Bugsplat model of a gear


#1

I’ve created a quarter gear and want to make 4 of it one solid. I was able to combine two of them, but if I try to explode the last group, it get a bugsplat. I’ve tried other orders of exploding but get the same error. Any ideas?

https://www.dropbox.com/s/cs17j4ddwnz1npq/gear.skp?dl=0 (10,4 MB)


#2

It splats for me, too. Weird.


#3

Delete the unexploded one and copy rotate the other.


#4

@DaveR: I’ve started with a little part of a downloaded model here, maybe there’s a little edge problem in that part.
@Box: I’ve tried that, but it doesn’t give a solid volume after the grouping. SolidInspector2 reported an unexpected error for this group.

I think I will recreate one teeth with simpler curves and start from there again…


#5

Did you try working at a larger scale?


#6

The gear has a diameter of approx. 100m, that should be enough :wink:


#7

Just curious, what’s the edge/face count on the quarter gear?


#8

You’re think it would be enough. I was able get it to explode successfully after scaling it up 100x.


#9

~40.000


#10

And you can get a solid of the hole gear?


#11

No. I was about to add to my previous post that then I tried something else and it splatted. SketchUp seems to get lost in thought for awhile before it rolls over on its back and gives up.


#12

something was odd with the file, I moved the origin, painted one segment, saved that out, made it a comp, rotated copy 59x…
and the file size read as 184kb…gear_seg_comp.skp (179.5 KB)

if I explode it into a single comp the file is solid at 10.5MB…

heres the single seg I used and it’s bigger than the full version???
gear_seg.skp (175.7 KB)


#13

I moved the top two 1/4 segments up by 10,000mm, exploded the bottom half, and then moved the top two back down by 10,000mm. There seems to be an odd split in the tooth at each end (circled in red) … maybe this is the root source of the problem? Also, when I moved the top back into place, I noticed that none of the 1/4 segments appear to be merged (as indicated by the surface highlight).

[added] I just noticed that the teeth are skewed … this explains the odd tooth hanging out that I noted above.


#14

Another approach … I isolated one tooth, made it a component, and then rotated it 6 degrees with 59 copies. Without exploding it, I exported it as an STL file then loaded it into MakerBot without any problems (it was re-scaled to fit by the MakerBot software). A sample print run seems to have no problems.

I know that this doesn’t seem to follow the watertight rules for the component, but the join of the components should still be a manifold volume. A nice side-effect of doing it this way is that the file size is greatly reduced.

gear2.skp (238.9 KB)


#15

@jimhami42, on the one I posted, I hid the Radius lines and used a tighter bounding box…

how’s it look in MakerBot…

john


#16

I misunderstood what you had done … otherwise I wouldn’t have posted an essentially duplicate solution :frowning:

Looks good:

BTW, I uploaded the one I made (pretty much identical to yours) to both ShapeWays and i.materialise:


#17

Thank you all for having a look at it. I’ve recreated one tooth contemporaneous to your solutions (but with a more simplified geometry).
I think it’s a great example how much trouble you can have if you download a model from an unknown source instead of doing it yourself :wink: