What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

What are the most common faults you see on servo presses?

marco_press

After 8 years running servo presses I've seen a lot of the same faults come up over and over. Figured I'd list the ones that eat up most of our downtime and see if other people's experience matches.

For us the top 3 are encoder faults (cable damage near flex points is the usual culprit), overcurrent trips during heavy forming, and position deviation alarms that come and go. Overtemp on the motor is up there too, especially in summer when the shop hits 35C+.

The annoying ones are the intermittent faults that don't throw a clear code — like the press just... hesitates mid-stroke for a split second then continues. We've been chasing one of those for months.

What faults eat up most of YOUR downtime? Curious if it's the same stuff across different brands or if some presses are worse for certain issues.

anna_plc

I'd rank these differently based on what I see in the field. Encoder faults are #1 by far —probably 40% of all service calls I handle. Overcurrent is #2 but it's almost always a mechanical root cause (gib binding, foreign material in die) rather than an electrical issue. The drive is just reporting what the motor is experiencing.

raj_pm

Good list. I'd add one that's not here: lubrication system faults. On our 3 servo lines, lube alarms account for about 20% of all stoppages. Usually it's a clogged distributor block or a broken feed line. Easy fix but it stops the press just the same. We started doing weekly lube system inspections and cut those stoppages in half.

pressroom_tom

had the overload fault 3 times last week. turned out to be a bad crimp on the encoder cable. 2 hours of my life I won't get back lol

carlos_mx

@pressroom_tom ha, classic — encoder cable causing an overload fault. That's the kind of thing that makes you question your sanity for a while before you find it.

I'll throw in my top annoyance: thermal faults on the drive during summer. We run 3 Komatsu H2W lines and every July/August the ambient temp in the pressroom creeps up past 40C. The drives start derating and eventually fault out. We ended up adding a dedicated AC unit just for the electrical cabinets. Not cheap but it eliminated the summer shutdowns completely.

Also want to second raj_pm on lube faults. We had a progressive distributor block crack on one press — hairline crack, almost invisible. Took us 2 days to find because the lube system was showing normal pressure at the pump. The crack was downstream. Now we check pressure at the last point in the circuit, not just at the pump.

alan_stamper

One thing nobody mentioned yet -- thermal faults. We run 3 Komatsu H2W servo presses and in summer the drive cabinet temps creep up past 45C. The drives start derating and eventually fault out. We added a small AC unit to the cabinet row and it basically eliminated those calls.

Also on the encoder side, I have seen a pattern where the encoder works fine at low speed but throws errors above 60 spm. Almost always turns out to be the cable routing -- if it runs parallel to the servo power cable for more than a few feet you get enough EMI to corrupt the signal. Rerouting the encoder cable through its own conduit fixed it every time. Cheap fix but hard to diagnose if you are not looking for it.

jim_apps

Same here. Encoder faults are easily 50% of our calls. Half the time it's just a loose connector.