BLtouch on Polar kinematics and some questions
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Okay that is great to hear that there is no special measurement needed for the Y offset phew.
Ah I see, well it's meant to be a fun experiment for my elementary students, it's never going to print anything high quality or precision, so I'm okay with it, as long as it can print at in the middle.
Interesting enough, I just found out it's not the mechanical parts that's offset in the middle, it's the nozzle I'm using (it's a cheap clone I'm also temporary using), it's just so slightly off due to the cheap hotend block. After a little hammering and twisting, it's not pretty much on point (like 0.1mm at most). Worse comes to worse, I can just add a very small hole int he middle of everything I build right? xD
Okay I will purchase the Maestro and get started, I can continue to post any problems or questions I have in this thread, if that's alright?
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@iamthebest22 If financially possible, I would prefer Duet 2 (Wifi or Ethernet) to the Maestro, because Duet 2 has an FPU and to my knowledge Maestro doesn't have it. The Polar kinematics uses tan, sin and cos functions to calculate the positions. Maybe @dc42 can tell whether this matters in respect to timing/stepper speeds.
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@JoergS5 said in BLtouch on Polar kinematics and some questions:
@iamthebest22 If financially possible, I would prefer Duet 2 (Wifi or Ethernet) to the Maestro, because Duet 2 has an FPU and to my knowledge Maestro doesn't have it. The Polar kinematics uses tan, sin and cos functions to calculate the positions. Maybe @dc42 can tell whether this matters in respect to timing/stepper speeds.
That's correct, the Duet Wifi or Ethernet can do the trig calculations much faster. In fact there is a special M-code (M122 P103) to time how long sine and cosine calculations take. I've just run it, and here are the results:
Duet 3: single precision 6.55us, double precision 12.07us
Duet WiFi/Ethernet: single precision, 2.14us ok, double precision 50.68us
Duet Maestro: single precision 31.83us, double precision 50.17usDuet 3 is running with cache memory disabled at present, it should get a lot faster when we enable the cache. RRF uses almost exclusively single precision maths, so it is the single precision speed that matters.
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Oomph if you only had just posted a few hours earlier >.< I already purchased the Duet Maestro >.<. Maybe in the future, right now I only plan on printing at like 30-40mm/s at most on this polar machine, so I think the Duet Maestro will be fine at that speeds for now? Or would the Duet Ethernet be a really much better choice? (Ethernet version because I have a 32 network switch in my 3d printer room so all my printers are on ethernet, except the ones running the duet wifi's) I can possibly cancel the order and get the duet ethernet cheaper (cause I got a discount).
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Question, my Duet Maestro is on it's way, I'm using the reprapfirmware online configurator, and I don't see the Polar as an option under Printer Geometry, do I temporary select Cartesian, and then later change the movement section under config.g as mentioned here?
https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwarePolarPrinter
Thanks
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@iamthebest22 said in BLtouch on Polar kinematics and some questions:
Question, my Duet Maestro is on it's way, I'm using the reprapfirmware online configurator, and I don't see the Polar as an option under Printer Geometry, do I temporary select Cartesian, and then later change the movement section under config.g as mentioned here?
https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwarePolarPrinter
Thanks
Yes. When assigning motor parameters and endstop inputs, treat the radial arm as X and the turntable as Y.
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Thanks, got the config sorta setup via configuration tool, just need to change the movement to polar and will post it here soon to confirm before my Duet Maestro arrives.
First thing, about the Bltouch offset, is it similar to Marlin (if that's okay to say here), so as you can see in the pic, the BLtouch is to the right and front of the Nozzle (you can see the homing switch for the X in the back also, that's the X maximum Radius, NO minimum X radius homing switch). So that means the offset if similar to the Marlin, should be -17.5mm for Y and for X should be +22.5mm? Is that correct?
Pics:
https://www.dropbox.com/s/is500e0kb6gc5kl/2019-11-15 23.39.37.jpg?dl=0
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@iamthebest22 said in BLtouch on Polar kinematics and some questions:
the BLtouch is to the right and front of the Nozzle (you can see the homing switch for the X in the back also, that's the X maximum Radius, NO minimum X radius homing switch). So that means the offset if similar to the Marlin, should be -17.5mm for Y and for X should be +22.5mm? Is that correct?
If in Cartesian coordinates +X is to the right and +Y is to the rear, that's correct.
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wait I just realized, if the radial arm is the X and turntable is Y, shouldn't what I said before be flipped? the X be -17.5mm and Y be 22.5mm?
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I just changed the config.g and the homeall, homez, homeradius, homebed, I've post it up here, I'm wondering these are correct? Thanks.homez.g homeradius.g homebed.g homeall.g config.g
