Problems printing N Gauge Chairs and loose jaws

[Chris Hodge]

Hi Guys,
Have just got myself a resin printer and wash/cure unit and am trying to 3D print some N Gauge chairs and loose jaws.
using code 40 rail.
I have watched James’ excellent videos and followed them almost to the letter apart from obviously the different gauges.
I can print the track bases ok using my filament printer without a problem.
Firstly the chairs.
Have printed some click fit versions but have found that the slot for the loose jaws have not appeared as they should.
All I can see is a small indentation where they are supposed to be.
Perhaps it is because of the very small nature of the chair that is too fine to allow proper printing? Any suggestions?
Secondly the loose jaws.
All I am getting is the raft and some small stubs which I assume are the beginnings of the supports.
If I watch the screen on the printer, I can see a series of small dots appear as the print progresses which I assume are the different layers being generated but of course you cannot see them physically until the print has finished.
If you look at the print preview, it seems that where the support cone narrows to a virtual point before the loose chair print is supposed to start doesn’t seem strong or wide enough to support the continuation of the printing of the rest of the jaw.Again it could be the fine size of the print. Again any suggestions?
I then tried to print some full chairs with both jaws in place.
I don’t know whether you have to set the rail dimensions to allow proper clearances but I have found that both jaws appear to have printed as one with no gap between them to allow the rail to be slid in Apart from a hole where the base of the rail will sit.
Also they are too brittle and fragile to allow a scalpel blade to be used to split them without them breaking off.
I have ordered some flexible resin to try and print some more user friendly versions. Watch this space.
I have started to follow RBTKraisee’s post concerning his issues and all the suggestions for remedying them so I might give that a try and see if I can print bases and chairs as one unit as per British Finescale but it is noted that warpage may be a problem with resin printing the bases.
Any suggestion will be very much appreciated
Regards Chris

 

[Steve_Cornford]

Hi Chris,
Firstly, what resin printer do you have?
Secondly, what resin are you currently using?
Regards Steve

 

[Chris Hodge]

Hi Chris,
Firstly, what resin printer do you have?
Secondly, what resin are you currently using?
Regards Steve

Hi Steve, thanks for the quick reply.
I am a complete newbie to resin printing so I don’t really know if I need to set any printing preferences other than exposure time as recommended on the resin bottle but I am using an Anycubic Photon Mono2 printer and Anycubic Water washable resin, I do not use 3D builder but use the Photon’s own repair/slicer program. I have just ordered some RESIONE TH72 flexible resin to try, possibly as a % mix with the Anycubic resin to make the full chairs without them fracturing.
regards Chris

 

[Steve_Cornford]

Hi Chris,
Sorry I should have said welcome.
Looks like your printer has 4096 x 2560 px compared to my Mars 2 Pro of 2560 x 1620 px, so therefore a higher resolution.

The Mars and Alkaid users on here use chitubox as a slicer, which has an option in the advance settings that lets us switch off a feature called anti-aliasing. Can you check if that is a feature on your slicer, and if so try switching it off.

It would be quite useful to know your layer & curing time settings.

Also we tend to align chair rafts along the shorter axis, see:-

Also I would recommend that you try mesh fixing with 3DBuilder first before slicing with the Photon software.

But please note I have not tried printing 2mm scale chairs myself, only 4mm scale.

I have tried resin printing some 4mm track bases just for experimental purposes as I do not have an FDM printer(yet), but i reduced the depth & width of the flanges and webs down to 0.5mm (when i remembered to) and I do not seemed to have suffered from curling unlike some others. Some bases are painted, some left bare, some stuck down, some not stuck down.

So far I have only used Elegoo IPA washable ABS-like (v1) resin unadulterated, and also a mixture of this resin with some Sirya Tech Tenacious black resin.

Have you read:-
https://85a.uk/templot/club/index.php?threads/n-gauge-plug-track-question.781/#post-8923

My understanding is that the current ELegoo ABS-like (v2) resin is not as good, and that Anycubic Abs-like v2 (which is wataer washable) is better so I have some of that on order

STeve

 

[Martin Wynne]

@Chris Hodge

Hi Chris,

Welcome to Templot Club.

The first thing to say is that I'm not yet convinced that plug track is doable in 2mm/ft / N gauge. I thought folks were pushing the limit when they started talking about 3mm/ft.

For 2mm/ft it is going to need some careful attention to dozens of quite critical settings.

If the chairs are flashing across between the jaws, the first thing to suggest is to reduce the exposure time. Then make sure that you have correctly entered your bullhead rail section dimensions.

If the chairs are brittle and fracture when trying to open them out, you are very likely using the wrong resin -- it needs to be a resilient type of resin and normally that means ABS-Like resin, preferably water washable such as this one:

https://uk.anycubic.com/products/anycubic-abs-like-resin-v2-package?variant=45845570945309

If the slots for the loose jaw pins are blocked, it is most likely down to inadequate washing, see this post:

https://85a.uk/templot/club/index.php?threads/problem-with-printed-loose-jaw-chairs.811/post-9418

cheers,

Martin.

 

[Chris Hodge]

@Chris Hodge

Hi Chris,

Welcome to Templot Club.

The first thing to say is that I'm not yet convinced that plug track is doable in 2mm/ft / N gauge. I thought folks were pushing the limit when they started talking about 3mm/ft.

For 2mm/ft it is going to need some careful attention to dozens of quite critical settings.

If the chairs are flashing across between the jaws, the first thing to suggest is to reduce the exposure time. Then make sure that you have correctly entered your bullhead rail section dimensions.

If the chairs are brittle and fracture when trying to open them out, you are very likely using the wrong resin -- it needs to be a resilient type of resin and normally that means ABS-Like resin, preferably water washable such as this one:

https://uk.anycubic.com/products/anycubic-abs-like-resin-v2-package?variant=45845570945309

If the slots for the loose jaw pins are blocked, it is most likely down to inadequate washing, see this post:

https://85a.uk/templot/club/index.php?threads/problem-with-printed-loose-jaw-chairs.811/post-9418

cheers,

Martin.

HI Steve and Martin
I will take on board the comments you mention and the difficulties with N Gauge
I have checked the current resin settings on the printer program. They are as follows:
Resolution 0.05mm
Exposure 2.50secs
Lift 6.00mm /4.00mm/s
Bottom 5 / 25.00s
Anti Alias set at 16 but there is no button to switch off, I am only able to reduce it to 1
As already mentioned, I have some flexible resin on order

I suspect that the failure of the loose jaw slot may be as you say, down to inadequate washing. (Down to my inexperience I think)

As regards to the full chairs with both jaws, I didn't set any dimensions for the code 40 rail which could have caused the issue with the flashing across between the jaws.(Again down to my inexperience)
regards Chris

 

[Steve_Cornford]

Hi Chris,
By resolution 0.05 does that mean layer height?
Does your printer go down to 0.01 layer height?
If so might be worth trying that, even if you will get 5 times the number of layers & hence 5 times longer to print.

Might also be worth posting a copy of your box file on here.

Steve

 

[Chris Hodge]

Hi again,
With reference to my earlier post and the statement. “Anti Alias set at 16 but there is no button to switch off, I am only able to reduce it to 1”, I have been on the Anycubic web site resin settings page and found that says “ANTI ALIAS setting 1”. So I have changed that on the printer settings.
Steve: with regard Resolution 0.05, that is indeed the layer height and Anycubic set this at the correct level.
I have also found the dimensions for the code 40 rail and have dialled them into the export settings with an extra couple of thou clearance.
Looking at the print preview of the chairs with both jaws, there appears to be a gap between the chair jaws so when I hopefully get the flexible resin later I will try another print.
regards Chris

 

[Steve_Cornford]

Hi Chris,
With 4mm scale chairs Martin recommends that we print at 0.05mm layer height.

So with 2mm scale chairs it might be worth experimenting with a smaller layer height to get a similar resolution of chair details.
If I am talking nonsense someone will be along shortly to correct me.
Cheers Steve

 

[Chris Hodge]

Hi Steve, Thanks for the suggestion.
I will alter the settings later and try it
regards Chris

 

[Martin Wynne]

Hi Chris,
With 4mm scale chairs Martin recommends that we print at 0.05mm layer height.

So with 2mm scale chairs it might be worth experimenting with a smaller layer height to get a similar resolution of chair details.
If I am talking nonsense someone will be along shortly to correct me.
Cheers Steve

@Steve_Cornford @Chris Hodge @James Walters

Hi Steve, Chris,

Bear in mind that the exposure time needs to be related to the layer height.

Also, very thin layers might not work for horizontal overhangs, such as the edge of the chair base beyond the plug. That's very thin and delicate in 4mm/ft scale and will be half as thin again at 2mm/ft.

I'm very wary about 2mm/ft scale and hi-resolution printers, and fear the chairs may need a re-design for such scales and printers. We may be pushing too close to the boundaries for home printers.

There must be a reason why James says he prefers the Alkaid printer.

I'm a bit surprised by all the recent plug track interest in 2mm/ft and N gauge. It's a size I know nothing about and didn't consider in designing plug track. My own main interest will be in 7mm scale when I can get round to it.

cheers,

Martin.

 

[Chris Hodge]

@Steve_Cornford @Chris Hodge @James Walters

Hi Steve, Chris,

Bear in mind that the exposure time needs to be related to the layer height.

Also, very thin layers might not work for horizontal overhangs, such as the edge of the chair base beyond the plug. That's very thin and delicate in 4mm/ft scale and will be half as thin again at 2mm/ft.

I'm very wary about 2mm/ft scale and hi-resolution printers, and fear the chairs may need a re-design for such scales and printers. We may be pushing too close to the boundaries for home printers.

There must be a reason why James says he prefers the Alkaid printer.

I'm a bit surprised by all the recent plug track interest in 2mm/ft and N gauge. It's a size I know nothing about and didn't consider in designing plug track. My own main interest will be in 7mm scale when I can get round to it.

cheers,

Martin.

Hi Martin,
I have always worked in N Gauge but with FinetraX and 2mmFS track parts and wagon kits and have built a few small layouts this way with the track plan designed with Templot.
I took an interest in Plug Track when you first announced it and I appreciate that it is still a work in progress, but with the recent developments and the excellent videos produced by James, I thought I would give it a try.
After all you don't know if it will work unless you try it.
Also being a complete newbie to resin printing, It is a steep learning curve with regards printer setting etc. and I will only learn by my mistakes and the input of the likes of yourself,Steve and others to rectify those mistakes.
I realise that I may not be able to print the jaw inserts as they are so thin and delicate for use with the gauge chairs. but as previously mentioned, I have managed to print some bases on my filament printer and with the resin printer even with default settings, the gauge chairs( no jaw slots unfortunately) on their own and also the full chairs but with the problem with the flash over between the jaws because I didnt set the rail dimensions in the export file to allow clearance.
So having set the rail dimensions and having checked the print preview which looks promising, I might get some positive results with the full chairs using the flexible resin to counteract the brittlness, that is due for delivery this afternoon and the printer settings I have discovered online and also Steve's suggestions.
I might even try and print the bases with the chairs integral as per Ross' thread along with Steve's suggestions as per FinetraX, but one step at a time.
regards Chris.

 

[Chris Hodge]

Hi again,
Here’s a quick update with the printing.
My delivery of flexible resin has been delayed so it will have to wait until next weekend to continue but in the meantime, following my earlier post regarding the print preview showing the desired gap between the jaws after adding the rail dimensions , I tried altering the print layer height and the exposure time but it didn’t work too well so have reverted to the default settings. I have printed a raft of full chairs using the Anycubic Water wash resin. It is still a bit too tight threading the rail without breaking them so hopefully if I increase the clearances a couple of thou and use the flexible resin it might work. As Martin has suggested, I might need to get some ABS resin.
regards Chris

 

[Steve_Cornford]

Hi Chris,
I found it helps to make sure you clean the rail with IPA or white spirit or something similar as it is surprising how dirty the rail is as received from supplier.
Steve