【转帖】block with helical slo

yang686526

block with helical slot
hi,
i am trying to get a helical cut in my model and the problem is that i want the profile of the cut to remain vertical while it follows the helical path (just like it would be manufactured i.e. the tool is stationary while the part rotates and translates).
tried to adjust the settings of the swept cut, but wasn't able to get a cut that would represent the actual part. i have the part file attached and would highly appreciate any suggestions.
thanks,
mike

this is basically the only application of the swept solid functionality added in sw 2008.   
-handleman, cswp (the new, easy test)
i tried using the swept solid functinality by creating a multibody part, but solidworks '08 just would not accept the part to create the sweep cut. the part i made was a long cylindrical part with a round base.
since the sweep cut is very new there are pretty strict conditions on how you have to set up the sweep.  did you follow the help instructions carefully?
-handleman, cswp (the new, easy test)
the 'cutting tool' has to be in contact (interfering) with the part being cut.

my guess is you missed this:
quote (sw help):
for cut sweeps only, when you select solid sweep, the path must be tangent within itself (no sharp corners) and begin at a point on or within the tool body profile.
-handleman, cswp (the new, easy test)
hi,
thanks for the replies. tried it again and this time it worked (attached file & was missing the interfering condition). but the problem still persists i.e. the profile of the hole is still the same as it is with a 2d profile cut. can't seem to figure out how i can get a cut resulting from the tool being stationary and the part translating and rotating.
i took a quick look at your file and found the solution. i first looked at your solid swept cut, and though that you could just change the path alignment type in the options to minimum twist, but that didn't work. i then supressed the swept cut, started a new 3d sketch, selected the helix in the feature tree, and hit convert entities. i went and created a new swept solid cut using the ball nose cutter solid, and the 3d sketch path, and selected minimum twist. this gives you the results you are looking for. i believe since the helix has a inherent normal that does twist, keeping minimum twist will still have it follow this normal, but if it is a simple 3d sketch curve, the cutter will stay normal to its profile with minimum twist selected.
rfus  
file:
mike,
is that really what you want?  vertical sides?  that's not what will happen when you machine the part in the way you describe.  as i understand it, you want the final shape to be the result of holding the cutter in the position you've modeled it in and then rotating the part about the z axis while simultaneously rotating the part about the z axis.  i hope you don't expect that result to be different from the second model you posted.  if you follow rfus's post you will get what you say you want, but that is not the result of the operation you describe.  it would be the result of holding the cutter still and moving the part along the x and z axes while simultaneously moving away from the cutter in the y axis then moving back to the original y position.   
-handleman, cswp (the new, easy test)
thanks rfus!....your idea of creating a 3d sketch from the helix worked fine.
the cutter will remain stationary in verical position, while the part will translate about z, rotate about z, and also translate about y.
now what in the actual operation will decide the twist of the cut. the angle of the cutter is the only factor that will change the twist, so keeping minimum twist will imply keeping the cutter fixed in vertical direction. i think the part should come out close to the model.