DIY CNC Camgrinder

My machine runs on linear slides, no problem.

The mathematics for designing a cam lobe for rocker arms or buckets involves the exact same code.

The difference is in simulating flexibility. That used to be approximated by the "Polydyne method" , but no one does that these days.

I can't imagine building a machine from scratch being economical. Casting your first bed will cost at least $20K let alone machining etc. Making a spindle?

There are some beautiful grinders out there, both manual and CNC to use as a platform. There was a Studer that is still on my "one that got away" list. I paid for it and when I went to make arrangements to have it moved he gave me my money back.

I live in New Zealand.. I cant pop down to the local store and pick a second hand one off the shelf. There were very few to start with of over here and as time marched on, they have become very scare. Besides, I only want a 500 mm bed which is big enough for GS1000 cams. .

I am busy ordering linear bearings as most CNC machines uses these today. I'm going to experiment with either granite blocks or, something I have wanted to try for a while, is cast iron swarf in an epoxy. I have a few bucket loads waiting here to try.

Either way I'm sure the grinding can be tuned, if need be, to speeds and feeds outside resonance areas.

PS There was no cast iron beds in the video I posted and they seem to get reasonable results so I will just use a bit of common sense in what I use.

I anyone knows about Polydynes I would appreciate a hand with some modeling.

The path to success in modern cam design is to write a software that models the shape of the acceleration curve first.
Then integrate to get a velocity and lift curve.
Then write a solver to adjust the dimensions of the acceleration curve until velocity and lift = 0.0 at the end.
Then optimise to get the dimensions you desire.
Then analyze in a CAD/CAE software, it would be a lifetimes work to come close to what they do now.

It would appear that you want to block any progress forward. EG $20K cast iron blocks or Lifetime work to come close.

Can you make some practice suggestion on going forward. We are all on this list because we work outside the square. Helpful comments would be appreciated.

marsheng wrote: It would appear that you want to block any progress forward.

He was talking about CAM software, not a cam grinder.
I see no reason why building a decent cam grinder would be impossible, it is a machine, so it should be doable as Andy proved on the video attached a while back on this topic. Producing the gcode for it might be a challenge, but since i have no experience with cam grinders, i can not offer more help.

I don't think its a Gcode issue at all.

Get the maths right in a custom component that outputs a count for X axis external offsets based on Z axis radial position and it will look after itself. eg at this point on the circle, the grinder needs to be offset by n millimetres.

Hope I got the axes right!