Resin-printed timbers - gauge and shrinkage

[John Walker]

I have been playing with plug track for a couple of months now in 3mm scale 14.2mm gauge and Scale 7. I have a Phrozen Mini 8K printer so I am using that to start with for chairs and sleepers. So far I have managed to address most of my issues using the forum and much fiddling!

I am getting varying results with the actual gauge achieved. At first I thought I had solved the problem by adjusting the rail head width but that doesn't seem to work now so I guess I was confused. That leaves me with a couple of questions to which I can't find the answers.

If I change the rail head width what effect does it have on chairs, sleepers and the relationship between them?

If the actual gauge is not quite the same as the chosen one is their a "proper" way to fettle it?

I was expecting some variation due to shrinkage of the resin but I don't think there is enough to explain my results.

Some of my progress is shown here: https://sites.google.com/site/swanagein3mm/track

Regards
John Walker

PS Martin, hope you are on the mend.

 

[Martin Wynne]

I have been playing with plug track for a couple of months now in 3mm scale 14.2mm gauge and Scale 7. I have a Phrozen Mini 8K printer so I am using that to start with for chairs and sleepers. So far I have managed to address most of my issues using the forum and much fiddling!

I am getting varying results with the actual gauge achieved. At first I thought I had solved the problem by adjusting the rail head width but that doesn't seem to work now so I guess I was confused. That leaves me with a couple of questions to which I can't find the answers.

If I change the rail head width what effect does it have on chairs, sleepers and the relationship between them?

If the actual gauge is not quite the same as the chosen one is their a "proper" way to fettle it?

I was expecting some variation due to shrinkage of the resin but I don't think there is enough to explain my results.

Some of my progress is shown here: https://sites.google.com/site/swanagein3mm/track

Regards
John Walker

PS Martin, hope you are on the mend.

@John Walker

Hi John,

Welcome to Templot Club.

Thanks for the link -- you are certainly doing things your own way. Is there some reason for not using the chair rafts?

If the gauge is incorrect, the primary adjustment is assumed to be on the shrinkage in X and Y directions. But printing the timbers vertically puts the gauge adjustment on Z, and getting accurate Z dimensions in resin printing is notoriously difficult and unpredictable, and affected by the exposure settings.

The chairs are primarily designed to fit the rail web, in the same way as the prototype jaws and keys -- the rail is not held by its width in the chair. When adjusting the rail fit the main thing to get right is the rail web thickness. There is an adjustment to tweak the fit -- this modifies the rail web thickness by %:

cheers,

Martin.

 

[Steve_Cornford]

I would second Martin's statement.
Resin print the timbering brick flat on the build plate just as output by Templot.
If you then measure the length of the timbers, and the length of the timbering brick over the outside faces of the end timbers they will be fairly accurate.
But if you measure the thickness there will be a noticeable discrepancy (ie the z axis is inaccurate)
Well at least that has been my experience.
But printing them flat gives an accurate gauge (in my experience, P4 and OO-SF)
Also use Templot to add a raft to the chairs as described in the may posts on here.
Steve

 

[Steve_Cornford]

Hi John,
This is what a Plugtrack Timber base looks like:-

This is the 3D-Tool preview option invoked directly by Templot.

This is the result having invoked STL export and mesh fixed by 3D Builder which was invoked by Templot.

This is a section of straight plain track in S3 gauge

Reards STeve

 

[John Walker]

Thanks Martin. I use Templot a lot and was on Templot Club but I had dropped off for some reason. Maybe caused by changing my email address. Anyway back now I am playing with plug track.

I'll try using the web adjustment rather than the head.

I haven't used the chair raft or the chair supports. I thought that would save a lot of cutting and trimming on assembly. The down side is that you have to be well organised to remember which chair goes where when you need the build plate for something else. Ideally you would only print the chairs as you need them and then assemble straight into the sockets.

I do prefer painting the chairs before assembly and I am experimenting with that. Basically a raft slightly thinner than the sleepers and masking tape on the back with sockets to hold the chairs. Then spray and transfer to the sleepers. That could also be the solution to storing the chairs in sequence.

Printing the sleepers vertically avoids the need for lots of supports and avoids the warping because there is much less pressure moving from one layer to the next. They are consistently printing at 25.5mm long for 3mm scale. Shrinkage of the sleepers has not been a problem so far. It certainly does not explain the problem with gauge. My plan is to move to laser cut timber once the experimentation is over.

Finding the right settings for the Elegoo water washable resin is proving tedious but I think I am close now. I have been getting good prints for the parts but very brittle rafts.

Regards
John Walker

 

[John Walker]

Thanks Steve.

My first print from Templot was a 3mm B8 V end complete with base, timbers, chairs, and rails! That helped to get my head round what to expect. However it has warped terribly. My settings have improved since then but it demonstrated the problem with using resin in the XY plane.

Printing the timbers vertically works well but only for straight turnouts so it won't work for the layout.

Regards
John Walker

 

[Steve_Cornford]

Hi John,
When you print the timbers horizontally you dont need any supports, just print straight on the build plate.
I did however reduce the thickness of the side flanges and webs by half.
Steve

 

[John Walker]

Hello Steve

I find I don't get a consistent thickness when printing on the build plate. A raft takes up any errors in levelling. My water washable resin also sticks like **** making it difficult to prise away without damage. I am gradually overcoming that by tuning the settings but not quite there yet.

Regards
John walker

 

[Phil G]

I am getting varying results with the actual gauge achieved.

Hi John,
certainly a novel approach to both chairs and sleepers/timbers, what type of chair fit are you using?
I can't help but wonder if both are having direct effect in your gauging issue though.
Vertically printed sleepers means the critical socket gauging dimensions are both exposed to any z height variation, as well as any residual resin left on the socket space.(we know from loose jaws) a very good almost aggressive wash is required to ensure the holes are the correct size, acknowledging these slot/ holes are smaller.

The direct printing of chairs onto the build plate opens up the possibility of some elephants foot effect forming. Again with a possibly impact on correct chair positioning/gauging.

Warping is a known issue with resin, very noticeable on long originally flat sections. Would be interesting to see what warping you end up with on vertically printed timbers.
more out of personal interest why 1.5 mm thick timbers, understand 3 mm is a smaller scale but the thickness of timbers can easily be hidden.
I tried to use 1.6mm thick sleepers in EMSF, but switched to thicker as that improved overall accuracy.
cheers
Phil,

 

[John Walker]

Hello Phil, and Martin

I am using press fit. I tried loose jaws but they were too easily broken (or lost) in 3mm scale. Also, as you say, getting a clean hole was too difficult.

My sleepers seem to be pretty stable. Certainly any variation does not explain my problems with gauge. Time will tell as resin does change with time and conditions. Long term I hope that problem will be resolved by moving to laser cut timber.

Any comments on laser cut ply vs bass wood? I am thinking about the fineness of the grain for 3mm scale?

In 3mm our sleeper thicknesses have historically been 0.8, 1 or 1.5mm thick. I find the thinner ones a problem when ballasting. If you stick them to paper templates then when dry ballasting the ballast jumps about all over the place on the paper. The extra thickness helps the ballast bind and stay put until I apply my sanding sealer diluted 50/50 with meths. On the outdoor 7mm railway I get away with varnish and white spirit but using that indoors causes the mix to soak into the ply and release all the plastic chairs. I don't know if the meths might affect resin chairs. Time will tell. I guess my final choice of thickness will depend on the material used. I note that some of the laser cutting bureaus warn of some variation in the thickness.

Martin: I have been looking at adjusting my web thickness but I already have a nice fit on the rail. I will try reducing it by 0.05mm and see what happens. However, thinking about your advice, if you have 2 pieces of rail with the same cross-section apart from the head then surely Templot needs to take the head width into account to arrive at the correct gauge?

Regards
John Walker

 

[Steve_Cornford]

Hi John,
Just to be clear, are you having a variation of gauge from sleeper to sleeper, or is the gauge consistent on all sleepers, but just the wrong gauge?
Steve

 

[John Walker]

Hi Steve

Just the wrong gauge.

John

 

[Steve_Cornford]

Hi John,
Just for testing purposes you could try gauge > modify current settings > modify track gauge giving you this screen:-

adjust the gauge , this changes the gauge on the current control template, so save it and then try your print.

If that works you could mint a new gauge from the S3 gauge with the adjustment and rebuild all your back ground templates.

Steve

 

[Steve_Cornford]

SOrry, supplementary question.
Was it over or under gauge?
STeve

 

[Phil G]

Any comments on laser cut ply vs bass wood? I am thinking about the fineness of the grain for 3mm scale?

Hi John,
that's a good question, I will have a bit of play with bass wood in the laser in the next few days and let you know my observations.
cheers
Phil,

 

[Martin Wynne]

Martin: I have been looking at adjusting my web thickness but I already have a nice fit on the rail. I will try reducing it by 0.05mm and see what happens. However, thinking about your advice, if you have 2 pieces of rail with the same cross-section apart from the head then surely Templot needs to take the head width into account to arrive at the correct gauge

@John Walker

Hi John,

Yes, but it controls the position of the sockets in the timber. Changing the head-width has little effect on the chair.

So in theory, if you are printing timbers vertically you adjust the Z-shrinkage setting to get the correct gauge:

In practice it is not that simple, because the resin shrinkage varies with the cross-sectional area -- chunky areas shrink a lot more than thin or narrow sections. The above defaults in Templot assume printing of the chairs, where everything is thin or narrow.

For the timbers this presents problems. Suppose by adjusting the above setting you get the correct gauge for plain track sleepers. The same setting won't work for turnout timbers because:

1. they are wider than sleepers and therefore an increased cross-section = more shrinkage.

2. but in between any two sockets creating the gauge there will be a third socket for the other rail. This part of the timber length will have a much reduced cross-section at the socket walls = less shrinkage over the length of the socket. All the sockets will vary in length on different timbers.

The result will be that the track gauge will be all over the place and vary through the turnout.

We have previously arrived at a consensus here that resin-printing is not recommended for plug track timbering bases, and my feeling is that printing the timbers vertically will make matters 10 times worse.

Have you looked at getting an FDM printer? The little Kingroon would be fine for 3mm scale as a stopgap until you can get set up with a laser-cutter.

cheers,

Martin.

 

[John Walker]

Thanks Phil.

Hi Steve

I have been playing with different settings not knowing quite what would affect what. On one occasion the gauge came out at 14.3, on another 14.4. Of course, I hadn't thought of adjusting the gauge. I'll try that.

I have just had another thought. If I make the plug loose in the slot length-wise then I can set the gauge using conventional gauges. That might solve another problem which has been bothering me.

My preferred method of construction would be:

- fix sleepers to paper template
- paint chairs

- fit chairs to rail
- fit rail and chairs into sleepers
or
- fit chairs to sleepers
- slide rail into chairs

The options depend on whether the rail will slide well enough through multiple chairs.

This method depends on the accuracy of fixing the sleepers to the template. A sliding plug would allow me to adjust for any error in that as well as any slight adjustment to gauge.

Happy days!
John Walker

 

[John Walker]

Hello Martin

I think I would rather put the cash towards experiments with laser cutting at a bureau to gain some experience in that medium.

Ideally a chosen bureau would be able to supply the material as well. Does anyone have experience of that and some idea of costs?

I have studied the thread where the subject of the bits falling out of the sockets was discussed but I didn't find a conclusion. Is this a problem?

Regards
John Walker

 

[Steve_Cornford]

Hi John,
I think you might struggle to get 3mm scale timbers with sockets laser cut due to there being a minimum width requirement between cuts (similar to a minimum width of etched material).
Perhpaps Phil G could try some for you.
Steve

 

[Phil G]

Hi John,
There are three basic principles to plug track, which from your run down of how to build track, are not being fully utilized.( which is your prerogative if you want to do it that way.)
the principal is,
The rails is held accurately in the chairs in the vertical plane ( i.e. rails are not inclined at 20 degrees as per prototype) the chair should slide smoothly in the rail but have no side play. option such as loose outer jaws are designed exactly to eliminate the need to slide all the chairs on the rails, however at 3 mm the actual lose jaw and the slot in the chair are very small and could well be too small to be practical.

The track gauge is automatically set by Templot by the relative position of the plug in the chair and the slots in the timber.

Within that premises there a several adjustment options which are designed to allow for any error in the process. IE things like actual rail web thickness not theoretical thickness, and shrinkage factors for the resin printed chairs, slot adjustment is also provide for in both FDM and laser manufacture of the sleeper/timbers.

The final part of plug track is to have a system where the spacing of the sleepers/timber is predetermine by plug track, using the Templot program to generate whatever you have drawn in Templot. IE there is no need to print a paper Template, nothing stopping if you want but once you have plug track dialed in no real need at all.

For the laser cut timber there is a system of nibs which hold the individual timbers or sleepers to the parent material, the laser also cuts out the plug slots. The chads that come out of the slots are normally fully cut out and either fall out during handling or need to be lightly pushed out with say a cocktail stick .Either way they are not an issue to me.

its important if using plug track as designed, to ensure the correct tolerances are used for all the key components.
You can step outside this concept but then its not really plug track, its simply a means of manufacturing components.
cheers
Phil

 

[Phil G]

Hi John,
I think you might struggle to get 3mm scale timbers with sockets laser cut due to there being a minimum width requirement between cuts (similar to a minimum width of etched material).
Perhpaps Phil G could try some for you.
Steve

Hi Steve/John,
Steve makes a very good point and with 3 mm its likely to impact on the total thickness of the wood being cutout as well.
It will also be directly effected by the power of the laser being used. For a diode type 20W seems to be about the sweet spot, as its a good trade between depth of cut practical and laser burn area (as the more power you have the bigger the actual hard burn area there is.
I have no idea about commercial lasers as they tend to be co2 machines.
I am busy today but should find a bit of time for a play tomorrow. If I get enough time I will use both my 10W and new 20W laser head, just to see.
Thinking more about it overall 3 mm maybe better suited to FDM printed sleepers, something I never thought I would say, but we can have a go and see what we get.
cheers
Phil .

 

[Steve_Cornford]

Back in 2021 I commissioned some test laser cut plywood timbers in 4mm scale.
The bureau I used recommended a minimum width between cut lines of 0.8mm and their laser had a kerf of 0.2mm.
In 4mm scale 12inch timbers are 4mm wide & the default socket width is 2mm, giving a material width of 1mm.
For plain 10" sleepers (3.33mm) a 2mm socket gives a material width of 0 66mm, so I reduced the socket width to 1.7mm thus giving 0.8mm material width alongside the sockets.
At 3mm scale this problem will be exacerbated.
Likely to give burn through between the two cut lines.
hopefully Phil s experiments will show us one way or another.
Steve

 

[Martin Wynne]

The bureau I used recommended a minimum width between cut lines of 0.8mm and their laser had a kerf of 0.2mm.

@Steve_Cornford @James Walters @Phil G

Hi Steve,

The 0.8mm might be the minimum they are happy to work to, rather than the practical minimum. James has suggested that a nib width of 0.5mm is good, so perhaps a socket wall of that width would work. Although it would likely make the sleeper very flimsy.

cheers,

Martin.

 

[Steve_Cornford]

3MM SCALE FIXED JAW CROSSING SOLUTION?
Taking a 3mm scale B7 turnout as an example, I have split the timbering base between the X2 and X3 timbers.
Let me call the base that starts with the X3 timber the V base (as it contains the V)

And the base that ends on the X2 timber the W base (well I convinced myself the the rails look like a W)

Starting with the V base, insert the fixed jaw crossing chairs.
Then just slide in just the wing rails.
Cut the wing front XY chair in half (the one which eventually will plug into the X2 timber), and slide each half onto the relevenat wing rail, then slide the L1 and S1J chairs onto the wing rail giving something like this:-

Now drop this V base construction (that now looks like an X!) vertically down onto the W base, engaging the clips and inserting the suspended plugs into the sockets giving something that approximates to this:-

The split XY chair would benefit from a dab of glue.
now slide in the point and splice rails of the V.

Fabricate the two check rails and slide the check rail chairs onto the check rails, then slide the stock rails into the check rail chairs.
Slide the remaining required chairs either side of the check rail onto the stock rail.
Plug this sub-assembly into the combined bases (I have at least managed to test this part of my suggestion in 4mm scale, OO-SF)
(this bit I have tested ok in 4mm scale)

This suggestion just might overcome the necessity of cutting the wing rails at the knuckle bend and sliding them in from each side.
Steve

 

[Phil G]

Hi Steve,
Are you envisioning this idea made with FDM or resin timbers? Or are you thinking laser cut as well here? the brick clips suggest the first two options.
cheers
Phil

 

[Steve_Cornford]

I was thinking resin timbers for testing the idea. But this is just for 3mm scale to overcome the problem of having to use fixed jaws rather than loose jaws. I personally think ply timbers with sockets would be too flimsy, but with resin or FDM you have the side flanges to strengthen the timbers alongside the socket positions.
The deep timbers with flanges that will be hidden under the ballast is a key part of the Templot plugtrack design.
Steve

 

[Steve_Cornford]

Ps the cutting of the XY chair in half might have to be done in CAD to achieve a zero width kerf on the cut, or print two XY chairs and make physical cut offset each way, then file(?) each of the two larger parts until they fit together in the socket before using.
Alll pure conjecture on my part, inspired by a comment Martin made in the Zoom meeting regarding long chairs for complex K crossings and the possibility of splitting them but using just one long socket to contain them.
Steve

 

[Martin Wynne]

but with resin or FDM you have the side flanges to strengthen the timbers alongside the socket positions.

@Steve_Cornford @James Walters

Hi Steve,

I've been wondering if that might work for laser by first half-engraving the timber outlines? A second full cut would then be made for the sockets and around the flanges. The flanges could be made narrower to minimise all the extra smoke caused by the half-engraving.

Without a laser to try it, I could be talking rubbish.

cheers,

Martin.

 

[James Walters]

Hello Martin

I think I would rather put the cash towards experiments with laser cutting at a bureau to gain some experience in that medium.

Ideally a chosen bureau would be able to supply the material as well. Does anyone have experience of that and some idea of costs?

I have studied the thread where the subject of the bits falling out of the sockets was discussed but I didn't find a conclusion. Is this a problem?

Regards
John Walker

Hi John,
I would be happy to laser cut a template for you and post it to you with the settings I've used. This should give you a good starting point from which to ascertain a way forward which suits you. I don't offer a laser cutting service, so this would be as a gift.

I am mindful that a sample laser cut track base cut with a range of kerf settings could well be advantageous in testing plug fits. I will provide a file for such a thing on the wordpress site in the next couple of weeks.

 

[John Walker]

Thank you James. I might take you up on that offer.

I watched your review of the Creality Falcon 2. You sound impressed. I was waiting to watch you use it in your next Plug track video. How long are you likely to have the Falcon?

At the moment the Falcon is on special offer at £699 but I don't know how long that might last.

Having understood a lot more about the Templot settings I have now printed chairs which are very tight in the sockets but do give me a correct gauge. I tried again by adjusting the "Chair plug clearances" but the plugs got bigger. I had forgotten that the setting needed to be negative to make the plug smaller!

Given Steve's concerns about the minimum width requirement my next job is to try reducing the plug width to 0.8mm and see if the chairs print alright. My guess is that they will be fine. In a 3mm scale 2.5mm wide sleeper that would give me a minimum material width of 0.8mm and leave a bit to spare.

I don't know if that width is smaller on any of the turnout timbers with the chairs on the skew. Perhaps Martin can tell us.

Bureau recommendations for 3D printing are very conservative and I guess it is the same for laser cutting. I agree with Martin and expect that the 0.8mm is well over the top. Shapeways introduced the "print it anyway" option to overcome that problem but then offered no guarantees.

Regards
John Walker

 

[Phil G]

Hi Steve,

I personally think ply timbers with sockets would be too flimsy, but with resin or FDM you have the side flanges to strengthen the timbers alongside the socket positions.

I tend to agree with you.
FDM timbers for 2 and 3 mm seems the most logical, maybe resin for 2 mm, but based on the curing we all get on resin rafts. I cant see resin being a long term solution for timber bases to be honest.
in 4 mm both FDM and laser are very viable, and for any scale above 4mm laser cut timbers come to the fore. I.e. the side flanges are less important but can still be useful with anything about 4mm maybe not required at all.

It has occurred to me, is it time to do some experimenting and see if there are indeed material options, that suit different scales better than others. If so it maybe worth noting this on the Templot forum pages. Or even in James word press work? Noting they would only be recommendations based on experimentation.
cheers
Phil

 

[Steve_Cornford]

Hi Phil,
I think you meant curling not curing

Personally I have not experienced curling on the resin bases I have printed, sprayed and then stuck down.
I even have some lengths of unpainted resin bases that I produced that had a continuous check rail on one side, not stuck down.
It is still level and no curling, but it does have 3 pieces of rail to hold it all together.

I believe the 2mm people are using resin base with integral chairs and then sliding the rails in in a similar manner to Finetrax.

The resin I have used so far is Elegoo ABS-like v1 grey, but I do now have a bottle of Anycubic ABS-like V2 which is the water washable kind but have not used it yet.

Also I am using an Elegoo Mercury v2 wash & cure machine.
This seems to have led arrays of two different colours, and also has a turntable to achieve a more even curing process.

I was only using resin bases for experimental purposes until I choose either lasercut ply or FDM bases.
I now have an FDM printer.

Steve

 

[Phil G]

Hi Steve,
I did mean curing but your right what happens at least to all my resin chairs (and other non railway related Items is they curl just after curing) I was not very specific with my meaning.
you maybe right the choice of resin could have a big impact on this, as well as the cross sectional area to be cured.

I am glad you now are in possession of your own kingroon.

You too can now at the very least now make your own jury of jigs

For what its worth, my long term plan is to use all three types of machine, IE resin for chairs, complete with as you mentioned the Elegoo wash station. which I purchased at the time of purchasing my mars 3 pro.
FDM printer for jigs and turnout toe timbers which require a vee to ensure the toe switch rail slider works correctly.
and a laser for the timbers and sleepers.
one thing is for certain nothing looks more like real timber than real timber.
cheers
Phil

 

[James Walters]

Thank you James. I might take you up on that offer.

I watched your review of the Creality Falcon 2. You sound impressed. I was waiting to watch you use it in your next Plug track video. How long are you likely to have the Falcon?

Hi John,

I'm going to try to have a plug track video out in a week or so, I've been especially busy lately which is a pain.
I will be keeping the Creality machine, that's a perk of reviewing it. I am really impressed with it. I've also just taken delivery of an Atomstack machine which I'll take a look at on the channel too. I've not powered it up yet, but it looks very nicely built and I expect it'll work just as well as the Creality machine.
Here's something I've been working on today, based on the original Evesham station. The quality of the cut from the Creality machine is excellent. Those glazing bars are .25mm thick.

 

[John Walker]

Hello James

That does look good. I have played with half etched glazing bars in 0.25mm nickel silver but they tend to distort. That shows when you have a bar on both sides of the glazing. I note that the Falcon 2 will cut through thin stainless steel so perhaps another string to my bow. On the other hand it may be the heat would be a problem for very narrow sections. The more I think about it the more uses I can find for a laser cutter.

I am working towards taking you up on your offer to trial cut a track base for me.

I have successfully printed chairs and sleepers with 0.8mm wide sockets. That has confirmed my thoughts about minimum widths for plain track but I note that there is less clearance on some of the turnout timbers. This shows part of my test assembly:

The gauge seems fine now.

I cannot stick the sleepers to the template accurately enough to thread the rail through all the chairs. I have had to cut the template to shift one of the sleepers. That should not be a problem with laser cut sleepers held in the sheet. As shown in one of the pictures on my web site I had no problem threading the rail through the chairs while they were still attached to my build plate. The chairs will sit snugly against the top of the sleepers but as you can see above the cockled template has caused some to rise.

Threading the chairs on the rail first has not been successful. The inner jaws are so delicate that a slight twist while handling causes them to break.

I thought I would prepare a crossover for you to trial cut but I may be leaping ahead too quickly. I would need to do some chair heaving at the crossings and I don't think that is ready yet. So, maybe just a turnout on a curve would be better. I want the curve because my method of trial printing won't work easily for timbers that do not have a straight alignment on one end. If it works for a curved turnout then it should work for everything else.

What would you need from me? I guess a box file for reference and a DXF. Beyond that I have no experience of Lightburn so if you can take it from the DXF I would be interested to see the associated Lightburn file. Should I use Martin's default 0.2mm kerf width?

Do you have 1.5mm ply or bass wood?

Regards
John Walker

 

[Martin Wynne]

The inner jaws are so delicate that a slight twist while handling causes them to break.

@John Walker

Hi John,

What resin are you using? Most of us are using the ABS-Like resins. This one is water-washable and very tough:

https://www.amazon.co.uk/gp/product/B0C7BFQZ2C

(Make sure to order the V2 version, they are mixed up on the page.)

cheers,

Martin.

 

[James Walters]

Hello James

That does look good. I have played with half etched glazing bars in 0.25mm nickel silver but they tend to distort. That shows when you have a bar on both sides of the glazing. I note that the Falcon 2 will cut through thin stainless steel so perhaps another string to my bow. On the other hand it may be the heat would be a problem for very narrow sections. The more I think about it the more uses I can find for a laser cutter.

I am working towards taking you up on your offer to trial cut a track base for me.

I have successfully printed chairs and sleepers with 0.8mm wide sockets. That has confirmed my thoughts about minimum widths for plain track but I note that there is less clearance on some of the turnout timbers. This shows part of my test assembly:
View attachment 8383
The gauge seems fine now.

I cannot stick the sleepers to the template accurately enough to thread the rail through all the chairs. I have had to cut the template to shift one of the sleepers. That should not be a problem with laser cut sleepers held in the sheet. As shown in one of the pictures on my web site I had no problem threading the rail through the chairs while they were still attached to my build plate. The chairs will sit snugly against the top of the sleepers but as you can see above the cockled template has caused some to rise.

Threading the chairs on the rail first has not been successful. The inner jaws are so delicate that a slight twist while handling causes them to break.

I thought I would prepare a crossover for you to trial cut but I may be leaping ahead too quickly. I would need to do some chair heaving at the crossings and I don't think that is ready yet. So, maybe just a turnout on a curve would be better. I want the curve because my method of trial printing won't work easily for timbers that do not have a straight alignment on one end. If it works for a curved turnout then it should work for everything else.

What would you need from me? I guess a box file for reference and a DXF. Beyond that I have no experience of Lightburn so if you can take it from the DXF I would be interested to see the associated Lightburn file. Should I use Martin's default 0.2mm kerf width?

Do you have 1.5mm ply or bass wood?

Regards
John Walker

Hi John,

The .box file for reference will be all I need. I'll export the .dxf and do the necessary with regard to Nibs/Snibs and Kerf.
I'll save the lightburn file and return them all to you with notes about the settings I've used etc.
I'm finding the Creality machine has a kerf of about 0.12mm. So I will probably go with that, but I'll print some chairs and experiment with what seems to work best. I suspect that in 3mm scale the effects of shrinkage/kerf settings etc will be more noticeable than in the larger scales and the settings will require some fine-tuning to get optimal results. An interesting challenge.

I'll also make some sample sections of timbering with the sockets cut at different Kerf settings so that you can try the fit of your plugs.
From memory, I don't think I've got any 1.5mm ply in at present, I'll check and if necessary get some.

Either post your file on here, or email it directly to me at: makeitminiature [at] outlook.com and I'll do my best

All the best,

James

 

[Phil G]

Hi James,
what material did you use? And what was the material thickness? for the below, Which I have to say looks fantastic
also very keen to see a like for like comparison with the Atom stack vs Creality 2

 

[Phil G]

Hi John,
I have the 1.6 mm bass wood ( well a small piece of it anyway). post your box file here and I will cut it bass if it fits,
It would make a good photo comparison with what James is doing. Noting I don't have enough time to print any chairs in the next few weeks.
cheers
Phil,

 

[James Walters]

Hi James,
what material did you use? And what was the material thickness? for the below, Which I have to say looks fantastic
also very keen to see a like for like comparison with the Atom stack vs Creality 2


View attachment 8385

This is a fabrication of 1mm and 2mm MDF, with a bit of 3mm ply for the sill. The window frame is .3mm laserboard.
The final version will have the sill replaced with 3mm MDF. I'm going to experiment with some stone textures too. Eventually this might find it's way onto my S4 Jubilee Challenge layout. The missing course of bricks is to remind me of the height of the brick plinth.
The corbelling will support an ornate gutter, which on the prototype extended across the gables. The original building still exists, but all the interesting features have now long-since been removed.