Axle compensation with well laid track

[EasternO]

If I laid track (and turnouts) that is perfectly level and at a gauge that suits the wheel standard, would I need to compensate or spring my axles on, for example, a 2 axle wagon?

 

I can't see why I would need to, but I've never built a layout before.

[Dave John]

The first question would be which scale and gauge are you intending to try ? 

 

Second question would be which rail profile do you want to build or buy track in ? 

 

 

[Miss Prism]

46 minutes ago, EasternO said:

I can't see why I would need to, but I've never built a layout before.

 

Ah, 'need'.

 

Suggest you build one wagon solid, and another one sprung.

 

Then you will be able to refine your feeling of need.

 

[Paul H Vigor]

If it's your first layout build might it be wise to keep things simple as you find your way?

[ikcdab]

You forgot the third component: chassis that are perfectly square and true too. If you could build this then you wouldn't need compensation, but it's an impossible dream and even if you could, wood and chassis move. With standard wheel profiles, the depths of the flanges take up these irregularities, but in the finer scales, the flanges are too small, hence compensation.  For locomotives, compensation is more important in order to keep electrical contact between wheel and rail.

So in a perfect world, compensation is not needed, but a perfect world is unobtainable. 

[Jeff Smith]

EasternO, yes it would be helpful to say what scale and gauge your layout will be.   RTR OO on RTL track on a reasonably flat surface - generally no compensation necessary however some loco's, eg 0-4-0s can benefit electrically, especially if using dead frog points.

[Izzy]

A lot of the main points have been covered but I would say that irrespective of scale or gauge two key aspects are the flange depth used and the weight of vehicles because as said with the best will in the world laying perfectly flat track is only possible in theory. 
 

Generally the small amount of axle movement found in free running locos/coaches/wagons with ‘fixed’ axles can be enough, it’s when flange depths start to get finer that some form of ‘compensation’ - however simply it’s done, becomes ever more desirable. And as said it’s quite handy for helping with electrical pick-up.

 

Say what scale and gauge is being considered to get rather more targeted advice.

 

Bob

[Barclay]

I don't find it necessary in EM gauge, using Gibson wagon wheels. I do compensate loco's, but that is more to improve pick up than to stop them falling off the track. In P4 there is more of an argument for some form of suspension I believe.

[Torper]

I model in P4. Short wheelbase vehicles run perfectly well without compensation (although most have added weight) as do coach bogies. So for that matter do my converted Hornby Black 5 and Bachmann Crab, both of which use the original RTR chassis, but all my kit-built locos are compensated or sprung.

Edited January 17, 2023 by Torper

[EasternO]

Thanks all, I didn't expect this many responses.

 

I haven't made my mind up on S7 or O gauge yet, but my 'layout' will be a fairly simple oval in the loft with one or two turnouts to storage lanes. The min radii will be fairly tight, maybe 3' 6" to 4' but I'll put the turnouts on straights.

 

The modelled era will be Victorian, so mostly 4 wheel wagons and coaches and mostly 6 wheeled locos.

[Barclay]

I have no experience in 7mm but I'm fairly sure that S7 couldn't cope with such small radii - these figures are only just OK in P4.

[Izzy]

1 hour ago, EasternO said:

Thanks all, I didn't expect this many responses.

 

I haven't made my mind up on S7 or O gauge yet, but my 'layout' will be a fairly simple oval in the loft with one or two turnouts to storage lanes. The min radii will be fairly tight, maybe 3' 6" to 4' but I'll put the turnouts on straights.

 

The modelled era will be Victorian, so mostly 4 wheel wagons and coaches and mostly 6 wheeled locos.

 

That kind of radius might just be possible in O-MF and especially if you use a measure of gauge widening to help, and with standard depth flanges won't need compensation, although all my small sound fitted light railway type O-MF locos have it along with stay-alives, but you'd need at least 6' minimum radius for S7 along with plenty of said gauge widening and most probably compensation on all rolling stock along with plenty of weight.

 

Bob

[RexAshton]

1 hour ago, Barclay said:

I have no experience in 7mm but I'm fairly sure that S7 couldn't cope with such small radii - these figures are only just OK in P4.

I think 0 Fine recommends 6' minimum radius for all but the smallest locos. A thing to consider with S7 though would be clearances around valve gear etc especially if you need side play to accommodate track radius.

[EasternO]

Thanks all. I may have over-egged what this 'layout' is. It's primarily a test track to build wagons on, plus the occasional 0-6-0. The loop is simply something to run locos and trains on while I work for entertainment.

 

The locos will be GE, so only coupling rods to consider, but I agree I will need to look carefully at how I include some sideways movement on at least one of the axles of an 0-6-0.

 

I'm not worried about pick-up as I'm planning on battery power with lever turnouts. It's not a decorative layout in any way, so hand-laid track soldered to PCB or similar.

 

Thanks again, I'll look more depth into S7 and see what I can achieve, otherwise I'll stick with O.

[PenrithBeacon]

I model in P4.

I have found that I can't build wagon kits square enough for them to run unless they're compensated. RTR wagons are fine because they're square as bought and are a serious pita to compensate. 

I use 3 point compensation because it's simpler than springs and at least as good. Use MJT compensation units, they're better than the S4Soc ones.

Mansplaining done.

[The Johnster]

There is another advantage to compensation, which is the the vehicles move more like real railway vehicles and seem less ‘jittery’.  
 

1 hour ago, PenrithBeacon said:

I model in P4.

I have found that I can't build wagon kits square enough for them to run unless they're compensated. RTR wagons are fine because they're square as bought and are a serious pita to compensate. 

I use 3 point compensation because it's simpler than springs and at least as good. Use MJT compensation units, they're better than the S4Soc ones.

Mansplaining done.

Mansplaining is never done, that’s the point of it…

If you can get to a Lego outlet, they will sell you a bucket of bricks for £6.  The bucket is about 8” tall and 6” diameter a useful plastic container on it’s own, and you can put whatever bricks you like in it until it is full, so long as the shop guy can close the lid. 
 

These have innumerable, by which I mean several, uses on layouts, one of which is as formers and jigs to provide square corners when you are building kit wagon bodies, or buildings.  Wagon kits need to be squarely built on flat floors to have any chance of running well, and in the case of vans and loaded wagons it may be worth sacrificing a few bricks, after all you’ve got plenty, to reinforce recalcitrant bottom corners.  Squarely built and well-ballasted kits with metal wheelsets running in brass bearings will run as well as any RTR wagon. 
 

Get a few 30 degree and 45 degree angled bricks in the bucket to help with roofs and gables on buildings.  Apart from that, I reckon about half and half square and double-square rectangles in different colours will best serve your needs. Bargain, but keep ‘em away from the kids or you’ll lose them!

 

That said, MJT 3-point is a great system.  Lego will still help with squaring up your bodies, though.

Edited January 18, 2023 by The Johnster
Spelling. What’s ‘comcenstation’?

[polybear]

Tony Wright doesn't use any form of compensation at all - and Little Bytham (00) runs rather well.....

[cctransuk]

On 17/01/2023 at 00:14, ikcdab said:

You forgot the third component: chassis that are perfectly square and true too. If you could build this then you wouldn't need compensation, but it's an impossible dream and even if you could, wood and chassis move. With standard wheel profiles, the depths of the flanges take up these irregularities, but in the finer scales, the flanges are too small, hence compensation.  For locomotives, compensation is more important in order to keep electrical contact between wheel and rail.

So in a perfect world, compensation is not needed, but a perfect world is unobtainable. 

 

It would seem that I have a miracle in my garage!

 

A ten baseboard, OO roundy-roundy, with no physical connection between adjacent baseboards and multiple tracks across baseboard joints; (my first serious layout).

 

Sixty years worth of loco and rolling stock building; (well in excess of 1000 items); none of which are equalised or sprung.

 

..... and derailments occur only as a result of turnout-setting errors on my part.

 

I'm of Tony Wright's opinion in this respect!

 

John Isherwood.

[ikcdab]

1 minute ago, cctransuk said:

 

It would seem that I have a miracle in my garage!

 

A ten baseboard, OO roundy-roundy, with no physical connection between adjacent baseboards and multiple tracks across baseboard joints; (my first serious layout).

 

Sixty years worth of loco and rolling stock building; (well in excess of 1000 items); none of which are equalised or sprung.

 

..... and derailments occur only as a result of turnout-setting errors on my part.

 

I'm of Tony Wright's opinion in this respect!

 

John Isherwood.

Hi John, I am the same as you.  I very rarely have derailments.  My point was that "standard" RTR wheelsets have flanges deep enough to cope with the inevitable irregularities in the track.  And within that I include items like Gibson wheels.  But if you want true scale flanges, as in P4, then you need compensation as true flatness in all the variables is impossible (very difficult?) to achieve.

[cctransuk]

7 minutes ago, ikcdab said:

Hi John, I am the same as you.  I very rarely have derailments.  My point was that "standard" RTR wheelsets have flanges deep enough to cope with the inevitable irregularities in the track.  And within that I include items like Gibson wheels.  But if you want true scale flanges, as in P4, then you need compensation as true flatness in all the variables is impossible (very difficult?) to achieve.

 

There was no suggestion of finescale wheels in the OP, though.

 

John Isherwood.

[Il Grifone]

Wilko do a cheap imitation of Lego (sold as a bulk bagfull - they do screws like this as well) and small packs of a Chinese copy (usually not Lego compatible) are available in Poundland.*

 

IMHO compensation** is essential on bogie stock though the bogies themselves can be rigid. short wheelbase four wheel stock can be rigid also. Later Dublo stock is equalised, so obviously Meccano Ltd. thought it worthwhile. Unfortunately their application of it was not thought through properly and probably made things worse.

*  Usual disclaimer.

** Referring to fine scale wheels and 3 point suspension or springing.

[The Johnster]

Cwmdimbath is not as large as Tony Wright or John Isherwood’s layouts, and I don’t run much faster than about a scale 30mph, tops, but my running is pretty good on track glued directly to baseboards.  I did make some effort when it was being laid to ensure level and smooth joints to adjoining pieces, which has paid off, not only in running but in pickup performance as well.  The main problems have been with Comet kit coaches on Comet bogies, which foul on the floors or solebars and derail on curves and over turnouts.  The answer is to use RTR or Stafford Road Works 3D printed bogies, but one has to keep an eye on buffer heights; this isn’t 70’s Hornby.  
 

My derailments are mostly down to operator error or poor driving, leaving turnouts wrongly set, that sort of inexcusable amateur error.  I’m getting better, more disciplined; set route, clear signals, check, make the movement, put back signals and reset the road to default, check, and only then consider the next move!

[DCB]

The devil is in the detail.   Full size railway wheels tyres are coned and the rail heads inclined inwards. that lets the wheelsets steer around corners  as coned wheels steer themselves around curves instead of the flanges grinding, Early railways used to suffer severe flange wear on curves, and derailments which progressive improvements in tyre profile and then super elevation eliminated.  Models even with "Scale wheels" often don't have coned wheels and rely on the flanges alone to stay on the rails.

Another thing is vehicles with coned wheel tyres sit on all 4 wheels unless they are seriously twisted, they just sit a bit askew when viewed  from above.  Ones with flat treads only sit on 3 unless sprung or compensated.   

What is not at issue is if you build a helix or any gradient on a curve you will rapidly need compensation or springing to stop the outer wheels derailing after they rise up off the track so high that the flanges  no longer engage with the rail top

There is no real answer but its pretty certain that rigid chassis give a lot less trouble than sprung or compensated ones. Parts which are not fitted can't cause trouble.

[Hal Nail]

Probably worth asking this in the 7mm section - more likely to be seen by people modelling in S7.

 

Conventional wisdom is S7 won't go round 4 foot curves compensated or otherwise. If you increase tolerances it might not then work on other S7 track so would defeat the object of both the stock being S7 and having a test track!