[smw19822002]

Hi SMW - Have you flipped parts before? When you do this the error is potentially twice the "clearance" in the fixture. Have to use chamfered pins or registers that are very tight to get correct registration both sides. Sorry no pics to look at. Peter

No I haven’t but I was wondering if that could be a potential issue. I’m using some of the cam screw type clamps and torquing the right one down first so it pushes the part to the left locking it against the fixture first. I do indicate each one since it’s a converted G0704 mill. Hasn’t really shown me that I need to but still just another double check.

[mactec54]

No I haven’t but I was wondering if that could be a potential issue. I’m using some of the cam screw type clamps and torquing the right one down first so it pushes the part to the left locking it against the fixture first. I do indicate each one since it’s a converted G0704 mill. Hasn’t really shown me that I need to but still just another double check.

If you interacted the hole X0Y0 and the chamfer is off with that hole, then it has to be in the program

[dazp1976]

If you interacted the hole X0Y0 and the chamfer is off with that hole, then it has to be in the program

Either that or, that is the backlash in the machine showing up.

No I haven’t but I was wondering if that could be a potential issue. I’m using some of the cam screw type clamps and torquing the right one down first so it pushes the part to the left locking it against the fixture first. I do indicate each one since it’s a converted G0704 mill. Hasn’t really shown me that I need to but still just another double check.

When you did both sides. Did you zero your WCS for X from the same table side (ie left side / corner)?.
If you do so, one of the sides will be against the backlash of the machine. If you have say 0.002" backlash in the machine this would show up on ONE of the sides.

When you flip it you should do for example..... on side 1- come in with cutter from bottom left corner.... flip it...... then come in from bottom right corner on side 2.
This means your cutter will be coming in from the SAME position for both x+y on both sides. If you've done it right, the spindle will have past any mechanical baclash when you set your starting position on each side.

If my dodgy explanation makes any sense to you.

[mactec54]

Either that or, that is the backlash in the machine showing up.



When you did both sides. Did you zero your WCS for X from the same table side (ie left side / corner)?.
If you do so, one of the sides will be against the backlash of the machine. If you have say 0.002" backlash in the machine this would show up on ONE of the sides.

When you flip it you should do for example..... on side 1- come in with cutter from bottom left corner.... flip it...... then come in from bottom right corner on side 2.
This means your cutter will be coming in from the SAME position for both x+y on both sides. If you've done it right, the spindle will have past any mechanical baclash when you set your starting position on each side.

If my dodgy explanation makes any sense to you.

If you indicate a hole ( X0Y0 ) the Backlash if any, would not be the cause of this much shift in cut

He needs to check his drawing to see where the problem is

[smw19822002]

If you indicate a hole ( X0Y0 ) the Backlash if any, would not be the cause of this much shift in cut

He needs to check his drawing to see where the problem is

I thought that to and I honesty can’t find anything in the model wrong but there is always a chance that I am overlooking something so I am going to take a look again this evening

[smw19822002]

I thought that to and I honesty can’t find anything in the model wrong but there is always a chance that I am overlooking something so I am going to take a look again this evening

Finally had a chance to go back over this thing. So i studied my model as close as I could and cannot find that the 0 point is wrong or offset to one direction. Chamfers in the simulation look to be even all the way around.

Completely removed the fixture and trammed the head. The head was out about .002 in the X direction and about .001 in the y direction. I adjusted the X but didn’t bother with the Y. I’m not making super critical parts so being out that little bit is never going to hurt anything not to mention it is a pain to adjust that column. After it was all done I checked it with the indicator and it is .0005-.001 out in a 6 inch circle in the table so I’m pretty happy with that.

I put the fixture back on and re-ran the same code just to see that it’s still the same result.

I appreciate all the input you all provided but I’m not really sure where to go from here.

[smw19822002]

Either that or, that is the backlash in the machine showing up.



When you did both sides. Did you zero your WCS for X from the same table side (ie left side / corner)?.
If you do so, one of the sides will be against the backlash of the machine. If you have say 0.002" backlash in the machine this would show up on ONE of the sides.

When you flip it you should do for example..... on side 1- come in with cutter from bottom left corner.... flip it...... then come in from bottom right corner on side 2.
This means your cutter will be coming in from the SAME position for both x+y on both sides. If you've done it right, the spindle will have past any mechanical baclash when you set your starting position on each side.

If my dodgy explanation makes any sense to you.

I did I use the same side for both operations. The closest left on side 1 and the hole on the left on side 2. I did think also that the backlash might be getting me so I re-ran the same code with the backlash turned off and still have the same result.