Author Topic: Bending Brass Rail  (Read 273 times)

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Offline Peaky 556

Bending Brass Rail
« on: Jul 16 2020 23:18 »
Can anyone offer advice from personal experience on a good way to pre-curve GRS brass rail?  I don’t have any sort of rail bender, but I have heard it said that “belly-bending” can be done.
I’m asking because I think that prebending the rail ought to prevent any cusps forming at rail joints as and when the fishplates relax.  This would need curving right to the very ends of the rail though.
My radius is down to 4.5m.
Many thanks,
Thank you,
Tim
Facebook.com/AppleTreeRailway/

Offline cabbage

Re: Bending Brass Rail
« Reply #1 on: Jul 17 2020 08:23 »
Tim,
I have some machined & unmachined wheel blanks that you could make a rail bender from. Failing that I do have my Fabricator!!!

Regards

Ralph

Offline Peaky 556

Re: Bending Brass Rail
« Reply #2 on: Jul 17 2020 08:31 »
Thank you Ralph, but I’ve dropped off here and not left myself time to procure or make some kind of gadget.  I suppose I’m looking for some advice along the lines of ...’bend it carefully around a water butt and tweak the ends with grips to make sure the curve reaches the rail ends...’ or something else pragmatic.
Thank you,
Tim
Facebook.com/AppleTreeRailway/

Offline IanT

Re: Bending Brass Rail
« Reply #3 on: Jul 17 2020 08:55 »
Try to avoid using the "grips" - you will probably get a kink.

Never used GRS rail (which I think is quite heavy section) but for Society rail, you could curve it around something (I guess you could use a water butt) or simply hold it at each end and gently bend it using your thumbs. For the ends try using a hard'ish rubber mat (I had some of that heavy multi-coloured rubber packing about 2" thick) and bearing down with a hardwood roller (something like the wife's rolling pin if you can get away with it). When bending anything, the 'ends' are always difficult because there is nothing to leverage against, unlike the mid-section.

So if you are going to do a lot - then some from of bending rollers would be better for this reason and will give a more predictable/repeatable curve.

Regards,

IanT
Nothing's ever Easy - At least the first time around.

Offline cabbage

Re: Bending Brass Rail
« Reply #4 on: Jul 17 2020 08:56 »
I curve the rail by narrowing the distance between the sleepers on the inside rail. I do have a 4.5m rail curve that I can throw you?

Regards

Ralph

Offline Andy B

Re: Bending Brass Rail
« Reply #5 on: Jul 17 2020 11:45 »
Tim,
Is your rail bull-head or flat-bottom?

Andy

Offline cabbage

Re: Bending Brass Rail
« Reply #6 on: Jul 17 2020 12:11 »
Andrew,
As far as I remember Tim has code 330 Vignoles profile track. The flat base will make it difficult to bend without some distortion...

Regards

Ralph

Offline Peaky 556

Re: Bending Brass Rail
« Reply #7 on: Jul 17 2020 17:01 »
Yes, it’s Code 330 FB.
Is the general concensus that pre-curving Rail is a good thing?
After all, in a tunnel it’s going to be rather awkward to realign/re-lay.
Thank you,
Tim
Facebook.com/AppleTreeRailway/

Offline cabbage

Re: Bending Brass Rail
« Reply #8 on: Jul 17 2020 17:20 »
Tim,

Most of my American Gauge One people pre bend the rail with a rail bender, all of them seem to use code 330 Vignoles profile.

Regards

Ralph

Offline John Candy

Re: Bending Brass Rail
« Reply #9 on: Jul 17 2020 18:08 »
Tim,
I used a GRS rail bender tool which you are welcome to borrow.
If you are worried about the tips, you could anneal ends before bending.
Alternative would be to crop ends after bending (since inner/outer tails will be different lengths, you will need to do that either way).
Regards,
John.
My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline Peaky 556

Re: Bending Brass Rail
« Reply #10 on: Jul 17 2020 22:40 »
Tempting John, and if I had more time, I’d love to come over, thank you very much.  I’ll have a go with other means over the weekend.
Btw, no-one has commented on the merits/demerits of pre-curving rail.  I’ve never done it before, but my tightest curve to date is more like 6m rad. I don’t think I have any cusps at joints, so I think the combination of track adhesive and ballast is doing a good job.
Thank you,
Tim
Facebook.com/AppleTreeRailway/

Offline John Candy

Re: Bending Brass Rail
« Reply #11 on: Jul 17 2020 22:50 »
I could send it by Hermes, if you can wait a few days.

The code 330 rail is very bend-resistant (by comparison with code 250) and the GRS sleepers are not very strong in the area of the rail clips.... bending the assembled track will likely over-stress clips and result in breakage.

Regards,
John.
My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline Peaky 556

Re: Bending Brass Rail
« Reply #12 on: Jul 18 2020 09:08 »
I could send it by Hermes, if you can wait a few days.

John that would be magic, as I am schedûled for track laying on Wednesday.  Hermes have been doing good service for me lately so if you can get it in the system ASAP there’s a very good chance.
Many thanks, will refund your postage of course,
Thank you,
Tim
Facebook.com/AppleTreeRailway/