some recently that retained a curve which is not what we're after. Vary the gauge of string with the wagon, thicker (11 thou) for white metal and heavier ones and 10 thou otherwise.
I use a Brassmasters axle alignment jig and fix the unit to the wagon floor with a drop of superglue. This allows the unit to be prised away from the floor with a flat blade if something gets out of line in assembly. It still happens occasionally.
Polishing the bearing (outer) face of the sprung carrier on a piece of wet & dry to remove burrs etc helps a lot. I solder the waisted bearings into the carriers with the tiniest amount of solder before I remove them from the fret.
Good luck!

Hi Beakie

One of the issues I've had is buffer height. I made models before I had the pukka height gauge. They are slightly low.



But they are the same as some rewheeled RTR vehicles.

In fact there's the same inconsistency between these two RTR vehicles.


But I don't think that inconsistency was caused by changing the wheels. This same wagon is here at the other end coupled to another RTR wagon. Both are Bachmann. Both are still with their 00 wheels. Although the wheel is slightly raised from the track I think it shows the same slight inconsistency, so it is not the fact that the grey guards van is rewheeled that causes it to be lower.




Of course it's difficult with different flanges to be sure what's going on. I made a little piece of dual gauge track so that the flanges were not an issue.



My slightly low trains have no problem mixed with other people's trains. What does matter is when and if you get to using AJ couplers. Their accuracy has to be spot on regardless of exact buffer height. Fortunately they are easily adjusted!

An obvious point is that wagons (real world) will ride lower loaded than empty, so as long as your low riders are all full, and your high riders are all empty they will be completely accurate.

jon price wrote:An obvious point is that wagons (real world) will ride lower loaded than empty, so as long as your low riders are all full, and your high riders are all empty they will be completely accurate.

And with a van, no one can tell the difference...

HTH
Flymo

Just to give you even more choices, Mr Beakie, on your next wagons you don't need to chuck the axleguards away as you can just slot the ones in the kit. Start by drilling the coned hole 2mm and butcher your way up and down from there - a little chisel filed up from a piece of 2mm silver steel is probably the easiest but a burr with a 2mm ball is very handy and cuts very quickly. You can use the same spring carriers as with your metal axleguards but they are available from several suppliers.

One problem is controlling endplay in the axle and I use Markits or Exactoscale plain flanged bearings only and set the axleguards 23.5 apart. My spring carriers fit around the bearing flange and all this avoids fiddling with little washers. I sometimes file the ends off the brass bearings to avoid needing a very deep slot. Other bearings and carriers will require a different spacing so be consistent.

Something to beware of - ensure the spring plates are held away from the wheels to avoid short circuits. When the controller trips you don't want to be staring at 150 wagons and wondering which one is the culprit.

Watch out for a peculiarity - waisted bearings have shallower cones than plain which I am convinced is a drawing error. There's no obvious reason for this but there's no mechanism for changing it.

Make sure you enjoy it, whatever your chosen method. It will evolve with experience, anyway.

DaveB

Watch out for a peculiarity - waisted bearings have shallower cones than plain which I am convinced is a drawing error. There's no obvious reason for this but there's no mechanism for changing it.

Its a bit more complex than this, cone depth is not very consistent, Masokits provides a cone depth gauge on some of their etches which allows you to sort out the bearings into 3 sizes and adjust your installations to suit.
Rgds

There was quite a bit about the various bearings designs in an article by Russ in Snooze 186

Cone depth is very consistent if you stick with one supplier so don't just chuck them all in the same bag. Further, that supplier's waisted bearings are shallower than their normal ones in line with the society drawings published in Scalefour News a little while ago. Someone - probably Russ - listed the depths used by various manufacturers with Exactoscale and Markits being the deepest enabling the solebar spacing to be kept nearer to the scale dimension.

I don't like messing about getting one bit to fit another - I just build the wagon to some dimensions, put the wheels in and that's it.

DaveB

Cone depth is very consistent if you stick with one supplier

That has not been my experience, you must be lucky.
Rgds

I bought some bearings from Markits last year and I'm due to order some more. Why should he suddenly make them a different depth? When the Exacto ones come back on the market I expect them to be to the society drg just as before. I'm sure Colin Seymour does his best to give a consistent product these days.

In the days of the original Alan Gibson bits they used to vary and he even did a large batch with 90 degree cones which were much shallower but I set my solebars at the same width each time, use new bearings and the wheels always fit - I have a lot of wagons. This is how I discovered that the waisted ones are different. I think it's a problem of the past - just dump your old stock and stick with one supplier. I buy them in 100s - that's only 25 wagons, less a few bearings lost on the floor.

DaveB

I'm with Keith on this, and its not just the bearing cups that vary, its the axle length and the "natural" distance between the W irons from kit to kit. None of these should be very big, but taken together can be big enough to be noticeable.

Follow this link to the CLAG website where Russ has gone through all of this with reasons and diagrams. The fact that the bearings do vary is an advantage as it allows us to chose a bearing depth to suit a given Kit W iron /wheel axel combination.

I'm not interested in the variables - I'm telling you how to avoid them. Take charge of your supplies and put the solebars in the correct place for the components you have, then do it every time. All my axleguards are the same distance apart, it's just quicker than messing about trying to find an odd bearing from way back. There's never been any problem putting solebars at my favoured spacing. I thought there might be some interest in an easier way for beginners like Beakie who seemed to be troubled by the variables but all we're hearing is more problems. I have well over 120 wagons, some of them rigid and have never seen the need to check axle length so mine are pretty consistent - the vast majority from Gibson.

DaveB

davebradwell wrote:I bought some bearings from Markits last year and I'm due to order some more. Why should he suddenly make them a different depth?

Tool wear, backlash in the machine and the fact that the datum for the depth is the back of the flange?

davebradwell wrote:I thought there might be some interest in an easier way for beginners like Beakie who seemed to be troubled by the variables but all we're hearing is more problems.

But of course - this is a P4 forum!

DT

davebradwell wrote:I'm not interested in the variables -

And I found them unavoidable, for reasons Bill just pointed out, and as Russ explains in his article to which I linked.

The fact is that anybody who starts putting assorted wagon kits together is likely to find that wheel axle/barring fit between W irons is inconsistent, and they are likely to think its their problem and not that is inherent in the kit/axle/bearing combination.. So I think it's a good thing that they understand why it happens, and what to do to work round it. So explaining what the variable are should help. The real engineers among us may well be able to measure their way out of this and find that the easiest way to do it, but, for the kitchen table modeller, knowing you can adjust the bearing/axle length to fit the wagon is a good workable solution.

Of course all this only really matters on a sprung wagon whch needs vertical W irons to function properly. Any rigid or compensated wagon can live with the W irons flexed away from the vertical.

Gordon Bennett! As there appears to be a stone wall preventing resolution of the bearing/axleguard compatibility issues, I'll go back to my main point which was to use the plastic axleguards, slotted, in order to save a lot of work replacing them and adding castings. What's wrong with that then?

DaveB

davebradwell wrote:Gordon Bennett! As there appears to be a stone wall preventing resolution of the bearing/axleguard compatibility issues, I'll go back to my main point which was to use the plastic axleguards, slotted, in order to save a lot of work replacing them and adding castings. What's wrong with that then?

Absolutely nothing - it's what I do.

DT