Binding motion on a new build

[figworthy]

9 hours ago, Barclay said:

I think there's a good chance that the crankpin system is what is causing your problems. I must admit I never use it and always run the rod straight onto the crankpin - the steel thread has never yet worn out the nickel rods, even on high mileage engines!  By the way have you considered writing up this build over on the Standard Gauge Industrial section, where there will be much interest I am certain?

 

Short of making some new rods, I'm not sure that I can dispense with the bushes.  In this case the crank pins are brass rather than steel, but I take your point.

 

As for a write up, oddly enough I have taken some pictures as I've gone along, largely for my own reference purposes.  I'd have to have a look at them and see if they are any good (I seem to have the knack of taking out of focus pictures).

 

Adrian

[Barclay]

11 hours ago, figworthy said:

 

Short of making some new rods, I'm not sure that I can dispense with the bushes.  In this case the crank pins are brass rather than steel, but I take your point.

 

As for a write up, oddly enough I have taken some pictures as I've gone along, largely for my own reference purposes.  I'd have to have a look at them and see if they are any good (I seem to have the knack of taking out of focus pictures).

 

Adrian

It would be good to see the build - I've never seen one on this loco. on RMWeb and I have the kit in the drawer to build one day !

 

Your comment about crankpins interests me as Gibson crankpins are steel machine screws with a countersunk head, screwed in from the back. Have you used a different type of crankpin, Markits maybe, and could their unconventional installation have created a difference in crank throw between the wheels? This could certainly cause the kind of problem you are experiencing.

[figworthy]

11 hours ago, Barclay said:

It would be good to see the build - I've never seen one on this loco. on RMWeb and I have the kit in the drawer to build one day !

 

Your comment about crankpins interests me as Gibson crankpins are steel machine screws with a countersunk head, screwed in from the back. Have you used a different type of crankpin, Markits maybe, and could their unconventional installation have created a difference in crank throw between the wheels? This could certainly cause the kind of problem you are experiencing.

 

The wheels and crankpins / bushes / nuts all came from Gibson's as part of the same order.  The pins are counter sunk, and are screwed in from behind, as you describe.

 

Captain Kernow has one that appears on his Callow Lane layout (scroll down the link for a couple of photos)

 

 

Adrian

[5050]

I don't use the Gibson 'nuts' until I'm virtually finished but instead use short lengths of wire insulation screwed on between thumb and finger.  In contradiction to the 'approved method' I also don't tighten the nuts fully onto the bushes, just 'nip' them, allowing them some potential movement and then, after snipping of the excess pin and filing down so it is just projecting from the nut, dab some nail varnish on to hold it.  This method has raised some hackles in certain circles but it has worked for me for many years and many locos.

 

BTW, never heard of the length of Gibson pins being a problem with GW wheel press.  I'm just about to fit some wheels to axles so I'll check this out first!

[D51]

Have you had a resolution of your problem?  I have been following with interest the problems you have been experiencing.

 

I hope all your wheels have the same crankpin throw.

 

I have usually used the "Romford" style crankpins (with the soldered washer) with Markits wheels, as this gives a very 'solid' crankpin relative to the wheels.

Frank

[figworthy]

On 29/08/2021 at 19:34, D51 said:

Have you had a resolution of your problem?  I have been following with interest the problems you have been experiencing.

 

I hope all your wheels have the same crankpin throw.

 

I have usually used the "Romford" style crankpins (with the soldered washer) with Markits wheels, as this gives a very 'solid' crankpin relative to the wheels.

Frank

 

Thanks.

 

Until I get some more crank pin nuts, I'm a bit limited in what I can do.  There is currently a delay on those.  See :

 

 

 

Markits would have been the preferred option, but they don't have the right sized wheels in their range.

 

Once I'm able to make more progress with this, I'll report back.

 

Adrian