Help with sweep

i projected a curve onto a cylinder.
when i sweep cut a rectangular profile, it rotates the profile.
i need it to stay in the same orientation as the start location for
the entire length of the curve.

the curve is a cam path projected onto a cylinder
the profile is a rectangle shape

 

Mike

A scroll cam huh. Don't even bother with a sweep. Make a sheet metal flat
pattern, roll it up, and fill up the spaces. This is better in several ways.
It's easiesr, more mathematically accurate, and you have the flat pattern
for programming the CNC.

Most CNC controls support "A axis mapping". This is a method where the cam
profile is programmed as if it were flat (unwrapped). A special line of code
is used to "wrap" the program onto a cylinder of a given diameter. This
method produces much better results, than four axis contouring, for things
like cams.

Regards

Mark

 

Muggs,

The method I use is kinda backwards from what I posted...(sorry).

What I usually do extrude a circle of less than 360 deg. (359.9 or so) as a
thin feature. I apply a thickness to it equal to the depth of the acutal cam
features. Then I "unroll" it by applying a sheetmetal feature using one of
the the edges on the seam (.1deg gap).

After I flatten it out I apply the cam features. For instance, a 30 deg slot
will equal a 30 deg helix etc. I save it in this form as a machining
configuration. Then I'll switch back to the default config., roll it back
up, and finish detailing the part for the assembly.

Regards

Mark

 

Muggs,

The method I use is kinda backwards from what I posted...(sorry).

What I usually do extrude a circle of less than 360 deg. (359.9 or so) as a
thin feature. I apply a thickness to it equal to the depth of the acutal cam
features. Then I "unroll" it by applying a sheetmetal feature using one of
the the edges on the seam (.1deg gap).

After I flatten it out I apply the cam features. For instance, a 30 deg slot
will equal a 30 deg helix etc. I save it in this form as a machining
configuration. Then I'll switch back to the default config., roll it back
up, and finish detailing the part for the assembly.

Regards

Mark

 

Here are examples of that method. It's easiest if the cam is cut into the
end of a cylinder. Making it in the middle kind of complicates this
process a bit.

http://myfilelocker.comcast.net/mlombard/SWParts/shetmetalcam.zip

Of course if you do a lot of this, you would be better off going to
Camnetics.com and getting you some software that does all sorts of cams
just by punching in the numbers.

 

Thank You Mark,

That works pretty nice!

Muggs