Generic powder machine controller

Powder and inkjet printing
david
Posts: 73
Joined: Wed Sep 21, 2016 8:43 pm

Generic powder machine controller

Post by david » Sun Apr 07, 2019 2:07 pm

Hi,

I'm designing an electronic controller for small powder machines (no long distance signal). I try to make it a generic configurable control box. The hardware is based on,

- 500MHz 32bit processor with FPU and 64MByte RAM for print image processing;
- 16MByte flash + TF card for storage;
- FPGA for digital signals up to 300MHz;

So far the following features have been done,

User interface:
- 3inch 320*480 IPS LCD;
- multi-point touch screen;
- speaker;
- Emergency stop;
- Power on/off with LED.

Communication:
- front USB socket as host or device;
- Wifi (optional);
- Ethernet (optional).

Motion:
- 5 stepper drivers; (2 piston, 2 sliding, 1 ink)
- many homing switch;

Printhead:
- high voltage power (42V);
- high voltage head driving waveform generator;
- 2 analog channel for temperature etc;
- 15 high speed digital signals (single-ended) for data and control;

Roller:
- rotation control;
- vibration control;

Ink:
- 2 ch pump driver (other ink station function supported from the motion part)

Please let me know if I missed anything major or any suggestion? I was thinking to add UV and heater, but since their application may vary, I'll probably only provide the control signal.

David

david
Posts: 73
Joined: Wed Sep 21, 2016 8:43 pm

Re: Generic powder machine controller

Post by david » Mon Apr 08, 2019 9:56 pm

it'll be something like this,
ctrl.JPG
ctrl.JPG (146.26 KiB) Viewed 1241 times
about 110mm x 105mm x 55mm

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dragonator
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Re: Generic powder machine controller

Post by dragonator » Tue Apr 09, 2019 5:49 am

Hello David,

I like the idea.

For what printheads are you designing this controller. With FPGA at 300MHz and 15 free I/O (and 42V) I can easily see the Xaar 128 on this, but something like the HP45 will not work on this, it simply needs more I/O (around 20). Is the 15 channels limited by your current hardware or by your design requirements. What voltage are the 15 channels on.

Are you boosting to 42V on board, or do you make this externally. How much current can you make using this power supply and can it be set to different voltages.

Are you going to write the motion side of things yourself or do you want to use something existing. Is this still possible with the computing power available? Motion and inkjet together are difficult to program.

Having a few mosfet 12V outputs is always handy, for stuff like fans and lights and relays. If this adds too many features, an output header so you can connect this might be an idea.

2 more ideas that work together. The first thing I have heard a few times is a need for a universal inkjet controller, not just for powder machines. If you have this, the ability to add an encoder might be very helpful to drive the inkjet. If people only want to use the inkjet side, having soldered motor drivers is expensive and not necessary. Also, If new motor drivers come along that are better, there is no way of using those. Do you solder the motor drivers to your board, or do you have the headers like a RAMPS board does.

david
Posts: 73
Joined: Wed Sep 21, 2016 8:43 pm

Re: Generic powder machine controller

Post by david » Tue Sep 03, 2019 9:43 am

QQ图片20190903104210.jpg
QQ图片20190903104210.jpg (355.61 KiB) Viewed 506 times
Second version of the PCB.

david
Posts: 73
Joined: Wed Sep 21, 2016 8:43 pm

Re: Generic powder machine controller

Post by david » Tue Sep 03, 2019 9:49 am

dragonator wrote:
Tue Apr 09, 2019 5:49 am
Do you solder the motor drivers to your board, or do you have the headers like a RAMPS board does.
The driver board is included but separated as the vertical PCB. There bunch of signals from the main board to the driver board under the FPGA control and a few other generic signals like I2C. So it is possible to just fan out those signals, i.e. by pass the integrated driver, or integrate servo circuit. For the moment they are 5 ch stepper drivers and 2 ch DC drivers but no encoder inputs. DC motor is for the pump.

david
Posts: 73
Joined: Wed Sep 21, 2016 8:43 pm

Re: Generic powder machine controller

Post by david » Sun Sep 29, 2019 7:10 am

alpha version update, functionally tested ok, going to be integrated to the printer.
20190929_150133.jpg
20190929_150133.jpg (328.53 KiB) Viewed 290 times

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dragonator
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Re: Generic powder machine controller

Post by dragonator » Sun Sep 29, 2019 9:17 am

That is one impressive looking board. I read that you have stepper motor drivers on there. Do you intend to use an existing motion driver or will you write one yourself. Does the motion run through the FPGA or the microcontroller.

maxt
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Re: Generic powder machine controller

Post by maxt » Tue Oct 01, 2019 10:11 am

looks great !

this one controls how many heads/colors ?

david
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Joined: Wed Sep 21, 2016 8:43 pm

Re: Generic powder machine controller

Post by david » Wed Oct 02, 2019 3:06 am

There is a driver board as seen at the left part (black PCB), which has 5 stepper drivers, 2 DC drivers, 2 opto switch input, 3 homing switch input, power on/off button input with LED, emergency stop input, 1 extension interface containing I2C interface and LDC interface. NB. LDC is my Local Device Control interface based on semi-duplex serial port (1 wire control).

The right side has 3 FPC connectors. The top one is for the powder tool (i.e. the roller), which has 1 stepper signal (driver on the powder tool) to control the roller and 1 DC signal to control a vibrator if required, and there is a separate PCB as the powder tool driver. The lower two FPCs are for the head tool (i.e. the inkjet printhead). The high pin count one is the data interfaces with 11 high speed I/O (individually shielded) 4 low speed I/O (group shield), 2 analog input and a stepper interface with feedback (for my servo stepper to drive the X motion of the printhead). The low count connector is for the power: 19V/24V DC, 42V DC, 2 ch waveform, and 5V, all fused. Supporting to the specific printhead is done with the FPGA firmware and a head breakout PCB.

So far the implementation supports a six colour EPSON head. The idea is to use two colour for the main glue and 4 colour for the aux glue and dye.

david
Posts: 73
Joined: Wed Sep 21, 2016 8:43 pm

Re: Generic powder machine controller

Post by david » Wed Oct 02, 2019 3:09 am

PS WIFI and Ethernet ports are reserved but not implemented yet.

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