Printing Showcase (Page 1 of 3)

Nice! Isn't this technology awesome!?

I printed this several days ago, and finally got around to finishing it.  One of my old cars was missing the end off the wiper stalk on the steering column.  Not a big deal, except that you can't find them anywhere..and I don't mean "can't find one cheap"...they're not to be found. (It's an '88 Alfa Romeo Spider Veloce; even with the internet it's hard to find certain parts for a vintage Italian sports car!)

I modeled the end-knob in Sketchup, printed at .1mm, sanded with 210-grit sandpaper, steamed it with acetone, then hit it with some steel wool to knock the shine down.  The matte finish exactly matches the rest of the plastic.

Only a true Alfista would be able to tell that it's not an original part!

This is one of the main reasons I got into 3D printing: to make various hard-to-find parts for my old cars.  Well, and wargames.
...and RC helicopter parts.  Military models. Stuff for the garage.  Shooting accessories. Trinkets for the wife and daughters.

You get the idea.

That label is part of the existing piece, I just did the end-cap part of the knob.

My Alfa Romeo Spider was missing a small cover that allowed access to the brake light embedded in the spoiler.  Several members on the Alfa forums I frequent were looking for a cover too.  The only one to be found was for sale on eBay for $90.  A forum member sent me some photos; I took some measurements and made a mold out of Play-doh.  For about $.55 worth of black filament (not counting prototypes), I made an accurate reproduction.

It snaps right into place, and keeps the dirt and rain out of my spoiler!

I love black ABS!

Nice work!!!

nice! been trying some of his models also as they are closer to N scale 1/160th, how much clean up did you have to do on yours? and what side did you have at bottom end or underside? also what slicer settings? mine still have gaps on small bridge parts and some support materials are hard to clean up in some positions. so your making them about HO scale? I will post some pics of my N scale prints and fails. some fails would make good war battered wrecks lol. he has 3 sets now and growing. mine take between 25min and 52min depending on model and settings so far. how long for yours?

I read a post on Thingiverse that someone was printing them at 187% size, but 200% seems to match up correctly with the 'store-bought' FOW vehicles.

I print them sitting on their rears...turrets and hulls.  That seems to give me the best results, and less support material required.  The gun barrels come out very good (notice the quad-.50 turret for the halftrack). Most of the clean-up required is removing the support material from around the road wheels of the tank treads.  Still, it's not too bad...a sharp exacto and a little patience.

I printed mine at .1mm layers, .35mm first layer, 8 perimeters, 4 top, 3 bottom.  In cooling, I have it slow down below 60 seconds, with a 5mm/s minimum.

If you have a particular model you want me to try printing with my settings, let me know.

I'm glad you got it working.  They are really great models. 

I'm hoping he does another WWII pack with jeeps, armored cars, and crew-served weapons.

n2ri sent me a link to this forum. Thanks for the comments.

Yes, there will be a pack 3 (and 4, and 5, and ... ) until pretty much every WWII tank and vehicle is done.
Currently modeled for the next pack are:
Medium B (WWI)
Medium C (WWI)
M3 Lee
M3 Grant
DUKW (open & closed)
Churchill VII
Churchill crocodile
Goliath
Goliath on trailer
Kettenkrad
Pak40 auf RSO
Sdkfz 10
Sdkfz 10/1 20mm flak (armoured and unarmoured)
Sdkfz 251/7 with assualt bridges
Sdkfz 251/1 stuka zu fuss
Pz III L/M/N
Radschlepper Ost
OT-34

I'll focus on Jeep, Dodge weapons carrier and M8/M20 soon.
M4A3E8, Chaffee, Hellcat, M4 105mm will all be in Pack 3 for sure. Amtracks might make it in too...

If I'm missing anything important, please feel free to let me know. ( And no, Mitch, the Ball tank is not important...    )

Regards,

Marco Bergman

The first thing before designing am item is to be well aquainted with the capabilities of your printer, because this will heavily influence your design.
For the UP printer, these are the following constraints which need to be considered:
Minimum wall thickness (XY): 0.7mm
Minimum trench (sharp definition) (XY): 0.4mm
Minimum trench (XZ): 0.2mm (rounded edges)
Minimum trench (sharp definition) (XZ): 0.4mm
Minimum thickness for things like mudguards (XZ): 0.6mm to avoid a lacy finish.
Prefered Zaxis step 0.2mm ( to suit UP Mini)

These numbers will determine what details need to be omitted, or beefed up overscale to print.

It is easiest to work off a good set of 2D drawings. However, many of these drawings are wildly innacurate, so picking good ones is essential. Checking known dimensions against the drawings is a good start. I tend to favor the later issues of Panzer Tracts and the Speilberger books for German vehicles. For US vehicles, the Hunnicutt series is the go-to set of reference. The Bradford books of scale plans are a good starting place especially for British and Russian vehicles, but often contain minor innacuracies. (Given the overscale effect of adjusting the model for printability, this is often not a real issue.) Also there are now many specialist modeling books like the Nuts and Bolts, and Kagero books which contain nice and accurate drawings.
( I have all the Speilbergers, most of the Panzer Tracts and Hunnicutts, plus over 200 reference books (including 30+ Jane's)... )

Once you have a good drawing, you need to establish the scale it is printed in by comparing the drawn size vs a known dimension. (Good drawings have a scale bar.) Just because the drawing was meant to be printed at 1/35, say, doesn't mean the printer got it right. The Bradford books especially suffer from this.
Usually there will be a 20ft bar ( or similar).
20x12x25.4 / measured size = scale factor
To get to 1/200, I then divide the scale factor by 200.
This resultant number is used to multiply every dimension measured off the drawing to give the 1/200 size.
Remember to double-check the real size/200 vs the measured size x resultant scale factor. They should be the same...

Drawing the unit, I always start with a side-on sketch showing the track outlines, wheels, and hull profile.
Sizes are adjusted to fit the parameters above, especially track thickness 0.6mm for delicate tracks, 0.8mm for heavier, 1mm for very heavy. Wheels are positioned so that they intersect the track by approx 0.2mm to ensure that there's something holding the tracks together.
See pic1

I tend to fully draw one side of the vehicle, where symetrical, and mirror all the events when done, then add all the assymetrical details.

This is the time where lots of reference photos are required, to see if that bit goes in, or out, and at what angle...  this is where you'll find the errors in the drawings. Minor ones I ignore, major ones I go with the photos.

Try to keep XZ axis gaps 0.5mm or bigger if you need to remove support from them. My most used cleaning tool is a chunky  Xacto holder with an old blade which I have filed off the cutting edges from. This makes a fine prodding tool with a 0.5mm thick, strong blade which is too blunt and unpointy to stab myself with.

Pic2 shows many of the above discussed points, ie thick trackguard brackets, wheels intersecting tracks, slightly exaggerated gap above track for cleaning out supports. It also shows one trick for making finer detail that the printer thinks it is capable of. Detail, either raised or recessed, with a 45 degree chamfer to its edges will print. You can get away with a mere 0.4mm wall on XY as long as the sides of the inside slope inwards at 45 degrees, same in XZ with raised detail as you can see on the tool boxes of the Luchs.

Model, pic3

I prefer to print my gun barrels parallel to the build table ie flat, which is why I draw them with flat bottoms, to give the support something to build on. At 1:200 you really can't see the difference.

One final note: on the Up, at any rate, for some reason you get nicer XZ surface finish AND far better results with the bottoms of wheels if you rotate the part 45 degrees in XY on the build table.

That is impressive.  You've certainly spent a lot of time, not just researching the armor subjects, but also determining the best results for the printing process.

Your screenshot of Solidworks is somewhat intimidating...that's a lot of buttons!

The 45 degree chamfer trick is interesting.  I'll have to try rotating the model 45 degrees XY too.  It never occurred to me to alter the orientation in that manner.

New Zealand? dont know why I thought you where from Germany must be thinking of dif guy on Thingaverse. yes I too have learned to watch some of those tricks about printer and how to lay object , set slicer for best support width etc even force support so many layers if only wanted on bottom area. also when rescaling need to run rescaled stl through netfab again to see if anything got out of watertight range etc. and anything long and thin needs layed flat so its not like a stack of tiny dimes or knocked over mid print. I even got the machinegun to print in 200th scale that way.