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3D Printing in 2mm Scale


TomE
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15 minutes ago, Kylestrome said:

There is one aspect of 3d modelling/CAD for 3d printing that I've never been able to understand, probably because it's obvious to everyone else but me. When you have a model ready to export as an STL, does it have to be combined as a single object with a continuous surface or can it remain as a group of separate objects?

 

David

I just put the various stl files on the platform - and try to have gaps between the rafts for the supports so they come off separately rather than together.

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15 hours ago, Jan W said:

I have a question about wall thickness for coaches.

From what I have read it seems that a wall thickness of approx. 1mm is recommended.

This would give problems with glazing, like the old rtr offerings.

If I draw a coach with a recess on the inside around the window aperture and leave a wall thickness of 0.4mm, would that print well?

I did something similar with a Dapol autocoach where I milled a recess for the glazing material on the inside.

 

I seems that buying my own printer will also be cheaper than printing through Shapeways.

The coaches I want to build are available on Shapeways but would cost around €75,- (incl. shipping costs). If I add that to the few parts that I already had them printed I would have spent half the cost of my own printer.

And I would make more use of 3D printing because it would be affordable...

 

Jan

 

IMG_20201018_165011896.jpg

Two points that puzzle me.

Firstly for harder plastics Shapeways can print down to 0.3mm. I normally go for sightly more than that. Rods(eg bars on windows) have to be minimum of 0.6mm thick.

Secondly 75 euros for a 2mm scale or N gauge model sound expensive. My coach bodies are usually less than half that.

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7 hours ago, rue_d_etropal said:

Two points that puzzle me.

Firstly for harder plastics Shapeways can print down to 0.3mm. I normally go for sightly more than that. Rods(eg bars on windows) have to be minimum of 0.6mm thick.

Secondly 75 euros for a 2mm scale or N gauge model sound expensive. My coach bodies are usually less than half that.

The coaches are in the Shapeways marketplace so the designer also gets his fee.

And shipping costs are rediculous (they are in Eindhoven, Netherlands so no international shipping)

I just cheched at Shapeways, prices in dollars:

2 coach bodies $64.54, handling $1.96, shipping $15.72, total $80.26

So not far off the €75 I estimated.

 

But since your experience is different I'll draw a simple box shape with the dimensions of the coach and see if printing my own design is more affordable. Thanks for asking!

 

Jan 

Edit: Simon, I just noticed that the coaches I'm looking for are your SECR push-

pull coaches! 

You offer a lot of very nice designs on Shapeways!

Edited by Jan W
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9 hours ago, Kylestrome said:

There is one aspect of 3d modelling/CAD for 3d printing that I've never been able to understand, probably because it's obvious to everyone else but me. When you have a model ready to export as an STL, does it have to be combined as a single object with a continuous surface or can it remain as a group of separate objects?

 

David

I might be misunderstanding what you mean but I'm thinking that you are referring to say a building, with say sides, doors and gutters etc as separate items  inside the CAD package, and you want to know if you need to combine them all as a single item prior to exporting the STL to print as a single item with everything included?

 

IF not, ignore the rest of this!

 

I use sketchup so other packages may vary but I just select all the objects I want to include in the one stl file and export it as a single file, so for instance I might click on the gutters, tiles, chimney, roof panel etc and make that one single roof print.

 

The main thing to ensure is that the individual items are solid and watertight, and  once I've sliced the file I always use the photon file validator in the case of the photon, or the chitubox slide thingy when using the Mars to check each individual layer to make sure that  there aren't any strange membranes, holes etc caused by combining the separate items as one.

 

So far I've never had any, all the weird issues I have had ( windows blanked out, strange rectangular holes etc that arent in the original stl) are caused by hidden faces, holes in the mesh etc that I'd missed because I hadn't checked the stl for these issues inside the CAD package prior to export

 

Sketchup has an add-on called solid-inspector that shows these up, other packages may have something similar.

 

 

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6 hours ago, Jan W said:

The coaches are in the Shapeways marketplace so the designer also gets his fee.

And shipping costs are rediculous (they are in Eindhoven, Netherlands so no international shipping)

I just cheched at Shapeways, prices in dollars:

2 coach bodies $64.54, handling $1.96, shipping $15.72, total $80.26

So not far off the €75 I estimated.

 

But since your experience is different I'll draw a simple box shape with the dimensions of the coach and see if printing my own design is more affordable. Thanks for asking!

 

Jan 

Edit: Simon, I just noticed that the coaches I'm looking for are your SECR push-

pull coaches! 

You offer a lot of very nice designs on Shapeways!

I keep busy. Designing is very addictive, but by designing for a variety of scales I have worked out what needs to be done for different scales. I use a software package which I had to pay for, not as expensive as some of the better known ones and it suits me. It is normally not a big job to resize any of my designs, but I initially only offer a small range.

Those costs, did not realise it was for two coaches, and that postage does look high. I wonder if that is for faster production. Shapeways now charge an extra if you want something quicker.

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3 hours ago, njee20 said:

And it’s pointless as they’ve seemingly got so few orders they ship ‘standard’ ones within a couple of days!

Yep, my last couple of orders using their 'cheapest' postal option were delivered in 4 days from ordering, they're obviously very quiet. Coupled to that the quality of their prints appears to be on a downward spiral.

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14 hours ago, Jan W said:

The coaches are in the Shapeways marketplace so the designer also gets his fee.

And shipping costs are rediculous (they are in Eindhoven, Netherlands so no international shipping)

I just cheched at Shapeways, prices in dollars:

2 coach bodies $64.54, handling $1.96, shipping $15.72, total $80.26

So not far off the €75 I estimated.

 

But since your experience is different I'll draw a simple box shape with the dimensions of the coach and see if printing my own design is more affordable. Thanks for asking!

 

Jan 

Edit: Simon, I just noticed that the coaches I'm looking for are your SECR push-

pull coaches! 

You offer a lot of very nice designs on Shapeways!

 

Don't make your box solid. That will certainly up the cost consdierably.

 

I loaded a set of coach roofs recently and the came out at under 10 euro each. Which is not much different than they were several years ago. Shapeways did themselves no favours at all by randomly messing with their pricing algorithms (seemingly on a daily basis at one point) but the end result did not increase their prices by as much as some think. As far as I can see you sometimes have to delete and reload models to get the current pricing  quoted. I have two accounts and in some case identical models have different prices in the two.

 

Also it is very important to set the orientation of your models correctly, which almost always is with the bottom at the bottom(!)

 

You didn't make it clear that the 75 euro was for two?

 

Shipping costs may seem high, but believe me postage costs here in the Netherlands are exorbitent (before the current situation I routinely drove to Germany to post stuff internationally)  and the likes of DHL et al don't seem particularly bothered about trying to undercut PostNL.

 

Chris

Edited by Chris Higgs
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1 hour ago, Gareth Collier said:

Yep, my last couple of orders using their 'cheapest' postal option were delivered in 4 days from ordering, they're obviously very quiet. Coupled to that the quality of their prints appears to be on a downward spiral.

 

I agree. Their delivery dates are just scaremongoring as far as I can see.

 

Chris

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14 hours ago, monkeysarefun said:

I use sketchup ...

 

The main thing to ensure is that the individual items are solid 

 

The problem i found with Sketchup was the conflicting advice on line that is out of data for the free version.

 

You need to group all the objects and check that the entity info says you have a solid object. Alo look out for internal boundaries where you have combined objects.

 

I've decided to try FreeCAD.

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2 hours ago, Chris Higgs said:

 

I agree. Their delivery dates are just scaremongoring as far as I can see.

 

Chris

delivery times can vary , just remember we are still living with a pandemic. Delivery times for many things vary a lot. Plenty of work for delivery companies at the moment .

Also be realistic on costing. If you commissioned someone to scratchbuild , even a basic,model how much would it cost? From the feedback I get , I think most people are happy to pay for something they, otherwise, would have to build a complex kit(which might not be cheap) or scratchbuild.

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The biggest driving factor in getting my Anycubic Photon was the postage from NY, NY to Australia from Shapeways (and I couldn't see a way to go back to Holland which perversely based on Chris' comments above was cheaper for me!).  Now I can print something in the morning, correct it at lunch, correct it again before dinner and have the "good copy" the same day rather than paying three lots of postage and having weeks of time waiting.  I haven't used Shapeways in over 12 months so cannot comment on how they are now, but I would not be at all surprised to learn they are going backwards as I found the prices went up, the quality went down and there is a rise in home 3D printers undercutting their business model.

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2 hours ago, rue_d_etropal said:

delivery times can vary , just remember we are still living with a pandemic. Delivery times for many things vary a lot. Plenty of work for delivery companies at the moment .

Also be realistic on costing. If you commissioned someone to scratchbuild , even a basic,model how much would it cost? From the feedback I get , I think most people are happy to pay for something they, otherwise, would have to build a complex kit(which might not be cheap) or scratchbuild.

 

I should have said shipping dates. Delivery times are indeed unpredictable at the moment. A number of things I posted to the UK took two weeks to deliver (two days is the old normal) and one parcel sent to me ended back with the sender after three weeks as (supposedly) having the wrong address on it. Reposted without amendment to the address which was correct it took 2 further days to finally arrive.

 

Chris

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7 hours ago, Crosland said:

[...]

I've decided to try FreeCAD.

I am vary pleased with FreeCAD. I was running Fusion 360 under Windows 10 on my work laptop (i7, 7th Gen with 16MB of RAM) and that was much, much slower than FreeCAD under Linux on my personal laptop (i5 Gen 6 with 8MB of RAM).

Edited by Valentin
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35 minutes ago, Valentin said:

I am vary pleased with FreeCAD. I was running Fusion 360 under Windows 10 on my work laptop (i7, 7th Gen with 16MB of RAM) and that was much, much slower than FreeCAD under Linux on my personal laptop (i5 Gen 6 with 8MB of RAM).

I assume you mean GB of Ram :D

 

Nick B

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No more split coach bodies for me! 
 

69159387-8D14-409C-AE40-351409D935AC.jpeg.d182af5264c014049deba710a369e6a5.jpeg

 

37982B97-D8CB-4FB4-BD9D-C50CB01865F9.jpeg.3b8c2a7501078f545674cb30ff8ded7c.jpeg

 

This thing is a bit of a beast, but early testing is showing that the upgrade is worth it.
 

So far prints are coming out nicely, with improved detail definition over the OG Photon. There is also no sign of Z wobble, and the speed of it is pretty impressive. I’m currently using up some Elegoo ABS like grey and it’s happily printing at 1.5 second exposure time.

 

As an example, printing a PALVAN on the Photon at 0.01 layer height would take around 13 hours. On the Mono that’s down to 7 1/2 hours. 
 

812B71B6-C4E4-4A4F-899B-37730D2D8029.jpeg.a778bbdd379838b0ab006f183bc8749b.jpeg

 

The vertical pixelation lines you can see in the image above are barely visible to the naked eye. I’m not sure why the iPhone camera magnifys them so much! 
 

Its early days yet, but so far I’m impressed! 

 

Tom. 

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1 hour ago, TomE said:

The vertical pixelation lines you can see in the image above are barely visible to the naked eye. I’m not sure why the iPhone camera magnifys them so much! 

Camera's try to enhance detail with a sharpening algorithm, I think that is what happens here.

On more advanced camera's this is adjustable but I would be very surprised if an iPhone (or any other phone) had this option.

 

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9 hours ago, TomE said:

As an example, printing a PALVAN on the Photon at 0.01 layer height would take around 13 hours. On the Mono that’s down to 7 1/2 hours.

Why are you setting the layer height at 0.01mm? For Photon (S) the range is between 0.025 and and 0.1mm; I assume the system will adjust the out of range value and set it to 0.025mm. I know it does this if you put any value smaller than 4.5 seconds for the delay between layers (for Photon S).

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The stated range for the Mono X is 0.01- 0.15mm, so I’ve always gone for the lower end of that range unless I needed something in a hurry. I haven’t seen it adjust it to a higher figure.  
 

I have encountered a strange issue on the PALVAN prints however, in that the last few layers seem to be compressed, or deformed:

 

2930F722-83FC-49A5-9647-F91C64EAE657.jpeg.ade9186cec1b37d920560265dbebcb5c.jpeg

 

I’ve never had this on the OG Photon so slightly baffled to what might be causing this at the moment. 
 

Tom. 

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30 minutes ago, TomE said:

The stated range for the Mono X is 0.01- 0.15mm, so I’ve always gone for the lower end of that range unless I needed something in a hurry. I haven’t seen it adjust it to a higher figure.  
[...]

You won't see the 0.01mm value adjusted in the GUI - the printer's OS just ignores any value lower than 0.025 or higher than 0.1mm.

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1 hour ago, Valentin said:

You won't see the 0.01mm value adjusted in the GUI - the printer's OS just ignores any value lower than 0.025 or higher than 0.1mm.

If the slicer assumes layers 0.01mm high and the printer's OS overrides it to 0.025mm wouldn't that result in the print being 2.5 times too high? The number of layers would not change.

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