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Open source low cost servomotor controller
Hey guys,
I would just like to announce my project, called Odrive. It is an open source high performance brushless servomotor controller, meant to be used with cheap hobby motors. It has 2 axes per board, and allows chaining multiple boards for more axes.
Let me know if you are interested in development, or want to get your hands on some early hardware.
Cheers!
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Re: Open source low cost servomotor controller
Now posted design, no posted software, no real description of features and functionality, kinda hard to have interest in a project with no content.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
websrvr
Now posted design, no posted software, no real description of features and functionality, kinda hard to have interest in a project with no content.
Sorry if it was confusing, the details of the project is in the link attached to the word Odrive in the original post. I can give the link explicitly here:
https://hackaday.io/project/11583-od...-motor-control
Cheers.
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Re: Open source low cost servomotor controller
Are you the creator of this work?
Since the project is being developed elsewhere, why is it being cross-posted here?
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
websrvr
Are you the creator of this work?
Since the project is being developed elsewhere, why is it being cross-posted here?
Yeah I am. I thought it would be interesting to reach out to this community too. Especially since I see the type of machines that will benefit the most are heavy machines that need high precision.
I was hoping to engage in a fruitful discussion on this forum about the project.
Cheers!
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Re: Open source low cost servomotor controller
I'm curious to know how you came into the 150A or 75A current specification since all the PCB software I have access too tells me 30A on 4oz stopped copper is the best you can hope for.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
websrvr
I'm curious to know how you came into the 150A or 75A current specification since all the PCB software I have access too tells me 30A on 4oz stopped copper is the best you can hope for.
Well, first of all this is peak current, it will for sure not cope with 150A continuous current. Also, I think I can get a fair bit of extra heat dissipation through the heatsink on the mosfets, and down the phase wires. In the end, only testing will show what the capabilities truly are. If it turns out that it is too weak for a number of CNC applications, then it should be fairly easy to increase current capability by just increasing the size of the board and mosfets.
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Re: Open source low cost servomotor controller
As I understand it, v3 doesn't exist yet? Are the design files available for v2?
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1 Attachment(s)
Re: Open source low cost servomotor controller
Quote:
Originally Posted by
James Newton
As I understand it, v3 doesn't exist yet? Are the design files available for v2?
I have a v3 on my desk atm, see attached picture. I am currently doing some basic tests to make sure that the hardware design is functional. When I have ascertained that that is the case, I will help people get their hands on some v3 boards.
Nevertheless, all the design files are available here:
- v3 Firmware is here
- v3 Board design is here
- v2 Firmware is here
- v2 FPGA logic is here
- v2 Board design is here
Cheers!
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Re: Open source low cost servomotor controller
The motors you show are open to chips getting in. Have you built a covering for them and do they not overheat with a cover.
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Re: Open source low cost servomotor controller
Macdowswe,
Very nice, clean looking board.
Please keep us in the loop, there are many interested users here.
Welcome to the Zone,
Jeff...
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
hoecken
The motors you show are open to chips getting in. Have you built a covering for them and do they not overheat with a cover.
Yeah they are open. I was thinking of making a shroud that houses a motor/encoder assembly, and that has an air inlet with an intake filter, and a fan for forced air cooling. This can probably increase the performance at low speeds fairly significantly since the motors own air cooling doesn't work unless they are spinning at high speed.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
jalessi
Macdowswe,
Very nice, clean looking board.
Please keep us in the loop, there are many interested users here.
Welcome to the Zone,
Jeff...
Cheers! Thanks! I will keep you up to date.
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Re: Open source low cost servomotor controller
Thanks for pointing to the files... I can't seem to find a Schematic for v3.... what format are those design files in? Is there a pdf or png of the Schematic that I'm missing?
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
James Newton
Thanks for pointing to the files... I can't seem to find a Schematic for v3.... what format are those design files in? Is there a pdf or png of the Schematic that I'm missing?
No problem. The design files are in Altium Designer. There is also a PDF in that folder. Here is a direct link: https://github.com/madcowswe/Servo/b...two_ax_PCB.PDF
Cheers (:
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Re: Open source low cost servomotor controller
Hey everyone,
There is now an update about board availability and the roadmap for the ODrive features on the project page.
If you are interested in getting an ODrive board, you should check it out.
Cheers!
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Re: Open source low cost servomotor controller
150A or 75A current through that PCB those FETs, those wires and those connectors?
Really?????
Cheers
Roger
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
RCaffin
150A or 75A current through that PCB those FETs, those wires and those connectors?
Really?????
Cheers
Roger
Yeah ;D
This is not a continuous rating, but peak rating. The continuous rating will be significantly less than that.
But it is the peak rating that is important, as the the torque peaks only during the first bit of acceleration in a move, and the last bit of deceleration. If you are using the torque to push continuously into a workpiece, the system should be dimensioned such that you would use much less current for that.
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Re: Open source low cost servomotor controller
Im impressed! This is a wonderful project! About time someone did this! You could also use this for force feedback in flying and racing simulations!
Sent from my iPhone using Tapatalk
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Re: Open source low cost servomotor controller
There is a way to put a encoder in this config , or i don't see one .
Thanks .
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
Andreiir
There is a way to put a encoder in this config , or i don't see one .
Thanks .
Yeah, the encoders plug into the top right part of the board.
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Re: Open source low cost servomotor controller
Sorry to dig up an old thread here, but whats the progress here?
I am doing some research around safety with CNC machines, and this interests me because it seems it would have the capability to detect when it has hit a foreign object, potentially allowing it to stop if it hits an errant hand before crushing it. Obviously this will only work for machines which have a fairly predictable load/friction, but considering most fingers can withstand 500N briefly before suffering permanent damage, and most CNC machines don't use anywhere near that much feed force, we might be able to design a machine which won't cut your fingers off accidentally.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
JustPassing
Sorry to dig up an old thread here, but whats the progress here?
I am doing some research around safety with CNC machines, and this interests me because it seems it would have the capability to detect when it has hit a foreign object, potentially allowing it to stop if it hits an errant hand before crushing it. Obviously this will only work for machines which have a fairly predictable load/friction, but considering most fingers can withstand 500N briefly before suffering permanent damage, and most CNC machines don't use anywhere near that much feed force, we might be able to design a machine which won't cut your fingers off accidentally.
Yes, this should be quite straightforward with ODrive. I already plan to do automatic machine mass/friction identification, and to use model based feed-forward for most of the control action. So it should be possible to look at the tracking error to identify if there are any major disturbance forces, and hence take action.
The ABB YuMi robot, that I was working on a few years ago, has a similar feature.
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Re: Open source low cost servomotor controller
I am very interested in this project. I have seen your videos and they are pretty impressive. I can see how it already could be applied to smaller machines such as 3D printers and small routers. I have a benchtop milling machine and was wondering if you have tried this on larger machines. Also, does this take step direction signals like a typical stepper motor driver, or some other method.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
109jb
I am very interested in this project. I have seen your videos and they are pretty impressive. I can see how it already could be applied to smaller machines such as 3D printers and small routers. I have a benchtop milling machine and was wondering if you have tried this on larger machines. Also, does this take step direction signals like a typical stepper motor driver, or some other method.
Thanks!
On the third video on the project page, you can see a demo with a 3kg mass moving 80cm.
Yeah, step/direction input will be, by popular request, the the first available interface to control ODrive.