Sample HiRes STL output file

[ArtF]

rofl... Now THATS funny.. lol

Art

[ftkalcevic]

This is really good timing.  I've just got my 3d printer running and wanted some things to test print.

I created a helical knuckle gear.  Output was 7MB.  I loaded it into Slic3r.  I complained about "The input file contains a hole near edge...".  I get this regularly so I just ignored the message.  However, when I tried to generate the gcode, Slic3r failed with "Can't call method "retract_length" on an undefined value".

So, I uploaded the .stl file to cloud.netfabb.com and let it repair it.  It came back as a 1MB binary stl.  Slic3r reads it without complaining.  It also generated the gcode, so it's printing now.

Frank

[ArtF]

Hi Frank:

  Thanks for that.  The current STL output is bad from GM, Ill release GT as soon as it can save all the stl's.
You might try the one I posted earlier, it should have no holes. Im working very hard to make all gears come out as totally closed manifolds. ( Which i the case of a bevel is a true bitch.). Im getting close though. :)

Please let us see the gear you print..Ill be doing so soon myself, so Im interested in how various printers react. Im hoping to support 3d printers ina  much larger way than before.

Thx
Art

[ftkalcevic]

Here are my gears. 

I have a makerbot plastruder mk5 hooked up to my cnc router.  I've replaced their motor with a geared dc motor with encoder.

I still have to tune my 3d printer.  The bottom layer still comes out wider than subsequent layers which makes gear meshing a problem. (you can see that on the rack and pinion zoomed image)  I also have problems with the plastic flow.  When the motion slows down, the plastic seems to continue oozing leaving clumps.  When I accelerate, it doesn't come out fast enough and leaves gaps - this was noticeable on the rack where it zig-zagged slowly printing the teeth, then zipped along the back.

The helical rack was created by taking a 2d rack from GM, and doing a profile extrusion along the path of the pinion edge.  This was done painfully using alibre design.  (I had to slice one tooth out of the pinion to make the object manageable by alibre design) I used GM to create the gear, netfabb studio basic to repair the stl, wings3d to cut out the tooth, instep to convert the stl to the step, alibre design to make rack, then exported as stl to slic3r.

This was printed using 0.3mm layers.  I think my nozzle has a 0.45mm hole (that was the largest drill bit that fit in the hole), but I got the plastruder so long ago I can't remember and it isn't for sale anymore.

Frank

PS  What's GT?

[ArtF]

Hi Frank:

  Nice photo's, thx. I appreciate the description, its what I commonly hear, ..use one program to edit this and another to do that
and a further one to do another thing..

GT is "Gearotic Thoughts" , GM has reached an internal level of complexity that its hard to expand, its also limited by its licensed extruder code. GT is the next iteration , at first it will be a post processing facility to load GM projects and reextrude them into stl's that are closed manifolds so that 3d printers will accept them
directly. It uses my own extruder code with no size limitations other than memory. Slowly it will grow to replace GM's functions with more intuitve and more powerfull ones. It will be released in alpha just for the use of creating stl's to print from in about a month or so I think. Its a new GUI, framework and class structure that shoudl be much more friendly for expansion. Its much like the day I had to dump Mach2 in favour of a more expandable mach3. Only this time the result will slowly take over, with functions added over time as we find we need them.

Thx
Art

[ArtF]

Ohhh, a photo of the gear in GT..

Art

[John S]

Opened the spiral bevel in cut 3D no problems, tooth shape looks good, same as yours.

However it machines lob sided ?



I know Cut3d can do them as i have actually cut them before.

http://www.youtube.com/watch?v=RV8Dq6mslnE

[ArtF]

John:

That picture looks weird to me for some reason.. I have cut3d and havent tried it on them.. Ill let you know what I find..

Art

[Ken_Shea]

Art,
That file loaded perfectly but cam in at almost 1700mm in diameter  :D

[ftkalcevic]

Slic3r liked it although I had to flip it in an external program.  No warnings.

This took 2 hours to print.  Scaled to 50%.  Those peaks are a bit of a mess.  Now I just need an extruder that dispenses white chocolate!

[ArtF]

Wow, not bad. ( Ken: sounds like it expected inches but got mm's? )

  One of the things about stl's is they arent metric or imperial, but simply numbers. Many go from
-1 to +1 and you scale to suit..gears woudlnt work well that way, so I put them out in mm's as a size
as printer people tell me almost all printing software is in metric primarily. Prcoessing software cares
not at all and is simply in units..

  Now those peaks will get taken care of. I figured out last night my scaling may be off on the teeth,
I have to look into ensureing the proper cone angles are being adopted, the teeth on my sample
look too high in the inside ring to me.. I'll be checking it today. Its a rather extreme gear, but wrong I
supect.. Ill let you know how that turns out.

  But I'm gratified to know it printed..thank you for the photo. :)

Art

[ArtF]

John:

  Im thinking my scaling routine may not be scaleing the tooth heigth properly over the cone length, those tips look a bit sharp.
Im mullingover a correction. :)

Art

[ArtF]

John:

 Yes, my math was screwy. :)

Ive deleted that helical bevel, its teeth were way too tall in the cone. Here is a better example of a helical bevel with proper tooth scaleing.

For those with bevel interest, take note that there are a few ways of generating bevels. A few differing "standards". Some , for example, some say the tooth
form of a bevel should basically be the spur gear outline when looked at from the outside face, the teeth should then twist and scale so everything terminates
at the imaginary cone apex. Other standards call for the center of the gear to be the spur gear tooth and the tooth scales outward to the outter face, and inwards to the
cone apex. ( This means a pinion of less facewidth would mesh in the respective center of the opposing wheel with empty teeth on each side. Ive opted for the original spec which
forces all bevels to mesh at the outside edge. So if a pinion of facewith 5 is meshed to a wheel of facewidth 10, the wheel and pinion woudl mesh from back edge
to center of wheel leaving the inside 5mm unused. ( If thats understandable.:-) )

 Here is a sample of a much better helical bevel and should be like most bevels you could purchase. In theory this bevel should mesh with any
OEM bevel of the same angle and module. It properly scales the teeth in respect to addendum and dedendum unlike the previous sample that made sharp
peaks on the top edge.

Thx
Art

[ArtF]

Hi Guys:

  Just an update..

  Just got notified my 3d printer will be shipped on Monday. ( Finally), so by next weekend I should be able to show some photo's of how the new stl's print.
Im getting closer to an alpha release of Gearotic Thoughts, which at first will be usefull primarily for 3d printer users, but will grow to eventually add more
functions and a better GUI to the general user of GM.

Thx
Art

[ftkalcevic]

Which printer are you getting?