Re: Upgrading Mini Kossel to Duet electronics January 24, 2015 03:20PM |
Registered: 9 years ago Posts: 21 |
Re: Upgrading Mini Kossel to Duet electronics January 24, 2015 04:36PM |
Registered: 10 years ago Posts: 14,672 |
Re: Upgrading Mini Kossel to Duet electronics January 25, 2015 07:07PM |
Registered: 10 years ago Posts: 14,672 |
Re: Upgrading Mini Kossel to Duet electronics July 17, 2015 02:03PM |
Registered: 9 years ago Posts: 280 |
Re: Upgrading Mini Kossel to Duet electronics July 17, 2015 04:38PM |
Registered: 10 years ago Posts: 14,672 |
Quote
shadowphile
Hi Dave, I have been relying on your kossel-to-duet blog and it has become my bible for this process, thank you! I have a bunch of parts on order so I'm still lining up my ducks. (or is that an American expression?)
You have suggested 0.9 degree motors but I have seen multiple comments that those and/or 1/32-step drivers are too fast.
I would think the Duet could easily keep up though, unless there is a limitation somewhere not related to the MCU speed or word size.
Re: Upgrading Mini Kossel to Duet electronics July 17, 2015 07:55PM |
Registered: 9 years ago Posts: 280 |
Re: Upgrading Mini Kossel to Duet electronics July 19, 2015 08:50AM |
Registered: 9 years ago Posts: 445 |
Quote
dc42
Quote
shadowphile
Hi Dave, I have been relying on your kossel-to-duet blog and it has become my bible for this process, thank you! I have a bunch of parts on order so I'm still lining up my ducks. (or is that an American expression?)
You have suggested 0.9 degree motors but I have seen multiple comments that those and/or 1/32-step drivers are too fast.
I would think the Duet could easily keep up though, unless there is a limitation somewhere not related to the MCU speed or word size.
0.9 deg motors or 1/32 microstepping would seriously stretch an Arduino Mega or similar atmega2560 electronics on a delta. But I expect the Duet to handle them adequately. At worst, travel speed might be limited to 200mm/sec instead of the 400mm/sec that I currently achieve with 1.8 deg motors and 80 microsteps/mm.
I ordered some new motors a few days ago (3 x 0.9deg JK42HM48-1684 for the towers, and a 1.8deg JK42HS34-1334 for the extruder). They are due for delivery tomorrow or Monday. So I will soon know for sure how fast the Duet can drive them. I also have some firmware efficiency improvements planned to improve the maximum speed.
Re: Upgrading Mini Kossel to Duet electronics July 19, 2015 09:27AM |
Registered: 10 years ago Posts: 14,672 |
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Koenig
Might I ask why you choose a smaller motor for the extruder?
Re: Upgrading Mini Kossel to Duet electronics July 27, 2015 05:19AM |
Registered: 9 years ago Posts: 445 |
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dc42
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Koenig
Might I ask why you choose a smaller motor for the extruder?
The 17HS19-1684S has too much torque for the geared extruder that came with my T3P3 Mini Kossel kit. To get the right amount of force (so that it the nozzle gets temporarily obstructed, it skips steps instead of grinding through the filament), I have to reduce the current to 400 to 500mA. However, this reduces the available extruder acceleration, because of the high rotor inertia of this long (48mm) motor. So I have a choice:
1. Keep the motor, but use a lower gear ratio, or even direct drive.
2. Keep the gearing as it is, but use a shorter motor with lower rotor inertia.
I chose (2) partly because it means that I can sell a set of 4 motors along with most of the parts from the Mini Kossel kit I started with. Also because the motor I chose is the same one used in my Ormerod printer, and I may copy the geared extruder design from that.
Re: Upgrading Mini Kossel to Duet electronics July 27, 2015 06:01AM |
Registered: 10 years ago Posts: 14,672 |
Re: Upgrading Mini Kossel to Duet electronics August 10, 2015 10:59AM |
Registered: 9 years ago Posts: 1,159 |
Quote
dc42
Quote
shadowphile
Hi Dave, I have been relying on your kossel-to-duet blog and it has become my bible for this process, thank you! I have a bunch of parts on order so I'm still lining up my ducks. (or is that an American expression?)
You have suggested 0.9 degree motors but I have seen multiple comments that those and/or 1/32-step drivers are too fast.
I would think the Duet could easily keep up though, unless there is a limitation somewhere not related to the MCU speed or word size.
0.9 deg motors or 1/32 microstepping would seriously stretch an Arduino Mega or similar atmega2560 electronics on a delta. But I expect the Duet to handle them adequately. At worst, travel speed might be limited to 200mm/sec instead of the 400mm/sec that I currently achieve with 1.8 deg motors and 80 microsteps/mm.
I ordered some new motors a few days ago (3 x 0.9deg JK42HM48-1684 for the towers, and a 1.8deg JK42HS34-1334 for the extruder). They are due for delivery tomorrow or Monday. So I will soon know for sure how fast the Duet can drive them. I also have some firmware efficiency improvements planned to improve the maximum speed.
Re: Upgrading Mini Kossel to Duet electronics August 10, 2015 12:59PM |
Registered: 10 years ago Posts: 14,672 |
Re: Upgrading Mini Kossel to Duet electronics August 10, 2015 04:02PM |
Registered: 9 years ago Posts: 1,159 |
Re: Upgrading Mini Kossel to Duet electronics August 10, 2015 05:34PM |
Registered: 10 years ago Posts: 14,672 |