Hurco BMC 20 Ultimax 3 Retrofit

I am going to check out my servos in a bit. But I have a bad feeling I have two bad servos. It is odd that I have the same overcurrent alarm on two drives. So I am going to check the caps, and the output SCR's to see if one of those is shorted out along with meggering my servo and cables.

But for now I have commented out my x and z and tried to get some motion out of the Y but I can not get them to move

I set the Zero on the drive so the servo is not hunting back and forth while sitting

I found a page with the servo tuning. But I have not found some of the exact components to put into the halscope. I can not get the hal scope to show anything either. Ill be back to messing with it in a bit.

Once I get some current amps knocked out I am going to hook up my main power contactor to my Estop SSR and have the 24vdc servo enable through 1 of the SSR's. I am going to actually move my lube pump to come on with the servo enable.

Well I pulled my servoamps out. Looks like I have one with a shorted out IGBT, one that the IGBT checks out ok, and one that has no alarm, and can not get any motion out of it.

I am thinking about running them up to a servo shop in the metromess next week, and ill take my servos for them to run them to see how they do also.

I keep thinking about replacing the servopacks with another servopack. $1800 repair or $3300 for new seems a bit steep. I am having a hard time thinking about that when I do not know for certain the exact condition of the rest of the machine.

Especially when there are tons of Allen Bradley Ultra 3k on fleabay cheap. Yaskawa has always seemed to be the most expensive by a large margin.

I actually got to spend some time on the mill tonight.

I put my ebay drive in and one of my drives that had a bad igbt that I changed (still have a problem on the one I changed parts on)

But I was able to get motion on the servo and servo drive while the servo was sitting on the floor. Seems like the servo is running one speed no matter what. It is almost like it is not developing enough torque to to move the axis when coupled. I am going to try my other drives again and ship off the ones that I am beating my head on.

Refuel outage is done in another 10 days so back to 40 hours a week! I cant wait.

Finally made some headway again!

I have two operational servo packs in it now. Third one should be here next week. Now onto pid tuning, once I hit the machine on command the x axis runs away until it hits the following error. Drives are zeroed out when idle, just runs when you turn machine on. Hopefully by then end of June I'll be making chips and changing tools!

Jake wrote:

Finally made some headway again!

I have two operational servo packs in it now. Third one should be here next week. Now onto pid tuning, once I hit the machine on command the x axis runs away until it hits the following error. Drives are zeroed out when idle, just runs when you turn machine on. Hopefully by then end of June I'll be making chips and changing tools!

OK, this is the classic servo runaway. In your .ini file, in the [axis_0] section, change the arithmetic sign of OUTPUT_SCALE to the opposite. This will cause the motor to move move in the correct direction when it is off the null point.

Jon

I'll give that a shot, I'm waiting on the amp to show up along with a new encoder coupling for the y axis !

When I swap the sign the machine wont move, just growls at me. The scales are going backwards, I need to figure out where to reverse that. The axis will move + when I ask to move -. I need to find the encoder input scaling also. Mine are 5k count encoders.

jmelson wrote:

Jake wrote:

Finally made some headway again!

I have two operational servo packs in it now. Third one should be here next week. Now onto pid tuning, once I hit the machine on command the x axis runs away until it hits the following error. Drives are zeroed out when idle, just runs when you turn machine on. Hopefully by then end of June I'll be making chips and changing tools!

OK, this is the classic servo runaway. In your .ini file, in the [axis_0] section, change the arithmetic sign of OUTPUT_SCALE to the opposite. This will cause the motor to move move in the correct direction when it is off the null point.

Jon

Jake wrote:

When I swap the sign the machine wont move, just growls at me. The scales are going backwards, I need to figure out where to reverse that. The axis will move + when I ask to move -. I need to find the encoder input scaling also. Mine are 5k count encoders.

OK, if the machine is behaving well but just moving in the opposite direction, you need to reverse the sign of both
INPUT_SCALE and OUTPUT_SCALE.

INPUT_SCALE is the encoder input scale. Generally, take the encoder line count X 4 X the leadscrew pitch in TPI, and you will get the correct value, unless there is a belt ratio. So, for 5K line encoders directly on a 5 TPI ballscrew, that would be 5000 X 4 X 5 = 100000.

Jon

question for yall.....



Is there something I am missing that I need to add to allow it to move only in the opposite direction that inhibits the directions?

Thanks again!!!!!

I am getting a bit further! I can move all three axis now!



When it hits the limit it quits and wont let me turn the machine back on. I have to physically move it off the limit to get it rolling again.