Experimental 3D plug track - up to version 244c

[Martin Wynne]

.
Another day, another tick-box. And barely any space left for it:

Handily placed with the cryptic label S1J on J1 There is no space for more explanation.

This is a S1J joint chair on timber J1 at the switch front:

There is also a S1J joint chair on J2, adjacent to the switch-front rail-joint in the usual way.

The original REA drawings show an ordinary S1 chair on J1 (and on any other switch front timbers between the switch toe and the rail joint, if there are any), with S1J on the joint timber J2 only.

However, many photographs show S1J chairs also on the J1 timber(s).

The new tick-box lets you choose between S1 or S1J on the J1 timber(s). I have set it ticked as the default, but I'm in two minds about that, I might change it.

Some pre-grouping designs used ordinary 10" wide sleepers for J1 and J2. There is an option for that in the custom switch settings -- it's been there right back to the beginning of Templot. If the switch front is set to sleepered, the above chair settings will be ignored and they will all have ordinary S1 chairs (S1J chairs won't fit on 10" sleepers).

cheers,

Martin.

 

[Martin Wynne]

.
I'm pleased to say that after a week-long battle I have finally got the flared end check-rail chairs mostly where I want them:

That's the normal REA CC parallel chair and above it the CCR angled chair for the flared ends. In EM.

If that was all that was needed it would have been done ages ago. Unfortunately it isn't:

Notice the near end of the near check rail. The timber has been shoved to a skew, changing the position of the chair on the rail. The check rail has been extended in length in front of the crossing. The flare length has been shortened, and the end gap on the check rail has been widened. Such things can be necessary in complex formations such as a tandem turnout, or to match the check rails for a specific prototype. But it still needs a matching chair:

I'm not entirely happy with this distortion of the prototype CCL chair for it -- the check rail seat could be improved (check rail seats are shorter than running rail seats because check rails do not need to support a vertical load).

But it will do for now, so that I can get on with the chairs for the V-crossing.

I knew from the start that the check-end chairs would be the most tricky part of the whole project, so I'm glad to have got this far now.

cheers,

Martin.

 

[Phil O]

Martin,

On the few occasions that an alteration to the flair angle is required I would have thought that a cosmetic chair/half chair would suffice, at least until you have created the V crossing chairs and other more important ones.

 

[Martin Wynne]

Martin,

On the few occasions that an alteration to the flair angle is required I would have thought that a cosmetic chair/half chair would suffice, at least until you have created the V crossing chairs and other more important ones.

@Phil O

Hi Phil,

It's tricky, because you don't want to have to put filler in an unwanted socket, before you can glue on a cosmetic moulded chair.

But since you wrote that I have done a bit more work and got it a lot better, and edited my previous post.

Some scrambled eggs helped -- there's no actual law against having them at 3am.

cheers,

Martin.

 

[Martin Wynne]

.
It's now 4 months since I released the last program update 236d, so it's high time I released another one.

I shall be releasing update 237c shortly, so that users can experiment with the check rail chairs, the one-piece switch block chairs, and the loose-jaw options for all chairs.

And also report any issues which I have missed. There are bound to be a few of those -- since 236d I have re-written the data structure for holding the chair detail for each template.

I ought to test everything thoroughly before releasing an update, but if I wait to do that it will be several more weeks before I can make some progress with the V-crossing chairs. But provided everyone understands that this is all still extremely experimental I think I can risk releasing my development version 237c as it stands.

To that end I have made a start by removing the conflicting S1 chairs which were running through the V-crossing area:

I should have done that months ago, it would have saved me a lot of grief from folks telling me they were wrong!

Hopefully 237c should be on the server later today.

cheers,

Martin.

 

[Phil G]

Hi Martin,
I have spending a few hours trying to catchup you all you guys re the progress of the very impressive plug track. Especially around the DXF/STL export page, and what all the options do abs mean. It struck me last night, and please don't think I am trying to make work for you here. Would it be better if the export page was basically broken into two pages? One for say chairing and rail work, (all the rail jigs would then also reside on that page). with the other page being devoted to timbering options of which there main, as there is 3D print with FDM, or resin, laser cut. Either with wood or card and then CNC machine options as well. Which really got me thinking there is a page alone in all timbering options.

I fully understand its still all very experimental and its you full intension to tidy up the screen with drop down options at some point in the future. just wondered if the about Idea was a logical stepping stone.
Ps Mars 3 Pro arrived today, so busy and unboxing trying to calibrate that at the moment.
Cheers
Kiwi Phil

 

[Martin Wynne]

.
Program update 237c is now on the server:

https://85a.uk/templot/club/index.php?threads/new-templot2-update-version-237c-now-available.651/

cheers,

Martin.

 

[Martin Wynne]

@Phil G

Hi Phil,

Thanks for your thoughts. It was good to chat on Zoom. Let us know how you get on with the Mars 3.

I keep saying that the whole plug track project is experimental, but I do wonder if folks understand what that means.

It means that all this stuff is just a temporary dumping ground for buttons and tick boxes while I find out what will be needed:

Eventually it will all be swept away and replaced with something else. At present I have only the haziest ideas what that might be. It will be time wasted if I try to do anything about it before I know what I'm doing.

At present the 2D and 3D exports are tangled up (even I can't remember what goes in which) and clearly need separating.

Then the track stuff needs to be separated from the utility functions for filing jigs, tweezers, GCODE editing, and suchlike.

But I can't design a sensible user interface until I know which bits of plug track work, which bits don't work, which bits are still work in progress, which bits are planned for the future, which functions are needed, and most importantly feedback from users.

Please folks, don't tell me about buttons and tickboxes yet. It is just too early to make any sensible decisions. Tell me about what you have printed, laser-cut, or CNC milled. On what machines. Using what settings. With what results -- especially the finished dimensions. At present I still don't know for sure that plug track actually works as a practical means of building track. There is no point in creating a user interface until I know that. On past evidence it will likely take many, many hours to come up with a good working interface, and I'm not going to even attempt it until I know what I'm doing. Thanks.

Major stuff still missing is brick/chairing indications on other outputs (printed templates, PDF, image and EMF exports, sketchboard, etc.), and updating the saving of custom settings (at present only a few of the settings make it into the file). It's difficult to do that until I know which custom settings are worth saving, and the whole business of custom non-REA chairs for GWR, etc., all of which is just a blank sheet at present. There is still a very long way to go before any of this plug track stuff can be considered ready for regular use. It's just one big experiment.

cheers,

Martin.

 

[James Walters]

Hi Martin,

I've just tried out laser cutting some timbering and the new nib/snib function. In principle its a fantastic addition in my opinion.
However, I am experiencing an issue. The default .35mm nib width is a little small and the timbers are dropping out of the fret.

I've tried adjusting the nib/snib geometry using the controls within Templot, but the seem to make no difference. It is as though the new settings don't update on the exported .dxf. Could I be doing something wrong?

From my perspective this is an excellent feature and I can't wait to make full use of it.

Best,

James

 

[Martin Wynne]

@James Walters

Hi James,

Many thanks, that's just the kind of practical feedback I need. Now I know that the default nib width isn't wide enough.

You can easily fix the bug by clicking the rebuild now button after changing the setting and before exporting the file:

I need to change that to be automatic for 2-D files instead of only 3-D. Sorry about that. Thanks for finding and reporting it.

You can see the effect of the change on the control template if you click this option:

And I've just noticed that menu item should say 2-D not 3-D. It never ends!

If it's not working, do a full generator > rebuild after changing the nib settings.

cheers,

Martin.

 

[James Walters]

Thank you Martin,

I've used the rebuild now button and all is working perfectly.

Here are two examples, both with the nib dimensions set to 0.6mm. One has the snibs set to 0 so that the waste drops out.

This really is a great feature.

 

[Steve_Cornford]

Hi James, that iiiiis looking good.
What thickness of ply did you use?
Steve

 

[James Walters]

Hi Steve, this is 3mm plywood. Cut on 100% power at 40mm/second.

 

[Phil G]

Hi James,
As Steve has said that looks very good.
Are you using a co2 laser to do this? if so what is the power rating of your laser?
also do you think it would be possible to create a similar result using a diode laser? and thinner ply say 1.6 or 2.00mm?
Cheers
Phil

 

[Martin Wynne]

@Phil G

Hi Phil,

James can provide chapter and verse, but this YouTube channel has a lot of CNC and diode laser cutting info. This latest video shows a 20W output diode laser unit which can cut 3mm ply at 1000mm/minute at 100% power. I don't know how that compares with others, but it sounds impressive to me:

This is a lower-powered 5.5W diode laser output which can cut 2mm wood at 230mm/min and 80%. Presumably it would do 3mm at a lower speed:

But if you build track on battens to clear the plug depth, you would only need to cut 1.5mm for the timbers:

The longitudinal battens are 4mm x 1.5mm stripwood or plywood. Easily available as 4mm timbering strip for plywood pointwork construction from the usual suppliers. Or as limewood strip from model boat suppliers. Or cut from 1.5mm mounting board. Or if you have a sawbench easily cut it yourself -- the exact width is unimportant.

That gives a total clearance depth for the chair plugs of 3mm or 1/8". The full depth is needed in order for the loose jaws to work as intended.

It's a well-tried trackbuilding method from the old days, here is a scan from a 1949 book:

cheers,

Martin.

 

[James Walters]

Hi Phil,
I'm using a 130w CO2 laser.
I'm quite certain that it would be possible to produce a similar result with a diode laser.
I've not used a diode laser myself, so can only speak from the perspective of friends of mine who use them and who have told me of their experiences.
One chap I know well for example has a 5w diode machine which takes 3 passes moving very slowly at 100% power to cut 3mm MDF. The machine was advertised as being able to cut 10mm think material.
The results are OK, but not as clean as might be possible with a higher powered machine running faster with less over-burn. As such I think I'd not be confident of maintaining the tolerances required to achieve true plug-track specs. A drop of glue would of course overcome any slop in the chair sockets, but I no experience on which to base thoughts around gauge accuracy. My gut feeling though is that it would be very doable with experimentation.

Possibly, and I've not thought this through, (and it would need Martin's approval) I might be able to supply some laser cut plywood samples from which folks could have a go at building some 'experimental' plug track lengths. Maybe that could be beneficial to the collective gene-pool of thought and feedback, with the benefit that we would all be working from a standardised component in terms of material and machine settings but with the caveat that we share our experiences here, rather than risk jeopardising the whole concept by commenting upon it on other fora.
Perhaps that might be a good way of proving the concept more widely and establishing a standard by which other methods could be judged for better or worse.

Just a thought.

James

 

[Martin Wynne]

Possibly, and I've not thought this through, (and it would need Martin's approval) I might be able to supply some laser cut plywood samples from which folks could have a go at building some 'experimental' plug track lengths.

@James Walters

Hi James,

That sounds a great idea. (You don't really need my approval, unless you were to start claiming some sort of copyright on the design work.) But keeping experimental results on here is definitely a good thing -- especially the failures!

One question I would like to ask coming from a CNC milling background -- if you make multiple cuts, do you make roughing cuts first, and a final finishing cut to size? Given that the removed material is scrap, my instinct would be to make one or more full power roughing cuts at say 0.3mm kerf, and then move over for a final finishing cut at say 0.2mm kerf on lower power -- to clean up the cut edge to exact size. Is that doable, or am I missing some essential difference between milling and laser cutting?

In this particular application, only the top 1mm or so needs to be accurately sized, so a final finishing cut for that depth would seem to be a good away to achieve the tolerances needed. What happens below 1mm is largely irrelevant -- the plug is tapered and the timber is hidden in ballast.

If the idea is feasible, can it all be done in the laser-cutter software, or would you want two separate kerf lines in the DXF (presumably in different colours), or would it need two separate DXF files?

cheers,

Martin.

 

[Phil G]

Hi James,

Thanks for your reply, you have just hit the nail on the head, in terms of my concerns. Ie. a lower power laser will lead to more passes, and far more likelihood of overburn. Which in turn will very likely impact negatively on the overall accuracy of the plug track concept. Hence the idea of thinner wood less overburn.

To your point Martin, I understand 1.5mm is optimum, it's just I can't yet find any 1.5 mm ply in NZ but I can get 2.00mm.

It would be good just to at least get a small sample from you James, (providing that's all ok with all) so I can do direct comparisons, as luckily my local laser and 3D retailer is keen to let me try before I buy, As long as I supply the wood.

My options with this retailer are only really diodes from 10W upto I believe 80W max.

Cheers

Phil.

 

[Martin Wynne]

To your point Martin, I understand 1.5mm is optimum, it's just I can't yet find any 1.5 mm ply in NZ but I can get 2.00mm.

@Phil G

Hi Phil,

Have you tried asking for 1/16" ply? The traditional sizes of thin plywood are 1/32" , 1/16" , 1/8".

(i.e. 0.8mm -- as Brook Smith rivetted track, 1.6mm, 3.2mm)

The same are the traditional sizes for copper-clad SRBP, plus 3/64" -- as SMP track.

My options with this retailer are only really diodes from 10W upto I believe 80W max.

With diode lasers you need to make clear whether that is input power, or output (cutting) power. There is a big difference between them.

cheers,

Martin.

 

[Phil G]

Hi James,

That sounds a great idea. (You don't really need my approval, unless you were to start claiming some sort of copyright on the design work.) But keeping experimental results on here is definitely a good thing -- especially the failures!

One question I would like to ask coming from a CNC milling background -- if you make multiple cuts, do you make roughing cuts first, and a final finishing cut to size? Given that the removed material is scrap, my instinct would be to make one or more full power roughing cuts at say 0.3mm kerf, and then move over for a final finishing cut at say 0.2mm kerf on lower power -- to clean up the cut edge to exact size. Is that doable, or am I missing some essential difference between milling and laser cutting?

In this particular application, only the top 1mm or so needs to be accurately sized, so a final finishing cut for that depth would seem to be a good away to achieve the tolerances needed. What happens below 1mm is largely irrelevant -- the plug is tapered and the timber is hidden in ballast.

If the idea is feasible, can it all be done in the laser-cutter software, or would you want two separate kerf lines in the DXF (presumably in different colours), or would it need two separate DXF files?

cheers,

Martin.

Hi Martin,

I like your question, and I too would be very interested in James' reply.

Coming from a similar background to you, I had almost exactly the same thought process, so I asked our local laser sales guy.

What was interesting is, he is also quite big on CNC routing, his comments were that you need to think about the power of the laser as analogous to the cutting length of a cutter. With a lower power Laser being similar to a short cutting face tool, with a long shank of the same diameter as the cutter.

Meaning you can do quite a few small cuts in the vertical plane but you can't then just move over and do a finishing cut because the laser just does not have the power, in the same way you can't use a short series cutter, when the work is thicker than the cutting face of the tool.

That made total sense to me.

It will be good to get other peoples views.

Phil.

 

[Martin Wynne]

Hi Martin,

I like your question, and I too would be very interested in James' reply.

Coming from a similar background to you, I had almost exactly the same thought process, so I asked our local laser sales guy.

What was interesting is, he is also quite big on CNC routing, his comments were that you need to think about the power of the laser as analogous to the cutting length of a cutter. With a lower power Laser being similar to a short cutting face tool, with a long shank of the same diameter as the cutter.

Meaning you can do quite a few small cuts in the vertical plane but you can't then just move over and do a finishing cut because the laser just does not have the power, in the same way you can't use a short series cutter, when the work is thicker than the cutting face of the tool.

That made total sense to me.

It will be good to get other peoples views.

Phil.

@Phil G

Thanks Phil.

I can understand that you can do only a single finishing cut, which might not reach very deep. But I would guess that by moving over a few thou to do that you could remove any overburn from multiple roughing cuts, which would have been made at an increased kerf offset to allow for it.

Giving a more accurate cut size for the finished result, at least down to the depth of the finishing cut. Which is all we would need for plug track.

But I don't know. I'm pretty sure the only way I can find out for sure is to get a laser-cutter of my own and try it.

cheers,

Martin.

 

[Martin Wynne]

I need to change that to be automatic for 2-D files instead of only 3-D. Sorry about that. Thanks for finding and reporting it.

@James Walters

Hi James,

• Actually this is a serious bug. Templates are not being automatically rebuilt for 3D either. Many settings will not be properly reflected in the exported file.

Very sorry about that, I will try to get a fresh release done later tonight.

Until then please be sure to click the rebuild now button before exporting DXF/STL files.

Martin.

 

[James Walters]

Thank you Martin, although it really is no trouble to click the rebuild now button. I hope this isn't causing you too much work.

 

[Cransford]

.
I'm pleased to say that after a week-long battle I have finally got the flared end check-rail chairs mostly where I want them:

View attachment 5258
That's the normal REA CC parallel chair and above it the CCR angled chair for the flared ends. In EM.

If that was all that was needed it would have been done ages ago. Unfortunately it isn't:

View attachment 5261
Notice the near end of the near check rail. The timber has been shoved to a skew, changing the position of the chair on the rail. The check rail has been extended in length in front of the crossing. The flare length has been shortened, and the end gap on the check rail has been widened. Such things can be necessary in complex formations such as a tandem turnout, or to match the check rails for a specific prototype. But it still needs a matching chair:

View attachment 5267
I'm not entirely happy with this distortion of the prototype CCL chair for it -- the check rail seat could be improved (check rail seats are shorter than running rail seats because check rails do not need to support a vertical load).

But it will do for now, so that I can get on with the chairs for the V-crossing.

I knew from the start that the check-end chairs would be the most tricky part of the whole project, so I'm glad to have got this far now.

cheers,

Martin.

Martin,

I've been following your work on this with keen interest.

I'm possibly missing something, but from the recesses of my mind I think bull head cover checks for turnouts were 8'-6" long so CCL/CCR chairs would fit design. For non-standard arrangements (such as a tandem) an extended check might be used. To avoid the issue with pushed timbers, would you be able to 'force' Templot to adjust any designed length to place the CCL/CCR chair without pushing timber? I'm aware of rules on position of flare relative to crossing nose, and guess any adjustment would only be minimal.

I will now take cover behind the toast rack!

Cheers,

Paul

 

[Martin Wynne]

@Cransford

Hi Paul,

Fully prototypical CC / CCL / CCR check chairs only make sense in S4-X, S7, etc. gauges. For 00/EM/P4 etc with flangeways wider than dead scale, something has to give.

At present to force an exact scale CCL/CCR chair you would need to adjust the check rail length and the flare length/opening so that the intersect on the timber centre-line results in a chair of the correct CCL/CCR dimensions. That's easily doable, but a rather tedious process for every check rail end.

I'm intending to provide some means to "lock" a scale CCL/CCR chair onto the end of a check rail, by splitting the check rail out onto a separate partial template. It would then be up to the user to adjust the check rail length and/or shove the timbers, so that the "locked" chair is fully over a timber. That's easy enough to program, the tricky part is what to do if someone tries to export a file while the chair is in fresh air between the timbers. At present that would simply generate an error, which might not be helpful. The same considerations apply to the end of the wing rail in parallel-wing crossings.

At present there are dozens of these ifs and buts in the plug track design which I have skated over for the time being simply to keep the number of tickboxes within reason, and to get a full turnout of some sort done within a reasonable timescale. And then similarly for the half-diamonds.

With all that finally achieved I will be able to draw breath, learn from user feedback, and go back to add all these twiddly details and settings needed. Not only such design issues, but also the track furniture such as switch anchors, spacer blocks, fishplates, etc., and special REA chairs such as L1CC, L1CCL, L1CCR, M1, S1N, S1O, saddle chairs, and all the other special designs which might be needed in a complex formation. And then go right back to the beginning and do it all over again for GWR. Im feeling tired just thinking about it.

cheers,

Martin.

 

[Martin Wynne]

.
Time to start yet another topic I think. 1000+ posts is plenty enough for one topic.

This one is a continuation from:

https://85a.uk/templot/club/index.php?threads/experimental-plug-track-continued.673/latest/

This time the word experimental is missing from the title -- but that doesn't mean it is missing from the project.

There is still a lot to explain, for FDM settings, resin shrinkage, laser kerfs, mesh-fixing, timbering bricks, chair options, and all the rest. See for example today's topic on parallel wing crossovers.

cheers,

Martin.

 

[Phil G]

Hi Martin,
I am looking for some advise here, I have a couple of issues, firstly I tried to use Templot to create an STL file for a C10 right hand turn out.
In order to start printing the chairs currently avaible for a turnout, as you suggested in the zoom meeting I first created a raft the size of my Mars 3 print area. This worked fine, however when I went into Chitubox to slice the STL I found its created a single file far to big to print because its spaced the chairs as per their correct position in the template.
given its a single STL file, there is nothing I can do in Chitubox to rearrange the chairs to get them condensed onto the build plate.
Is there a practical way to do this inside Templot that I am missing?

Anyway I thought ok, export as a 3D DXF file and reposition the chairs inside the CAD and then re-export as a STL from the cad.
So far no matter what I have tried I can't find a way to open the exported DXF in my AutoCAD package. I don't know if the problem is my cad package will not open the exported DXF from Templot. Or if there is an issue actually exporting out of Templot. I have tried rebuild now function and also the rebuild in the generator, neither have resulted in a DXF file I can open.
Are you able to see if you can get a DXF being generated in the current version of Templot to open in your Turbocad, As that would at least tell me if the issue is my cad or not.
Thanks
Phil

 

[Derek]

@Martin Wynne some time back in the old Templot forum, you very kindly produced a REA specification scissor as I was having issues similar to @Terry Downes. It was also because I had 'assumed' it was a standard 6ft, when in fact (IIRC it's supposed to be 6ft6 or 7ft between the inner rails).

If you still have that on your computer, perhaps it would help Terry? I'm afraid I lost my copy when I replaced the HDD, though I have a PDF of it if that might help.

 

[Martin Wynne]

as you suggested in the zoom meeting I first created a raft the size of my Mars 3 print area.

@Phil G

Hi Phil,

No I didn't suggest that -- or if I did I was wrong. I tried to explain the whole of plug track as fast as I could and even so the clock went well past midnight on the last Zoom meeting. I'm sorry about that. The thing is that plug track just isn't really ready yet. There is too much to explain and too much unfinished. You can do lots of stuff already, but what you can't do is read the instructions for it because I haven't written them yet.

If you make a raft the full size of the build plate it is likely to create too much suction to print properly -- and might even damage the FEP film. Somewhere back in this topic I suggested a maximum raft size of around 1500 sq. mm from my own experience on the Mars 2 Pro. I have no way of knowing if the same would apply for other printers, but I suspect it would. Here is what a successful build plate looks like on the Mars 2 Pro for making chairs:

For how to do that, start reading at this post:

https://85a.uk/templot/club/index.p...3d-printed-cnc-milled-laser-cut.229/post-2030

At present I don't suggest creating the chairs for a single template, as you found it will waste too much space. The idea is to create the chairs for a timbering brick, and interlace them for several bricks at the same time using partial templates, so that you can fill the build area more economically. Unfortunately I didn't have time to explain the whole process of extracting timbering bricks -- most of it is on here, although there have been lots of changes since this topic:

https://85a.uk/templot/club/index.php?threads/extracting-a-3d-timbering-brick-from-a-track-plan.295/

We can go through some of this at the next Zoom meeting if wanted? But we must do it s l o w l y otherwise I will forget to mention some important detail.

Later today I will prepare a sample STL file for printing the chairs for a C-switch and post it here.

At some stage I will write a function to bunch together the chairs for a single template for easier printing, but I haven't done that yet because it is actually an extremely complex function to write. Chairs will need to be inserted in the DXF file in a different place from where they are generated, in such a way as to minimise the space between them while still leaving room to use the Xuron cutters on the supports, and at the same time creating a reference chart for which chair is which on the raft. With all the different chair sizes it will be a major jig-saw puzzle. Like lots of other things it will have to wait until I have at least finished the chairs for a full turnout.

I don't have AutoCAD so I'm sorry I can't advise you about it. Somewhere in the Open File dialog after selecting the DXF file type, there will be a button labelled Options or Setup or some such. That's where you tell AutoCAD that it's an ASCII-type DXF, that the units are in mm, etc. If there is an option to choose a DXF version, choose one of the earliest versions, not the latest one.

DXF files from Templot 237c can definitely be opened in CAD programs. The two I have here are TurboCAD and DesignSpark Mechanical, here is a current default chairing DXF from Templot opened in each of them:

• but please note everyone, you do NOT need CAD programs or CAD skills to use Templot plug track.

No doubt someone else on here is using AutoCAD and can advise. Anyone?

cheers,

Martin.

 

[Phil G]

Hi Martin,
Thanks for the advice, just to clear my intension is not to charge in and make a turnout as such, its simply to try and print all the chairs you have done so far. This is because I am working with my local laser supplier to try and dummy up a few trail burns with the equipment he is selling.
In order to give this the best shot, I want to be able to test with all chairs you have developed so far. or putting it another way, as you like to say, this is purely an experiment to see what happens with the laser approach.

The D10 was simply I had to start somewhere, and I am envisaging Heaton Norris Junction uses quite a few 1 in 10 vee angles, to be honest I am not sure of the correct size switches they look like either C or D from what I have done so far. I think I am going to need some advise on that subject soon
I have attached a a photo of bank of P chairs and Jaws I have just printed. 9 rafts is about as much as you can get in one print, I am only doing 9 because I noticed I am currently wasting more resin on clean up after printing, so the more I can get on the build plate without over loading it the better off I am.

Re the DXF file thanks for the confirmation clearly something wrong with my AutoCAD as each time, all it does is open an empty drawing.
2D works fine but not 3D.
I will have to go deep into the internet rabbit holes to find out what's wrong with my cad approach.
thanks Phil,
PS the experimenting is also the reason for the 2mm ply, its all I can get in a hurry at not crazy lead times or prices.

 

[Cransford]

@Cransford

Hi Paul,

Fully prototypical CCL/CCR check-end chairs only make sense in S4-X, S7, etc. gauges. For 00/EM/P4 etc with flangeways wider than dead scale, something has to give.

At present to force an exact scale CCL/CCR chair you would need to adjust the check rail length and the flare length/opening so that the intersect on the timber centre-line results in a chair of the correct CCL/CCR dimensions. That's easily doable, but a rather tedious process for every check rail end.

I'm intending to provide some means to "lock" a scale CCL/CCR chair onto the end of a check rail, by splitting the check rail out onto a separate partial template. It would then be up to the user to adjust the check rail length and/or shove the timbers, so that the "locked" chair is fully over a timber. That's easy enough to program, the tricky part is what to do if someone tries to export a file while the chair is in fresh air between the timbers. At present that would simply generate an error, which might not be helpful. The same considerations apply to the end of the wing rail in parallel-wing crossings.

At present there are dozens of these ifs and bits in the plug track design which I have skated over for the time being simply to keep the number of tickboxes within reason, and to get a full turnout of some sort done within a reasonable timescale. And then similarly for the half-diamonds.

With all that finally achieved I will be able to draw breath, learn from user feedback, and go back to add all twiddly details and settings needed. Not only such design issues, but also the track furniture such as switch anchors, spacer blocks, fishplates, etc., and special chairs such as L1CC, L1CCL, L1CCR, M1, S1N, S1O, saddle chairs, and all the other special designs which might be needed in a complex formation. And then go right back to the beginning and do it all over again for GWR. Im feeling tired just thinking about it.

cheers,

Martin.

Martin,

Good morrow dear sir!

I read your comments with interest, and funnily think you've covered my thought from another direction by locking the CCL/CCR chairs relative to check. Although my history of track design was BR bull head, a long time ago, I'd have expected checks to fit turnout without 'tweaking' because the timbers were set to/from crossing nose at same centres across lower crossing angles (think the higher number angles were different but I only ever came across Neasden South as a "high speed" bull head turn out!), which in turn covered length of standard check. Fully agree minefield starts with anything else!

I'll now leave you be to enjoy an Easter egg!

Paul

 

[Martin Wynne]

Re the DXF file thanks for the confirmation clearly something wrong with my AutoCAD as each time, all it does is open an empty drawing.

@Phil G

Hi Phil,

As far as I know that's what happens in every CAD program. Or at least it's what has always happened with any file from anywhere that I have ever opened in any CAD. It starts off with a blank screen after opening the file.

The very first thing you have to do is click the fit to extents button:

Which causes it to zoom the screen to fit the contents of the file. Why it can't just do that for itself is one of the mysteries of life that I have given up trying to fathom.

cheers,

Martin.

 

[Phil G]

Hi Martin,
Thanks for the input, what is embarrassing is I work with AutoCAD 2023 in 3D all be it as either DWG files STP files or in full blown inventor everyday as my job. Which I have to admit I find very boring.
So I was surprised I could not open your file. And did originally think the issue was in Templot export.

what is very weird is back in the 80s it was Autodesk the owners of AutoCAD who developed DXF files in the first place.
after I bit of topical research its already becoming obvious Autodesk are actively making it hard to open and save DXF files in AutoCAD even in 2D, no doubt there will be some very obscure tick box hidden somewhere, I need to find to open the file.
cheers
Phil

 

[Phil G]

Hi Martin,
Just a quick question about P chairs and loose jaws for P chairs,
I am I missing something, because unlike the S chairs and jaws the loose jaw on the P type has nothing to clip the rail against to lock it in place. So the question is why bother with loose jaws on the P Chairs? would they not be stronger just formed from a single chair and jaw STL file?
cheers
Phil

 

[Martin Wynne]

@Phil G

p.s. Phil,

Your photo:

I found on the Mars 2 Pro that to minimise tolerancing issues, it is best to have the loose jaws oriented the same way on the build plate as the chair bases they are intended to fit. I don't know whether this is down to printer resolution issues, the Chitubox slicer, or differential resin shrinkage.

Likewise, you may find differences in sizes between the same chair rafts printed in "portrait" and "landscape" arrangements.

p.p.s. In Chitubox there is some "image blurring" function which inexplicably is ON by default and needs to be turned off for engineering work. See previous posts by Steve about this.

This is all the detailed stuff that is important but is easy to forget to mention. My head is full of this stuff but I've no idea how to get it all written down in instructions that folks will actually read.

cheers,

Martin.

 

[Phil G]

Hi Martin,
Great tip I will ensure there all in the same orientation,
I have also attached screen shots of my setting (derived by using the cones of calibration in 4 corners) to get build plate flat and best exposure time for Elegoo ABS-like grey at 20 degrees. you can see I am down to 2.2 seconds and 0.04 for the Z
so far I am very happy with the results
Cheers
Phil,

 

[Martin Wynne]

Hi Martin,
Just a quick question about P chairs and loose jaws for P chairs,
I am I missing something, because unlike the S chairs and jaws the loose jaw on the P type has nothing to clip the rail against to lock it in place. So the question is why bother with loose jaws on the P Chairs? would they not be stronger just formed from a single chair and jaw STL file?
cheers
Phil

@Phil G

Hi Phil,

That's correct. However if you use solid P slide chairs the rail cannot be dropped vertically onto the chairs. It would need to be "hooked" under the outer jaws in the process. That's not too difficult if you use all loose jaws, but gets fiddly if you combine them with solid jaws on other chairs which need to be progressively firmed down for bash fitting.

In other words, we have the paradox that you don't really need loose P jaws if all the other jaws are loose, but ideally you DO need them if all the other jaws are solid.

It's all obvious once you try it, but is confusing to grasp beforehand.

cheers,

Martin.

 

[Phil G]

Hi Martin,
Got what your saying now, I am finding my loose jaws on the P chairs are exactly that a bit loose, turn the chair raft over they fall out
It could be your comment about different shrinkage? more experimenting required.
Either way next plan, is a raft of P chairs only, and then a raft of P jaws that way I can see if I have consistent rafts and if so but still loose I can adjust.
Just as an aside, do you? Or could you offer an option for fixed jaws on the P chairs only?
Cheers
Phil

 

[Martin Wynne]

Hi Martin,
Got what your saying now, I am finding my loose jaws on the P chairs are exactly that a bit loose, turn the chair raft over they fall out
It could be your comment about different shrinkage? more experimenting required.
Either way next plan, is a raft of P chairs only, and then a raft of P jaws that way I can see if I have consistent rafts and if so but still loose I can adjust.
Just as an aside, do you? Or could you offer an option for fixed jaws on the P chairs only?
Cheers
Phil

@Phil G

Hi Phil,

Yes, that's easily done. Untick this box:

Or at least, I think it's done. I don't remember specifically testing it with all the others switched on. If it doesn't work I will fix it.

If the loose jaws are too loose you can change the pin size and tolerancing by clicking the loose jaws... button.

In 237c remember to rebuild now!

cheers,

Martin.

 

[Martin Wynne]

p.s.

If the loose jaws are too loose you can change the pin size and tolerancing by clicking the loose jaws... button.

In fact you can change everything by clicking the buttons.

In 237c remember to rebuild now afterwards!

Martin.