Experimental Plug Track: 3D-printed, CNC-milled, laser-cut

[Steve_Cornford]

But Martin, first you will need 7mm scale Plug Track to run it on!
Chicken and egg....
Talking of which I had mine scrambled this morning.

 

[AndyB]

@Marsh Lane @Steve_Cornford

Hi Rich, Steve,

Those default dimensions are the prototype BS-95R dimensions in S scale (1:64). It's very unlikely that the code 87 BH rail matches them exactly, especially the web thickness.

This is how the rail section is dimensioned:

BS-95R prototype dimensions in red. The dimensions in black relate to a sample of C&L rail from AndyB in 2016. Later batches may vary.

You can see that the all-important fishing faces are dimensioned from their intersect on the rail section centre-line. The head and foot depths can then be derived if needed.

n.b. the dimensions in black are NOT metric equivalents of the dimensions in red.

cheers,

Martin.

Hi Martin,

I don't think I have any C&L rail (at least not as far as I can remember).

The only bullhead I have is SMP which is strictly a bit narrow for 1:76.2 although I quite like it, but we better not get into all that again

Cheers!

Andy

 

[Martin Wynne]

.
I have added this note to the yellow panel at the top of this topic:

"Please do not send Templot files to commercial laser cutting or 3D printing firms while this project is still experimental, because the results are unpredictable and possibly wasteful."

It's important, because apart from not wasting your money, I really don't want the idea to get about that Templot Plug Track doesn't work. We all know how impossible it is to correct a wrong idea once it has hit the internet. Because at present of course it doesn't actually work -- it's all still experimental and not fully released.

It's also being thwarted by the present egg shortage.

I'm currently struggling to get the slots through the plug for the handed check-end chairs -- I've used up all my coloured pencils. Whose mad idea were these loose jaws?

Martin.

 

[Steve_Cornford]

Hi Martin,
Could you rotate the "peg" and "slot" by 90° and then have the slot have an open side for draining?
Slide the check chair onto stock rail and plug in.
The portion of the plug under the stock rail part of the chair is solid and therefore normal strength.
Once the loose jaw is pegged in the wedge effect will give full strength to the check rail part of the chair.
Steve

 

[Martin Wynne]

@Steve_Cornford

Hi Steve,

Thanks for the ideas. I would prefer to keep the loose jaw interchangeable with all other outers on 4-screw chairs if I can. Also, the pin needs to flex outwards sightly as the key clips under the rail head. If the pin is rotated 90 degrees that might not work.

I think I shall get there in the end. It just needs a lot of code, without any silly mistakes:

There are reams and reams of that stuff.

Eventually I shall post it all as open source as before, but I can't do that until it is all working. I can't remember how much 3D stuff there is in the original TemplotMEC code which I open-sourced in 2018. There has been some 3D rendering options in the DXF export from the beginning, but not with chairs or any thought of 3D printing.

cheers,

Martin.

 

[Martin Wynne]

@Steve_Cornford

Tweezer Alert

Hi Steve,

I've noticed that if the tweezers are left with the resin tips in contact under pressure, the resin shanks distort over time, losing some of the grip.

It's a good idea to insert a spacer between the ends of the tweezers so that the tips are not in contact, when they are not in use.

cheers,

Martin.

 

[Steve_Cornford]

Hi Martin,
Thursday morning's silly question.
Are the tweezer tips scale related, or are they just one size at the moment like the Filing Jig?
The ones I have printed so far were produced with gauge set to EM.
I have just found my store of 8BA nuts and bolts, longest is 3/8" so might have to perform a bit of countersinking!
Steve

 

[Martin Wynne]

@Steve_Cornford

Hi Steve,

At present the tips are just one size, for 4mm/ft scale loose jaws. The present code was just a try-out to see if it worked.

It's an interesting question because in the larger scales they may need to fit Mole grips!

https://www.wonkeedonkeetools.co.uk/mole-grips/a-brief-history-of-mole-grips

I have just found my store of 8BA nuts and bolts, longest is 3/8" so might have to perform a bit of countersinking!

I made the shanks far too thick at 6mm, the mark 2 version is thinner.

cheers,

Martin.

 

[Martin Wynne]

1. Chairs. For these you need a resin printer. The one which we (Steve, Charles, and I, and no doubt others) are using is this one. It's currently available at a so-called "Black Friday" price on Amazon. There are more recent, bigger and better(?) resin printers available at greater cost, but the results we have been getting from this little Mars printer are excellent:

.
It seems the Mars 2 resin printers have now ceased production and are out of stock from Elegoo. Replaced with the more expensive Mars 3 Pro:

https://www.amazon.co.uk/ELEGOO-Purifier-Protector-Precision-5-62x3-5x6-8-Mars-3-Pro/dp/B0B4JN6KX4/

If you wanted a Mars 2 Pro it would be worth googling around smartish to find one still in stock anywhere -- there was just 1 left on Amazon UK a few hours ago, but it has now gone.

It's annoying because for the plug track I wanted to make it easy for beginners by saying "get one of these, and use these settings". Now I can't do that because I can't prove for sure what settings work best on a Mars 3, without getting one. I'm back at the beginning in having to rely on conflicting reports and advice from others -- invariably referring to printing fantasy figures and little boats, not track chairs.

Martin.

 

[Steve_Cornford]

Unfortunately I think this will be the case with both resin & fdm printers, a particular model only seems to be in production for a couple of batches before they are superseded.
However I think you have established the principal of plugtrack & demonstrated what is achievable.
Fir that I for one am grateful
Steve

 

[James Grundy]

p.s.

Looking at DesignSpark Mechanical again set me thinking about how little non-Templot use I have made of my 3D printers in the last couple of years. Checking on RMweb to see the popularity of DSM v. Fusion360, I found this -- designed in DSM and printed on a Mars 2 Pro in 7mm scale:

linked from https://live.staticflickr.com/65535/52117434249_2813187b92_b.jpg

See:

https://www.rmweb.co.uk/topic/17410...here-to-start/?do=findComment&comment=4926660

I must not get distracted from Plug Track. I must not get ...

Martin.

If only I were modelling in 7mm those wonderfully scale looking wall thicknesses would be practical!

I'm having great fun putting together a body for an Aspinal A class in Fusion 360, but I wish I had put the dimensions into context sooner. It's all well and good drawing up a scale thickness cab wall until it comes off the printer looking like wet newspaper in 4mm. Still terrifically rewarding.

I'm looking forward to having a go with the track once the new ubiqitous "railway room" is completed. Though my Saturn has developed a patch of dead screen seemingly to spite me. Oh well, good excuse for a fancier machine on the horizon.

 

[Martin Wynne]

.
Here's a New Year project for someone who wants to try a bit of plug track on an existing layout.

A common problem is to make a track fixing at baseboard joints which is robust but invisible.

You could print something like this, to replace the last few sleepers of the track and the cork underlay:

Make the base slab rectangle a reasonable thickness. Drill through and screw it to the baseboard. All to be hidden under the ballast.

The clip is optional and could be used to align with the same on the next baseboard while fixing. Saw through the clips before separating the boards.

If the rail ends ever got damaged, it would be easy to pull out the chairs and replace them, without disturbing the original base or its alignment.

Martin.

 

[Charles Orr]

.
Here's a New Year project for someone who wants to try a bit of plug track on an existing layout.

A common problem is to make a track fixing at baseboard joints which is robust but invisible.

You could print something like this, to replace the last few sleepers of the track and the cork underlay:

View attachment 4879

Make the base slab rectangle a reasonable thickness. Drill through and screw it to the baseboard. All to be hidden under the ballast.

The clip is optional and could be used to align with the same on the next baseboard. Saw through the clips before separating the boards.

If the rail ends ever got damaged, it would be easy to pull out the chairs and replace them, without disturbing the original base or its alignment.

Martin.

 

[AndyB]

If only I were modelling in 7mm those wonderfully scale looking wall thicknesses would be practical!

View attachment 4877

I'm having great fun putting together a body for an Aspinal A class in Fusion 360, but I wish I had put the dimensions into context sooner. It's all well and good drawing up a scale thickness cab wall until it comes off the printer looking like wet newspaper in 4mm. Still terrifically rewarding.

I'm looking forward to having a go with the track once the new ubiqitous "railway room" is completed. Though my Saturn has developed a patch of dead screen seemingly to spite me. Oh well, good excuse for a fancier machine on the horizon.

Nice Caledonian 0-6-0. I used to see them all the time a few years ago. Not sure about the firebox on that one. I think it should be narrower at the bottom.

Please carry on

 

[James Grundy]

Nice Caledonian 0-6-0. I used to see them all the time a few years ago. Not sure about the firebox on that one. I think it should be narrower at the bottom.

Please carry on

Hi Andy,

Not quite a Caley type in this case, though I do wish the L&Y machines had retained the wing plates between smoke box and sanders. A highlight of victorian elegance I reckon.

This one is destined to be an A class, like the real one thankfully preserved and owned quite coincidentally by a Mr Andy Booth, and accordingly has parallel firebox lower sides.

.
Here's a New Year project for someone who wants to try a bit of plug track on an existing layout.

A common problem is to make a track fixing at baseboard joints which is robust but invisible.

You could print something like this, to replace the last few sleepers of the track and the cork underlay:

View attachment 4879

Make the base slab rectangle a reasonable thickness. Drill through and screw it to the baseboard. All to be hidden under the ballast.

The clip is optional and could be used to align with the same on the next baseboard while fixing. Saw through the clips before separating the boards.

If the rail ends ever got damaged, it would be easy to pull out the chairs and replace them, without disturbing the original base or its alignment.

Martin.

Now there is an idea. I have often wondered about how to improve on the tried and true PCB sleeper firmly fixed at the join. My prospective layout project will need a good few such joins so i'll certainly give this a try. Could be some while though, as these things always are.

 

[AndyB]

Hi Andy,

Not quite a Caley type in this case, though I do wish the L&Y machines had retained the wing plates between smoke box and sanders. A highlight of victorian elegance I reckon.

This one is destined to be an A class, like the real one thankfully preserved and owned quite coincidentally by a Mr Andy Booth, and accordingly has parallel firebox lower sides.

Thanks for that James.

I should have spotted the missing wing plates The cover over the rods under the smokebox has a very Caley look about it.

Sorry for the distraction.

Cheers!
Andy

 

[Martin Wynne]

.
Some notes about using plug track with thin laser-cut ply timbers:

https://85a.uk/templot/club/index.php?threads/what-thickness-of-trackbed-do-you-use.314/post-5672

FDM timbering bricks replace both the timbers and the battens, but otherwise similar track-laying dimensions.

Martin.

 

[Nick Allport]

Hi everyone,

I'm new to the forum, but not new to Templot.

I posted this yesterday on the 3D Plug Track thread on the Scalefour Society forum. I've been following this with interest because the idea of printing my own track-building components is hugely attractive, I live in Portugal so it's not very easy for me to get parts, plus I'm an advocate of radio control and although I'm not quite there with printing everything yet, that is definitely an option for me.

I've just acquired an Elegoo Saturn 2 resin printer, and after a week of setting it up and running test prints, I finally tried printing the example loose jaw chairs stl that's back a few pages in this thread. And I have to say I'm completely floored by the results.

Martin mentioned that you're putting together a catalogue of settings, which obviously I'm happy to share. I'm using Elegoo Standard Grey resin, I've switched off the Image Blur (as mentioned somewhere), and I have Exposure Time set at 2.5 with Bottom Exposure Time set at 30, the rest is all out of box but I can share everything if needed.

So I guess my next question is, can I print some sleepers?

This is all hugely exciting!

Many thanks, Nick

 

[Martin Wynne]

@Nick Allport @Steve_Cornford

Hi Nick,

Many thanks for that. Welcome to Templot Club.

I see that you are using the Elegoo Standard resin. Most of us have been using the ABS-Like resin which is claimed to be more resilient than the standard resin and slightly flexible.

The pins on the loose jaws need to flex slightly as the key passes the rail head and clips under it. Have you yet tried assembling some rail in the chairs to see if that works ok with the standard resin?

There have also been some suggestions to mix different resins, although that seems a bit messy and unpredictable to me.

The jury is still out on using resin printing for the timbering bases (instead of FDM), and whether to print the chairs integral with them, rather than separate press-fit chairs. If you make them integral, I can see difficulties in properly washing out the slots for the loose jaw pins. When I tried some resin-printed bases, they curled up significantly after a few days and would be difficult to lay flat. That can be avoided by fully UV curing them while still on the build plate, but that makes them more difficult to remove from it. Steve is conducting some experiments on all this and can report more fully.

You mentioned battery radio-control, i.e. resin-printing the rails too. That means the whole thing could be printed in one go, no separate chairs or loose jaws needed! No doubt Chitubox will want to add some supports under the rail between the timbers. The rails might be strong enough to allow the timber webs to be omitted, which would likely solve the curling problem. It would mean I have to do some work on the DXF export to add solid ends to the rails, nose for the vee, etc. Have you given any thought to the moving switch blades and stretcher bars?

cheers,

Martin.

 

[Nick Allport]

Thanks Martin.

I've actually just printed six of the test_slotted_resin_brick_fixed stl just to see what would happen, I'm just drying them now, then I'll cure them and see how they do over the next few days. I fear that you're right though and they won't stay flat. So I guess next purchase is going to be an FDM printer...

To be honest I'm not keen on the idea of printing everything including the rail as I really enjoy the process of building track, but I'm happy to try it.

Personally I love the idea of separate timber bases and the plug-in loose jaw chairs.

The question on resin, I've cured the chairs for 1 minute and attached six of them to a piece of rail with no problems or breakages, the loose jaw just snaps in. But the next resin order I do I'll get the ABS-Like. Does this require different exposure settings?

Any recommendations on an FDM printer? I've been looking at the Anycubic Kobra Max, which has a 400 x 400mm print area, seems ideal for timbering bases.

Many thanks, Nick