Preview Goes Review

[feldbahn.de]

Hi all,

a few weeks ago, I posted a first glimpse at my latest 3D-prints
Then came my rehab, and a vacation - together with one or another surprise ... so it took a little longer until I could take the photos and write down some words.

Currently these items are available from Shapeways:

- O&K Patent Track in 0n30/0e (16,5mm gauge), as well as in 0f (12mm gauge):




- Tipper wheels resembling 11" (280mm), 11-3/4" (300mm), and 15-3/4" (400mm) prototype wheel diameters, designed to build your own wheelsets:



For those who'd like to read more words, or see more pictures, feel invited to visit my related blog entry

Herzliche Real 3D Grüße
Ralf

PS: The corresponding axleboxes came off the printer today, and will be in my mail-in sometimes next week ...

[finescalerr]

I am glad you are feeling better and can't wait to see the parts painted and weathered. -- Russ

[feldbahn.de]

.. can't wait to see the parts painted and weathered.

Russ,
I think first I'll need another workshop with Marc or someone else from the group of true modeling artists 
I'm more the technical guy  and up to now not have tried my hands on much making the (model-) world more colorful ... or even weathered - as long as you don't take my full size car into account 
Ralf

[feldbahn.de]

Hi all,
some might remember I reported about 3D printed axle-boxes for tip carts. Unfortunately I still didn't find time to fasten them to a frame, have a test run, and then finish the print file.

But in the meantime at least I managed to close a minor gap
I try to keep my personal modeling as close to 1/4" scale as possible. Therefore I wanted my steel ties (ribbed, and hat types), as well as the Patent Track printed to the correct gauge.
So I regauged all parts to 0n2 (1/2 in. gauge) and even more have them already uploaded to Shapeways: https://www.shapeways.com/shops/atelier3d

Narrow-re-gauged Regards

[finescalerr]

I followed your link and the parts your have designed are wonderful. Question: Have you printed your 1:48 scale rail joiners (120 Dachschwellen 0f für Peco c.80)? If so, how clean are the nut-bolt-washers? How well does Shapeways resolve tiny detail? -- Russ

[feldbahn.de]

Hi Russ,

no not yet, rail joiners are still on the todo-list. Maybe I even won't have them printed because wall thickness is set to a minimum of .3mm (.0118"). This would scale out about 50% oversized, and then might interfer with the flangeway. I think I will better cut them from cardboard, emboss them and/or add extra bolt detail.

For the details available with Shapeway's new FXD I fished out my old non-binary bellows, mounted the EF-Adapter kit, and took some binary images (photos taken with Canon EOS 70D, Novoflex bellows at full extension, 50mm lens, 1/4 sec., f4.0). Together with the respective screenshots of the 3D file they might give quite an idea about todays possibilities

First you see the pin to which the neighboring trackframe will connect. Also the railclamp and bolt is clearly shown:



The second pair of images shows the joining hook. The connecting rod between the rails is .396mm (.0156") in diameter ... causing Shapeways to share some tears for free "wires" should have at least double the diameter



The details of the rail fasteners on both types of steel ties should need no further words:



Finally the testprints of the axleboxes show todays limits: .25mm (.0098") diameter bolt with a nut for .444mm (.0175") wrench size is below crisp detail capabilities ...


Any dimmensions shown in the screenshots are in mm (25.4mm = 1").

Beneath the plain size of a detail it also important to know about the printer's working direction.
Although the FXD resin is UV-cured within a resin-bath, residue covering crisp details may harden as soon as the part is risen above bath-level. This seems to be either due to stray UV-rays or is simply a case of "air-hardening". Therefore it is important to design any print-files that remaining resin can easily drip off.
Since my axlebox print-files must be printed to allow surplus resin to run out of the bushing, the bolt and nut shown in above photo might also be less crisp due to resin not dripped of as expected.

Detail-printed Regards

[finescalerr]

Thank you, Ralf. Based on your very helpful photos and drawings I think the 0.0625-inch diameter parts I had in mind are much too small. -- Russ

[feldbahn.de]

Russ, at the moment my smallest single part that prints without discussion is the axlebox with these overall dimensions - this time readily converted to inches



As you can see from the close-up photos, FXD print surface is not perfectly smooth. So the .004" (.1mm) given for embossed and engraved detail is more a theoretical than a practical value.
Therefore I think a part with an overall diameter of .0625" (1,588mm) might print, but success is largely dependent on its surface detail.

Maybe before uploading a part to Shapeways you might try another way.
Just recently Formlabs announced the release of a new SLA printer, their Form 2. This printer is designed to print with layer thicknesses of .001", .002", .004", .008", and a laser spot size of .0055". These properties are a bit better than with their previous Form 1(+) model, and similar to shapeways' standards. A test print I received from Formlabs shows, that their printer's output doesn't really stand behind shapeways' print quality.
Formlabs printers are typical printers used in FabLabs, that want to offer a more serious quality than that printed by FDM "toy"-printers.
So maybe you could try to locate a FabLab in your area, and ask if they already print with a Form 2. Maybe they find time to try a single part of your design before shapeways asks you to fill their minimum bounding box with several parts that in the end might proof unprintable ...

Fund-raising-for-my-own-Form_2 Regards

[finescalerr]

Thank you for that very helpful information. I am certain others on our forum also are glad you told us about FormLabs. -- Russ