3d bevel gear problems

[Richard Cullin]

i have just got my home brew 3d printer working and was hoping to print a set of bevel gears , i have tried replicato rG and slic3r and they both do a marvelous job on spur gears but neither  will produce the shaft hole for a bevel gear, is it me or are the bevel stl files not quite right ? the model looks nice in replicato rG but the gcode produced  fills the shaft hole in. for what its worth the shaft hole when viewed  in google sketch has no sides .
ps it would be nice to be able to have a flat on the shaft hole for those with  3d printers , its a bit messy using google sketch to add the flats in and google sketch 7 or 8 has trouble with bevel gear too

[ArtF]

Richard:

   I think your right, I messed up the shaft hole by not adding sides to it. Not sure about the flat as yet..perh aps I can option it, but I have added that shaft hole to my todo list. Since the bevel is the item I really want to 3d print when I have a 3d printer, its something I had way in the back of my mind to check at any rate. The helical may have the same issue, both of those gears are my triangle code as opposed to the library creation of the other stl's, so its something I cant blame on other's code.
Art

[Richard Cullin]

i have a couple of more thoughts about the bevel gear stl output, 1. gears print best with the flatside down ,could the stl output be rotated around the  x or y axis by 180 deg     2. the z axis 0 would be better at the bottom of the gear  3. the back of the gear would be better being completel y flat 4. netfabb finds various errors with the stl files and cannot fix them without degrading the whole gear
there may be something there that can be fixed
i have found that i can erase the entire centre of the gear in googlr sketch , then add my own centre , rotate the lot then export it to slicr3  and get a decent prints with shaft holes too  see pics

[Richard Cullin]

ps cant spell , carnt type , car;t rule a straight line , cannot drill a hole in the center of anything , thats why i love cnc machines

[ArtF]

Richard:

   Ive recently fixed the shaft holes so the stl is complete on those. I will add to my schedule to look at inverting the direction normal on them as well.
The closing disks Ill have a look at to see if I can switch those out. Bevels unfortuna tley need to be done internall y as single triangles all over as the
solids library chokes on them if it tries to make them. ( Support is absolutle y zero from the library vendor). So Ill see what I can do at next release.
Though Ive fixd a few things, and added sprockets now, I cannot release till september as Ive got the code torn down quite a bit for future additions .

Thx
Art