Router 2600 Pro
1/4" ball nose end mill
Do you know why we get this type of machine marks on the left side of our CO2 dragsters and F1 cars? It is really strange. The Pitsco blanks are off by .5mm on the 42mm width. The y-offset is ok.
We have been machining the cars using 2 machining plans (raster roughing at 80% and raster finishing @ 10%).
Any thoughts?
Uneven cutting with Router 2600 Pro
Moderators: Martin, Steve, Mr Magoo
Uneven cutting with Router 2600 Pro
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When you are roughing the tool may be flexing slightly due to the bigger cut or billet deflection.
When you are doing the roughing cut in the cut plan set the finishing allowance to 1mm.
This will leave a minimum thickness of 1mm over the model to be removed by the finishing pass (where finishing allowance is set to 0)
If you do this it should resolve the problem
When you are doing the roughing cut in the cut plan set the finishing allowance to 1mm.
This will leave a minimum thickness of 1mm over the model to be removed by the finishing pass (where finishing allowance is set to 0)
If you do this it should resolve the problem
If the cutting tool is flexing on the Roughing pass, you may need use a larger diameter tool.
You will need 4 separate .fnc files for each car, Roughing RHS, Finish RHS, Roughing LHS & Finish LHS.
You will need to have 2 Work Offsets created, Roughing & Finishing, X & Y would be the same but the Z would be different.
On our Compact 1000,
X=-265.000, Y=76.400, Z=-35.400, would be the Roughing Work Offset
X=-265.000, Y=76.400, Z=-38.400, would be the Finishing Work Offset
This would leave 3mm of material for the Finishing pass to remove. Adjust the Z offset as needed.
To run this setup using the same cutting tool;
In Quick CAM 3D, go thru the whole process like usual and select the Roughing Plan and name the file “Roughing RHS”.
Go through the process with all the same settings than choose the Finishing Plan and name it “Finishing RHS”
In VR Milling, open the Roughing RHS.fnc file and Activate the Roughing Work Offset. Run the file.
Then open the Finishing RHS.fnc and activate the Finishing Work Offset. Run the file.
You will then have to add the Mirror code to each file and “Save As” LHS files and repeat the steps above changing the Work Offsets for each of the LHS files as you run them.
DO NOT adjust any numbers in the “Machining Boundary” area (Min. or Max.)
“Step Down” adjusts the depth of cut for each pass of the cutting tool
In the Roughing Raster Machining Plan, you can change the “Finishing Amount” (lower left of window) to leave a couple of mm’s of material for the finishing plan to remove.
This would be easier than the extra fnc files and Offsets.
After the tool paths are “Calculated”, they are shown as white lines over the model. With your mouse you can zoom in/out and rotate the model and you can see how close the tool path is to the model. In the “Roughing Raster”, try 10mm Step Down and 5mm for Finishing Amount, rotate and zoom in looking at the back of the model. Then do a “Finish Raster” plan and the tool path lines will projected closer together and closer to the model. Delete those 2 plans and then try 15 for the Step Down and 3 for the Finishing Amount. You’ll see the difference in the tool path lines. Then add the Finish Raster plan and look at the lines, notice the difference.
With the Roughing Plan set at 10mm Depth of cut, you can see 3 different levels of tool paths as it goes down into the block. With the 15mm Depth there are only 2 levels.
On both of theses, the paths are far apart.
With the Finishing Plan, there is only 1 tool path down very close to the model and the paths are very close together.
It helps to “Extend Toolpath” in the X & Y by about 20mm each before you get too the Machining Plan just for DEMO purpose.
This will move the “dark sides” of the billet out, away from the model so you can zoom in and see the tool paths
You will need 4 separate .fnc files for each car, Roughing RHS, Finish RHS, Roughing LHS & Finish LHS.
You will need to have 2 Work Offsets created, Roughing & Finishing, X & Y would be the same but the Z would be different.
On our Compact 1000,
X=-265.000, Y=76.400, Z=-35.400, would be the Roughing Work Offset
X=-265.000, Y=76.400, Z=-38.400, would be the Finishing Work Offset
This would leave 3mm of material for the Finishing pass to remove. Adjust the Z offset as needed.
To run this setup using the same cutting tool;
In Quick CAM 3D, go thru the whole process like usual and select the Roughing Plan and name the file “Roughing RHS”.
Go through the process with all the same settings than choose the Finishing Plan and name it “Finishing RHS”
In VR Milling, open the Roughing RHS.fnc file and Activate the Roughing Work Offset. Run the file.
Then open the Finishing RHS.fnc and activate the Finishing Work Offset. Run the file.
You will then have to add the Mirror code to each file and “Save As” LHS files and repeat the steps above changing the Work Offsets for each of the LHS files as you run them.
DO NOT adjust any numbers in the “Machining Boundary” area (Min. or Max.)
“Step Down” adjusts the depth of cut for each pass of the cutting tool
In the Roughing Raster Machining Plan, you can change the “Finishing Amount” (lower left of window) to leave a couple of mm’s of material for the finishing plan to remove.
This would be easier than the extra fnc files and Offsets.
After the tool paths are “Calculated”, they are shown as white lines over the model. With your mouse you can zoom in/out and rotate the model and you can see how close the tool path is to the model. In the “Roughing Raster”, try 10mm Step Down and 5mm for Finishing Amount, rotate and zoom in looking at the back of the model. Then do a “Finish Raster” plan and the tool path lines will projected closer together and closer to the model. Delete those 2 plans and then try 15 for the Step Down and 3 for the Finishing Amount. You’ll see the difference in the tool path lines. Then add the Finish Raster plan and look at the lines, notice the difference.
With the Roughing Plan set at 10mm Depth of cut, you can see 3 different levels of tool paths as it goes down into the block. With the 15mm Depth there are only 2 levels.
On both of theses, the paths are far apart.
With the Finishing Plan, there is only 1 tool path down very close to the model and the paths are very close together.
It helps to “Extend Toolpath” in the X & Y by about 20mm each before you get too the Machining Plan just for DEMO purpose.
This will move the “dark sides” of the billet out, away from the model so you can zoom in and see the tool paths
I dont understand why you use the the different roughing and finishing offsets. 
Simply allowing a 1mm finishing allowance on the roughing pass will resolve the problems.
Raising the z offset will leave 3mm material on the top of the part but not change anything down the sides
The tool will still touch and make the marks 
The flexing I mentioned was partly due to the tool but mainly the material.
When taking a bigger cut the tool is pulling the material towards it and can leave marks as shown above.
The finishing allowance option will leave 1mm over the whole surface of the model (effectivley scaling it up 1mm) so while the makrs will be visible they will be removed by the finishing pass.
Simply allowing a 1mm finishing allowance on the roughing pass will resolve the problems.
Raising the z offset will leave 3mm material on the top of the part but not change anything down the sides
The tool will still touch and make the marks The flexing I mentioned was partly due to the tool but mainly the material.
When taking a bigger cut the tool is pulling the material towards it and can leave marks as shown above.
The finishing allowance option will leave 1mm over the whole surface of the model (effectivley scaling it up 1mm) so while the makrs will be visible they will be removed by the finishing pass.