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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.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
macdowswe
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.
Well yes, I saw that video. However, I am wondering if it has been tried on a larger machine. A 3 kg mass on linear rails is still really nothing compared to what I am talking about. I'm considering trying it on my milling machine so I am talking more like a 40-50 pound mass moving vertically at at least 200 inches per minute. It is driven by a ball screw, but rides on dovetail slides which will have considerable more friction that linear rails. Has anyone attempted anything like this?
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
109jb
Well yes, I saw that video. However, I am wondering if it has been tried on a larger machine. A 3 kg mass on linear rails is still really nothing compared to what I am talking about. I'm considering trying it on my milling machine so I am talking more like a 40-50 pound mass moving vertically at at least 200 inches per minute. It is driven by a ball screw, but rides on dovetail slides which will have considerable more friction that linear rails. Has anyone attempted anything like this?
Ah fair enough. No, I haven't done anything like that. I don't think it will be a big issue though, as long as the gearing is well dimensioned.
Get a board, and try it ;D
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Re: Open source low cost servomotor controller
Quote:
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.
I do not share your optimism. If all you are running are 2 mm cutters into timber, that's fine. But try running a 2" face mill across steel and see what forces are involved. Or try running a 1/2" drill into steel.
There is a reason why larger machines have larger motors - and safety doors.
Cheers
Roger
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
RCaffin
I do not share your optimism. If all you are running are 2 mm cutters into timber, that's fine. But try running a 2" face mill across steel and see what forces are involved. Or try running a 1/2" drill into steel.
There is a reason why larger machines have larger motors - and safety doors.
Cheers
Roger
Yes, I agree with you. The method I outlined will only work if your fault force is much higher than any unmodeled disturbance force that occurs during normal operation. For some machines and applications, that is the case, and for some it won't be.
Cheers
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
macdowswe
Ah fair enough. No, I haven't done anything like that. I don't think it will be a big issue though, as long as the gearing is well dimensioned.
Get a board, and try it ;D
Are boards available and if so, where and how much do they cost?
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
109jb
Are boards available and if so, where and how much do they cost?
I will be facilitating a couple of production runs at different stages of maturity of the project. I expect that the early prototypes will be around $100, and with a larger run later on will be closer to $50. You can check out the details, and sign up for a board at any stage, here: https://hackaday.io/project/11583-od...nd-development
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Re: Open source low cost servomotor controller
https://cdn.hackaday.io/images/2665861480778750936.jpg
The time has finally come for the manufacturing run of ODrive v3.1. They are now on the way, and should arrive early to mid January.
At this stage, around 20 board kits are going out the people who signed up to the "Inital development" phase. They have not been all allocated yet, you can signup here.
Since the boars are going out to just a small group of early developers, I will have the time to personally get you up to speed with the codebase and help to get going with the hardware. Then, together, we can prepare some stuff that is a bit more stable and a bit more documented for when the alpha testing begins.
The cost for me to get this small batch of boards manufactured was $96 per board, so that is the amount I need to ask for a kit, plus shipping.
The kit involves basically everything seen in the above picture, and consists of:
- ODrive v3.1
- USB Programmer
- A set of the optional large gauge wire screw terminals
- A set of pin headers
- Some nylon standoffs
I hope that ODrive will be able to help you make an awesome robotics project, thank you so much for your contribution to helping people have access to open robotics hardware and software.
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Re: Open source low cost servomotor controller
Is it just me or is $96.00 for a kit a little pricey based on what is provided?
It's a shame eagle files aren't available, I'm almost certain my friend could have this board made and populated for $50.00 or less each in a small quantity like 50pcs.
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
websrvr
Is it just me or is $96.00 for a kit a little pricey based on what is provided?
It's a shame eagle files aren't available, I'm almost certain my friend could have this board made and populated for $50.00 or less each in a small quantity like 50pcs.
The design is available on GitHub, CircuitMaker, and CircuitHub. Please let me know where you looked and failed to find the links, and I will put the links there.
The price is quite high, I agree. This is because I used a turnkey professional manufacturer, CircuitHub, and only did a run of 28 boards. If your friend can have the boards made for less, that would be fantastic for the project.
Please let me know if you, or your friend, would be willing to help with that.
Cheers,
Oskar
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
macdowswe
The design is available on
GitHub,
CircuitMaker, and
CircuitHub. Please let me know where you looked and failed to find the links, and I will put the links there.
The price is quite high, I agree. This is because I used a turnkey professional manufacturer, CircuitHub, and only did a run of 28 boards. If your friend can have the boards made for less, that would be fantastic for the project.
Please let me know if you, or your friend, would be willing to help with that.
Cheers,
Oskar
I guess you didn't understand what I was saying.
Your schematic and PCB layout file are not usable by my friend, he only works with eagle files and wont waste time trying to convert the ones you have.
He has a preference for Version 6.3.0 but can accept Version 7.x if you have a licensed copy to generate unrestricted files.
If you need a licensed version of eagle so you don't have any board restrictions, this can possibly be arranged.
What this means is if you can't give me the schematic and PCB layout files in eagle format i wont be able to have my friend make the boards but he did estimate cost to be around $46.00 each (based on parts and board size) for a quantity of 50pcs and less on larger quantities.
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Re: Open source low cost servomotor controller
Your schematic and PCB layout file are not usable by my friend, he only works with eagle files and wont waste time trying to convert the ones you have.
Tough.
The world will not dance to your tune. The plans are FREE, for heavens sake!
Cheers
Roger
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Re: Open source low cost servomotor controller
Quote:
Originally Posted by
RCaffin
Your schematic and PCB layout file are not usable by my friend, he only works with eagle files and wont waste time trying to convert the ones you have.
Tough.
The world will not dance to your tune. The plans are FREE, for heavens sake!
Cheers
Roger
It never ceases to amaze me that someone says something which clearly indicates they didn't think before they responded or lack the faculty to see value in an offer.
RCaffin, why would you inject this nonsense?
Are you really that clued out that you can't understand the benefit provided by my friends offer if the files are in eagle format?
Since you seem pretty clueless I'll clarify it for you, no eagle files and my friend wont produce the boards inexpensively, you don't have to be a rocket scientist to understand this, just have some common sense and the ability to read.
Since it is doubtful you will make an offer to produce the board at a reasonable cost I fail to see how interest will be maintained for a product that is not reasonably priced when there are full and complete retail solutions at a fraction of the current cost.
For $62.00/pc I can buy a 6.5A/80V (AC 20V-80V / DC 20V-150V) stepper driver including the heatsink with an MOQ 10pcs and since the current cost is so high for an incomplete solution it wont help it survive past the OP's personal project and even he realizes this.
So, you are saying people should buy the product despite it's inflated costs just because you think they should, yeah right, good luck with that logic.
In closing, I would like to thank you RCaffin for informing me that the project doesn't need any help to produce the boards at a reasonable price and that it can live with the over/double priced product which doesn't make it an affordable or reasonably priced solution which in turn contributes to it's demise.
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Re: Open source low cost servomotor controller
Not wrong planet - wrong galaxy.
Cheers
Roger
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Re: Open source low cost servomotor controller
I bought 5pcs of 15A/60VDC (STM32F103TBU7) based servo drivers at $38.00/pc and the heatsink requirement is nothing more than a small strip of 1in wide aluminum flat-stock due to the very low IRDs of the FET's used and this price was based on a run of 200pcs.
While I have the eagle files for this driver, making more of this driver is not an option because what is lacking is firmware and the one person who has working firmware is no longer sharing it after others like yourself decided you didn't want him around here contributing to any projects.
Basically what I see is a lot of people like RCaffin who are actively sabotaging viable projects and products and for the life of me I can't understand the logic which dictates that an inexpensive servo solution should not be available to the home/hobby user but it appears that many people don't want it as they make efforts and expel energy preventing it.
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Re: Open source low cost servomotor controller
I couldn't see it anywhere but are you planning on producing 3 axis boards?
Very cool looking project, major props getting it out there!
cheers, Ian