CAD CAM EDM DRO - Yahoo Group Archive

Re: [CAD_CAM_EDM_DRO] Cam making....

on 2007-03-24 08:53:48 UTC
Hi Ian,

as a second thought i would forget the manual method of drafting and scanning and draw the cam in Autocad. Many years ago i used autocad to produce cams for Swiss Auto lathes.You should be aware that the min rad on the cam must be greater than the cam follower, My approach would be to calculate the rise's and falls and the angle then draw these on autocad from x0,y0 ie Line, 0,0 to @length<angle. then join all the end points wit a polyline using the Fit option be careful this may cause true position of the thro of the can to be outside the true path. (only Pedit the parts of the line that require it if you have true dia's in the path leave these alone)make the path up of several polylines if need be.

Neville

NEVILLE WEBSTER <nevillewebster@...> wrote:
hi ian,

you could try PEDIT pick the line then use FIT as the option this will smooth the polyline but keep all the critical highs and lows

Good luck

Neville

xj5373 <ian.c.haynes@...> 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

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Discussion Thread

xj5373 2007-03-24 08:20:49 UTC Cam making.... NEVILLE WEBSTER 2007-03-24 08:27:46 UTC Re: [CAD_CAM_EDM_DRO] Cam making.... NEVILLE WEBSTER 2007-03-24 08:53:48 UTC Re: [CAD_CAM_EDM_DRO] Cam making.... NEVILLE WEBSTER 2007-03-24 09:18:27 UTC Re: [CAD_CAM_EDM_DRO] Cam making.... NEVILLE WEBSTER 2007-03-24 09:51:40 UTC Re: [CAD_CAM_EDM_DRO] Cam making.... Mark Vaughan 2007-03-24 10:56:54 UTC RE: [CAD_CAM_EDM_DRO] Cam making.... Alan KM6VV 2007-03-24 11:35:17 UTC Re: [CAD_CAM_EDM_DRO] Cam making.... xj5373 2007-03-24 15:03:56 UTC Re: Cam making.... Peter Reilley 2007-03-24 16:39:12 UTC Re: [CAD_CAM_EDM_DRO] Re: Cam making.... Mark Vaughan 2007-03-25 05:37:45 UTC RE: [CAD_CAM_EDM_DRO] Re: Cam making.... BRIAN FOLEY 2007-03-25 09:18:18 UTC Re: [CAD_CAM_EDM_DRO] Re: Cam making.... David G. LeVine 2007-03-25 13:16:47 UTC Re: [CAD_CAM_EDM_DRO] Re: Cam making....