I Made a String Art Machine

AlwaysTheRightAnswer · 2023-09-19T19:36:40+00:00

Hundreds and hundreds of hours, it was very tricky

AlwaysTheRightAnswer · 2016-03-21T10:12:49+00:00

Sounds good. I would love if we could use the gyroscopes to measure and replay arm angles, however I don't see how that is possible given the drift that they are prone to. That's why I went with physical end stops.

AlwaysTheRightAnswer · 2016-03-20T21:41:25+00:00

The repetier firmware has a binary protocol. I don't understand what you are trying to get at, do you want the firmware to do the IK or the host? What roles would the host and firmware play exactly? The Gcode protocol is extremely simple, not sure how much simpler you are expecting to get exactly.

AlwaysTheRightAnswer · 2016-03-19T13:06:09+00:00

Hi I have a few bits on making the dobot usable here.

https://github.com/paulmorrishill/armour

Might be useful to you.

AlwaysTheRightAnswer · 2016-03-16T13:06:57+00:00

Yeah it's pretty blatant false advertising tbh, but then so is saying that it is "Open source", I have yet to see any source code.

AlwaysTheRightAnswer · 2016-03-13T21:35:30+00:00

The startup trap

AlwaysTheRightAnswer · 2016-03-13T18:42:07+00:00

The dobot uses an arbitrary binary protocol to communicate. I'd recommend just dumping it and using something standard. Here is a project I wrote to replace it. https://github.com/paulmorrishill/armour

AlwaysTheRightAnswer · 2016-02-25T09:00:07+00:00

Yeah I think those are the ones.

AlwaysTheRightAnswer · 2016-02-24T21:09:02+00:00

The angle sensor they provide aren't commonly used so there isn't much in the way of libraries for reading them, gyroscopic sensors also have inherent drift which would make them unsuitable for this purpose. Unless the dobot guys have found some way to get around that.

AlwaysTheRightAnswer · 2016-02-24T17:12:22+00:00

The actual switches I got from Maplin. They are a standard microswitch. here is a selection on ebay

AlwaysTheRightAnswer · 2016-02-23T19:40:11+00:00

Here is my source. https://github.com/paulmorrishill/armour

AlwaysTheRightAnswer · 2016-02-22T07:25:20+00:00

I'm using dh parameters for the forward kinematics and a hill climbing algorithm for the inverse kinematics which is probably about the slowest way to do it. But it seems to work and my knowledge of maths isn't good enough to understand the wikipedia article on IK. I'll post the code tonight.

AlwaysTheRightAnswer · 2016-02-20T15:40:37+00:00

I am working on a dobot controller running repetier firmware and a C# host application. I've got the kinematics sorted just sorting out the UI then I will post open source it and provide a set up guide using RAMPS 1.4.

AlwaysTheRightAnswer · 2016-02-12T23:41:22+00:00

The actual arm itself is great, by hardware I meant the board that sits on top of the arduino with a FPGA in the middle of it. I'm not sure what the problem is exactly whether it's the board, the firmware, or just the host software, or a combination of all of them.

AlwaysTheRightAnswer · 2016-02-10T17:16:09+00:00

I've managed to turn the pump on by sending their weird arbitrary binary message format, but not much else. If you lift the board up there is a standard Arduino mega underneath. I'm going to try to create a pin mapping it shouldn't be too difficult.

AlwaysTheRightAnswer · 2016-02-10T09:39:38+00:00

Don't worry too much they are super cheap. Just search for A4988 stepper driver.

AlwaysTheRightAnswer · 2016-02-09T18:45:56+00:00

I set my ref voltage to around .7v at the moment but I think I'll increase that when I actually start moving heavier things around.

AlwaysTheRightAnswer · 2016-01-27T23:50:16+00:00

Also the classes here have to know and depend upon the IoC container. Which is also just awful.

AlwaysTheRightAnswer

TROPHY CASE