With Laurie and Trever from our club, Moira Miniature Rail, last Sunday
afternoon we curved a pile of 20 x 10mm mild steel bar as rail for the SR(G)R, along with some 20 x 20mm RHS for the curve and points jig.
Interesting learning experience as the resilience of the bar varied quite a bit. Each couple of metres took the bending differently. I expected that once we set the roller correctly it would just be a matter of feeding in the lengths... Wrong. Each piece needed adjustment or re-rolling, or un-rolling. An hour or so's work took four...
The RHS was another matter. We did the short outer curve first - went well. The inner curve was the fed. Being a shorter radius, it should have required a second pass. Disaster it curved way too much. We worked out that the welded seam was on the inside, whereas with the first piece it was on the side.
As the tube is rolled then welded it is apparent that the rolling work hardens the steel and welding the seam anneals that side. So the welded side is 'softer' and bends more easily. didn't think that through first... So an hour was spent trying to reduce the curve. Live and learn.
This morning I have tacked up the curved bit of the combo straight-curve-points jig. This is upside down in the first two pix... Right side up in the third... to assemble the track and outside rails of the points upside down - in order to weld the sleeper ties on from under the rail. Neater?
Most of the ties under points will be continuous across all rails. Just placed some pre-cut and drilled straight ties here to play with spacing. Then I will fire up the band saw...
Well, having made a jig for curves, I had to try it out! So another 'play' day for me.
With Laurie and Trever from our club, Moira Miniature Rail, last Sunday 
Interesting learning experience as the resilience of the bar varied quite a bit. Each couple of metres took the bending differently. I expected that once we set the roller correctly it would just be a matter of feeding in the lengths... Wrong. Each piece needed adjustment or re-rolling, or un-rolling. An hour or so's work took four...
The RHS was another matter. We did the short outer curve first - went well. The inner curve was the fed. Being a shorter radius, it should have required a second pass. Disaster it curved way too much. We worked out that the welded seam was on the inside, whereas with the first piece it was on the side.
As the tube is rolled then welded it is apparent that the rolling work hardens the steel and welding the seam anneals that side. So the welded side is 'softer' and bends more easily. didn't think that through first... So an hour was spent trying to reduce the curve. Live and learn.
This morning I have tacked up the curved bit of the combo straight-curve-points jig. This is upside down in the first two pix... Right side up in the third... to assemble the track and outside rails of the points upside down - in order to weld the sleeper ties on from under the rail. Neater?
Decided to electrically switch points using a 50mm throw linear actuator through a sprung bellcrank!
