7mm Straightening up - or who makes a "Jim Crow" for 7mm?

Dog Star

Western Thunderer
The last couple of packets of steel rail have featured an attractive curve in each piece of rail and one which is not in the least bit welcome. I can cope with a curve in the horizintal plane... what gets me is when the rail has a curve in the vertical plane!

The most recent batch has an uniform curve from end to end and with an offset of about 1.5cms at the mid-point (of a 1 metre length). Getting the rail straight before use is a real pain and seems to take forever. How do you straighten yours?

thanks, Graham
 

Stevesopwith

Western Thunderer
If I understand you correctly, if one end of the rail is down, the other end would be 3 cms up in the air ? ... more than can reasonably just be sprung into place, and coming close to being unfit for purpose.

I'm doubtful of the effectiveness of any sort of 'finger and thumb' method.... I presume you've already tried drawing it over the edge of a bench, applying downward pressure while keeping the section vertical: I imagine it twists, and is difficult to achieve consistency

For speed, ease and reliability you really need a specially made adjustable rolling device ..... like my rail bender, but with rail thickness grooves to hold the rail in it's 'vertical' plane; and even then it won't tackle the last few cms of a length; and this really shouldn't be necessary to make the product useable.

Have you brought the issue to the attention of the supplier?

What a pain!

Steve.
 

Dog Star

Western Thunderer
If I understand you correctly, if one end of the rail is down, the other end would be 3 cms up in the air ?
Roughly - yes.

I'm doubtful of the effectiveness of any sort of 'finger and thumb' method.... I presume you've already tried drawing it over the edge of a bench, applying downward pressure while keeping the section vertical: I imagine it twists, and is difficult to achieve consistency.
Yup - exactly so. The only method which works consistently is to set the head of the rail against a one metre ruler (ruler flat on workbench) and then adjust with finger and thumb whilst pressing the rail against the work surface.

For speed, ease and reliability you really need a specially made adjustable rolling device ..... like my rail bender, but with rail thickness grooves to hold the rail in it's 'vertical' plane; and even then it won't tackle the last few cms of a length.
Yup again - a most desirable tool, as necessary as milk in tea. If you read my thread on Hartley Hill you will note that I often use a rail length longer than necessary to get the flowing curve to the end of the required length.

Have you brought the issue to the attention of the supplier?
Certainly. "Cannot understand what happens to your supply". Three separate batches of 10 of one metre lengths of steel rail.

regards, Graham
 
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Stevesopwith

Western Thunderer
Is he saying it was straight when he posted them?
Have you had any satisfactory batches during the same period?
How was the rail packed? In any case, surely postal damage would produce local and variable bends, not an even curve over a metre length.
It sounds like something at fault in the manufacturing process.

My sympathies...... Steve.
 

Simon

Flying Squad
That sounds really tedious but reflects my experience with Cliff Barker's 3m lengths of code 180 rail too. I have had two thoughts about this (in relation to my experience)

1.) He supplies the 3m lengths coiled, maybe this introduces a vertical bend to the rail.

2.) I am laying the rail with correct inclination, on a curve, maybe this encourages a vertical bend. Like you my rail ends are "up".

In practice I have found that laying the track and the application of mechanically effective fishplates loses the problem, and at least our rail joints won't be"dipped":))

He now supplies the rail in 2m lenghs max in straight bundles, I haven't tried using this yet.

My conclusion is (I think) that it is to do with basic geometry and having inclined rails, on the "big" railway the rail is massively heavy and effectively much less "stiff" than in our model scenarios and "sits down" in the chair much more readily.

Simon
 

mickoo

Western Thunderer
Could you not clamp it over it's length so it's flat and then apply heat from a blow torch and then let it cool, that might take the stresses out of it and let it settle flat when cold, not sure how hot it'd have to be and you'd probably spend as much time cleaning it up afterward as manually straightening.
 

Dog Star

Western Thunderer
As far as I recall, from conversations with Brian Lewis / Len Newman over the years, all code 124 rail is drawn from wire and from just the one die.

The idea of annealing / stress removal is attractive - I do not have the opportunity to follow that course so I have resorted to physical deformation in the vertical plane before the rail is cut to the required length.
 

Simon

Flying Squad
I ended up doing the same as you Graham, but by putting the rail in a vice held "head to foot" and then deforming it in the required direction, several times at several places along its length.

You can (have to) be quite brutal but I was surprised how effective the method was, I have rescued some scrap pieces for use in points using this method. I test for straightness by eye and laying the rail upright on the workbench edge.

Cliff's 2 yard lengths are in any event straight - could you not find a better supplier?

Simon

Blimey, this thread is a bit "Lazarus" ..
 

Overseer

Western Thunderer
I am not sure if it will work with steel rail but an effective method of getting rid of stress in nickel silver rail is to connect it in series with a light bulb and pass current through it to warm it up from the inside. I haven't tried code 124 but for smaller rail a car brake light works. It doesn't seem to need to get very hot. You might need a headlight for the larger rail, and possibly the car battery to provide enough current flow. Time required depends on the rail size and current. Fixing a crocodile clip to a beam so the rail can hang down with another crocodile clip on the bottom of the rail to complete the circuit makes it easy to treat a batch of rail. The wires obviously need to be heavy enough for the current. Might be worth a try.
 

JimG

Western Thunderer
I am not sure if it will work with steel rail but an effective method of getting rid of stress in nickel silver rail is to connect it in series with a light bulb and pass current through it to warm it up from the inside. I haven't tried code 124 but for smaller rail a car brake light works. It doesn't seem to need to get very hot. You might need a headlight for the larger rail, and possibly the car battery to provide enough current flow. Time required depends on the rail size and current. Fixing a crocodile clip to a beam so the rail can hang down with another crocodile clip on the bottom of the rail to complete the circuit makes it easy to treat a batch of rail. The wires obviously need to be heavy enough for the current. Might be worth a try.

I did that with some 2mmFS Code40 wire rail which came in a coil. In my case I cut the rail into 18" lengths, held one end of the rail in the bench vice, the other end in a clamp, and used my Graskop RSU in maximum setting to heat it, while giving the rail a sharp tug to straighten it out. Not quite the same as code 180 rail, but an RSU could provide the current necessary to heat the rail. You might have to keep an eye on the RSU if you are going to have it powered up for many minutes rather than a few seconds since the transformer and leads may only be rated for short term use. The Code40 rail was starting to go red hot after a few seconds when the power was taken off. :)

Jim.
 

Dog Star

Western Thunderer
Did you get this sorted out Graham?
No.

I wrote in an earleir post that I had not had the problem with Nickel rail... no longer true. Two separate packs of Hi-Ni 7mm BH rail have passed over the bench in the last twelve months, both from C&L at shows, one in Dec 2013 and one some time in 2014. Not sure which, one pack was usable without effort whilst the other needed sorting before use - what surprises me is that the rail with a vertical curve is flat otherwise.

The S7 Group has introduced a rail curving tool, works like rolling bars. I have seen this tool demonstrated for forming the horizontal curve in rail, no idea yet if the tool can remove the vertical curve in the rail.
 

Osgood

Western Thunderer
….
Certainly. "Cannot understand what happens to your supply". Three separate batches of 10 metre lengths of steel rail….

If it is any help, I think I know why your rail bends in transit. Try pushing a 10 metre length of rail through a letterbox - it is going to go everywhere. I'd have thought 1 metre lengths would be the limit…….
 

Dog Star

Western Thunderer
... I think I know why your rail bends in transit. Try pushing a 10 metre length of rail through a letterbox...

Arf, arf, :))

You are not taking this seriously. Anyhow, I collected the stuff at shows, the problem is getting the 10 metre length out of the exhibition hall without being hit by backpacks and big white boxes.
 

David Taylor

Western Thunderer
No.
The S7 Group has introduced a rail curving tool, works like rolling bars. I have seen this tool demonstrated for forming the horizontal curve in rail, no idea yet if the tool can remove the vertical curve in the rail.

If you know someone with a lathe they could put a groove in the rollers to allow you hold the rail head-to-foot between them.
 

daifly

Western Thunderer
Graham. The GW models 6" mini roller and rail bender works as you describe. Although intended to form curves in sheet material, it also has grooves in the roller to assist in forming the horizontal curve, as suggested by David above. I have one which you are welcome to borrow and try - I can give it to you at Kettering or post it directly.
Dave
 
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