Is there any news or blog on the Duet3

dc42

Yes, we changed to barrier strips on the Duet Maestro and we intend to use them on all future boards.

OG3D

@dc42 are you taking into account of adding a closed loop stepper control with an absolute encoders? I seen talks about it in the past but was curious if your taking this into account for next gen duet. Any replies would be appreciated.

Thanks,
OG

dc42

You can already use step/servo drives if they have standard step and direction inputs, and several Duet users do this already. What's more interesting would be using BLDC motors and encoders.

Martin1454

@dc42 Have you considered to make an expansion board with diffrent stepper drivers like the TMC2130 so we can get stealth chop on the X/Y axis? I know the maestro have them, but would love to be able to use some with the duet

OG3D

@dc42 so with steps and direction inputs the absolute position would not be known to duet? my thought towards absolute position encoder is that the printer will always know it position thus with a well build print no need for homing or mesh grid compensation between every prints.

deckingman

@og3d said in Is there any news or blog on the Duet3:

................... my thought towards absolute position encoder is that the printer will always know it position thus with a well build print no need for homing or mesh grid compensation between every prints.

Does an absolute position encoder retain the absolute position when power is disconnected? i.e when the printer is turned off? That's the only advantage that I can see because as long as you don't power off the motors at the end of every print, then the absolute position is retained. So it is currently only necessary to home when the printer is first turned on, not for every print. Likewise any mesh compensation (although a well build printer doesn't need it ).

OG3D

To my best knowledge absolute encoder will know its position after power cycle, I think its due to absolute encoders are providing a unique position values.

The place that I work they have a machine that has absolute encoders in its servo motor. It does not require homing sequence at startups.

dc42

Are absolute encoders for linear position actually available, at affordable prices?

Mabover

@dc42 the CUI AMT20, AMT21 and AMT23 sentries of encoders offer absolute output in spi, rs485 or ssi respectively and support software zero position setting. They can be had for about 50USD from digikey.

They also have incremental encoders and commutation encoders for BLDC motors that don't already have commutation sensors, they set the commutation position relative to the motor pole position via software in a guide they provide.

https://www.cui.com/amt-modular-encoders

JoergS5

This post is deleted!

kuhnikuehnast

As the TCT starts today, is there any chance to get an info / Look about new products on the Roadmap? Would really like to come over, but from germany it is quiet far...

Phaedrux

@kuhnikuehnast https://forum.duet3d.com/topic/7010/duet-3-demo-at-tct/12

OG3D

@dc42 Yes they aren't cheap. I have been think about DRO for quit time similar to this.
https://www.igagingstore.com/6-Absolute-Digital-Readout-DRO-Stainless-Steel-Su-p/205470.htm

I know the DROs aren't fast enough to keep up with the motion but it could be used a reference to pull the positions when requested, like during boot up. What do you think?

DocTrucker

Any updates? Still on track for Q2 this year as mentioned on another thread? Higher VIN limit? Presumably targeting a higher price?

dc42

@doctrucker said in Is there any news or blog on the Duet3:

Any updates? Still on track for Q2 this year as mentioned on another thread? Higher VIN limit? Presumably targeting a higher price?

A batch of Duet 3 pre-production main boards is scheduled to be assembled this week or next. Following testing and some firmware work on them, we expect to provide some to key customers in February. We won't know how many working ones we have until we have tested them all. Many of the prototype boards failed testing because of a manufacturing difficulty related to the new stepper drivers, but we think that should be solved in this iteration.

The price will certainly be higher, because the stepper drivers will cost more and there will be 6 of them. The higher specification processor and the CAN bus interface also contribute to the higher cost. So we expect the Duet 2 WiFi/Ethernet to continue to be mainstream for most applications.

The maximum VIN voltage will be higher, probably around 35V-40V.

DocTrucker

Thanks, thats great.

Coincidentally has anyone shared or blogged about the relevant regulations that need to be met for shipped kits and prebuilts? I'm aware documentation should be in place for CE marking but it's largely the manufacturer's responsibility to ensure it is complete, unless it is called for then there is a fixed time in which it has to be delivered. Outside the remit of the machinery directive?

Grogyan

I somehow missed the news on the upcoming Duet3

Have been rather slow with my projects, one of which requires higher power stepper drivers than what is commonly in use, and was looking at getting Duet2 for this.

I really like the direction of Duet3
Happy to see someone formally bring in CAN bus to 3D printing.
two small issues I see, are no mention of if the process has an inbuilt FPU.
And
Not using the USB-C connector for interfacing.

T3P3Tony

@grogyan

In built FPU: the SAM 4E MCU in the Duet 2 have FPUs.

USB-C: this is still too expensive to make it worth it for a connector that is only required for initial setup, if at all. Micro USB is ubiquitous and cheap (I bet nearly everyone has one of these cables in a draw).

A Former User

@t3p3tony said in Is there any news or blog on the Duet3:

@grogyan

In built FPU: the SAM 4E MCU in the Duet 2 have FPUs.

USB-C: this is still too expensive to make it worth it for a connector that is only required for initial setup, if at all. Micro USB is ubiquitous and cheap (I bet nearly everyone has one of these cables in a draw).

To keep cost at a reasonable level I think what you pointed out for the usb is right. For a connector only used for setup (in best case only 1 time in a lifetime) the cheapest but still reliable (THROUGHHOLE of course, NOT those only one side surface-mount-=)§)(/)=§("!!! ) usb-connector would do. ( I know you guys have and will choose only throughhole on every possible moving-cable since you did that in the past. Just wrote that because I stumbled in my so far young life enough times over consumer-electronics where they took the cheaper only smd-usb-connector and that for sure will come of the pcb after a few times un-/plugging the cable)

XTL

That looks like RJ-45 on the CAN? Is there a reason for such a large connector? I've used 4-pin RJ-11 in the past and that's already more than enough pins for CAN and would even carry a pair plus voltage and even ground if needed.

USB-C is indeed a minor nightmare unless you can get some sort of module for it with an interface chip and that would not be very cheap either way. Also, cables can be quite brittle unless you get very very good ones. Available functionality in full implementations is brilliant, of course.