Building 3D track

[Martin Wynne]

.
This is a topic to talk about actually building track using 3D methods -- 3D-printing, laser-cutting, CNC-milling, etc.

Using both the built-in Plug Track functions in Templot in whole or part (still extremely experimental), see:

https://85a.uk/templot/club/index.php?forums/plug-track.34/

and additionally users own 3D developments and ideas.

I know a lot of users are getting very confused by all the different options and methods being discussed. I'm hoping that separating actual modelling and track construction topics from the topics about Templot software developments might add some clarity. Maybe.

If you are posting in this topic, please make very clear in red ink whether your pictures and discussions are about your own 3D developments, or are derived from Templot plug track. Thanks.

Martin.

 

[ralphrobertson]

Hi Martin,

The ability to generate chairs is a fantastic step forward and I have been experimenting with this a little bit. I have an Anycubic Photon 3D printer and a Darkly Labs Emblaser 2 laser cutter and I am keen to explore the possibility of using these tools to create normal P4 track and, for now, preserving more traditional techniques for turnouts.

The Emblaser cuts card much easier than ply and I have used card extensively in the machine with shellac which produces a really strong end result. The photo below shows some 3D printed chairs from 228a together with some sleepers cut from 1.5mm mounting board. As you can see I have had to reduce the size of the socket hole in order to preserve a reasonably strong edge to the sleeper.

Is there anywhere in 228a which enables me to change the size of the plug on the chair base please? I have set the hole in the sleeper at 3mm x 1.5mm which should be just as strong as the size you are using but I can't see anywhere where the size can be changed - am I missing something please?

Ralph

 

[Martin Wynne]

Is there anywhere in 228a which enables me to change the size of the plug on the chair base please? I have set the hole in the sleeper at 3mm x 1.5mm which should be just as strong as the size you are using but I can't see anywhere where the size can be changed - am I missing something please?

@ralphrobertson

Hi Ralph,

That looks great! Thanks for posting.

I'm aware that the chair plug size weakens plain track 10" sleepers. That's the reason for adding the bottom flanges on the 3D printed sleepers.

Currently the plug dimensions match the centres of the base corner radius on the chairs, i.e. 6" (2mm) wide and 12.5" (4.17mm) long. I'm sorry, at present there is no means to change that. There will be eventually some means to change almost everything, including fully-customizable chair designs, but we are not there yet.

That leaves the base overlapping the plug by 1" (0.33mm) all round, and I'm a bit reluctant to change that. I have made the base as close to scale thickness as I dare, and even now they are a bit fragile with the occasional corner breaking off (prototypical if it is only "occasional"). If the base overlap is increased by reducing the plug width, I fear it will be necessary to increase the base thickness even more to avoid damage.

The L1 bridge chairs have a larger corner radius, and a correspondingly wider plug overlap, but the sockets still get very close to the edge of the timber. I will cross that bridge (!) when I get to it. Fortunately L1 chairs are not used on 10" wide sleepers.

But all that will be up to the user in the end. It just takes time -- I wanted to get 228a released because all this has been in development for about 3 years now. I accidentally released some of it in 227a so there didn't seem much choice but to do a proper release with at least some intended functionality. It's also great to get some feedback such as yours, many thanks.

In the meantime you have a couple of options:

1. edit the DXF/STL files in a CAD package to reduce the plug width.

2. some plain track -- on soft ground, in tunnels, and under water troughs, was laid with 12" wide sleepers, also the end joint sleeper of some track panels was 12" wide. Strictly speaking that would require S1J chairs, but not always. You could try fitting the 6" wide plugs in 12" sleepers to create a short length of such track.

It might be some time before I can do a release with adjustable plug sizes, but I might be able to post a STL file with reduced plug widths shortly for you to try.

If you are using 1.5mm thick sleepers I suggest increasing the plug depth slightly -- that's the chair / socket fit... button on the DXF dialog. I added a bottom taper on the plug since setting the default, and I think the plug now needs to be a fraction deeper for a good fit in the sockets.

cheers,

Martin.

 

[ralphrobertson]

Thanks for replying so quick Martin. I realise the way I work is a bit different to most and to change Templot just for me is a nonsense. I have already generated a pair of S1 chairs with no plug and I had intended to try to add a plug of my own to make them fit my sleepers so for now I can pursue this line thanks. I will let you know how I get on in the next few days.

Ralph

 

[Martin Wynne]

@ralphrobertson

p.s. Ralph,

Silly me.

There is a way to change the plug width. But only by changing the length at the same time. Change this to say -0.25mm and the plug width and length will reduce by 0.5mm:

That was intended only as a fine tweak to accommodate variations in resin shrinkage rather than for design purposes, but you can of course set whatever you want. The socket clearances would need to be changed by the same amount.

At chair / socket fit... button.

I haven't actually tested the above, but have no reason to think it won't work.

Sorry I didn't think to mention this in my previous reply.

cheers,

Martin.

 

[ralphrobertson]

Cheers Martin, I will give it a go and see if I can make a match to my sleepers. If not I will try and get a suitable size that works for my laser cut card sleepers.

Ralph

 

[ralphrobertson]

Thanks Martin, I will try this out tomorrow. I have only been building one set of chairs anyway, it is easy enough to replicate them in the slicer software and that makes the repair quick and easy to do.

I will keep you updated with the result.

Ralph

 

[ralphrobertson]

Hi Martin

Been trying various things out today and printed some chairs with the -0.5 setting and using the card sleepers I cut with a 3mm x 1.5mm socket here is the result so far.

The chairs have just come out of the printer so they aren't very strong and they are not glued down only placed in position. The gauge is wrong by 1.5mm which I will change on the cutting of the timbers. The resin is Elegoo water washable which has not really worked with the card sleepers when they are still wet from the ultrasonic cleaner and one of the chairs has a jaw broken away. I am quite pleased with the outcome and will continue to do some trials to see if this is going to work for me.

I have exhausted the Elegoo water washable resin and have some other Anycubic stuff around which I can try but I am thinking I need something stronger - any ideas please?

Is this the right place to post this or would you prefer me to post it on a thread somewhere else?

Ralph

 

[ralphrobertson]

Forgot to mention the rail is steel rail from Scalefour Stores, I don't know the origin but can find out if you need to know.

 

[ralphrobertson]

I bought some new resin and printed some S1 chairs. Very happy with the result of printing chairs despite using default settings, quality can be improved if I want by increasing the number of layers printed. Changed the plug size to reflect cutting a socket in some shellac soaked card sleepers using 1.5mm good quality (Daler-Rowney) mounting board. Then I glued the chairs into the timbers using 5 minute epoxy but I am not really happy with the result. I will do some more trials to see if I can get a better fit between the plug and socket before trying out the 3D printing of timbers. I do have a PLA printer but I far prefer the quality that comes off the resin printer and rarely use the PLA one nowadays. Also tried cutting some timbers in birch ply but my Emblaser just finds it too hard a material to cut easily. No problem if you have a much higher powered laser cutter but I avoid birch ply and always use poplar ply on the Emblaser if I need to use plywood. Sadly I haven't found a source of poplar ply in anything under 3mm thick.

Results of latest trials:

 

[ralphrobertson]

This shot might be a bit clearer.

 

[Martin Wynne]

@ralphrobertson

Hi Ralph,

Thanks for the photos. Looking promising. I was hoping to try mounting board in the Silhouette cutter, but the thickness was beyond it. As for plywood, no chance.

Are you using the 2-D DXF for the laser cutter?

You can then adjust the socket size to match your plug settings. You can also change the sprue dimensions. Use the generator settings to remove the timber extensions, do a rebuild after making all settings. You could add further webbing using rectangles in the background shapes.

The filament printer is great for jobs such as the filing jigs:

But detailed models in 4mm are beyond it, especially in the toughened PLA. Even in 7mm I struggled to produce reasonable chairs:

The chairs were added in ordinary PLA using a smaller 0.2mm nozzle, but took ages to print. They were difficult to thread the rail through, and being ordinary PLA easily broken. For chairs the resin printer is the only sensible option.

The main or only advantage of the filament printer is the much greater work size, which is why I'm trying to use it for the timbering bricks. But finding the best settings to produce clean accurate sockets 2mm wide with no stringing across them is a challenge. Surface strings can be trimmed out (tedious), but stringing across the sockets at lower layers is a pain to deal with. There are so many options and settings in the slicer software that it could take months of trial and error to find the optimum set-up. But I'm confident I can get there in the end. I haven't tried the plug track yet in 7mm scale -- I'm sure it will work well, but require dozens of bricks for a pointwork formation of any size.

cheers,

Martin.

 

[ralphrobertson]

Are you using the 2-D DXF for the laser cutter?

No, all my drawing use Coreldraw, something I have been using for all my drawings for over 10 years. The cheaper version I currently use doesn't support DXF although I do have an old version which does (stashed away on an old laptop somewhere which I can use if I have to). Here is the drawing I am using at the moment, socket size can easily be adjusted to what I need.

I will try some more tests to see if I can get the fit right.
No, all my drawing use Coreldraw, something I have been using for all my drawings for over 10 years. The cheaper version I currently use doesn't support DXF although I do have an old version which does (stashed away on an old laptop somewhere which I can use if I have to). Here is the drawing I am using at the moment, socket size can easily be adjusted to what I need.

I will try some more tests to see if I can get the fit right.

 

[Martin Wynne]

The cheaper version I currently use doesn't support DXF

Hi Ralph,

Does it support EMF metafiles? For 2-D you could export those from Templot instead of DXF. I will check how much of the chair/socket detail is included in them.

cheers,

Martin.

 

[ralphrobertson]

Does it support EMF metafiles?

Yes, Coreldraw seems to support everything apart from DXF and DWG unless you pay for the full version at just under a grand.

 

[ralphrobertson]

I have spent the last few days refining the technique of making the latest Templot enhancements work for me. I realise that not everyone will have the sort of equipment that I have to hand but I wanted to see if the ability to 3D print chairs would work. The photo below shows that I have cracked making straight track, which for me is all I want, I am happy with ply and rivet turnouts and cosmetic chairs (I am modelling 18.83mm P4 track) but I don't want flexitrack for plain track and doing ply and rivet with cosmetic chairs can be a pain. I know this is a bit like making my own flexitrack but here I can control the gauging which in flexitrack you can't and past experience has shown me that the way flexitrack adjusts itself can sometimes cause major issues.

The photo shows the first length of track I have made using this method. I have painted it but I will probably do some more work with the colouring to get a better representation of the prototype.

The method I used is a combination of 3D printing the chairs with a plug and laser cutting the sleepers with a socket. A lot of work was done making the plug and socket size correct but I think I have got that right now. The sleepers are cut from 1.5mm mounting board and shellacked to beef it up. The sleepers are then placed into the spacing jig and the chairs mounted into the sleepers. They are then removed from the jig and the next step is to glue the chairs to the sleepers from underneath using 5 minute epoxy (I will get some 20 minute epoxy to make this easier for me but I don't have any to hand right now). The glued sleepers are put onto a piece of celluloid to dry after which they can be peeled off and any excess glue trimmed off.

Once the glue has hardened the sleepers are put back into the spacing jig and the rail is threaded through the chairs. You might notice on the photos there is a small mark by one of the sockets on the white side of the card, this is a marker to ensure that all sleepers are put in the same way into the jig. Once the rails are threaded the completed track piece can be removed and the ends of the rails can be made to the right length and squared off.

Shellacked timbers being inserted into the spacing jig

Chairs being taken from the 3D print and pushed into the sockets on the sleepers. (A few stray pieces of resin to be cleaned away yet).

A pile of sleepers with the chairs put in waiting gluing.

The sleepers having the sockets glued placed on a sheet of celluloid until hard - the celluloid in this case is a clear binding cover sheet.

The sleepers flicked off the celluloid sheet leaving dry glue behind and a pile of completed sleepers.

The rails threaded through the chairs. One chair broke and one wasn't seated properly but otherwise I was pleased with the result.

A closeup of the painted track.

Hope this inspires others to have a go, this is a fantastic enhancement to Templot Martin and thank you for adding it in, it will save me hours filing rivets and cutting chairs in half to glue on ply and rivet track.

Ralph

 

[Steve_Cornford]

Ralph, thanks for the useful information. I am beginning to see the benefits of your card timber solution.

I have received my trial lasercuts, and have attached photos:-

Timbers-and-Jig
Trackbed
I have also attached the box file from which the dfx was derived

For trial purposes I used 3.2mm ply for the trackbed rather than cork, as the cork was not available in this sheet size. from my supplier.
The idea being that the trackbed just has sockets, which use temporary locator plugs to locate the timbers.

I included a straight B7 turnout and a curved B7 turnout.

I know the experimental chairs option is not ready yet for turnouts, but I beleive I have learnt something from this trial.
The sockets on the turnout timbers on the exit stock rail are gardually angled in respect of the timber, and that makes these timbers asymetrical so when using them it will be necessary to take great care that they are they right way round and the right way up.
A bit like taking care to ensure your bullhead rail is the right way up!
So I can see that 3D printing turnout timbers with flanges and connecting webs as Martin has demonstrated is probably a better solution than ply timbers as you can't go wrong with the orientation or seuquence of the timbers.

Back to the ply trial.
Turnouts
Another thought occured to me that pending the whole gamut of turnout chairs, one could use a hybrid approach, and use the plug-track approach for those timbers that that use S1 chairs, and other means for the other timbers. For example copper clad timbers and etched chairs for the Slide chair timbers, Pre-constructed croosing vees and cosmetic chairs etc. Plastic chairs glued to ply timbers etc.
Having output the DFX file it is relatively easy to delete the unwanted non S! sockets.

 

[timbersgalore]

Wow - just what I been waiting for.

I have been making track for a while using my laser to cut the sleapers and then building the track on top using traditional methods(2mm and 4mm scales). Using a plug and socket to locate the chair is a briliant idea. Better still I can get templot to draw the socket, thanks Martin.

I have just aquired a 3D resin print, very impressed. I model GWR trackwork so have been designing my own 3D printed chairs.

I will share below what I have acheived in a couple of days playing around, still work in progress, my goal is to tackle complex track formations. I have a lot of chairs to design.

Cut from 1.5mm ply (birch 3 ply). I cut the outside sprues off prior to glueing down since it was not need for strength and would be a pig to remove. I normally paint the ply prior to cutting but wanted to make track fast.

I successfully changed the socket width to 1.5mm. This leaves enough meat for strength. I have previously used the shadow of the rail as a sprue and it worked well even with the 1.5mm wide socket.

Martin I am looking forward to sockets appearing within the turnout section. This would be useful even if the chair are WIP. For my prospective sockets on the 2D DXF are all I need.

 

[Steve_Cornford]

Hi TimbersGalore,

Would you mind me asking what laser are you using?

In your pictures shown you appear to have the grain of the ply aligned with the short edge of the sleepers, or are they sanding marks?

Also it would be usefull to know what resin printer, and what resin you are using.

Steve

 

[timbersgalore]

Steve

It is the grain of the birch ply. I was in and hurry and cut it will the grain going across. If it was for real I would have found another sheet with the grain going the other way.

My laser is a "TEN-HIGH" Laser Engraving Cutting Machine 400x300mm 40W CO2 Laser" which I upgraded with the Cohesion3D G code controler. I prepare the files and control the laser using LightBurn. Cutting ply I acheive better than 0.1mm accuracy.
My resin printer is a Phrozen Sonic Mini 4K using 4K resin at 0.030mm layers.

 

[Martin Wynne]

I cut the outside sprues off prior to glueing down since it was not need for strength and would be a pig to remove.

@timbersgalore

Hi (no name),

Looking good.

I see that you have full-depth webs below the rails. How are you planning to remove them after tracklaying? Any sort of cutter or blade will force the timbers apart. A Dremel disc might be an option, but tedious to do. Or if you leave them in place how will you disguise them in the ballast - the top of the ballast is normally level with, or a fraction below, the timber top. Flat-bottom rail is wider than bullhead and closer to the timber, so tends to hide such webs. But for bullhead track the daylight between the rail and the ballast is a characteristic feature:

(This question also applies to all the commercially available laser-cut timber bases -- but when I ask it the answer is always silence. )

For the Plug Track I intentionally placed the sprues outboard of the sleepers to make prototypical ballasting possible below the rails. I think you would do better to remove the webs before tracklaying (or not have them in the first place) and leave the sprues in place. If you don't apply any glue to the sprues they are easy to remove after tracklaying by holding a pair of flush cutters vertically (Xuron cutters, supplied with the resin printer).

For the FDM printed timber bases the sprues are omitted, but the webs and timber flanges which replace them are only 1.5" thick (0.5mm in 4mm scale) and easily hidden under the ballast.

p.s. notice the GWR chairs in the pictures. Which for pointwork are fixed with plain square-head coach screws (unlike REA chairs with tapered ferrules and bosses for the screws). But for plain track the GWR chairs use through-bolts from below with nuts on top. So ideally you need two types of GWR S1 chair -- one with plain screw-heads as above for use in pointwork, and one with a bit of bolt showing above the nut for plain track:

Alternative bolt-tops will be an option in Templot for the GWR chairs, but oh my, there is such a long way still to go.

Hardly anyone will notice the difference in 4mm scale, but I have to think ahead for 7mm and the larger scales.

cheers,

Martin.

 

[timbersgalore]

Martin
Thankyou for you comments. I placed the web under the rail as it seemed to work on the pre made bases I have used. I assummed I could hide it with ballast but I have never got as far as balasting any track. I will give the spruces a try.

How far to go on detail when it is hard to see with the nacked eye? If I can sucessfully print it I will have a go at modeling it.

Timbers

 

[timbersgalore]

I am amazed at the level of detail acheivable by the Sonic mini 4K. I think it is helpful to model the detail as it helps to get the big stuff right. Martin thankyou for the chair pictures. Mine arn't as good as the old track near me is still part of network rail. I have the drawings for the chair plan views but I am having to work out the cross section.

I have refined my ordinary char and made a stab at the SS chair:-

printed on a phrozen sonic mini 4K. Aqua 4K resin, XY 0.037mm Z 0.030mm.

 

[timbersgalore]

This afternoon I print some chairs from the templot files. I first had to fix and unsupported island formed at the bottom of the rail clip.

A you can see I droped them on the floor!

Timbers

 

[timbersgalore]

HI Martin
Regarding the rail and grip on it. I found the templot chairs quite a sloppy fit on the 4mm society rail. I would say you have overdone the allowance for rail side taper. It would be helpful the know what are the profile numbers for "C&L / EMGS/ S4Soc code 75" rail. What is "Fish centre" How is the fish angle measured (between what).

The accuracy I am achieving with the sonic mini 4K is amazing so far what I draw is what I get.

I have kept the grip parallel to the rail and find my chairs easier to thread than the plastic chairs form the 4mm society. I am using a web thickness of 0.4mm

I am in the throws of making a "test of method" track sample. It consists of a GWR 12ft heel V7 with return curve. Rather than post detail here it is probably better I start another topic elsewhere. I will be using a laser to cut the sleeper base as I get far superior results compared to the FDM printers I have (I have three!).

Timbers

 

[Steve_Cornford]

Hi Timbers,
As you have a laser, have you thought of cutting a cork(or ply) trackbed layer just with sockets, then make the chair pegs deeper. That way you dont need to have sprues on your timbers, and you can cut the timbers with the long edge parallel to the grain. Then the longer pegs locate the timbers onto the trackbed layer.
Good luck with your "test of method"
Steve

 

[timbersgalore]

Thankyou Martin
Than helps me a great deal. I can now see that the sample in fornt of me is undersize. My web is 0.40mm (measured by filling off the head/bottom then micrometer).
Timbers

 

[timbersgalore]

Martin

I did mean undersize compared to the nominal values for the C&L track. I estimate that my rail is between 10 to 20% undersize. I think I could have fixed the problem using the presets you have already build in. I don't think the taper on the key was causing the sloppy fit.

After adjusting my CAD to describe the rail profile it terms of fish, I have done a lot of experiments to get the rail grip right. I started of with daylight under the key and adjust the prints to get a good grip of the web. The rail was still sloppy in the sense it was easy to roll the rail from vertical. Rather than fill completely below the key I have tried only filling below the key at the centre of the key, shown purple below.

The is still a bit of roll. I printed this with FootWidth set to 1mm, My rail is 0.9mm.

I think this demonstrates the benefit of customising the 3d print to the actual profile of the rail to hand. The other option is to deliberately make the rail a tight fit but I that is not an option if using a brittle resin.

I think it will take a least another iteration to get something I am happy with.

Steve: my sub layer already has the sockets cut in it.

 

[Steve_Cornford]

Hi Timbers,
Can you confirm that the concept of sockets in the sub layer works ok for you, and that it is practical to do away with any timber sprues?
If it does we can bunch the timbers up and get the most economical cuts of timbers.
Steve

 

[Martin Wynne]

I did mean undersize compared to the nominal values for the C&L track.

@timbersgalore

Hi Timbers,

Those are not "nominal" values for C&L rail. They are just random test data. Please ignore any dimensions you find in the current program release. It is all just dummy data used to test the programming and the process. I grabbed just any data that I had to hand. It is almost certainly wrong. My big fear in releasing unfinished stuff is always that someone will regard it as definitive info and start using it for real. Or worse still post it elsewhere on the web.

It is all utterly experimental at this stage. I will let everyone know when Plug Track has reached a stage where it can be used for actual models, but it won't be for some time yet.

I think you have your key too small and your outer jaw too low, which probably explains why the rail is not being firmly held upright. The key should completely fill the space between the rail head and foot, and the top of the jaw should be level or fractionally below the outer face of the key:

Also the rail seat/platform should extend across to the jaw, so that the rail can be dropped into the chair before being keyed across into place.

Making the rail vertical does affect the dimensioning to some extent. But check rails are always vertical, so the jaw dimensions from the inside of check rail chairs can be a reference. For REA chairs all outer jaws are 5.11/16" above the underside of the chair (except 2-level chairs and thick-base chairs).

Here is an actual GWR / BR(W) 2-bolt S1 chair. The top of the outer jaw is 5.5/8" above the underside of the chair. The jaws are 4" wide at the top:

cheers,

Martin.

 

[timbersgalore]

Martin
Don't worry I am taking very little form the templot chairs. My height comes from measurements of the plastic chairs from the 4mm Soc. The only reason I looked at the stl from templot was to provide you with feedback.

On the other hand the pictures of the fullsize chairs are gold dust to me. Plus your written feedback has been most helpful. Are the close up of the chair casting from your own private collection or are the available on the internet?

 

[Martin Wynne]

Are the close up of the chair casting from your own private collection or are the available on the internet?

@timbersgalore

Hi Timbers,

That chair has been in my garden for about 40 years.

I dragged it into the sunshine and took the pictures this afternoon.

cheers,

Martin.

 

[timbersgalore]

Hi Timbers,
Can you confirm that the concept of sockets in the sub layer works ok for you, and that it is practical to do away with any timber sprues?
If it does we can bunch the timbers up and get the most economical cuts of timbers.
Steve

Steve
I haven't explicitly tried, though it is an idea that appeals to me. Even though I made the spruces only 1mm wide and took precaution to get no glue under them they were remarkable resistant to being removed(but achievable). The sockets cut by my laser have a taper. I set may laser up (kerf offset) so that I get my nominal dimensions at the bottom. I put at taper on my plugs but slightly less (room for glue). I would need to re jig this so that the sub layer provides the positive location for the chair (provide clearance on the sleeper sockets). That done it stands a very good chance of working out OK. I would recommend using birch ply for this layer.

I would still want to attack a spruce to the timbers so that I did not end up with a bag of match sticks.

I would still want to atach a spruce to the timbers so that I could lift them from the cutter.

Timbers

 

[Martin Wynne]

Laser cutters are capable of understanding shapes. What it means is that when presented with a nested set of rectangles they work out what is inside and outside. The result is that the cut planner can works out which bits to cut first. It also means that the laser can provide the Kerf offset. It would be worth checking whether a cutting service is automatically applying it own kerf offset to closed figures. That said it would be usefully to have the timber outline and chair socket layers on there own layers. Here is a screen shot showing the cut layer from my recent test:-

View attachment 2154

A little shape manipulation is required to join the spruces to the timbers.

@timbersgalore

Hi Timbers,

Thanks for the screenshot. Is that from a Templot 2-D file or 3-D file?

For 2-D the timber outlines and sockets are on separate layers:

In the 3-D files the timbers and sockets are all in one layer because they form a single solid object.

Laser cutters are capable of understanding shapes.

There are no rectangles or other area shapes in the Templot 2-D DXF files. Everything is a simple Line entity. The files are, or were originally, intended primarily for import into a CAD program for further track and layout design purposes.

For use on cutting machines there are other types of machine in addition to Laser cutters -- blade cutters, photo-etching, CNC milling machines, presses, stamping and blanking machines, etc.

I want to provide as many options and settings as possible to make the Templot DXF useful, but ultimately it is down to the user to know their own machine and how best to use the Templot DXF on it. If the kerf adjustment is not wanted, the layers can be switched off or the kerf width set to zero.

At present home laser cutters are much more expensive than an FDM printer, so the latter is more likely to be available to many Templot users. At least for the present my main focus is on the FDM timbering bricks for Plug Track. There has been a lot of recent discussion in this topic about laser cutting, but I suspect the majority interest will be in FDM printing for the timbering. I may be proved wrong as machine prices change, but I still feel that FDM printing will be the most user-friendly option for home pointwork construction, and is capable of excellent results comparable with injection-moulded track:

Also, an FDM machine can be used to make the rail filing and bending jigs needed.

cheers,

Martin.

 

[timbersgalore]

Very much the 2D dxf. I am still basicly using the same work flow as for 227. I have descovered it is very straighforward to place my own socket outlines using the track edge and timber centre line. Is everything you mentioned in the live version of 228 or is it unrealeased?

You track sample looks good, is that 7mm scale?

I have just completed another iteration of the GWR 95 chair. I used no fill below key but with the key heights fixed. I have also switched to ABS like resin. The Phrozen stuf as very little smell. Even able to use it in the house! I still have a small tweek to make the jaw height the same. The good new is that with a close fitting key the rail is firmly held.

Timbers

 

[Steve_Cornford]

Hi Timbers,
Thanks for sharing all that useful information.

Laser Cutting
For my experiments the laser cutting service I used (4D model making materials) did not mention that their laser cutter understood shapes nor did they tell me what software they used to control the laser cutter.
When I asked them about the difference between their meaning of an inner cut(blue) and and outline cut(green) they just stated that the laser cut all the blue lines first then the green lines.
The principle being that if the timbers were cut before the sockets they could not guarantee that the sockets would be in the right place.
They required artwork with 0.076mm line width.
They also stated that if i wanted timbers 4mm wide and 32mm long I should add half the kerf (in their case 0.2mm) to the dimensions all round, and as far as the sockets were concerened (inner cuts) that I should subtract half the kerf all round.
Using Templot 228a, Martin suggested a work around to achieve this as far as the timbers were concerned, and he had already suggested a method to Ralph for adjusting socket size which I used.
I then used Inksape to open the resultant .DFX file so that I could copy the sockets to a separate layer and change their colour.
Martin has kindly added this experimental ability in to his next Templot release, together with the enhancement of putting the sockets in a separate layer thus making it easy to also produce a cutting file for a trackbed layer that the acts as a jig for the timbers layer, thus obviating the need for sprues holding the timbers in the right position.

The chairs I produce ( using an Elegoo Mars 2 pro, arriving in next 3 hours) will have longer pegs so that they go through the timbers and into the trackbed layer.
Also in my experiment I output both a straight B7 turnout and a curved B7 turnout, as I wanted to see whether there was any difference in the socket poitions on the timbers between a curved and a straight turnout.
Martin has since confirmed that there is no difference.
This means that I can get all the timbers cut as straight turnouts, and get the grain oriented parallel to the long edge of the timbers, also bunch them together to minimise cutting costs.

Rail Profile
I have just measued the web thickness (without filing head or foot) of some of the rails that Wayne Kinney has provided in 4 OO-SF B7 turnout kits with my cheap(powerfix) digital caliper and they appear to be 0.39mm. I checked the accuracy of the calipers using a 0.40mm thick feeler gauge (draper).
I believe Wayne sources this rail from the E.M.G.S.
I then tried measuring some rail lengths purchased from Scalefour Society a couple of years ago and these had 0.39mm thick webs.

Steve

 

[timbersgalore]

I got stuck on the idea of modelling Camborne station, prior to lifting the goods yard. It has two slips, a crossover, and 3 turnouts in an impossibly small space. Until I got of copy of David Smiths book I thought it was impossible. I have now almost got a templot track plan, I have the rails placed but timbering is a worry.

I made this to prove I could join laser cut sections together (The main line is at the top, bay on the right, good on the left)

I have been given new hope that I can do it, if I use plugs on the chair and socket on the timbers. In the short term the only place I can get GWR chairs with plugs on is if I design and print them myself.

Timbers
To be continued ...

 

[timbersgalore]

My short term goal is to find a way of reliably making a GWR loose heel switchs. I got on reasonably well following the Morgan Designs Instructions but I hope that with computer controlled machines I can do better. The 3D printer enables me to print my own chairs and my current hope is that I can make functional 1S, 2S & 3S chairs to better support the heal.

There are may challenges to overcome one being how to assemble the switch on the trackbase. The is where I hope plug in chairs will help.

This is just a trial assembly to see how I am going. The SS* chair has a functional stud block and it is my intension that the switch rail ricks in the 1S chair. I am working on the 2S chair and this will provide firm support for the end of the turnout rail. (The switch rail is junk from my desktop and not quite the right shape.)

 

[Phil O]

Hi Martin,

Loose heel switches only have 2 bolt fishplates, see my photos of special chairs in the show and share section of the old forum.

 

[Martin Wynne]

@Phil O

Hi Phil,

It's Timbers building the GWR switches, not me.

Here are links to your topics with the GWR chair photos:

topic: 182 - GW special chairs
topic: 184 - GW special Chairs
topic: 186 - GW special chairs
topic: 187 - GW special chairs
topic: 188 - GW special chairs
topic: 189 - GW special chairs
topic: 190 - GW special chairs
topic: 191 - GW special chairs
topic: 192 - GW special chairs
topic: 204 - GW special chairs

To find them again, put "GW special chairs" (with the quotation marks) in the Full Templot Search.

cheers,

Martin.