Help me get connected to my Duet2Wifi
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@Phaedrux Im confused by the equation.
Hmin = full_steps_per_rev * rated_current * actual_current/(sqrt(2) * pi * rated_holding_torque)
What is sqrt? and this is in algebraic format correct. So I would calculate full steps x rated current x actual current (A) and calculate sqrt x2 then x pi x rated holding (B). then divide a with b right?
I have never had any luck with stall guard in general. Is there a way to turn it off but have senseless homing like on a prusa? Since this is on a coreXY that I will want to print at speeds above 100mm/s It could become a problem could it not?
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@Kwad3d said in Help me get connected to my Duet2Wifi:
Is there a way to turn it off but have senseless homing like on a prusa?
Yes, that's exactly what you're doing now. You don't have to use both. You can use either or.
It would help me to know what your motor model is. Do you know the rated current? If it's detecting a stall already at M913 80% perhaps your M906 current in config.g is set too low.
If you tell me the rated current and whether they are 0.9 or 1.8 degree motors I can calculate the value using my spread sheet.
@Kwad3d said in Help me get connected to my Duet2Wifi:
Since this is on a coreXY that I will want to print at speeds above 100mm/s It could become a problem could it not?
No, no problem at all. Your max speed was limited to 100mm/s in your config.g and I suggested increasing it to 200mm/s, but you could raise that even more if you want.
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@Phaedrux there LDO brand motors on X and Y at 0.9 deg. Model 42STh47 1684MAC Standard size motor. no other information about the motors was provided by the retailer of the machine and I could not find the required info on the LDO site.
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Do they look like this?
https://www.printedsolid.com/products/ldo-nema-17-motor-ldo-42sth47-1684mac
If so, 1.68a rated.
If that's the case, then the current you have set in M906 in your config.g is quite low at 800ma. Try changing that to 1400 instead.
Now your homing file might work better with M913 X70
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@Phaedrux Yes. the # number on the end is different on mine but I think that's a batch number or something
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@Phaedrux WIll that help with the stall issue or can I disable it
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@Phaedrux Does this look ok for my Homex file? I changed the current for x and y already
M400
M913 X70 Y70 ; drop motor current to 70%
M400 G91; relative positioning
G1 H2 Z10 F12000 ; lift Z relative to current position
G1 H1 X-320.5 F10000 ; move quickly to X axis endstop and stop there (first pass)
G90 ; absolute positioning
M400
M913 X100 Y100 ; return current to 100%
M400 -
So at this point you should have
M203 X12000.00 Y12000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X1500.00 Y1500.00 Z100.00 E10000.00 ; set accelerations (mm/s^2)
M906 X1400 Y1400 etc etcThat homing file looks ok, does it work?
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@Phaedrux No same stuff. Bed lowers but the X axis remains motionless and the X location changes to 0. I need to disable the stall detection. I have been printing a long time and that feature will ruin more prints than it will potentially save.
I also had my travel speed set to 300mm/s on the coreXy. So do I need to up my limit to 300 right. Don't have any reason to go beyond that.
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But you don't even have an m915 in your config.g to enable stall detection.
Once it thinks it's homed can you jog the axis around like normal?
Try reducing the speed of the homing move to 6000
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@Kwad3d I never got enough information to solve the equation myself. If stall detection is off then what if preventing the homing procedure. Seems to me it is on and I would rather have it turned off. There has never been a print saved by senseless homing in my shop but I have had several failures so I turn it off on printers like my prusa. Yes after it thinks its homed it moves. just will not move beyond the zero position set by the homing move.
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I need to disable the stall detection.
Seems to me it is on and I would rather have it turned off.
if you don't have m915 in your config its not on and you don't need to disable it, its off by default.
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Ok im making a serious recommendation for the Duet team... order a SKR with some 2209 or other drivers capable of senseless homing and see how simple it is to set up. Only took a few minutes. I have been on this all day. How do I get the axis to just grind into the home position? I know the spot I want to be in in-between there and where im at now.
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The length of your homing moves? Motor current? Friction? Assumptions?
Paste your homing file(s)?
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@Kwad3d said in Help me get connected to my Duet2Wifi:
what if preventing the homing procedure.
It's not preventing it, it's just detecting a stall immediately and saying you are homed. False positive.
Please post your config.g again along with your homing files. Let's see what's up.
@Kwad3d said in Help me get connected to my Duet2Wifi:
Ok im making a serious recommendation for the Duet team.
I hate to break it to you pal, but the problem isn't the duet, the firmware, or the drivers. The forum isn't flooded with people unable to configure sensorless homing.
So let's put our thinking hats on and figure out what's going on. With a bit of patience you've made it this far, and we got farther faster when you weren't being crusty.
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@Kwad3d said in Help me get connected to my Duet2Wifi:
How do I get the axis to just grind into the home position?
why is that a goal?
butG1 H2 X-320.5 F10000should do it.G1 H1 X-320.5 F10000as you had it like will move to the endstop and stop.To see the difference in H1 and H2 paramterer https://duet3d.dozuki.com/Wiki/Gcode#Section_G0_G1_Move.. core xy ..
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@bearer Ok. Im on a coreXY so im a little confused by the documentation on H2. Im getting the impression that that is for a single motor move but I have a tandem motor set up for X and Y. Am I overthinking it and just try the H2 instead?
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H2 works a bit different on a CoreXY. Normally it just ignores endstop status and allows a requested move to work, but in a delta and corexy it also targets a single motor move.
What bearer is saying I think, is that if you want to ram the print head into an axis, using H2 to ignore the homed state and execute the move would give you that.
Anyway, back to actually tuning your homing moves...
Did you ever try this to see what combination of motor current and feed rate works?
Example
M913 X30
G1 H1 X-300 F10000
M913 X40
G1 H1 X-300 F10000Also, just to eliminate the mechanical side, is this a new printer build or one that was working previously?
Since it's detecting a stall, is it a false positive, or is there actually some binding on the XY motion?
If you detect the belts from the motors are you able to move the print head around smoothly and freely?
With the belts attached, are you able to slowly move the head around with mostly equal resistance in all direction?
If the mechanics are all clear, then we're left with two parameters to tune for sensorless homing to work, motor current and feed rate.
Motor current will depend on your motor specs, we think the rated current is 1700 and 80% of that for normal usage is 1400.
Then we need to find the lowest percentage reduction of that which still allows for normal movement. So start at M913 X10 and then try to jog the axis (don't try a homing move at that point. You can send G92 X100 to force the x axis as homed btw to allow you to jog it normally.) If it doesn't move, up it to M913 X20 and repeat. When the motor reliably moves you've found the right motor current percentage for sensorless homing.
Next would be finding the right feed rate.
If it's still stalling all the time, then we need to dig a bit deeper and would ask that you post your config.g, your homing files, the results of M122, and of sending M98 P"config.g". Also some more details about the printer. We're not in the room with you, so we only know the details you provide.
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@Kwad3d
yes h2 is not for corexy movements. H1 is correct -
@Phaedrux just as the forum is not flooded with people having problems on social media you don't see anyone who is using it successfully either and most people recommend against attempting it. In fact on the group for the Sec kit there are plenty of people who have swapped to a duet but went through the trouble to design mounts for ends top switches on a machine designed to use senseless homing and not a single person in the group I have seen has senseless working. Im not crusty just pointing out the night and day difference between setting up senseless homing between duet and a marling board. Marlin has a single setting to make homing less or more responsive and doesn't require over a day to set up correctly. Simple fact is it is way easier to do on marlin and Duet3d for all its advantages over marlin is clearly falling short on senseless homing compared to marlin. Again not crusty just facts. Kind of like being a Alcoholic. You can't begin to make things any better if nobody will admit they have a problem.
With that said.. Yes the printer worked just fine on Marlin before the board swap and had zero problems homing without endstop switches.
I did try every combination of current from 800-1400 and adjusting the drop current settings from %50-90 on every current setting. I also played with feed rates but in general were moving the wrong direction collectively. on the standard current and feed settings I could get it to home on occasions but all the suggested alterations have resulted in not a single successful homing move.
As for the motion system it was smooth when build only around 6-8 weeks ago but I can remove the belts to confirm its not contributing to the problem.
At this point I have already designed and printed manual endstop mounts as it will be the shortest distance to get to a usable state for the board.
