Oh, it’s an extruder… were thinking of getting a Form 1 though. Please keep us updated on your project, I might try to follow in your footsteps XDD
well i got the printer today, but it’s going to take some time to assemble it and learn how to work with it.
Yay!
Done with the build.
https://dl.dropboxusercontent.com/u/562961/2013-08-24%2017.36.14.jpg
Everything has been tested and is working. Now I just need some minor calibration and I can get started!
*update
Ok here we go.
for a yoyo design I picked an old one I had lying around.
You should see a render here: (click+drag to rotate)
https://dl.dropboxusercontent.com/u/562961/render.swf
It was optimized for 6062 aluminium so I had to add quite some weight, but I managed without too much difference in overall look.
Here is a screenshot of the crossection in autocad:
https://dl.dropboxusercontent.com/u/562961/screenshot.jpg
The green profiles is how it is actually going to be, the orange one is modified to be able to print it, otherwise there is a void underneath the axle area which will cause the whole thing to implode. I figure I can easily remove the excess plastic with my router. The circled area is still worrysome though. We’ll have to see how the printer manages that.
The profiles on the right are a mockup of the Chiko kit, so to be able to calculate a weight, because they haven’t arrived yet. It won’t be spot-on, but at least I have a half-decent estimate. The whole chiko set with axle, silicone and bearing should weigh about 22 grams according to my calculations. If anyone knows an exact weight, please let me know.
22 grams is a lot of center weight, so I shifted most of the plastic material to the rims. I don’t know the math behind gyration and such, so the whole weight distribution is pretty much done by gut feeling.
some specs:
material is PLA
C bearing
53,6 mm across
45,7 mm wide
weight is dubious. As you can see, the calculated volume is 19000 mm³, so about 19 cm³ (you gotta love the metric system 8) ) But when I import the object into my 3D printer software, it says it needs 22.8 cm³ to print a half. So I’m not sure which one will be closest to reality. I went on with the autocad calculation, if it turns out too heavy, I can still print at 95% density or so…
so 191.24 (avg. PLA density) is about 23,6 grams
23,62 + 22g (axle system) is 69,2 grams.
Of course there’s a lot of guessing involved atm, I will have to print a half and wait for the axle setup to arrive to be able to optimize the design so it’s exactly where I want it to be.
One thing I’m having trouble with is revolving from 2D profile to 3D object. I always end up with a ‘faceted’ surface.
https://dl.dropboxusercontent.com/u/562961/screenshot2.jpg
The first is exported straight from autocad using the autocad revolve function. The second was revolved using sketchup. Anyone know how to revolve to a smooth round shape?
Well thats it for now. I may do a print test tomorrow.
Grtz
For sketchup, it’s only displayed that way. Sketchup actually recognizes it as a smooth curve.
Actually it is the exact opposite.
After some research and trial & error I found out that Sketchup sees a circle as a closed line comprised of straight segments. Default is 24 segments to a full 360°.
There is a smoothing modifier with adjustable treshold which only smoothes the appearance in the viewport (or for rendering purposes) but the segments are always there.
Since the revolve (follow me) function needs a circle as a guide it will adapt the number of segments of the reference circle. So after some digging I managed to draw a circle with 128 segments (so basically perfectly round) and used it to revolve. Success!
I also figured out the weight issue. Autocad calculation was right. I can actually find the same value in my 3D printer software. But apparently, there’s a difference between volume of plastic needed to make the part, and the volume of the part itself. Probably has to do with high temperatures > expanding material > yada yada yada.
And more importantly, i figured out there is actually a setting in the software that takes care of ‘overhanging’ areas by means of a thin support structure which you can break away after printing has completed.
So there was nothing keeping from trying out a print. Full density and full resolution.
So here’s the gap side (topside of print)
https://dl.dropboxusercontent.com/u/562961/2013-08-30%2017.44.10.jpg
worked out pretty well
but the inside (underside print with ‘support structure’) is totally messed up. I call it the Frankenyoyo.
https://dl.dropboxusercontent.com/u/562961/2013-08-30%2017.44.32.jpg
more tests later…