Drag on LMS Coronation Scot Coaches

[DarkRedCape]

Still a way away from getting a proper layout with baseboards, but my little triple oval does me well for now. I ran all nine of my new LMS Coronation Scot coaches with all wheel pickups and capacitors. The board that my ovals are on has 10 adjustable legs underneath and the surface is as level as I can make it, but the coaches seem to have heavy drag on them.

I had to double head a Britannia class and a King class loco to be able to pull them. The Britannia would pull them, but not from a standing start. I think the entire rake being on an oval doesn't help, and it would be different if it was on a straight length of track. The oval they ran on was a radius three.

I put a needle heads worth of teflon oil on the ends of the axles and it made a noticeable improvement, but when pulling the nine coaches by hand and then letting go, there is quite a lot of pull back where the coaches recoil. I think testing them individually would help detect which were the worst offenders.

Does anyone else have the coaches, and if so, a full rake of nine? If so, could you share your own experience with the coaches in terms of drag.

Despite the stated issue, it was nice to see and hear them going round, especially with the lights off so I could see the glow from the coaches.

[atom3624]

Fingers to you!!

I had a devil of a job, and not close to totally happy.

Both of my Kitchen cars are the worst, the longest 65' coach probably the best.

I found attempting to fine-tune the lamp pickup fingers does help a lot, but also the alignment of the wheels in the bogies / bogie manufacture is not ideal, and they can catch the brakes as well.

Some additional fine-tuning is still required on mine, but I'm keeping them back in their boxes until I have enough patient time to work on them properly without getting frustrated!

I did get far enough for my single latest tooling Coronations to haul them, but it is fairly heavy going - like hauling 12 normal coaches.

Al.

[What About The Bee]

Hi DRC 👋.

Of course, I don't own any of those coaches, completely out of my era. But tractive effort is not reserved to one model.

In my view, numerical values will prove useful. How much tractive effort do your locomotives supply? How much drag do your coaches offer?

This light duty spring scale https://www.google.com/shopping/product/4591460253409083003 has a 50 gram capacity, 3% accuracy, 100 graduations. 0.5 grams per graduation.

There are heavier duty spring scales, at 100 grams, 250 grams, etc

What you need DRC, is a Dynamometer Car. As do I.

Science!

Bee

Edit: Pesola Spring Scales are available down to 10 grams capacity! If we assume the same number of graduations, that is 0.1grams per graduation.

[morairamike]

Trying to pull 9 coaches on an oval will take a lot more effort than on a straight. As well as the friction of the pick ups, there is the added effect of the coaches being pull effectively sideways against the edges of the rails. Once you get a straight built I think you will find totally different results.

On my layout the curves make a difference to the loco and train speed.

[atom3624]

Simon may have said in the Hornby Model World series pre-empting the new LNER Coronation coaches, that the LMS Coronation coaches were the best coaches yet, but obviously the QC prior to despatch left a lot to desired.

Mould, presentation, etc - lovely.

Execution - for me consistent (as little as possible) rolling resistance - very poor - some acceptable, others for no obvious reason other than poor execution, really quite reluctant to roll.

Even on the straight, if your standard, unmodified and perfectly healthy Coronation can haul them comfortably, you're lucky.

I monitor the motor performance - visually rather than actual multi-meter determined current requirement, but relative to how far I turn the controller before they move, then how smooth, and for a brief period, how fast - and have also increased the locomotive weight fairly considerably. I like a minimum of ~450g for large express steam locomotives, which isn't excessive, and less than the new H-D models with the same chassis / motor.

Al.

[Blanman]

I have all nine coaches and the new Queen Mary. Unmodified it wouldn't even pull the coaches on a straight level track without wheel slip so as soon as it came to a bend.. no chance! I ended up packing every spare space in the loco body with lead sheet and liquid gravity, and it still struggles sometimes, especially from a standing start when on a curve. Beautiful coaches but poor design! DCC Concepts style spring pickups would be a much better option than wiper pickups. Makes me wonder how this got past testing into production? 

Paul

[atom3624]

The coaches are an unfortunate pain in the vernacular!!

I tried easing off the pickup 'fingers' for the lighting - still considering only having pickups on one bogie.

The worst offenders are definitely the kitchen cars, but I think the main problem, once the pickup fingers are optimised, are the moulded brakes - too close to the wheels, and can catch / drag.

You could consider removing, or 'done properly', removing, realigning and replacing with a safe gap to avoid catching the wheels.

Al.

[Blanman]

I am going to fit DCC Concepts spring pickups first then go from there. It's a bit of work but I have used them before. Wiper pickups are ok for a single coach/wagon for an end of train light but I have had problems before fitting them to full rakes. As for for brake pads, I'll look into your suggestions, thanks.

Paul

[flyingfox4475]

When Hornby brought out the new Corronation Scot coaches I got a 9 car set. The Coaches were to heavy to be pulled by the latest version of the Princess Coronation Scot loco's. I found that the Kitchin cars were the casue of the most drag.  When the second batch were brought out, I bought 2 more kitchin cars and found that they were much freer running. Now my latest versions of the Princess Coronation class locos will manage the full 9 car set with out wheel slip.

 

[atom3624]

I keep looking at the coach boxes, saying to myself 'I know what the problems are, I just need a little time to work on them properly (and patience!)', but the boxes still remain on the shelf!!  Pity.

This weekend, perhaps!

That 68' coach (the longer one) if I remember was the freest running of the lot - rolling almost like 'a normal coach', so I could use that as a reference point.

Al.