DC motor replacement for 3D printers
Posted by rklauco
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Re: DC motor replacement for 3D printers May 07, 2016 12:46PM |
When you produce like 100k units.. prices will drop A LOT in china 
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Re: DC motor replacement for 3D printers May 07, 2016 02:16PM |
The price model for printers is nuts, a set of genuine toner cartridges for my color laser is nearly as much as buying a printer. Obviously I'll buy cheap refills and hope for the best
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What is Open Source?
What is Open Source Hardware?
Open Source in a nutshell: the Four Freedoms
CC BY-NC is not an Open Source license
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Re: DC motor replacement for 3D printers May 08, 2016 05:36PM |
Well, I suspect the whole project will be a big success now
I used parts of 2 old Canon printers - paper feeders for the both Z axis, belt from one of its printhead and DC motor for the paper feeder, too. I re-purposed the tensioning mechanism from the printhead, too. I had to do that - without the dynamic tensioning, the axis started VERY slow.
However, the circular strip has a VERY high resolution. I am tracking just one of them (no need for now to track both if they are powered by a single motor).
To move few cm down, I had to simulate 50000 steps (!!!).
Here is the video out of it.
Not only is it extremely precise, it's also fast.
The motor operates on 9.08V now, however it is capable of running on 24V apparently.
I start to love DC servo.
I used parts of 2 old Canon printers - paper feeders for the both Z axis, belt from one of its printhead and DC motor for the paper feeder, too. I re-purposed the tensioning mechanism from the printhead, too. I had to do that - without the dynamic tensioning, the axis started VERY slow.
However, the circular strip has a VERY high resolution. I am tracking just one of them (no need for now to track both if they are powered by a single motor).
To move few cm down, I had to simulate 50000 steps (!!!).
Here is the video out of it.
Not only is it extremely precise, it's also fast.
The motor operates on 9.08V now, however it is capable of running on 24V apparently.
I start to love DC servo.
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Re: DC motor replacement for 3D printers May 09, 2016 03:39AM |
LOL
Today I measured the physical resolution.
The system does 350.000 steps per 94mm of movements. Therefore the resolution is 0.000268571mm per step
I think this is beyond any practical usage, so I'll introduce 10x multiplier to step input...
Today I measured the physical resolution.
The system does 350.000 steps per 94mm of movements. Therefore the resolution is 0.000268571mm per step
I think this is beyond any practical usage, so I'll introduce 10x multiplier to step input...
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Re: DC motor replacement for 3D printers June 07, 2016 03:49PM |
Well, I found one unexpected issue with the Z axis.
Due to VERY high resolution of the movement (4096 steps per mm) I run to the limit of ATtiny85.
While driving it using serial port, the ATtiny is OK and can drive the movement quite fast.
However, when connecting it to RAMPS, it has to cope with interrupts for both the optical encoder inputs AND the step input.
And this is too much - as for each mm of movement it will receive 4096 + 4096 interrupts.
The result? It will try to move the axis, but after 7-8mm of movements it gets "wild" and starts to move uncontrollably in one or the other direction full speed
I have to connect oscilloscope and find out, what's going on...
Due to VERY high resolution of the movement (4096 steps per mm) I run to the limit of ATtiny85.
While driving it using serial port, the ATtiny is OK and can drive the movement quite fast.
However, when connecting it to RAMPS, it has to cope with interrupts for both the optical encoder inputs AND the step input.
And this is too much - as for each mm of movement it will receive 4096 + 4096 interrupts.
The result? It will try to move the axis, but after 7-8mm of movements it gets "wild" and starts to move uncontrollably in one or the other direction full speed
I have to connect oscilloscope and find out, what's going on...
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Re: DC motor replacement for 3D printers June 10, 2016 03:52PM |
Major achievement here.
Changing one word in the source file and all of a sudden, everything works!!!
I had to define the target1 in source code as LONG, not INT - as the Zaxis has mental resolution.
I am now able (while still having multiple of 10 steps) to do movement on Z axis with precision of 0.0025mm.
I call it quite good - that's 2.5 microns
Not really usable, but it's amazing this is achieved using only scrapped parts from old 2D printers.
Changing one word in the source file and all of a sudden, everything works!!!
I had to define the target1 in source code as LONG, not INT - as the Zaxis has mental resolution.
I am now able (while still having multiple of 10 steps) to do movement on Z axis with precision of 0.0025mm.
I call it quite good - that's 2.5 microns
Not really usable, but it's amazing this is achieved using only scrapped parts from old 2D printers.
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Re: DC motor replacement for 3D printers June 10, 2016 11:20PM |
Quote
rklauco
Major achievement here.
Changing one word in the source file and all of a sudden, everything works!!!
I had to define the target1 in source code as LONG, not INT - as the Zaxis has mental resolution.
I am now able (while still having multiple of 10 steps) to do movement on Z axis with precision of 0.0025mm.
I call it quite good - that's 2.5 microns
Not really usable, but it's amazing this is achieved using only scrapped parts from old 2D printers.
Great resolution there. What is the speed you can reliably move your Z and how accurate & repeatable is the move compared with the same setup with steppers?
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Re: DC motor replacement for 3D printers June 11, 2016 03:18AM |
Can't compare to stepper as this platform never had one
Repeatability is 100%, no problem there.
The speed is determined by the usage of 8mm rod - therefore I can do 90mm in 12 seconds currently at 12V, but the motor is 30V capable
Repeatability is 100%, no problem there.
The speed is determined by the usage of 8mm rod - therefore I can do 90mm in 12 seconds currently at 12V, but the motor is 30V capable
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Re: DC motor replacement for 3D printers June 20, 2016 03:11PM |
This is an excellent point!
However, my original motivation was a bit different - I am looking for something much quieter then my NEMA17 printer - that is seriously loud. My wife cannot sleep in the next room when I print something.
And, I can already tell you, that the DC motors, although still having some issues, are WAY quieter than this.
The other motivation was price - but, as I found out, the cheap price is probably only for OEMs, not for general public - as I was not able to get my hands on a quadrature encoder or the encoding strips within a pricerange that would not closely copy a price of a whole 2D printer with such parts
So for now, the quiet operation (and option to salvage the parts from 2D printers) remains my primary motivation.
However, my original motivation was a bit different - I am looking for something much quieter then my NEMA17 printer - that is seriously loud. My wife cannot sleep in the next room when I print something.
And, I can already tell you, that the DC motors, although still having some issues, are WAY quieter than this.
The other motivation was price - but, as I found out, the cheap price is probably only for OEMs, not for general public - as I was not able to get my hands on a quadrature encoder or the encoding strips within a pricerange that would not closely copy a price of a whole 2D printer with such parts
So for now, the quiet operation (and option to salvage the parts from 2D printers) remains my primary motivation.
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