GearHeads Corner

Is there a tutorial (video or text) that shows how to create custom spokes? 

I know the dxf files are in C:\Gearotic Motion\Spokes and I've tried editing them with various fee CAD programs like DoubleCAD XT 5.  But the end result is a spoke that does not look correct.  Instead of figuring out what I'm doing wrong, I thought it might be good to start clean and learn the correct way to create custom spokes.

My end goal is to make a swoopy spoke similar to the attached picture. 

Hi:

  If you look at a real spoke, youll find there is a part that is above a Y of zero, and part below. The spoke is broken
at that point and a shaft holde and boss inserted. So long as you understand that fact, your spokes will normally work.

  As I recall, they must also be a clockwise polygon, but Ill check that and fix it if true, I can enforce such things as that internally now.

Art
 

I have Draftsight ('cause it was free).  I use v-carve pro.  I have a couple of designs of animal outlines (sheep, my wife is a knitter) I made and can CAM from v-carve.  However, with my limited understanding of such things, I have been largely unsuccessful in creating a custom spoke that Gearotic likes (i.e., makes available -- i see the dxf file in the list but when selected it doesn't show up in the gear).  Without understanding tools that might be available within or out of draftsight, I have been left to manually creating a polyline of an image file (the only way I know to get a drawing from crv to dxf - via jpg).  I gets lots of nodes.  It might not even be clockwise (if that is still a requirement, Art), I cannot determine the direction -- i look at the properties screen and although the answer might be there -- i still don't realize it (after RTM).

I also have used Inkscape's trace function to create a polyline/polygon.  But still need to (perhaps) convert it to a polygon, and make it clockwise (if that is still relevant).

So, any suggestions (even if autocad commands -- which I've had some success "translating" into draftsight) -- to make certain it's a polygon, or make it one if its a polyline?  And to confirm and change if necessary, the direction (clockwise)?  Thanks in advance for you help.

Brian.

Brian:

Hmm, before I answer this I will finish todays development, and check the spokes to be sure Im now fixing the orientation.
Ill then get back to you with how to do it more easily..

( I love the wooden gear above, I made a similar BIG gear out of african hardwood a couepl years back.. I love the heft and feel
to such a gear, they just look nice as they are.as pieces of art..

Anyway..back to you soon on this one.

Art

Brian:

  Ive looked ( and made a small change) at the way spokes are handled. They are normal DXF's, and spokes and indicators have their own set
of rules.

  In order to subtract properly the orientation was important, it no longer is. Instead, as of next version to draw a
spoke, you should center it in the Y.. so there is as much below zero as above. .. the highest Y value will now tell the system
that this contour is the outside.. its orientation will be set accordingly, the other contours in the file will be corrected accordingly.
  The only important item is that all contours be closed contours. In vectric this means to select the contour and close it.
    When you select such a contour in Vectric, it selectes all point with one click. No need to group it..

  Try this with just making the outside have the most points in it ( the current rule inside..). The system surrently see's the contour
with the most poiints as being the outside one..

Art

   

Art,

Thanks for the instruction.  Curious about your reference to closing (join) the figure within vectric.  That I am able to do, and reliably.  And that would have been my first choice of program to use; however, I am unable to export that to dxf for use by Gearotic.  I've been trying to do that within draftsight, but have only managed to get it to 31 vectors following a fit operation (need to join) and have yet to get it to join - maybe because my drawing is scaled too big -- something I need to learn about.

I will try it again keeping your tips in mind (using a R2007-2009 ASCII format dxf) when the new version is published.

Thanks.

Brian.

Having fun.

Brian:

I use vectric for all the spokes.. I did many of them, Bob did the rest. All I do is draw a shape I like with 0,0 as center.
I then make sure the contours are closed, select them for export as dxf, and Gearotic loads them directly.. BUT, Ill bet
your doing it in inches.. Spokes are designed in metric.. that just occured to me and may be the issue. They are all scaled
of course in the program, but for example indicators all go form +1 to just under 0 in the Y.. spokes are all with 0,0 in center...

  Id try opening a spoke in vectric in metric, change it a bit and save it.. youll find pretty quick I think whatever the issue
is..
Art

Got it -- yes, inches.  And, your comment compelled me to look more closely and (re) discover I was incorrect looking to Save As for a dxf option, when I should be using Export for dxf.

Thanks.

ArtF wrote: Brian:

I use vectric for all the spokes.. I did many of them, Bob did the rest. All I do is draw a shape I like with 0,0 as center.
I then make sure the contours are closed, select them for export as dxf, and Gearotic loads them directly.. BUT, Ill bet
your doing it in inches.. Spokes are designed in metric.. that just occured to me and may be the issue. They are all scaled
of course in the program, but for example indicators all go form +1 to just under 0 in the Y.. spokes are all with 0,0 in center...

  Id try opening a spoke in vectric in metric, change it a bit and save it.. youll find pretty quick I think whatever the issue
is..
Art

Art,

I created the attached.  I've set 0,0 to center of vector.  At least one of the examples in ..\spokes\ has the machine start at lower left but 0,0 appears to be in the center of the drawing.  Don't know about clockwise or not.  The scale appears to me to be pretty much what I see in the examples.  Otherwise, I am unable to discern any differences which would prevent this dxf from being properly treated as an acceptable (other than aesthetics, perhaps) spoke.

I CAN and will wait until the next release if some of the changes you made will reduce the parameters I need to control (i.e., Gearotic will take care of more than presently in importing dxf spokes).  thanks.

Brian.

still having fun.

Brian:

  I forgot a rule.. each spoke should be 102 units tall. This allows it to be scaled without me checking for size..

Change yours to += 52 in the Y and it loads..

  It uses from +50 to -50, the rest is so it hooks into the boss and the rim...

Art

That did it.  Thanks!

Please see rendering attached.  I like the ability to tilt the angle of the spoke into the rim and shaft.  The wooden gears worked out well, but are not practical -- would need to thicken the tabs.

Thanks, again.

lol..nice..

Art

Cool!  Would you consider uploading the dxf for a retired former sheep farmer?

Kirk

from one farmer to another ...

BTW.  Based on the prototypes I cut out using this, I would modify to either remove the cutouts in the "tabs" or thicken the "tabs".  It was designed to resemble a cable stitch as much as I could make it but aesthetics maybe should yield to performance.   Also, if you want the spoke to remain "square" to the rim (yes, I know it is not called square but I didn't want to confuse myself referring to orthogonal to the tangent or some such nonsense) and the shaft, you will need to square the ends of the tabs.

Thanks for the flattery of asking for the dxf.  We have Moosehead lake nearby just not a mooselake that i know of (Moose pond, yes that I know of two around here).

Brian.