N gauge turnout aluminium jig design help

[Harry]

I am trying to complete a CAD design for finescale N gauge point jigs. Almost the same as the Fast Track jigs for American N gauge. Ie there will be a slab of a material (I was thinking aluminium) that will have the lines milled in to take the key pcb sleepers and the rails.

 

It will have correct spacing for n gauge track and the idea is that turnouts made using it would go well with the easitrac that I'm using.

 

The questions are - is aluminium the best material for this? Considering that soldering will be done while the rail is in the jig. If not, what other material would be? And if it is, does anyone have a suggestion of a company that can use a CAD drawing to mill out the very small and precise dimensions needed to achieve this?

 

Thanks in advance for any suggestions.

[Etched Pixels]

Why not just use the existing 2mm SA ones. Apart from needing to tweak the templates I don't see what else is required, and you can cut new templates easily enough. Or see N Gauge Forum for the upcoming N gauge products using a milled point base with insertable chairs into pre-milled holes.

 

Alan

[-missy-]

Hi Harry.

 

The only thing to consider is that any large block of metal (be it Aluminium, Brass, etc) acts as a very good heatsink and any metal that is touching it directly would be very difficult to solder too. As long as the bits that are soldered dont come into direct contact with it then it shouldnt be a problem. If you are worried then an alternative material to use is paxolin or grp (like thick PCB material) as this doesnt conduct heat as much.

 

Missy.

[MikeTrice]

You might like to look at the FastTracks jigs which are similar but for American NMRA standards. Their instructions/videos might provide useful information.

[Harry]

Thanks for the replies.

 

2mm jigs wouldn't be any help other than to form the frog and bend the wing rails. The flange way gaps would be completely different so would not be appropriate for n gauge. If you look at the fast track ones you will see what I am after.

 

I could just try the fast track ones but its much more fun making your own isn't it?! Its like a loco builder only buying ready to run! And probably cheaper in this instance as the fast track ones are all over $50 and that's for each size so if you wanted a b8, b7 and c10 for example you're looking at over $150 without p and p from America.

 

Will make enquiries to see how much it would be with paxolin perhaps and email a few CNc milling companies for rough prices.

[grahame]

The 2mmFS SA ones would be no good, but there are already jigs available for making crossing vees in N gauge scale to finer tollerances (NMRA) than those on Peco points; 

 

 

 

 

The 'N' in 'N 1 in 7' indicates it is for N gauge rather than 2mmFS.

 

G.

[Harry]

Are those available from the 2mm assoc shop Grahame? I'm a member but can't see the parts on the shop list- any idea of part number?

 

Which make of roller gauges are you using - mine are markits ones, are they same tolerances? Think markits are for code 55 as well and not 40.

 

I'm guessing th jigs you've photographed are only for BH rail are they?

 

Thanks for reply, really useful.

[grahame]

They're N gauge jigs so are not available from the 2mmSA - generally they won't have anything N gauge.

 

I've no idea if your roller gauges are to the same tollerances as mine. I purchased them at the same time as the jigs (don't know their make) and they are fine for the code 40 rail.

 

The rail is inserted upside down so I guess they will accept both FB and BH rail. I don't think they are specific for one only.

 

I obtained them all through a friend - Noel Leaver. Although I am a memeber of both the NGS and 2mmSA neither seem to cater for such finescale N projects. However, check out Wayne Kinney's developments; http://www.britishfinescale.com/

 

G.

[Harry]

Thanks for reply, I thought th might be Noel's. I've been in contact with him a while ago and sadly he doesn't have any plans to do another run at the mo.

 

Will check out your other link though- thanks!

[Harry]

How did Noel produce the original? Does anyone know if it was outsourced or made using a milling machine at home?

 

That's all I want to produce.

[Etched Pixels]

Thanks for the replies.

 

2mm jigs wouldn't be any help other than to form the frog and bend the wing rails.

 

There I disagree. The turnout assembly jig is a machined block which holds the sleepers in place and has some fixed attachment points.

 

The rail positioning is done by templates which is why you only need one jig not one per point type. If you cut new templates for 9mm then it will work for N as well and position the frog V, the outer rails and the straight blade, the curved blade being set from the curved outer rail using the roller gauges.

 

You need different spaces for the check rails.

 

The bits for the Easitrac plastic pointwork won't help you that much but the jigs intended for etched trackwork will help you a great deal. All you should need as far as I can see are

- spacers (just bits of material the right thickness)

- new jig templates (which I guess you could ask Bill Blackburn about manufacturing)

- code 40 N gauges, available from several sources such as Micro Engineering in the USA.

[Harry]

Thanks for the replies all - I have completed a CAD drawing of the jig I'd really like to machine and have attached 2d picture of it.

 

 

Hopefully this makes it clearer what I'm after. The jig would have slots to file the rail to make the v which would also bend the wing rails the correct angle, hold the v in the correct position while soldering and then combine the v and wing rail with N gauge flangeway gaps while soldering the whole assembly (I have used 0.8mm as I already adjust the Back to Back on all my models to be consistent). The jig would have the capability of doing 1:7, 1:8, 1:9 and 1:10 all on same jig.

 

  Would Bill Blackburn be able to machine this out of some 6061 plate aluminum? Or anyone got another contact/company who may be able to? Tolerances are quite fine.

[Kris]

That is a massive area of metal which will cause problems for soldering, as it will act as a heat sink. The much smaller 2mm association versions suffer from this.

[Rabs]

Although, once the distance to the edge is more than about 5 times the size of the joint the metal block is 'big' so making it bigger makes only a small difference to the heat transfer from the heat source.  I absolutely agree that it might be a problem though.  Perhaps you could consider making it in a high temperature plastic such as polyamide or tufnol.

[raymw]

Hi Harry,

 

You could try 'firstcut' -linked from http://www.protolabs.co.uk/

submit your drawing and get a quote - 3 day delivery is cheaper! If I were you, I would redraw it to take up much less real estate. Aluminium works fine. I've made similar jigs, but for 7mm (supplied 'em to C&L some years ago), but I wouldn't want to make them for 2mm, my mill spindle doesn't spin fast enough for the small cutters required.

 

I would be interested in the price that firstcut suggests - please let us know. Tufnol would be OK, but I do not think it would last as well as ali, but good enough for the first few dozen, I expect. You will want to drill some holes in it, so you can insert a rod to push the rails out of the slots, once you've soldered them. With care, you could cut wedges, strips, etc. from a thin sheet and pin/superglue them to a backing piece to fabricate your own jigs. Strip the copper from some pcb material, and cut the fibreglass sheet, if you can find nothing else.

 

Best wishes,

 

Ray

[Marbelup]

I have previously made jigs for soldering the crossing "vee" (frog) from MDF and cardboard.  No heatsinking problems, and the cardboard lasts for many frogs before getting a bit charred from soldering.

 

More recently, I just drew the frog angle onto a piece of MDF, position the 2 prepared rails, and clamp them down with a screw and rectangular-shaped washer for soldering.  

 

I work with FB rail and the rail is positioned bottom down.  It might be different with BH rail, which I have never used.

 

I make the closure and wing rails separately and glue the rails onto basswood sleepers with Pliobond (letting it dry first, then gently heat with soldering iron to fix in position).  When assembled and everything aligned, I turn the turnout upside-down and solder a piece of brass bar or wire across the top of the frog and the wing rails to hold them in alignment and provide electrical continuity.

 

I made about 40 turnouts for my layout but many had custom geometry to fit the location, so not practical to make jigs.  I just made them over a printed paper template with the sleepers stuck down with double sided tape.  All sleepers are wood, no PCB ones.

[Tricky-CRS]

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