How about using a slitting saw? In either case I think you need a strip of heavy metal with a series of suitable clamps down its length. So how about a V groove down a strip with pairs of holes down its length. So you use bridges screwed on to clamp the round section. After you have milled a bit flat replace the bridge behind this area with a flat one to continue the clamping action. I think you need at least 3 bridged/pairs of holes and 5 would be better.

frank

College do true half round as well as the flatter section beading

hi steve,

i am not quite sure what loco you are building, but in UK fullsize loco work 'half round' beading wasnt half round but as you describe 'flatter'.

not sure if the above helps.

most half round brass beading for ME isnt half round either and more akin to fullsize in my experience.

for steel, you will have to adopt the methods adopted by the current fullsize 'new' builds.

cheers,

julian

Edited By julian atkins on 27/01/2016 22:49:11

Or you could soft solder or glue the 5mm round to a length of board, steel or whatever and run it across a belt linisher until you get it down to size. Might be quicker than milling it a few feet at a time if you need large lengths.

Steve's model looks to be a larger gauge – so the methods described above probably are more appropriate. Cold 'Rolling' sounds an interesting approach.

But for anyone modelling to a smaller scale (G1 or G3) – then a simple grove in a wooden block (pressed or cut) , with round wire stretched across it, will enable half-round to be draw-filed. No solder or adhesives to clean up afterwards and although it's a manual operation, it doesn't take long to set up and to produce short lengths.

Regards,

IanT

Edited By IanT on 28/01/2016 10:21:47

Hi Steve,

I have never tried to do this but I will suggest a way that might work.

Take length of steel bar and bore a 5 mm clearance hole through the it. Mount the bar on the milling machine so that the hole is horizontal and machine away one end of the bar to expose the hole. Continue milling down until the hole is bisected. Make and mount a steel cover over the bisected section but leave a gap between it and the unmilled section.

With this mounted on the mill set the milling cutter running in the gap and push the 5 mm steel bar through the hole. As it passes the milling cutter it is cut to half the thickness and then enters the semi circular hole on the other side. The semi-circular hole stop the bar from twisting. Out of the end of the semi-circular hole will come the half round material.

As I said, I have never tried to do this so iI do not know if it will work but it might be a way forward.

Mike

By Jason's Red arrow.

There does not seem to be any change of diameter of the round section as it pases from handrail to capping on the cab side, looks more like the panel could be inserted into a milled slot on the underside of the rod?

Some ideas above seem impressively ingenious but I can’t help thinking that some devices might constantly jam up with swarf especially if milling dry or bottle-dribbles. I think a full flush of cutting fluid would work best. What do the team think?

DMB The moulding box method I suggested which is the same as Michael's I use quiet often for small timber mouldings and don't have a problem with sawdust clogging but agree swarf or a burr may jam thinds up and it would be easier done on brass than steel.

For anyone wanting to make larger flat section then this is a good nethod.

For myt Fowler which has a very flat "D" section around teh tender I just filed it.