|
|
Post by alanetm on Dec 7, 2013 21:00:43 GMT
Has anyone found an easy way of making the reverse bend to the bunker corner?
At the moment I am looking at using copper pipe and quartering it, but the problem with this solution is bending the pipe to the correct radius to start with without formers such as in a conduit bender. Another possible way is to copper beat flat plate (or even half a tube) around a former.
The full height of the bunker would be of three pieces with the two vertical pieces either side of the reverse bend.
Hopefully a plate work master can give me the best solution.....
Alan
|
|
dscott
Elder Statesman
Posts: 2,433
|
Post by dscott on Dec 23, 2013 2:03:23 GMT
I have pondered this several times as I need 3 pairs of these as all GWR bunker backs are the same and for painting preferably made from steel sheet. One idea is to have a former like the ones used in boiler plates with the sections opposed then the curves filed in. Next an outer section cut the thickness of the sheet bigger is pressed over guided by pins that also hold the sheet in accurate register as there is a cut for the corner which has been arrived at by trial and error. hence the use of steel. the bottom curve is a compound one that even in Swindon works gave problems hence all the bunkers being the same so they must have made up a press tool or two to form them.
Now if we all club together and invest in some 20mm plates being water jet cut out and filed, this can solve our problem.
David.
Who once spent 2 years working allongside a sheet metal expert of 32 years!!!
|
|
|
|
Post by Deleted on Dec 23, 2013 22:20:38 GMT
Hello all-------------thought these close-ups might be of use ??.....You can clearly see the nature of construction and the use of a press.. |
|
jma1009
Elder Statesman
Posts: 5,884
|
Post by jma1009 on Dec 23, 2013 22:46:59 GMT
hi alan,
ive done one GWR bunker in 5"g. i made the sides (full height) and back (up to the reverse curve) out of one piece of steel. the top part of the back (straight) was a separate piece - the sides were curved round at the top from the large piece and fixed to the top of the back with thin sections added on the inside and rivetted together.so thats most of the bunker done including most of the side curves. the reverse curve was bent and fitted with a strap rivetted on the inside on the lower half. the reverse bend radiused ends were done in copper and soft soldered in position.
hope this might be of some help.
cheers,
julian
|
|
jma1009
Elder Statesman
Posts: 5,884
|
Post by jma1009 on Dec 29, 2013 23:16:21 GMT
   a few pics of the above description taken awhile back. bit of filler required on the bottom of the reverse bend! cheers, julian |
|
|
|
Post by Laurie_B on Dec 30, 2013 11:57:20 GMT
Hi Julian,Alan and all. Thanks for posting those pics,they've very helpful,although I'm a long way off making the bunker on my loco. Attached is photo taken at the SVR shareholders/members weekend last year,that may be of interest.  |
|
|
|
Post by Deleted on Jan 2, 2014 21:52:15 GMT
Good shot of the rear, R/H buffer as well-----------
|
|
|
|
Post by alanetm on Jan 5, 2014 16:47:26 GMT
Thanks guys for the responses.
Decided to beat the reverse bend from copper and then silver solder the top and bottom curves made from copper pipe to it.
This has worked OK for the first one done. Now for the second one.
Used simple soft wood formers as they were only going to be used once.
The option of forming the upper and lower rear plate with curves was second choice but it was close run thing.
|
|
|
|
Post by Deleted on Jan 5, 2014 17:05:39 GMT
------------ or MDF is good for formers as well.........
|
|
