I have a 35-sided wheel and I need to extrude 5 evenly-distributed spokes. Since 35 is evenly divisible by 5, there are 5 normals in the wheel that give the exact angle of each of the 5 extrusions. Unfortunately none of them line up along any standard axis.
How can I extrude along those 5 normals?
I don’t think that the extrude along normals function is in blender yet. It would make a really great and useful feature though.
In the meantime I can suggest a couple possible workarounds.
The messiest way would be to scale the extrusions away from the center of the wheel, then scale each extrusion down to the size you want. however, thats really iffy and time consuming.
A better way I can think of would be to extrude one spoke. Then select the spoke and use the spin function to duplicate it around the center.
360 degrees and 5 steps should do the trick. Just remove doubles afterwards and get rid of the faces that will end up inside the mesh.
hope that helped 
extrude -> esc -> alt s will extrude along normals
GreyBeard
Hmm, I think I’ll backtrack and try the Alt-S trick.
I actually liked the SpinDup idea better, because I had one nice spoke built. In practice however it doesn’t work because I’ve never been able to get Blender to find the center of a circle. I’ve tried several different methods, but spindup is never able to get the spokes lined up correctly to the original wheel that I built.
If there’s a trick to finding the correct center of a circle, it could come in handy. What I’ve done is to take evenly spaced verts and Alt-M merge them to the center but that did not find the correct center for SpinDup. Then I tried taking those verts and scaling them to 0.0 which should also be the center but that doesn’t work either. 
So, Alt-S will have to do for now.
wow cheers greybeard, didn’t know that, that makes life a little bit easier
for multiple faces there is script in the python forum… not sure if has been updated? “extrude along normal” selects faces even if next to each other as individual faces, …uvsphere becomes a spikey ball etc.
hmm, alt-S is the shrink/flatten function. I thought that acted more like scale along normal whereas extrude along normal would be making a straight extrusion along the normal. Its still really useful, but I don’t think its exactly what he was looking for. For a circular object, Alt-S would have the exact same effect as scaling away from the center of the circle.
Are you sure the spindup method isn’t working? I tried it with a simple test and it worked fine. (just read my previous post, it should have been 5 steps, not 6 
)
I’ve never been able to get Blender to find the center of a circle
do you mean that center new no longer resolves to the center of the circle beacuse of uneven detailing (ie-the spoke)? You can try just selecting the original circle and snapping the cursor to the selection. Was the base circle itself modified? because that would throw the spin off. maybe showing a screenshot of the thing in editmode would help.
The spinDup function per se, worked fine. But, if you can’t find the correct center of the circle, then spinDup only makes a mess of things.
After finishing the wheel with alt-S, (which the documentation erroneously says only works for curves), I went back and tried the spinDup method again, using your method of finding the center of the circle. It worked! I didn’t realize you could snap to a selection of multiple verts and it would find the center. So what I was doing, (select the circle, shift-D, esc, alt-M to center point, snap cursor to selection), for some reason was coming up with the wrong center point for my spinDup. Simply selecting the circle and using snap cursor worked much better for some reason.
Or, maybe I was selecting some stray ‘behind’ verts. That happens to me all the time, and it’s really aggravating. I wish blender would just select the front vert all the time instead of randomly selecting verts in back that I obviously don’t want. Here’s a screen shot of my wheel. You can see from the depth of the wheel how in front view it would be easy to select the wrong vert from a stack of verts and not notice.
nice to see that it worked
Also, if you find it difficult to select things like you said, you could hide unnessential parts of the mesh (H key). Just unhide after you’re done (alt H)
good job and nice looking model.
zdk1:
extrude -> esc -> alt s =along normals straight out. (now anyway, never worked for me before???)
the trick is don’t move the verts or it will scale at right angles to normals.
you can LMB after extrude but carefull not to move the verts!!!
aditionally… if you have a face selected(all 4 verts) and do the above it will extrude with straight edges, but if there is no face( a tube) it will extrude and expand.
