Messin' With Resin - 3D printed track

AndyB

Member
As my birthday is next month (not saying which one) and the price of resin 3D printers has dropped a lot I took the plunge into resin and ordered something called an Elegoo Mars 2 Mono. Should arrive Saturday.

The build surface is a bit small but the resolution is pretty good so it will be interesting to see what it can do. The "mono" refers to the LCD that acts as a shutter for the UV light. Monochrome LCDs attenuate the UV less than color LCDs and that reduces the exposure time for each layer. It's supposed to be a few seconds so something as low profile as 00 track should not take too long to print - I hope!
 
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As my birthday is next month (not saying which one) and the price of resin 3D printers has dropped a lot I took the plunge into resin and ordered something called an Elegoo Mars 2 Mono. Should arrive Saturday.

The build surface is a bit small but the resolution is pretty good so it will be interesting to see what it can do. The "mono" refers to the LCD that acts as a shutter for the UV light. Monochrome LCDs attenuate the UV less than color LCDs and that reduces the exposure time for each layer. It's supposed to be a few seconds so something as low profile as 00 track should not take too long to print - I hope!
Happy 75th Andy.....did you get somebody to pay for your 'present'?

Rob
 
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AndyB

Member

Hi Martin,

When I eventually get it up and running (which could take a while :) ) I'll be interested to see the amount of detail it can produce and the resilience of the final part. The "acid test" might be to see how close I can get FB rail secured by Pandrol clips, although that's probably pushing it a bit.

Cheers,
Andy
 
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Martin Wynne

Admin
Location
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Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add helpful replies.
Hi Andy,

I didn't have a birthday, but I did have some Amazon vouchers left from Christmas. I say "did have" because you can guess what happened. :)

Elegoo on its way, should be here tomorrow. Also some of the "ABS-like" resin, which is alleged to be less fragile than the standard resin. We shall see.

I've been thinking about resin printing for some time. I was very disappointed that I couldn't get better results from the BIBO filament printer for proper chairs, at least in 4mm scale. Even in 7mm they are fragile, and easily damaged when threading rail through them:

2_201859_050000000.jpg


A hybrid approach seems more promising. Slide-on resin chairs which locate onto a filament-printed base. Doing both at once allows more precise dimensioning than using injection-moulded chairs, and the chairs can be tweaked for the best fit on the rail. Also far more special chairs can be printed than are available from the trade.

Narrow 6" wide Z chairs, side-by-side on a timber for example:

3_z_chairs.jpg

Sorry, I don't know who posted this, maybe Phil O? Another discovery in the archive.

There would be no way of doing that with filament printing in 4mm scale, and very tricky in 7mm.

The material cost of filament-printed chairs is almost nil, it will be interesting to see how the cost of resin chairs compares.

cheers,

Martin.
 
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Hi Martin and Andy,
I will watch with interest how you get on with these printers. It was good of Richard to point us in the direction of the video as it answered some of the questions I had floating around in my mind.

A few more beginner(me!) questions :-
Does the software supplied give you an estimate of the amount of resin that will be used for the print ?
Does the print time change if you put 4 servo mounts on the design at once ? Maybe the answer is obvious and I haven't thought that one through :confused:
Is there a chance of distortion when curing the parts with a lamp ? There was a mention of window ledge/sunshine possibly causing issue but presumably a proper lamp setup would work fine.
When the mount was being cut off the cutters made a noise that suggested the material was quite 'hard' - unlike what happens if you cut a C&L chair off the sprue. Will the resin be flexible enough to grip the rail if used for chairs - time will tell on this one I guess?
If you just chairs this way is it likely there would be a suitable adhesive to bond them to ply sleepers?
My only use of 3D parts so far has been wagon buffers from Shapeways used to replace poorly shaped ones on kits and the quality of the parts and ease of use was fine.

As a final point - is there a possible intention for a library of chairs/baseplates/etc to be made available for use by Templot users. It doesn't make much sense for several people to be working away on a design for the same item.

Rob
 
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AndyB

Member
Hi Andy,

I didn't have a birthday, but I did have some Amazon vouchers left from Christmas. I say "did have" because you can guess what happened. :)

Elegoo on its way, should be here tomorrow. Also some of the "ABS-like" resin, which is alleged to be less fragile than the standard resin. We shall see.

I've been thinking about resin printing for some time. I was very disappointed that I couldn't get better results from the BIBO filament printer for proper chairs, at least in 4mm scale. Even in 7mm they are fragile, and easily damaged when threading rail through them:

2_201859_050000000.jpg


A hybrid approach seems more promising. Slide-on resin chairs which locate onto a filament-printed base. Doing both at once allows more precise dimensioning than using injection-moulded chairs, and the chairs can be tweaked for the best fit on the rail. Also far more special chairs can be printed than are available from the trade.

Narrow 6" wide Z chairs, side-by-side on a timber for example:

3_z_chairs.jpg

Sorry, I don't know who posted this, maybe Phil O? Another discovery in the archive.

There would be no way of doing that with filament printing in 4mm scale, and very tricky in 7mm.

The material cost of filament-printed chairs is almost nil, it will be interesting to see how the cost of resin chairs compares.

cheers,

Martin.

Uh oh! What have I done now? :)

I sent for the same resin and it has arrived. The printer is now supposed to be here on Friday. As usual I have some heretical ideas about how to make all this work. Whatever happens I'm sure it will be quite entertaining.

Cheers,
Andy
 
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Martin Wynne

Admin
Location
West of the Severn UK
Info
Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add helpful replies.
You have probably set back the launch date for Martin's boat :)

Hi Rob,

Not to mention the radio-controlled trains on plastic rails. :)

Answers from someone who as yet knows nothing:

Does the print time change if you put 4 servo mounts on the design at once ?

In theory the print time is determined only by the Z height of the component. We shall see. Unlike filament-printing where the volume of the component and nozzle size determines the print time.

Is there a chance of distortion when curing the parts with a lamp ? There was a mention of window ledge/sunshine possibly causing issue but presumably a proper lamp setup would work fine.

I've got 2 boxes coming, a red box and a yellow box. The red one does the printing, and the yellow one does the washing and curing afterwards. I didn't know that you could use a window cill instead (presumably only in daylight hours). It seems to me that there is a green one missing for a full set. :)

When the mount was being cut off the cutters made a noise that suggested the material was quite 'hard' - unlike what happens if you cut a C&L chair off the sprue. Will the resin be flexible enough to grip the rail if used for chairs - time will tell on this one I guess?

I believe the standard resin is quite brittle. But I've ordered some "ABS-like" resin which is claimed to be tougher and more flexible. That may mean it's not so good for fine detail. We shall see. Andy has just said that he has ordered the same stuff. It's a bit more expensive.

If you use chairs this way is it likely there would be a suitable adhesive to bond them to ply sleepers?

Some folks are supplying resin chairs now, so I assume there is an adhesive.

As a final point - is there a possible intention for a library of chairs/baseplates/etc to be made available for use by Templot users. It doesn't make much sense for several people to be working away on a design for the same item.

Yes indeed, that's what I'm hoping for. See at: https://85a.uk/templot/club/index.php?resources/categories/cad-and-3d-printing.9/ there is already a category for 3D files.

I'm also hoping to generate 3D files in Templot for direct export.

cheers,

Martin.
 
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AndyB

Member
Hi Martin and Andy,
I will watch with interest how you get on with these printers. It was good of Richard to point us in the direction of the video as it answered some of the questions I had floating around in my mind.

A few more beginner(me!) questions :-
Does the software supplied give you an estimate of the amount of resin that will be used for the print ?
Does the print time change if you put 4 servo mounts on the design at once ? Maybe the answer is obvious and I haven't thought that one through :confused:
Is there a chance of distortion when curing the parts with a lamp ? There was a mention of window ledge/sunshine possibly causing issue but presumably a proper lamp setup would work fine.
When the mount was being cut off the cutters made a noise that suggested the material was quite 'hard' - unlike what happens if you cut a C&L chair off the sprue. Will the resin be flexible enough to grip the rail if used for chairs - time will tell on this one I guess?
If you just chairs this way is it likely there would be a suitable adhesive to bond them to ply sleepers?
My only use of 3D parts so far has been wagon buffers from Shapeways used to replace poorly shaped ones on kits and the quality of the parts and ease of use was fine.

As a final point - is there a possible intention for a library of chairs/baseplates/etc to be made available for use by Templot users. It doesn't make much sense for several people to be working away on a design for the same item.

Rob

Hi Rob,

As we have come to expect Martin has provided a comprehensive response to your very valid questions. I doubt I can add anything.

I'm mainly interested in determining what is feasible/practical. Should be interesting as long as I don't do myself in with the pong from the resin :)

Cheers,
Andy
 
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Thanks Martin, your answers are considered and to the point as usual. A scale 4mm scale Pandrol baseplate would I think indicate the technology is where we want it to be but I suspect that may be another generation or so in the future.

Andy, looking forward to see how you get on.

Rob
 
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Martin Wynne

Admin
Location
West of the Severn UK
Info
Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add helpful replies.
Hi Andy, Rob,

My feeling is that the new kits from Wayne Kinney are a game changer for building bullhead pointwork in 4mm scale:


If as I hope he will, he makes the cast crossings and machined switch blades available separately, it's possible to imagine creating bespoke pointwork directly from Templot, by 3D printing a base designed to accept those components. Then building even quite complex pointwork reduces to cutting rails to length, sliding on the chairs, and plugging them into the printed base. It hardly needs gauges even.

A lot to think about.

cheers,

Martin.
 
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AndyB

Member
Hi Martin and Andy,
I will watch with interest how you get on with these printers. It was good of Richard to point us in the direction of the video as it answered some of the questions I had floating around in my mind.

A few more beginner(me!) questions :-
Does the software supplied give you an estimate of the amount of resin that will be used for the print ?
Does the print time change if you put 4 servo mounts on the design at once ? Maybe the answer is obvious and I haven't thought that one through :confused:
Is there a chance of distortion when curing the parts with a lamp ? There was a mention of window ledge/sunshine possibly causing issue but presumably a proper lamp setup would work fine.
When the mount was being cut off the cutters made a noise that suggested the material was quite 'hard' - unlike what happens if you cut a C&L chair off the sprue. Will the resin be flexible enough to grip the rail if used for chairs - time will tell on this one I guess?
If you just chairs this way is it likely there would be a suitable adhesive to bond them to ply sleepers?
My only use of 3D parts so far has been wagon buffers from Shapeways used to replace poorly shaped ones on kits and the quality of the parts and ease of use was fine.

As a final point - is there a possible intention for a library of chairs/baseplates/etc to be made available for use by Templot users. It doesn't make much sense for several people to be working away on a design for the same item.

Rob

Hi Rob,

Beware servos. They seem to have a sort of digital interface but it's really just analog. They are susceptible to drift and interference. Despite my great antiquity I do have some understanding of how these things actually work (or fail to work) but rather than try to explain that I've come to the conclusion that I might as well bash my head against a brick wall, a lot, and repeat.

Andy
 
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Charles Orr

Member
Location
Leicester UK
Hi Andy,

I use servos to operate all my turnouts using MERG software.
I have had no problems at all.
I use a small pcb mounted on a 3D printed servo mount .
This PCB contains the servo driver and a relay to provide frog polarity switching.
The two end points for the servo and it's speed can be set very acurately and the relay changes over half way between the the set end points. Other versions of this use solid state switching instead of the relay

Charles

20210311_073438.jpg20210311_073422.jpg
 
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