Re: [CAD_CAM_EDM_DRO] Cam making....

Hi Ian,

Just a thought, if you have the CAD program, draw the cam directly!
What do the curved surfaces look like? Are some of them simple parts of
circles? Are there simple tangents between the arcs? All simple enough
to draw. Even if you have to approximate arcs with curve fitting; I'd
think you'd be able to very accurately draw the shape of the cam. After
that, I'd suggest using a rotary table and milling the outline of the
cam as a rotated surface.

Cams for the model V-8s and other small gas models rely on a cam
following fixture to grind cams. they use a grinding wheel in the last
steps to finish off the hardened cam.

I'd suggest checking with the I.C. lists, or BAEM. I'm no expert on cams!

Alan KM6VV


xj5373 wrote:

>Firstly, many thanks for all the help with the ELCB problem.
>
>My miller spends a lot of its time making patterns for lost wax
>casting parts for obsolete engines mainly associated with Morgan
>Three Wheelers and now and then the odd exotic motorbike.
>Latest idea is to make cams. A colleague is planning to draw the cams
>5 times life size on paper (probably a bit of magic goes into this
>step....) so step one is to scan the drawing into the PC and get a
>JPG. I then want to convert to a CAD file so have come across IMG2CAD
>which allows me to convert the scan to a DXF file. This then is
>loaded into my copy of Autocad LT. The cam shape is a 3D polyline and
>if you zoom in it is pretty bumpy. The plan then was to scale the
>drawing back to normal size then feed the DXF file into Mach3 to
>generate the G code. A dry run indicates that all this works but I
>would like to smooth the polyline in Autocad LT before sending it to
>Mach3.
>My knowledge of Autocad is limited at best and I have had a poke
>about looking for a command that will allow me to smooth the polyline
>but so far no luck.
>Does anyone have any advice on smoothing my scanned polyline cam
>profile in LT or even a better idea on how to go about this?
>Thanks
>
>Ian
>
>