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You posted the images in JPEG format but with extension HEIC (gimp data format).
People who cannot see them should download them to a local directory and change extension from HEIC to JPG or JPEG. Then they will be able to see the images.
by
hercek
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Delta Machines
One of these two or both of them are wrong: diagonal rod length delta radius
Steps per mm can be wrong too but then it is not a typical bowl shape. It's a bit more complicated.
You can try this:
If you are not scared of math and want to understand it more then try this:
by
hercek
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Delta Machines
No specific recommendation on a shock damper.
QuoteArnix
E.g. i can locate object and place the "extruder" right on top of it but when i lower the head down, arms are moved aside and it's quite hard to lower the arm down, on that specific location.
If the location below is mechanically reachable (*) then it looks like firmware bug.
(*) Do all the arms have enough free movement to follow platfor
by
hercek
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Delta Machines
The shock damper probably plays the major role. It also lowers maximum acceleration.
You can change the resonant frequency with the gearbox and steppers and that will influence vibrations too. E.g. bigger gear box ratio will increase resonant frequency. If that moves it far enough from the frequencies induced by movement than that will help too.
by
hercek
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Delta Machines
Adding an encoder on a stepper can make it kind of like a servo.
May be somebody will chime in to tell you whether DUET board can support some encoders. If so then you should select the ones supported by DUET and update firmware (if it does not have support for it).
I used only RM44SC. Not with a 3D printer. It would be good enough to mount on your steppers (before the gearbox). But it is probab
by
hercek
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Delta Machines
The problem is that our machines are open loop.
Most probably your steppers skip steps (e.g. at crash). If they skip steps then there is no way for firmware to know where the head is located because firmware does not know how many steps were skipped. The firmware state and mechanical machine state are not synchronized. The only way to resynchronize an open loop machine is to home all axes again.
by
hercek
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Delta Machines
Marlin keeps constant speed of carriages instead of platform (at least it did about a year ago, not sure about the latest version).
The result is that the hotend speed is slower in the radial direction near the edge of a heatbed.
Tangential speed of the platform will continue to be high.
Other option is what dc42 mentioned. Reduce your acceleration and jerk settings globally or on the fly with
by
hercek
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Delta Machines
The upward pull on flying extruder will pull up platform and that will add preload on diagonal rods. It will help if some of the diagonal rods are not almost horizontal. You can also add independent preload with a spring along diagonal arms. This would help more because the direction of the force would be better.
The short bowden of flying extruder will damp high frequency (low amplitude) moveme
by
hercek
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Delta Machines
I did not do the math for rotational delta so this is only an educated guess.
It depends what you mean by linear.
If you mean from the point of view of torque needed to lift one arm then possibly yes (the non-linear gear may need a different transfer function).
If you mean from one delta coordinate to one cartesian coordinate then not because one cartesian coordinate depends non-linearly on more
by
hercek
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Delta Machines
Did you add it?
AFAIR, you did not respond to the other guy's question of when rotary delta support will be added to reprap firmware.
by
hercek
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Delta Machines
You can find equations for linear delta here:
But you are probably building rotational delta (based on your previous post). Google it or write down the equations describing positions of the platform based on each each stepper motor position and solve the equations.
I'm do not know whether there is any open firmware supporting rotational delta. There is one other guy building rotational delta
by
hercek
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Delta Machines
You have incorrect steps per mm. That is the reason why your Z dimension is wrong.
If your XY dimension is fine (while having wrong Z dimension) then you have also incorrect both delta radius and diagonal rod.
by
hercek
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Delta Machines
Firmware defines how the printer will home. But it looks like your printer starts to home correctly but endstops are not working. There is g-code to report end stop status. Check whether the status changes properly when you activate end stop manually. Maybe you can find something for end stop testing in your LCD menu too.
If you do not like what your closed firmware is doing then replace it (thi
by
hercek
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Delta Machines
OK, thanks. I doubted you did the same as we do with rotors (since they do not rotate) so I wanted to make sure there is not something special I did not know about.
by
hercek
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Delta Machines
What do you mean by dynamic balancing of arms?
by
hercek
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Delta Machines
QuoteRedemptioner
Sounds like your next upgrade will be a floating extruder
That may have bad impact on maximum acceleration because he uses magnetic joints.
by
hercek
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Delta Machines
"Salmon skin" or "rings" on the walls of the prints are more likely related to incorrect decay mode for the used stepper. We had a thread about that here. Current has influence too but I would guess bad decay mode if it is not a duet board. Motor current can have significant influence on dynamic errors (errors due to high acceleration and rather low holding torque at microstep level) but these sh
by
hercek
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Delta Machines
If you do not need precise parts then use also grid based interpolation to level the bed. You may need this if your bed is not planar or when your printer is not precise in a way which cannot be fixed by calibration. If your bed probing reports peak to peak errors of 0.3 mm then you can assume non-linear errors of this order in XY directions too.
If your bed is planar and your diagonal rods do n
by
hercek
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Delta Machines
Quotefrankvdh
Can you share your method please? I have some errors in my printer that I suspect might be caused by tower tilt, but I'm not sure.
The general approach is the same as I published in 2013.
Quotefrankvdh
How do you know that the measured error is due to tower tilt?
Because the maxima notebook shows bigger errors when the calibration does not compensate for the tilt. Also I know that
by
hercek
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Delta Machines
I looked at a possibility to calibrate out tower tilts of a linear delta printer. Each tower can be tilted in any direction. I have a printer with deviation of about 0.8° from the ideal perpendicular direction. That is quite a lot.
I also calibrated (micro)step length. This may be useful if belts are not tightened the same. Though it is more likely to diverge.
The good news is that it does not
by
hercek
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Delta Machines
On my RAMPS 1.3:
* pin header marked E1 is for stepper motor and not a temperature sensor
* pin header marked T0 is for (probably hotend) temperature sensor
I have only 2 temperature sensors: hot-end and heated bed. A very old version of Repetier works fine with it. I have only one extruder. I do not know about the latest version.
by
hercek
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Delta Machines
Quotedc42
At 20000mm/sec^2 acceleration the machine sounded much rougher and there were missed steps. I was getting a lot of motor stall warnings, so they might have been caused by insufficient motor torque rather than anything else. Again, no joint detachments. This was on a print with a lot of sharp corners.
2G is about what I would expect with 400 g movable weight and 10N holding force for one
by
hercek
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Delta Machines
Ok, thanks. So you correct tower positions and one common tilt for all the towers together (which is the same as one bed tilt) plus end-stops and possibly also diagonal rod length. That is still 9 parameters only. Is that correct?
It is a good result anyway. Good job. If you ever to get support for towers tilted in different directions (i.e. 13 parameters) then please make a big post somewhere h
by
hercek
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Delta Machines
It will not work without firmware supporting your machine type. You need to get the proper firmware support first.
by
hercek
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Delta Machines
Can RepRap FW auto detect towers which are not equidistant and compensate for it?
Or do all the towers need to be tilted in the same direction?
by
hercek
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Delta Machines
QuoteBarracuda72
I dont want miss it anymore...so much comfort...perfect 1st layer..no matter if i triy a new nozzel..chage from normal hotend to volcano....airbrush nozzle..just hit print and the printer do the rest and give me a perfect layer. for that comfort im willing to have more weight because even now im far away from the limit, this system have.
First layer quality is not a feature of m
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hercek
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Delta Machines
QuoteBarracuda72
It doesnt matter how fast the Rotors rotate..if you take a look at the Heli mechanic you can see that there not much movment in the ball joints..they just adjust the pitch and yaw of the rotor blades.
Ooooo, but it does matter how fast the rotor rotates. Helicopters do not tilt the whole main rotor when you move the collective stick. They only change the pitch of the blades and t
by
hercek
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Delta Machines