Thanks for your response Dave as I was just about to write the same thing, if you were to put a dial gauge you could move all the axis and spindle especially if I were to use a prybar I am afraid that the only thing that I would use the prybar for is to smash the machine (joking) as for reinforcing the machine at the points you have marked (Craig) I was already looking at doing this, but the gantry is very solid and believe me I have pushed very hard at where the connections are but I will reinforce it anyway just to make sure.
Thanks for the input all ideas and advice taken on board it is very much appreciated.
Alan

Acceptability is based on what you are willing to live with. If it bugs ya, fix it.

That's why they make several sizes of linear rails and shapes. All have a tolerance of their own. Most projects are based on a dream and how much money you can throw at it. A crowbar would develop much more load then most cutters would produce. But if each joint/axis gives ya .002" by just forcing it a little by the time ya get to the cutter tip it might be .006 or more. There is always a sweet spot on a machine & setup. Plus the direction of cut can seen to be better in one axis direction as to others. Learn to program with this in mind. Draw/CAD and write gcode/or CAM to optimize or take in account for what you know are issues you have learned from past projects.

If he was cutting wax it might be a perfect part. I can bet that cutting steel or aluminum it would bark like a wet dog.

As far as my machines (have three mills I built at present, have plans for one more) Each have issues of their own. So depending on the part design, depends on what machine it will go on.

Plus that's what sandpaper is good at, smoothing up little issues.

Alan, just curious and I'm sure you have checked this already with a dial indicator but are the axis moving the proper distance when commanded to? 

Can you run the same shape only keep coming up until the walls have a little step that is absolutely vertical? Or, probably even easier............... can you cut a pocket the same shape (oval) with vertical walls for a test? Make the step down the same as your using in previous programs for step over and the step over the same as well.  Make the walls deep enough so that it takes several passes to get to the finished depth....... Maybe 1/2 inch.

Brett

Hi Brett
machine does move exactly the distance programmed i.e.if I ask the machine to move 1" inch it moves 1" inch and that is the same for the "X","Y" an"Z" axis , am a bit busy at the moment but will then machine up as you have requested, do you want me to use a ball nose or end mill cutter?
Alan

The same cutter you used for the previous parts would be great.

Thanks,
Brett

Have just started machining will post a picture once it is finished
Alan

Did you say if the grooves were always along the same axis, or do they vary?
Looks like your using an offset finish toolpath. Have you tried a raster finish path?
My machine probably has far more flex than yours, and using Aspire, I've done 3D carvings at 175ipm with no issues. I can probably move my spindle close to 1/16" if I push hard on it.

I don't believe that Aspire is the issue, either. 99.99% of similar type issues you see at the Vectric forum are machine issues. I also happen to be an Aspire beta tester, so have a bit of additional knowledge there.

Am using Raster finish tool path, the grooves always seem to be in or around the same area no matter what angle I machine parts from, the parts in the pictures are machined at an angle of 90 degrees, at the moment I am machining what Brett has asked me to do which is machine a pocket into the same shape (Oval) using the same tool, I am in agreement with you on Aspire that is for sure not the problem the problem does lie within the machine somewhere but do not know where else to look at the moment hopefully when I finish machining this part Brett might have some idea.
Thanks
Alan

Brett
here is what you asked me to machine it is just under 1/2 inch deep and it has come out without any lines or marks anywhere so what does that tell you about the problem??
Alan

That the raster based software generated the waves. check your setting on resolution of the created raster file. I set mine quite high so I don't have a stair stepping effect. But I am using ArtCam when I do raster files.