OAK/DYN4

[martyscncgarage]

This is good to hear. I’ve got some DMM drives and cables coming this week. They seemed pretty sure they would play nice with the OAK. It’s going to take them 6 weeks to build my servos so I’ll just have to wait until then to find out myself.

There is a good chance you have corrected cables and DYN4 firmware.
Marty

[jj84774]

Stupid question: will DMM servos with updated firmware work on either an OAK or ACORN system?

[martyscncgarage]

Stupid question: will DMM servos with updated firmware work on either an OAK or ACORN system?

That's a question for DMM. Give them the firmare revision off the side of the drive.

I should say I believe you should have no problem as they drive needs to be configured differently for the two controls. But call DMM and ask.

[martyscncgarage]

I got my responses from DMM, my contact was on vacation. He is playing catch up.
Marty

[cncsnw]

Back in July, Marty wrote:

LOGIC DRIVE POWER: You are correct, all standard drives (Estun, Delta, Yaskawa, Centroid AC/DC) are kept powered up but motor supply can be cut. This is in order for the encoder to remain powered up so position can be held. I let DMM know about this. I too experience a "twich" of the motor shaft on power up early on. Presumeably, during an E-Stop condition, the motor relaxed a tad, the drive saw the encoder position change a bit, and was trying to get it back into position and could not because there was no motor power. As soon as motor power was restored, it then corrected the position issue.

This would normally relate to the "POS ERR CLR" signal, on pins 13 and 14 of the Oak header. If that signal (which I believe is 5V, differential) is wired to the drive, and the drive is configured to accept it, then the "twitch" can be avoided when power is restored. The Centroid PLC program will assert POS_ERR_CLR any time the E-stop contactor is open (SV_STOP) is set, and the drive in response should keep its error counter zeroed out: i.e., wherever the motor shaft happens to turn to, that is where it wants to be when power is restored.

However, the DYN4 manual (at least the version I downloaded in September) indicates that disabling the drive via the ENA signal is supposed to have this effect already. From page 36:

The servo position error is cleared when the drive is disabled using the ENA input and does not accumulate
when the drive is disabled.

On a separate note, your experience with landing the cable shield on the DB25 connector shell is interesting. The cable shield should already go to pin 30 of the Oak axis header, which in turn is connected to chassis ground through the Oak board. So, if the DB25 shell at the DYN4 drive is grounded to the drive chassis, and the drive chassis is wired back to your panel ground, then by landing the cable shield on the DB25 shell we are creating a loop. Maybe forming loops with signal cable shields is not as bad a thing as I have been lead to believe it was....

[martyscncgarage]

On a separate note, your experience with landing the cable shield on the DB25 connector shell is interesting. The cable shield should already go to pin 30 of the Oak axis header, which in turn is connected to chassis ground through the Oak board. So, if the DB25 shell at the DYN4 drive is grounded to the drive chassis, and the drive chassis is wired back to your panel ground, then by landing the cable shield on the DB25 shell we are creating a loop. Maybe forming loops with signal cable shields is not as bad a thing as I have been lead to believe it was....

Hi Marc,
The DB9/25 chassis is isolated from ground as DMM points out. There is no continuity from them to the drive's chassis ground.

I just got my cables back from DMM, I have drives which they tell me have the correct firmware, I am just caught up on my work, so I can get back to testing and provide hopefully a positive conclusion to the testing.

More very soon as I intend to use OAK/DYN4s on the FADAL TRM I have and then my Bridgeport Torq Cut 22. I have all the drives/motors/and cables for those projects. Just need time! Likely after the first of the year.
Marty

[martyscncgarage]

Long time in coming, but I finally had a chance to bench test OAK along with the DYN4 Drives and firmware modofications.
It looks very promising. Bench testing went well. (See video)

The Acid test is when I build the back panel and install the system on the FADAL TRM (Tool Room Mill) soon.

Right now, it looks like DMM got it right so far....

[slodat]

Thank you for the video, Marty! Questions..

Do you have a link to the cable you are using for the DYN4 motor power?

Are you doing 120 or 240v for the DYN4 logic power?

[martyscncgarage]

Thank you for the video, Marty! Questions..

Do you have a link to the cable you are using for the DYN4 motor power?

Are you doing 120 or 240v for the DYN4 logic power?

Just buy 16 gauge three conductor cable. I had it on hand. I do like to use shielded cable when I can buy it. But I don't thinkt its necessary.
I am running 240VAC motor power.
Keep in mind this is their LATEST DYN4 Firmware and I think they had to correct a wiring issue with the servo drive cables from OAK to DYN4.
If yours are older than several months, then you need to contact DMM to have the drives shipped back to have the firmware upgraded and the Servo data cables modified.

Marty

[slodat]

Are you running 240v to the DYN4 logic (the red/black twisted to the two glass fuses) as well?