In terms of drilling cycle selection, we generally have three choices: G73 (chip breaking cycle), G81 (shallow hole cycle) and G83 (deep hole cycle). So the question is: is there a more optimized method?
It is a good choice to use G73 when processing hard-to-break materials, but other working conditions are good when there is no spindle center (water) cooling.
This cycle will break the chips after a short dwell time or a small retraction distance, but it requires the drill bit to have good chip evacuation capabilities. A smoother chip discharge groove will allow chips to be discharged more quickly, avoiding interference with the next drilling. The chips become entangled, destroying the quality of the hole. Using compressed air as auxiliary chip removal is also a good choice.
When the machine is equipped with central spindle cooling (water outlet) and the tool also supports central cooling (water outlet), it is the best choice to use G81 to process the holes.
The high pressure coolant will not only remove the heat generated during drilling, but also lubricate the cutting edge faster. The high pressure will also directly break the drilling chips, so the small chips generated will be discharged. The hole is synchronized with the high pressure water flow. It avoids tool wear caused by secondary cutting and reduces the quality of the machined hole. Since there are no problems with cooling, lubrication and chip removal, it is the safest and most efficient solution among all. the three drilling cycles.
If working conditions are unstable, using G83 is the safest choice.
Deep hole machining will cause the drill cutting edge to wear too quickly because it cannot be cooled and lubricated in time. The chips in the hole will also be difficult to evacuate in time due to the depth. The chip flute blocks the coolant, not only will this greatly reduce the tool life, but the chips will also make the inner wall of the machined hole rougher due to secondary cutting, creating a vicious cycle.
If you raise the tool to the reference height -R every time you drill a small distance -Q, it may be more suitable when processing near the bottom of the hole, but it will take a long time when processing the first half of the hole. hole, resulting in unnecessary waste.
Is there a more optimized method? Here are two G83 deep hole circulation methods.
1：G83 X_ Y_ Z_ R_ Q_ F_
2： G83 X_ Y_ Z_ I_ J_ K_ R_ F_
In the first method, the Q value is a constant value, which means that from the top to the bottom of the hole, the same depth is used each time for processing. Due to the need for processing security, the smallest value is generally selected. , which also means minimal metal removal rate and considerable loss of processing time.
In the second method, the depth of each cut is represented by I, J and K respectively. When the working conditions at the top of the hole are good, we can set a larger I value to improve the processing efficiency; When the working conditions in the middle of the hole are average, we use a gradually reduced J value to ensure safety and efficiency. When the working conditions at the bottom of the machining hole are severe, we set the K value to ensure the processing safety.
In actual use, the second method can increase your drilling efficiency by 50% and costs nothing!
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