Seven Axis Interpolation Robotic Project

Marinoter · 27 Dec 2018, 19:21

Hello everyone,
After watching the Duet3 video, I'm wondering if current Duet release or next Duet3 can interpolate seven stepper motors with the integrated trinamic drivers, in the following mix (in terms of fluent, voltage and current):

1xNema 34, 3xNema 23 and 3xNema 17, having also control for at least 4 servos.
My goal is to have a standalone robotic device running Gcode.. (I Know kinematics will be a challenge!)

Many thanks!

dc42 · 27 Dec 2018, 22:20

The Duet WiFi or Duet Ethernet, plus a DueX5, should already be able to do that already. It gives you 10 drivers, up to 9 of which can be axes, and 7 heaters of which 5 can be repurposed as hobby servo drivers.

yaman · 27 Dec 2018, 23:10

you will need beside Duet 2 Wifi 3d controller , Duet Expansion Breakout Board
to drive your stepper nema 34, max power can give you Duet Wifi 2A for each drive

dc42 · 28 Dec 2018, 07:54

@yaman said in Seven Axis Interpolation Robotic Project:

you will need beside Duet 2 Wifi 3d controller , Duet Expansion Breakout Board
to drive your stepper nema 34, max power can give you Duet Wifi 2A for each drive

Actually the maximum is 2.4A peak, not 2A. Enough for some Nema 23 motors, but not Nema 34. So the Nema 34 at least will need an external driver.

Using the external stepper breakout board and the DueX5 together is not possible. However there are several options available to you:

Choose Nema 23 motors that can work with 2.4A or less. Use both a DueX2 and the external stepper breakout board. You will need a 50-way ribbon cable with 3 connectors on it so that you can connect both boards.
Choose Nema 23 motors that can work with 2.4A or less. Use a DueX2 or DueX5. For the Nema 34 motor, use an external driver connected to one of the two additional stepper driver pins on the CONN_LCD connector. You will probably need to use a buffer chip to level-shift the CONN_LCD outputs to 5V and increase the current drive for the external driver.
Use external drivers for the Nema 23 motors as well as the Nema 34. Use a Duet + external stepper breakout board. That board gives you 2 servo outputs. You will need to tap into the expansion connector to get at the spare heater channels, which you can use for the additional servos. If your servos need a 5V control signal, you will need to use a 74HCT chip or similar to level shift them to 5V.

Duet 3 will probably be able to drive everything more easily. We showed a Duet 3 prototype driving Nema 34 motors at TCT last September.

Marinoter · 28 Dec 2018, 08:08

Many thanks @yaman and @dc42 for throwing me light on this!

Hmm.. Duet3 sounds promising.. any estimation on release date or any link where follow progress?

Again, thanks and best regards!

dc42 · 28 Dec 2018, 08:14

We hope to release Duet 3 in Q2 2019.