Clearance for CSB wires

Winander
Posts: 121
Joined: Thu Mar 20, 2014 12:19 pm

Clearance for CSB wires

Postby Winander » Fri Feb 14, 2020 1:46 pm

What vertical clearance is required for CSB wires without impeding the suspension?

I am trying to arrange frame spacers in a diminutive 0-6-0 prototype that uses High Level hornblocks. Am I right in assuming that the lowest position on the High Level CSB jig ('A') would automatically require trimming of the hornblock cheeks to avoid interfering with the wire?

At the moment I have chosen to use position 'C' - the highest - but now have problems locating the frame spacers. As I am using split axles these are 1.6mm thick copper clad i.e. 'chunky'.

In the picture below, the hornblocks have been loosely positioned in the correct vertical position (with the locking tab against the top of the cutouts). As can be seen the bottom of the hornblocks will require trimming to match the frames....
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Richard

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Will L
Posts: 1689
Joined: Sun Jul 20, 2008 3:54 pm

Re: Clearance for CSB wires

Postby Will L » Fri Feb 14, 2020 7:01 pm

Winander wrote:What vertical clearance is required for CSB wires without impeding the suspension?

I am trying to arrange frame spacers in a diminutive 0-6-0 prototype that uses High Level hornblocks. Am I right in assuming that the lowest position on the High Level CSB jig ('A') would automatically require trimming of the hornblock cheeks to avoid interfering with the wire?
Yes
At the moment I have chosen to use position 'C' - the highest - but now have problems locating the frame spacers. As I am using split axles these are 1.6mm thick copper clad i.e. 'chunky'.

In the picture below, the hornblocks have been loosely positioned in the correct vertical position (with the locking tab against the top of the cutouts). As can be seen the bottom of the hornblocks will require trimming to match the frames....


In theory, to ensure enough clearance wherever the frame spaces go, you need a hole through them that is at least 1mm plus the width of the wire. In practice a 2mm hole ensures enough clearance, allowing for any minor inaccuracy in locating the hole centre and in locating the space against the frame. These holes should be centred on a line 0.5mm above the line through the fixed fulcrum points. The high level axle block fulcrum tabs centre the wire about 1mm from the face of the frames, therefore the holes need to be drilled 1mm from the edge of the spacer, i.e. right against the edge.

When putting in the fixed fucrum points in, do ensure they line up with the fulcrum points on the axle blocks so the wire runs along behind the frame in a straight line which lines up with the centre of the holes in the frame spacers. It will also be much easier to thread the wire if it doesn't zip zag.

Winander
Posts: 121
Joined: Thu Mar 20, 2014 12:19 pm

Re: Clearance for CSB wires

Postby Winander » Fri Feb 14, 2020 7:38 pm

Thanks Will, that is very helpful.

Regarding the fixed fulcrums, I will use a stiff wire with everything assembled before soldering the fixed fulcrums so that everything is in line and it's easy to thread the proper wire in.

I am using some rather nice looking fulcrum fixings supplied by Lanarkshire models found here http://www.lanarkshiremodels.com/lanarkshiremodelsandsupplieswebsite_200.htm, item code CBS000. They have nice long 0.7mm spigots.
Richard


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