V-bit doesn't work?!

[Dan]

An interesting approach to cut miniature gears using a slitting saw:

https://www.youtube.com/watch?v=rgv0q23Bx0Q

Don't know how it works as the slitting saw seams to be cutting sideways as well, while it is only designed to cut forward...

Dan

[ArtF]

I suspect its a very fast in and out motion, its too small to see the resultant alias marks. Its a grea technique, but only for microminiature gears I suspect..

Art

[Nate]

Don't know how it works as the slitting saw seams to be cutting sideways as well, while it is only designed to cut forward...

As long as the chip load is small enough, it shouldn't be that different from cutting into a tilted surface.

[Dan]

Dan:

  I had a request for tapered bits for that reason. I will try to add this in the fall, I think I can do it just by correcting for the
angle of the taper. In actual fact a 20% taper will produce a PA of 20 by natural math.. so I know it will fit in there somehow.
Wont be till Oct. time frame though.

Thx
Art

Hi Art,

Are you going to work on adding this?

Thanks,
Dan

[ArtF]

Dan:

  This one Im looking into as well.

Art

[ArtF]

Hi Dan:

  Ive finished investigating issues with allowing VBits and such, the problem is twofold, first, the program is no longer using
involution theory for toolpaths, it now uses graphics so that its compatable ( as much as can be) with other tooth forms,
from pulleys to Epi's. ).
  This means I cant simply zero out the pressure angle or convert it because the shape is already identified as the
target tool touch locations. This means at best a non flute shape would touch on the tangent point of the shape,
but wouldnt actually shave anything else. Not much of a solution Im afraid. Gearotic 1.0 used involution to calculate
a tooth, it could actually have done the job, trouble is it was good only for involutes, no other shape.

  I have though modified the program for next release, if you use a tapered bit, it will compute the tangent points
from the bottomflat location of contact. This means in theory you can use a tapered bit with less than pressure angle
taper to get a proper profile. It could help with small tools, it isnt really tangental shaving though
unless its a straight flute...

Art

[Dan]

Hi Art,

Can't say I understand everything you said ;) , just think you're saying it can't be done... but with a V-bit who's taper angle smaller than the pressure angle it could be done - that's exactly what I was wanting.

Dan

[ArtF]

Dan:

  A bit hard to explain. While you can as of next update use a tapered bit ( or a vbit ) in the algorithm, it isnt really shaving an
involute, the angle of the bit will not raelly shave, so long as its lower than pressure angle it may not gouge, but it will make the shape
point by point up the curve. It may work for you, but its not a proper shaving, Im not so sure the result will be pretty. The curvature between segments will not be correct.. since the algorithm is based on graphics, not involution math, I cannt change it to suit that type
of bit properly....

Art

[Dan]

Art,

What do you think about this method:

https://www.youtube.com/watch?v=_LYaMqaUpqw

The "shaving" is achieved by the tool moving radially and not along the X axis.

Dan

[ArtF]

Dan:

  That ones a bit of a cheat isnt it? lol..

I see from the videos that definitely allowing tip inwards is a good idea, that one Im looking into doing now,
Ill give some thought on the rest..

Art

[John S]

Gearotic 1.0 used involution to calculate
a tooth, it could actually have done the job, trouble is it was good only for involutes, no other shape.

 
Art

I really loved Gearotic 1.0
Pity it couldn't have co existed alongside 2.0 as all many want to do is just involute teeth.
No fancy tickers, let the Lucas Pacemaker take care of those  :D

[ArtF]

John:

  It does exist and can run alongside. Check the downloads page, its there for download, just unzip to the gearotic
folder and make an icon for it...

Art