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jamesg

3D Printed Wagons

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Following a demonstration at last year's Warley show, I purchased a basic 3D printer (Wanhao Duplicator i3 Mini), with little clue of what I was going to use it for.  Once I had gotten it to print some basic objects, I obtained copies of "Railway Wagon Plans: 1960s to the Present" by John L. Fox and "British Railways Wagons: the first half million" by Don Rowland.

 

The POA wagon pictured was designed in Solvespace, an easy to use parametric CAD program, then sliced and printed in one piece with supports.  This is probably the largest wagon from the book that can be printed in one piece on my printer, given the small build volume.  It came out fairly well, the only issue being that the supports are tricky to remove.  Any details such as brakes and brake hangers would only make that problem worse.

 

An alternative I tried was printing the wagon upside down with support inside the wagon.  There was a lot of warping around the top corners with this method, possibly due to poor build plate adhesion.  The unsupported rim at the top of the wagon came out much better.  I don't know what to do about that at the moment.  I've been using a brim of about 5-6mm with smaller items to improve adhesion, though the small build volume of the printer limits the brim to 3mm with the POA wagon.

 

A photograph of the POA wagon, currently lacking couplings and buffers (they wouldn't fit in the build volume).  This version was printed right way up; the bottom of the rim around the top is rough where the printer has had to bridge the gaps between the supports.

 

post-27523-0-18804500-1546710661.jpg

 

The drawing exported from Solvespace.

 

post-27523-0-74546700-1546710674_thumb.png

 

The printer is currently working on a 009 scale quarrymen's carriage from the Ffestiniog railway, which is more suited to this printer's capabilities than OO scale models of modern rolling stock.

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Hi James - well that's certainly a good start!

 

A lot of people print their models at an angle as it helps guard against too much suction. Printing at an angle may also allow you to print longer models. I have printed a few things including bogies, and have found that by printing upside down I don't need to have a lot of supports around the axles boxes etc, and so don't have a problem with detail in this area. If you're using resin that cured in UV, you might find that removing supports and doing a quick sand is easier before your cure your model.

 

Although he's using a different printer, it's worth having a look at what Knuckles/Sparkshot's up to in this part of RMWeb. Also, there is a learning curve no matter what printer you get, but this can be helped if you're on Facebook where they have an active official Wanhao group that can help you.

 

cheers

 

Jason

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I have found the Colorfabb PHA/PLA filament is much less prone to warping than either ABS or pure PLA. Also, if you use "blue tape" on your print bed, 3M #2090 tape provides strong adhesion, even compared to other 3M tapes.

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Sorry, you said it's an i3, is saw that and for some reason my brain said d7.

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Thank you both for your replies.  I'll try printing the POA wagon at an angle to begin with, as that can be done without any additional materials, then try the #2090 tape.

 

I did look briefly at resin printers, then decided against as they seem to require a lot of cleaning and the material is not so readily available.

 

Here are a couple of quarrymens carriages in 009 gauge.  They print fairly well on the Wanhao printer, with no warping as long as the bed is leveled correctly.  Some sanding is required to remove the lines from the curved roof.  The couplings are a simple hook and loop made from wire which fits into two holes in the block at each end of the chassis and is secured with glue.

 

post-27523-0-81099500-1546898812.jpg

 

They were called 'zip-fastener' carriages as the men had to sit with their knees interlocked.

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Just a little update on progress so far.  Rotating the POA wagon by 45 degrees and printing upside down seems to have improved the quality of the print significantly.  There is no bridging visible from the outside when printed upside down.  When printed 'right way up', there is a lot of bridging between the steel ribs on the sides.

 

post-27523-0-99904100-1548602981.jpg

 

The wider brim has reduced warping; the end nearest the camera lifted up slightly, it's not as bad as it looks in the photo.

 

009 narrow gauge prints are going very well and don't suffer from warping at all.  As well as the quarrymen's carriages, I drew up an approximation of Vale of Ffestiniog (not for rivet counters) for the Kato tram chassis.

 

post-27523-0-35158800-1548603114.png

 

It is printed in two sections; the top section is 'right way up' and the lower, light grey section is upside down.  It's pictured here with some quarrymen's carriages.

 

post-27523-0-97492300-1548603003.jpg

 

I printed a 'spare' Vale of Ffestiniog and painted that one blue.  It is pictured with the quarrymen's carriages and a Parkside Dundas model of the later, glazed type of carriage.

 

post-27523-0-43311300-1548603008.jpg

 

Meanwhile, I'm practising drawing in Solvespace.  A useful approach when designing for an existing chassis such as the Kato chassis is to draw a bounding box of the chassis and subtract it from the model to ensure a good fit.  For instance, here is the bounding box of the Kato chassis.

 

post-27523-0-24336400-1548604017.png

Edited by jamesg
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