3D Printing in 2mm Scale

[TomE]

Guys

If and maybe its a big if, what sort of cost would you think there would be in a simple unfinished unpainted print of a single wagon. Not including wheels, couplings etc..

The finish from what I'm seeing is starting to really look excellent after a few test runs. So question is what would a wagon body cost from one of these home printers rather than somewhere like Shapeways.

 

In terms of raw material, probably not that much if we're talking small wagon in N Gauge. As mentioned above though, the real cost comes from time spent drawing up the models in the first place, and this needs to be done in software that allows for commercial use. Fusion 360 for example is free to use but only if you are doing for hobby purposes or personal use. 

 

Tom.  

[millerhillboy]

Do you have the CAD for what you want? That’s going to be the time consuming (and thus expensive) bit.

No didn't have anything in mind (well apart from a cowans sheldon and a decent lowmac) but no I wouldn't really be in position to do CAD. I was just thinking if Tom or Steve had a print that you'd done for their own purposes but that someone else liked I was just wondering what they think it *might* cost to make it worth their while to print and sell on.

 

What strikes me is that their prints with a little work are already better than Shapeways prints that I've seen.

Edited November 29, 2018 by millerhillboy

[justin1985]

It's back to question of cost of any cottage industry kit isn't it? Do you price to include development costs, or just materials and direct costs?

 

500ml of resin is about £25. Depending how thick walls are, how many supports are needed, and even being generous with amounts lost to wastage, you're probably talking about barely £1 worth of resin per N gauge wagon. BUT, it's also probably at least 4 hours of printing time, time and IPA spent cleaning it up, etc.

 

As Tom says, the most significant part of the real "cost" of the wagon is the time spent developing the design, testing failed or compromised prints etc. So do you say as a consequence you'll charge more for the wagon? Or do you take it on the chin because its your hobby and you would have done it for your own modelling anyway?

 

No different from an etched kit, or anything else really!

 

J

[The Great Bear]

In terms of raw material, probably not that much if we're talking small wagon in N Gauge. As mentioned above though, the real cost comes from time spent drawing up the models in the first place, and this needs to be done in software that allows for commercial use. Fusion 360 for example is free to use but only if you are doing for hobby purposes or personal use.

 

Tom.

 

As someone using 360 for same purpose as this thread, my understanding is Fusion 360 is free for startup/snall businesses

[TomE]

Yes, you’re correct there. From the Fusion website:
 

Fusion 360 is free for startups generating less than $100k/year in total revenue or wholly non-commercial hobbyist users.

Tom.

Edited November 30, 2018 by TomE

[Caley Jim]

I price my etched kits to cover the cost of having them done by the etcher, including the set up costs of the photo tools and price then per square centimeter of etch (rounded to the nearest 10p or so). As I am primarily making them for myself in the first instance I'm prepared to take the cost of my time on the artwork and the trial etches. In any case, how do you price your time when it's your hobby and not a business.

 

Jim

Edited November 30, 2018 by Caley Jim

[TomE]

For anyone thinking of trying Fusion360 to produce CAD models for printing, I found this chaps tutorials easy to follow and informative:

 

 

This weekend is the first quiet one I've had for a while so planning to really put the Photon through it's paces! 

 

Tom. 

[bridgiesimon]

To be honest I've been aware of that project for a long time, and its never been delivered yet. I know it seems to be imminent but its been that way for a long long time.

 

The individual integrally involved with the development of that project has been really ill hence the lack of development of the project, I am aware that it is still on the cards and will be delivered at some point in time.

 

Best wishes

Simon

[millerhillboy]

The individual integrally involved with the development of that project has been really ill hence the lack of development of the project, I am aware that it is still on the cards and will be delivered at some point in time.

 

Best wishes

Simon

That's great to hear Simon, I've known its been on the cards for a while knowing Russ as I know you do too, so hopefully it'll be along soon enough.

[Chris Higgs]

I just got a run of 20 of the anhydrite wagon that can be seen here:

 

http://www.rmweb.co.uk/community/index.php?/topic/101505-new-etched-wagon-chassis/?p=3031988

 

Now all I have to do is get the etched chassis designed.

 

Chris

[TomE]

Thanks to Kylestrome of this parish, who kindly sent me over some PALVAN drawings, I've run a "quick" test print off to check how some of the smaller details would appear since I underestimated how large they needed to be on the boiler. 

 

A little bit of tweaking here and there is required on rivet size, and the sections of bracing that extend beyond the bottom of the body need beefing up as I lost most of them removing the supports, but otherwise it hasn't come out too bad:

 

 

This has had no cleaning up work done to it at all, except the usual post print IPA bath & scrub.

 

Tom. 

Edited December 3, 2018 by TomE

[justin1985]

That looks amazing Tom! No visible stepping anywhere. How did you orient and support the print?

 

You've been working very quickly too! Alas I haven't had the time to sit down and finish any of my designs yet - work has totally taken over in the last few weeks

 

J

[TomE]

Thanks Justin. 

 

This was done at 20 degrees in the x axis and 10 degrees in the z axis with supports laid out in a similar fashion to Steve's van on the previous page. 30 degrees in the x axis seems to be the favorite but I wanted to bring the print time down a little for this test. 

 

I may try adding the chassis as part of the print, although the original intention was to use an association etch with N Gauge wheels for use on Ropley. 

 

Tom.  

[Kylestrome]

Thanks to Kylestrome of this parish, who kindly sent me over some PALVAN drawings, I've run a "quick" test print off to check how some of the smaller details would appear since I underestimated how large they needed to be on the boiler.

 

That was fast work! Mighty impressive.

 

David

Edited December 3, 2018 by Kylestrome

[millerhillboy]

quality is really very very good isn't it? better than what shapeways are doing would that be fair?

[TomE]

I had a Palvan from Shapeways and it needed extensive cleaning up before it could be painted, losing some of the fine detail in the process and is still not 100% smooth. 

 

Although the print above has a couple of areas where some work is needed, you could probably get away with painting it straight off the printer. The roof in particular is impressively smooth. 

 

I think the Photon is capable of producing better quality prints than Shapeways, but there are a lot of variables that all need to be just right to get the best from it

 

Tom. 

Edited December 3, 2018 by TomE

[Nigelcliffe]

quality is really very very good isn't it? better than what shapeways are doing would that be fair?

 

There are other 3D print companies offering different materials and methods at different prices. 

[The Great Bear]

Thanks Justin.

 

This was done at 20 degrees in the x axis and 10 degrees in the z axis with supports laid out in a similar fashion to Steve's van on the previous page. 30 degrees in the x axis seems to be the favorite but I wanted to bring the print time down a little for this test.

 

I may try adding the chassis as part of the print, although the original intention was to use an association etch with N Gauge wheels for use on Ropley.

 

Tom.

Looks very good, smooth sides. The 10 degree twist is that along the line of the coach or around the vertical? What's the purpose?

[TomE]

Looks very good, smooth sides. The 10 degree twist is that along the line of the coach or around the vertical? What's the purpose?

It’s along the line of the van, the theory being it helps hide visible pixels from the printing process. I did print a boiler with the twist and it didn’t feature the visible lines along the sides that can be seen in the one on the first page.

 

Printed alongside the PALVAN were a couple of these. They can occasionally be seen around the yard in the run up to a Day Out With Thomas events. Again, no clean up other than a bath in IPA.

 

 

Tom.

[The Great Bear]

It’s along the line of the van, the theory being it helps hide visible pixels from the printing process. I did print a boiler with the twist and it didn’t feature the visible lines along the sides that can be seen in the one on the first page.

 

 

Thanks. Did you then add extra support to the overhanging side or was the modest tilt not enough to need this?

 

My prints also have horizontal lines more obvious, the model was printed at 45 degrees or so it isn't layer lines.

 

Also shows stepping in the tumblehome. Hmmm.

 

As a result of the failed print I have gunk on the lcd screen, so this niggle isn't my immediate problem!

[Atso]

Thanks. Did you then add extra support to the overhanging side or was the modest tilt not enough to need this?

 

My prints also have horizontal lines more obvious, the model was printed at 45 degrees or so it isn't layer lines.

 

Also shows stepping in the tumblehome. Hmmm.

 

As a result of the failed print I have gunk on the lcd screen, so this niggle isn't my immediate problem!

 

For my own wagon, I did not bother supporting modest overhangs (up to c. 0.75mm). By turning the model c. 10 degrees on the Z-axis, you should be able to reduce the stepping on the tumblehome so that is is barely visible (or not at all) under a coat of primer - see below. Your coach so some signs of warping, this is typical with an open box structure (especially with a roof at the top!). To help combat this, try putting in cross bracing in the CAD. I use 1mm wide by 0.6mm high at with a spacing of 1.5mm between each one and cut these out (carefully) with a knife after curing and sand smooth if required.

 

 

The coach above was done using a 0.02mm slice.

[The Great Bear]

For my own wagon, I did not bother supporting modest overhangs (up to c. 0.75mm). By turning the model c. 10 degrees on the Z-axis, you should be able to reduce the stepping on the tumblehome so that is is barely visible (or not at all) under a coat of primer - see below. Your coach so some signs of warping, this is typical with an open box structure (especially with a roof at the top!). To help combat this, try putting in cross bracing in the CAD. I use 1mm wide by 0.6mm high at with a spacing of 1.5mm between each one and cut these out (carefully) with a knife after curing and sand smooth if required.

 

Gresley 51ft Full Third Experiment.jpg

 

The coach above was done using a 0.02mm slice.

 

Thank you. I will try the twist to see if that improves things. Regarding the warping, yes it's an issue. I had tried props but every 20mm or so (bear in mind I'm printing stuff for 4mm, despite the title of this thread, but there's good stuff in this topic so am interloping.) This helped but had unintended effect of diagonal marks on sides stemming up from where the props were. I'd also seen similar mark coming from the corner of the coach. I guess it's to do with stresses in the model during printing from changes in section and stiffness of parts. 

 

Current approach is to put model in hot water in the sink and straighten sides by clamping to a bits of wood inside the coach. Seems to more or less work,

 

With the closely spaced props as you described how did you deal with supports to the underside of the model and the roof, didn't the props get in the way - that was one of the reasons behind my wide spacing to allow supports to the underside of the roof, which tests proved was needed. 

That coach looks great, by the way:)

 

Thanks again,

 

Jon

Edited December 4, 2018 by The Great Bear

[Atso]

Thank you. I will try the twist to see if that improves things. Regarding the warping, yes it's an issue. I had tried props but every 20mm or so (bear in mind I'm printing stuff for 4mm, despite the title of this thread, but there's good stuff in this topic so am interloping.) This helped but had unintended effect of diagonal marks on sides stemming up from where the props were. I'd also seen similar mark coming from the corner of the coach. I guess it's to do with stresses in the model during printing from changes in section and stiffness of parts. 

 

Current approach is to put model in hot water in the sink and straighten sides by clamping to a bits of wood inside the coach. Seems to more or less work,

 

With the closely spaced props as you described how did you deal with supports to the underside of the model and the roof, didn't the props get in the way - that was one of the reasons behind my wide spacing to allow supports to the underside of the roof, which tests proved was needed. 

That coach looks great, by the way:)

 

Thanks again,

 

Jon

 

Hi Jon,

 

Many thanks regarding my coach test print - it is a very old file, was never finished and needs completely redoing to correct some errors that I've discovered.

 

20mm is too far apart for the cross bracing as it still allows the part cured resin to warp before it reaches the next brace. Regarding supports, I use my old B9Creator software to generate the supports and then export the file as an STL. It doesn't have an auto support function but does have an x-ray function which allows you to see inside the model to add the supports. I find this much more useful and ChiTu Box offers something similar, although I don't find it as easy to use (but I do do my slicing in ChiTu). I believe that both programmes are available for free (ChiTu certain is).

 

Just out of question, what exposure times are you using?

[Chris Higgs]

For my own wagon, I did not bother supporting modest overhangs (up to c. 0.75mm). By turning the model c. 10 degrees on the Z-axis, you should be able to reduce the stepping on the tumblehome so that is is barely visible (or not at all) under a coat of primer - see below. Your coach so some signs of warping, this is typical with an open box structure (especially with a roof at the top!). To help combat this, try putting in cross bracing in the CAD. I use 1mm wide by 0.6mm high at with a spacing of 1.5mm between each one and cut these out (carefully) with a knife after curing and sand smooth if required.

 

Gresley 51ft Full Third Experiment.jpg

 

The coach above was done using a 0.02mm slice.

 

I'm just trying to get into laser cutting acrylic to do windows for tiems such as this. There is a Dutch company who you send a file to and they cut, but also thinking about getting my own machine. Anyone any expereince orf that?

 

Chris

Edited December 4, 2018 by Chris Higgs

[Atso]

I'm just trying to get into laser cutting acrylic to do windows for tiems such as this. There is a Dutch company who you send a file to and they cut, but also thinking about getting my own machine. Anyone any expereince orf that?

 

Chris

 

Not yet at my end I'm afraid Chris. I would love to be able to play around with a laser cutter but that is something for the future. To date, all of my glazing has been of small windows where Krystal Klear has been sufficient.