Which Duet has the fastest external drivers
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I'm comparing the different Duet boards for use in my upcoming 3d printer. So far I've only used the Duet 2, but would be willing to upgrade to Duet 3 (6HC or Mini).
As I will be using external stepper motor drivers, I'm only concerned with the maximum step frequency for those.
afaik the Duet 3 6HC is the fastest, but offers no connections for external drivers, same with the Duet 3 Mini.
Connecting the 1XD Expansion Board limits the step frequency to the 48 MHz chip, so around 50KHz according to the wiki.
Seems like I'm left with the Duet 2 and it's Expansion Breakout Board, although I've not seen any benchmarks for the expansion board.Am I missing something?
Which would be the best performing Duet for a 3d printer (X,Y,Z,E axis) with four external drivers?
Why is there a 1XD Expansion Board with such a low performance chip, compared to the 6HC? People, that would spend money on a 6HC, external drivers (stepper or servo in my case) surely would take a 10-20€ more expensive 1XD, if it means 5-10x the step rate.
While I'm at it: how about a 3XD to fully utilize faster chips. I'd guess there are many people, that wouldn't need just one external drive in their setup, so a 3XD could offer greater performance with the chips cost increase "spread across" mutiple axis.
Thanks!
Sources:
Benchmarks from another topic
https://forum.duet3d.com/topic/15308/what-is-the-maximum-step-rate-of-duet-3-board/8
1XD benchmarks from wiki
https://duet3d.dozuki.com/Wiki/Duet_3_Expansion_1XD -
Currently if you need external drivers then in some cases the Duet 2 is faster and in other the 1XDS would be faster. For example if you need to run a kinematics where a lot of calculations are required then the Duet 3 with 1XDs may be faster than the Duet 2. Alternatively if you are just going fast on a cartesian XY stage then the Duet 2 may be faster.
often a limiting factor is the step timing requirements of the external drivers.
We will bring out a 6XD however development is taking time due to other priorities.
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@marius-breuer the maximum step rate of the EXP1XD was increased in firmware 3.3, to around 95kHz AFAIR. Most external stepper drivers are limited to 200kHz or lower anyway.
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@t3p3tony my printer is intended to be a corexy, single Z-axis motor, single extruder. However lot's of addons are "in the works", so I'd tend to future-proof my machine by going with the Duet 3 6HC.
For the 6XD: are we talking 2022, 2023?Thanks!
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@marius-breuer its on the drawing board but delayed. I very much want to have the design done and prototypes ordered within weeks, but I have wanted that for months now!
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@marius-breuer Here it is! New restock on dhm-online.com
Come and find your duet 3 new products: duet 3 6xd and more https://www.dhm-online.com/brand/14-duet3d
