We started to have some accuracy issues with our machine.
After slotting on top of the part we have 93,2 mm, on the bottom we have 92.7 mm. Height of the part is 80 mm. We are using Revtool slotting tool with fresh 16mm width insert so I assume this problem is not tool related. On other parts with different tools we had same problem with top being wider than bottom.
- Regarding on top of the parts is 93.2 , on the bottom is 92.7mm , it mean slotting (Ram) moving into inner hole is tilting 0.5mm/80mm , the possible reason caused by clamping fixture (3 Jaws chuck .. ) or work piece . You can open backward flywheel cover and switch speed lever to 0 disengage (left step of 1 , see the below video ) , then use hand to move the Ram slide from top to bottom and checking the vertical between Ram and work piece by dial gauge , If you use dial gauge to test Ram running manually from top to bottom is not within +/-0.03 mm , you need to find the error between clamping fixture perpendicularity and Rotary table surface.In our experience , the problem may be caused by work piece not install vertical with rotary table surface , so finished work piece top and bottom size is different.
Please understand that hard jaw can’t make sure perfect vertical with chuck base , if you need very accurate , you need use soft jaw and turning the soft jaw to make sure the jaw was vertical with chuck base.
- The Ram movement is tilting backward about 0.01-0.04mm/300mm base on rotary table surface , while you set tool direction No.1 , the cutting force on Ram guide way backward, The Ram will tilting forward a little 0.01-0.04mm, so the real ram running up to bottom will be straight. The Ram running perpendicularity (vertical) is according to rotary table surface. You need to check and confirm after clamped work piece is perpendicularity (vertical) with Rotary table .
- Please also check the clamping position is absolute stable , some customer clamps his work piece at few length or clamping not perfectly, so while real slotting process , the work piece moving due to cutting force.
Here we send you simple video about how to test work piece vertical with Ram moving or not :