Accucraft C-19 live steamer - the GWRR goes Fn3 with wheelspin!

[Westcott]

Finally plucked up courage to steam the C-19 for the first time.
No problems at all - she ran beautifully as a light engine.
So I then added all of my Fn3 stock, see below.
She started this without effort, and ran easily up the 1:70 bank (1.4% grade) a couple of times.
Then she started slipping her wheels.
The exhaust beat stayed constant, there was just not enough grip.

This is a heavy engine, so I was rather surprised to see her lose grip.

How do you get enough grip, other than by avoiding gradients?

 

[PaulRhB]

First off what a beauty

How do you get enough grip, other than by avoiding gradients?

It depends why she lost grip.
Did you check to see if any oil got on the track or wheels from steaming up?

The next thing I would check is the rolling stock, I used to have a few of the Accucraft wagons and they weren't particularly free running until I added the brackets to the bogies as the sideframe springs twist the frames causing binding on the axle ends. Are they Accucraft and did you fit the little brackets on the inner faces of the sideframes?

Ok possible culprit number three, the track, do you have a dip where the loco spins or a sudden change in gradient or sharp curve somewhere along the train that suddenly increases rolling resistance?

A final possibility is that although she's heavy she has a much larger power to weight ratio than the real one and may just be breaking away when hitting a dip and just needs a bit less regulator to allow the wheels to bite again, that's obviously easier with Radio control.

Just some things to check before modelling the flatlands

 

[Rhinochugger]

Yep, love the loco and the whole train

But that's a fairly weighty consist, so you also may need to check that all axles on the rolling stock are well oiled ( 'hic 8D ) and also remember that our out-of-scale curves add a fair bit of friction. Having said that, the 1:20.3 stock has finer wheel standards as well as body mounted couplers, all of which should help to reduce friction on the curves.

As Paul says, you may just have a tad too much grunt at times. Might be worth just checking that the loco wheels are free of oil/grease.

On the other hand, if you really need to try it out a bit more, you can always bring it round here..............

 

[bobg]

I agree with all the above, if they doesn't solve it, remove one wagon at a time and try again till ity does manage. I would suspect that the problem is oil where it shouldn't be as you said it managed first time. I lube my stock with 10/50 motor oil, I find 3in1 too thin and doesn't stay put too long.

Love it! (The loco that is )

 

[Westcott]

Chaps, thanks for the suggestions!

The slope is a smooth steady 20m of 1:70 with a gentle transition from level.
The curves are 3m radius minimum.
The consist is indeed a bit weighty, especially the caboose.
I checked all of the cars for ease of rolling before starting - they seemed OK.
She puffs along the level with a steady beat, when she starts up the slope the beat remains constant, but the speed drops off as the wheelspin increases.
All with the gas and the throttle turned down.

My LS Aristo Mikado hauls 22 (smaller) cars up this same slope with noticeable effort, but no slips.

I will check the track and driving wheels carefully for oil.
She managed the first couple of laps without any slippage, pulling up the bank in fine style.
Whatever happened started after that.

 

[Richie]

Very nice looking Hamish Any video footage

 

[Rhinochugger]

She managed the first couple of laps without any slippage, pulling up the bank in fine style.
Whatever happened started after that.

OK, belay the last suggestions - put all the grease back onto the wheels !!

 

[wpandyr]

Westcott,
From what you describe it sounds like oil on the track but it could also be the springing on the axles not allowing all the drivers to maintain firm contact with the rails, or the pilot truck spring may be too strong and lifting the drivers slightly.

Good Luck, it is a lovely engine.

 

[David BaileyK27]

This engine suffers the same problem as the K27 and C21 in that the centre two sets of wheels do not touch the track, I have altered sveral engines to make all 8 wheels touch the track by taking a bit out of the keeps under each of the cetre 4 axleboxes, at the same time removing some of the springs and cutting down the rest so that the engine sits on the springs and is not rigid on the keep plates this will vastly improve the adhesion and riding qualities of the engine.
At Diamondhead several years back I took my modified C21 ( Coal fired as well) and it pulled more that a K27, but after modifying the K27 it would pull as much as the c21.
David Bailey http://www.djbengineering.co.uk/ < Link To www.djbengineering.co.uk

 

[Sea Lion]

That's really interesting David. Did anyone ever say why the middle sets of drivers were presumably designed (rather than an accident) not to touch the rail? The only possible reason I can think of is to have them high up enough to allow the loco to negotiate really tight curves, but surely not with a loco of this size?

If the reason was to cope with tight curves can you advise what radius you can get your modified locos round with all wheels on the rail?

Happy steamings,

John

 

[Charles M]

This locomotive has the 2 center drivers blind, that is they have no flanges to contact the rail.

The drivers on this locomotive have very slick stainless steel tires. I have seen two other models that exhibit the same problem with any oil film. They also tend to work better with the steam pressure at a maximum of 40 lbs. They get slippery when operated above this pressure even without the oil problem.

Check the wiper contacts on the caboose for track power pickup. When they touch the wheels it is just like having the disc brakes on a car working. I have the short caboose from Accucraft and have bent the wipers away from the wheels and this helped with the pulling power of my live steam C-16 locomotive.

Charles M

 

[Westcott]

... Any video footage ? ...

http://www.youtube.com/watch?v=VEnnsw-KcPk&feature=player_embedded < Link To One video right here!

Thanks to everyone, especially Cliff at Accucraft, the slipping seems to have been overcome.
A combination of checking driver heights and springs, and oiling the tender's wheel bearings seems to have done it.

 

[Richie]

... Any video footage ? ...

http://www.youtube.com/watch?v=VEnnsw-KcPk&feature=player_embedded < Link To One video right here!

Thanks to everyone, especially Cliff at Accucraft, the slipping seems to have been overcome.
A combination of checking driver heights and springs, and oiling the tender's wheel bearings seems to have done it.

Very nice Hamish made light work of those wagons :love: