System and method for controlling a feed-speed to a bandmill
A method and system for controlling a feed-speed to a bandsaw having a sawblade trained around a drive wheel and a spaced-apart driven wheel, and a strain adjustment mechanism for adjusting the strain on the sawblade by changing the spacing therebetween. The method includes sensing a change in the spacing and making a corresponding change in the feed-speed. The system controls an input device for feeding a workpiece to the bandsaw, and includes a sensor and a controller for performing the aforementioned functions.
1. A method for controlling feed-speed of a workpiece to a bandsaw, the bandsaw having a sawblade trained around a drive wheel and a driven wheel that is spaced apart from the drive wheel so as to define a spacing between the driven wheel and the drive wheel, and a strain adjustment mechanism for maintaining constant tension in the sawblade by continuously adjusting said spacing to automatically compensate for changes in the length of the sawblade, the method comprising sensing an increase in said spacing as the workpiece is being fed toward the sawblade at a feed-speed, and making a corresponding reduction in the feed-speed.
2. The method of claim 1 , wherein said step of sensing senses a displacement of a portion of the strain adjustment mechanism.
3. The method of claim 2 , wherein the step of sensing measures said increase.
4. The method of claim 3 , wherein the step of sensing includes measuring an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
5. The method of claim 4 , wherein said step of sensing includes measuring a permanent change in the strain of the sawblade by comparing an average of a plurality of measured changes in the strain of the sawblade before a reference time, with an average of a plurality of measured changes in the strain of the sawblade after said reference time.
6. The method of claim 3 , wherein said step of sensing includes measuring a permanent change in the strain of the sawblade by comparing an average of a plurality of measured changes in the strain of the sawblade before a reference time, with an average of a plurality of measured changes in the strain of the sawblade after said reference time.
7. The method of claim 2 , wherein the step of sensing includes sensing an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
8. The method of claim 7 , wherein said step of sensing includes sensing a permanent change in the strain of the sawblade by comparing an average of a plurality of sensed changes in the strain of the sawblade before a reference time, with an average of a plurality of sensed changes in the strain of the sawblade after said reference time.
9. The method of claim 2 , wherein said step of sensing includes sensing a permanent change in the strain of the sawblade by comparing an average of a plurality of sensed changes in the strain of the sawblade before a reference time, with an average of a plurality of sensed changes in the strain of the sawblade after said reference time.
10. The method of claim 1 , wherein the step of sensing measures said increase.
11. The method of claim 10 , wherein the step of sensing includes measuring an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
12. The method of claim 11 , wherein said step of sensing includes measuring a permanent change in the strain of the sawblade by comparing an average of a plurality of measured changes in the strain of the sawblade before a reference time, with an average of a plurality of measured changes in the strain of the sawblade after said reference time.
13. The method of claim 10 , wherein said step of sensing includes measuring a permanent change in the strain of the sawblade by comparing an average of a plurality of measured changes in the strain of the sawblade before a reference time, with an average of a plurality of measured changes in the strain of the sawblade after said reference time.
14. The method of claim 1 , wherein the step of sensing includes sensing an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
15. The method of claim 14 , wherein said step of sensing includes sensing a permanent change in the strain of the sawblade by comparing an average of a plurality of sensed changes in the strain of the sawblade before a reference time, with an average of a plurality of sensed changes in the strain of the sawblade after said reference time.
16. The method of claim 1 , wherein said step of sensing includes sensing a permanent change in the strain of the sawblade by comparing an average of a plurality of sensed changes in the strain of the sawblade before a reference time, with an average of a plurality of sensed changes in the strain of the sawblade after said reference time.
17. A system for controlling an input device for feeding a workpiece to a bandsaw, the bandsaw having a sawblade trained around a drive wheel and a driven wheel that is spaced apart from the drive wheel so as to define a spacing between the driven wheel and the drive wheel, and a strain adjustment mechanism for maintaining constant tension in the sawblade by continuously adjusting said spacing to automatically compensate for changes in the length of the sawblade, the system comprising:
a sensor for sensing an increase in said spacing as the sawblade is turning and the workpiece is being fed toward the sawblade at a feed-speed; and
a controller for controlling the input device to make a corresponding reduction in the feed-speed.
18. The system of claim 17 , configured so that said sensor senses a displacement of a portion of the strain adjustment mechanism.
19. The system of claim 18 , wherein the sensor is adapted to measure said increase.
20. The system of claim 19 , adapted for measuring an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
21. The system of claim 18 , adapted for sensing an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
22. The system of claim 17 , wherein the sensor is adapted to measure said increase.
23. The system of claim 22 , adapted for measuring an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.
24. The system of claim 17 , adapted for sensing an increase in said spacing that accumulates over a time sufficient for inferring that the sawblade is accumulating irreversible wear or damage.