JOHN-IRELAND (Customer) asked a question.
I'm a fabricator and I've been working on a personal project — building a small industrial cup-printing machine from scratch. I want to see if I can actually pull it off, and I figured this community would be a great place to ask.
Hi all,
I'm a fabricator and I've been working on a personal project — building a small industrial cup-printing machine from scratch. I want to see if I can actually pull it off, and I figured this community would be a great place to ask.
The basic concept is a rotary indexing table (4 stations to start) that carries cups through four zones: load, print, UV cure, and eject. A servo drives the table index and a second servo spins each mandrel during the print pass. Cup loading and ejection would be pneumatic. I'm planning to use a Ricoh Gen6 UV inkjet printhead, which fires from an encoder signal off the mandrel-spin servo rather than from the PLC directly. Target throughput is around 2,000 cups per hour on the prototype, with the goal of scaling to 4,000+ later by adding stations and a second printhead — without redesigning the core frame or control system.
For the control side I'm thinking a PLC-based state machine with servo drives on EtherCAT, distributed I/O, and a basic HMI. I want to keep the architecture simple and use off-the-shelf industrial components wherever possible.
A few things I'd love input on from anyone who's tackled something similar:
1. What AutomationDirect PLCs and servo drives would you recommend for a 2-axis EtherCAT setup like this (table index + mandrel spin)?
2. Is the Do-more or Productivity series a better fit for a state-machine-heavy application, or would you go a different direction?
3. Any tips on handling the encoder fan-out from the mandrel servo to an external printhead controller — does AD carry anything suitable for that?
4. General lessons learned running pneumatic pick-and-place in a tight 1.5–2 second cycle time.
I'm not a controls engineer by trade so any pointers — even just "read this manual first" — are genuinely appreciated. Happy to share more details about the mechanical side if it helps.
Thanks in advance!
You know what they say about opinions! I would like to give my opinion on your question #2. I believe the BRX Do-more PLC is the choice over Productivity for your state-machine-heavy application. Yes the Productivity has the Drum and Sequence instructions, but the Stage programming of the BRX is very powerful. We have done many state-machine-heavy applications with, initially DL PLCs, then the Do-more for the DL bases, then the BRX using the Stage programming. I cannot see how we would have done them without the Stage programming.
Yes the Productivity has the Drum and Sequence instructions
I do not use the 'Sequence' instruction.
I have only used the 'Drum' instruction for light/sound patterns.
I build my own sequencing routines. I usually need more steps and more output capability than the Drum provides.
I think that any PLC platform from AD could do this job -- if EtherCAT is not a hard requirement
"1. What AutomationDirect PLCs and servo drives would you recommend for a 2-axis EtherCAT setup like this (table index + mandrel spin)?"
I would personally look elsewhere if you are set on EtherCat. Automation Direct does sell 1 model of PLC and 1 model of Servo that an do EtherCat, but I havent personally used it and I also havent seen anyone post yet about actually liking the platform. I have seen some posts complaining about the PLC though. Both options come from LS Electric and from what I have heard use a rather old platform:
https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/ls_electric_plcs_(stackable_micro_-a-_brick)/motion_-a-_specialty_modules
https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/ls_electric_plcs_(stackable_micro_-a-_brick)/motion_controllers#
https://www.automationdirect.com/adc/shopping/catalog/motion_control/ls_electric_ix7_(ix7nh_series)_ethercat_and_modtcp_servo_systems
"2. Is the Do-more or Productivity series a better fit for a state-machine-heavy application, or would you go a different direction?"
Both of these are capable of doing what you want, and there are pros and cons to both platforms. Both would control the Servo's with quadrature step/dir style pulse inputs rather than EtherCat though.
Do More has great stage programming, and could make your program execute faster because of it.
Productivity is easier to learn IMO, and their AMC# motion controller has a rotary table instruction already. Or you could use simple move or maybe even Preset Tables instruction. So the actual programming may be much easier and take far less time with Productivity than anything else.
But again, with either of these platforms you will be using older style step/dir pulse inputs to control the servo position.
"3. Any tips on handling the encoder fan-out from the mandrel servo to an external printhead controller — does AD carry anything suitable for that?"
I would imagine whatever servo you use should have a pulse output capability for following the servo position. That pulse output should be able to be fed into the inkjet pulse input. If you need voltage level conversion between them then yes automation direct sells one to convert from open collector to line driver or vise versa.
I am a big fan of the keep it simple approach. EtherCat is fantastic for advanced motion and multi-axis coordination, but a rotary table and a spinning mandrel could be done as simple as a CLICK Plus with step and direction out to a SureServo2. The SureServo2 fits because it has simple step/dir or analog in plus a scalable encoder output. If you want to get fancy and minimize discrete wiring, switch to a Productivity with EtherNet/IP but consider the simplest approach is usually the best.
Another thought, since the indexing table has known, fixed positions, you could set up the index move in the SureServo2, and then trigger the index move by sending a digital signal from the PLC to the SureServo2. And then the PLC waits for the move-complete signal from the SureServo2 until moving to the next control step. This way, the PLC would not need to send out step/dir to index the table. I agree and would probably use the relatively few I/O wires over the EtherNet/IP.
[3] Fast look -- I do not see anything from AD for this.
Baldor makes a simple encoder splitter/buffer. I am not suggesting that this will work for you, but these things are available.
https://www.baldor.com/Shared/manuals/1266-396.pdf
https://genesisautomationonline.com/products/motrona-gv204-pulse-splitter-for-incremental-encoder-signals
I have used equipment with something so simple as some digital logic gates with Schmitt trigger outputs for this. This equipment was NOT high speed, so that might be something to consider.
I am not suggesting that either of the linked items will work for your application -- just trying to provide a starting point for you.