Tree J-250 Mill High/Low range question

[swarf-sweeper]

When setting a spindle speed above 1500 rpm, I get an alarm that says to shift to High range. Conversely, if the last speed was set above 1500 and the new speed is below that, I get an alarm asking to shift to Low range. As far as I can tell, there is now range lever or button. What am I missing here? This mill has a Dynapath Delta 40 control.

Thanks.

 

[Metalurgent]

I retrofitted a J250 with Linuxcnc. On my machine, I have to lift the top panel and swap the belt between two pulley options for hi-lo. Is yours the same setup? I can't comment on how dynapath handles the "shift" alarm or how the control knows what range the machine is in. Is there a switch up there that toggles when the belts are shifted over? Or is your j250 laid out differently? Geared maybe?

 

[swarf-sweeper]

It has a two step pulley in the top and the means to swap the belt around. I have the belt on the top position which would operate at high range since its the larger pulley. However I can enter a spindle speed of 100 rpm and the spindle is turning pretty darn close to that. I guess I should measure the spindle rpm with a rpm gauge and see its running at exactly 100 when the belt is in the upper position.

No switch that I can see and if it’s geared in hidden in the head somewhere.

 

[Metalurgent]

If you're in high range and programming 100rpm, my guess is that the frequency of the vfd driving the motor is very low and thats whats triggering the alarm. I'm running the original yaskawa vfd and it has a Hertz display as standard. Maybe yours too? There are probably ranges set in the control to optimize the speed/torque control and protect the motor and drive. The motor is cooled with an external fan, but I expect running it at very low, or very high frequencies is not recommended, so the control alarms.
Its annoying sometimes if you want to go as fast as you can to mill something and then slow it way down to tap. My j250 isn't set up to rigid tap ( I'm working on it..) but I can tap using a compression-tension holder. I swap belts to get lo-gear and I get the torque and accurate rpm that I need to make it happen. The specs on the J250 give the two recommended ranges.

 

[swarf-sweeper]

If you're in high range and programming 100rpm, my guess is that the frequency of the vfd driving the motor is very low and thats whats triggering the alarm. I'm running the original yaskawa vfd and it has a Hertz display as standard. Maybe yours too? There are probably ranges set in the control to optimize the speed/torque control and protect the motor and drive. The motor is cooled with an external fan, but I expect running it at very low, or very high frequencies is not recommended, so the control alarms.
Its annoying sometimes if you want to go as fast as you can to mill something and then slow it way down to tap. My j250 isn't set up to rigid tap ( I'm working on it..) but I can tap using a compression-tension holder. I swap belts to get lo-gear and I get the torque and accurate rpm that I need to make it happen. The specs on the J250 give the two recommended ranges.

 

[swarf-sweeper]

This mill has all the original electronics from the factory including the Yaskawa spindle drive. I had to send that out for repair when I brought the mill home earlier this year. I’ve spent the past few months since learning to program the control and getting the machine in shape. I have a pulley bearing squealing on occasion that I need to replace. At the same time I’ve been learning a cad cam system that spits out the code for this control. Its been a fun learning experience and I’m yet to to make a chip!

So It sounds like if I want to get accurate speeds and feeds, I need to flip that belt anytime I eclipse 1500 rpm (this is the threshold where the control alarms). The alarm is nothing more than a message requesting that I shift to either high or low range. I have the manual for this machine but do not recall seeing any mention of the ranges. I’ll have another look see. Thanks!

dan