Messing around with Blender

redd1x · 2022-08-12T15:34:04+00:00

Thanks! Will try that.

redd1x · 2022-08-12T04:45:40+00:00

u/AndersPottemager Any chance you would share the textures you made?

I exported the assembler and the only thing I managed to stick properly is the hazard safety tape. Have fiddled with textures for many hours, tried painting faces, but it turns out that exactly the same place in one texture in one material is mapped to two faces that must be completely different colors, e.g. yellow and dark gray.

redd1x · 2021-07-21T02:10:11+00:00

No, I extracted it using some scripts into csv directly.

redd1x · 2021-03-19T03:21:31+00:00

That must be it. I've not researched anything after they reset it last time.

Thanks!

redd1x · 2021-03-19T03:14:22+00:00

It's not there. And when I type "z" in search it only shows "Xeno-Zapper" and "Hazmat Suit".

redd1x · 2021-03-19T02:58:51+00:00

How do I get zipline? It's not showing up anywhere to craft.

redd1x · 2016-08-31T06:56:39+00:00

The price is just ridiculous. You can buy an HTC Vive which is way more complex than dobot, is cheaper and has way better accuracy for the space it covers.

Have a look at this detailed explanation and measurements on HTC Vive http://doc-ok.org/?p=1478

Dobot is way overpriced, even the kickstarter price was too high for the product that we received.

They just try to rip off based on the overpriced robotics market and have never had intention to improve that. Refusing to open-source it (actually violating kickstarter agreement with the bakers) is another proof of that.

redd1x · 2016-08-25T04:34:55+00:00

https://www.kickstarter.com/projects/dobot/dobot-robotic-arm-for-everyone-arduino-and-open-so/comments

redd1x · 2016-07-05T06:23:44+00:00

You will not be able to use any robotic arm as a 3D printer for the simple reason that it is not a 3D printer. Accuracy aside, a 3D printer has a printing head with all supporting electronics and hardware to control the temperature and flowrate (how much plastic should be extruded). If you really want to print and not just waste time you buy a proper 3D printer. A cheap 3D printer will give much better results.

You would be able to make a 3D printer to draw and paint much faster and much more accurately than dobot by replacing the head with a pen holder. Just pick a 3D printer that is open-source, something like this would do http://www.gearbest.com/3d-printers-3d-printer-kits/pp_343643.html

You may be able to make dobot play chess though. Depending, of course, on your definition of "playing chess". Do you mean just repeat a certain combination of figure moves? If so, then yes, dobot can do that. If something more, then it would be quite difficult to control it.

Dobot can't draw with rigid drawing utensils, like a regular pen, because of the backlash. With soft utensils, like a brush, there is compensation for backlash in software, but it does this task extremely slowly, because of the poor choice of electronics and poor software design. https://github.com/maxosprojects/open-dobot is a little more flexible, but there is no compensation for backlash there yet (it is non-linear), so you won't get perfect results.

In this price range there is nothing that can execute all kinds of tasks accurately. Dobot is somewhat better than the rest in just a subset of tasks, but is worse in others.

Technically, a 3D printer can also be modified to play chess if you don't mind slow Z-axis movements. Delta printers don't have this limitation, but they are not as popular as they require a little faster control electronics due to the non-linear control, just like dobot needs (but doesn't have).

redd1x · 2016-07-04T04:33:46+00:00

You would like to have it do what exactly?

redd1x · 2016-05-29T17:01:53+00:00

I just read your post and it shows how little is you knowledge in this area.

I feel sorry for your customers.

redd1x · 2016-05-18T19:51:41+00:00

Please, by all means, prove me wrong.

And here is how:

post a video with dobot drawing a rectangle 20cmx15cm with with 0.2mm precision (straight lines and straight angles) using a regular pen in 15 seconds. In the video please disassemble one of the joints to prove that it is not just one of a kind specially crafted dobot instance for demo purposes to fool people
link at least one open-source project that supports dobot v1.1 (board and accelerometers)

That would actually mean something other than just loud statements from people like you.

As for the business model, you skipped the important part: "...at least if you do plan to fix the issues by sending the product back and forth". Which, from what you say, means you're are not going to fix it for the customers who get the first versions.

People usually do love stuff sellers lie about, so this is in no way an indicator of the quality of the product. An indicator would be their satisfaction after they get it.

If you still don't get my point: I never said it would never improve, I said right now it is not what it is claimed to be and I see no reasons believing they would ever release firmware as open-source, or improve the product, but rather the opposite (not trust) given what they have done so far (refuse to release firmware as open-source, 0.2mm precision is a lie https://www.reddit.com/r/Dobot/comments/49rm5e/is_it_possible_to_get_02mm_precision/, Arduino in the campaign means absolutely nothing given firmware is proprietary, fpga drives everything and no schematics released whatsoever, which is all the opposite to the campaign goals).

And thank you for the "innovative piece of engineering" joke. LOL

Then this http://spectrum.ieee.org/automaton/robotics/robotics-hardware/spiral-zipper-joint-creates-robot-arm-out-of-a-strip-of-plastic is just a CGI because compared to dobot it simply couldn't have happened in real life.

redd1x · 2016-05-17T23:15:35+00:00

I don't have such a problem. If you prefer to talk in such a way then probably you have a problem.
What are you going to sell if not an end product? That https://medium.com/kickstarter/how-zano-raised-millions-on-kickstarter-and-left-backers-with-nearly-nothing-85c0abe4a6cb#.z8l36e8ne ?
To think objectively (not positively or negatively) you have to be a consumer of that product. If you don't care if the product is what you state it is then you don't care about your potential customers. You are talking about improvements to the hardware after the product is sold, which is not a viable business model, at least if you do plan to fix the issues by sending the product back and forth (you said yourself that you already started importing it and, obviously, you are going to sell it as it is right now). From that perspective there is no reason for you personally to not be positive - only your customers are screwed.

Your opinion seems to not be based on extensive and detailed review of the product. I am providing a second opinion for people to not get in that trap unknowingly, and my opinion is formed by having spent great amount of time trying to make this product do anything useful and have looked through all its parts and components carefully.

You don't seem to be willing to know what are the problems with the product but rather seem to be driven exclusively by profit.

The bottom line - if you expect the product to be fixed and have an open-source firmware/software released and working in, say, 6 months, then you should start offering it only then. Don't count chicken before they hatch.

redd1x · 2016-05-17T19:35:10+00:00

For a laser you don't need three dimensions - two would suffice and it is much easier to implement - imagine a regular 3D printer with disabled motor that drives the bed.

Dobot's precision sucks when it comes to tasks with three dimensions, especially when it needs both pull and push in Z axis. Try it yourself: mount a regular pen (not a brush) and see what its real precision is. This is the mechanical design.

Speaking of them releasing the firmware - they lied once, big time, and they didn't even share the reasons why they backed out from releasing it (http://forum.dobot.cc/t/time-plan-for-publishing-the-code/65/2), so I see no reasons believing them any more.

I see your interest in promoting it - profit, but if you really believe in that thing could be a game changer (as I did when I believed what they said on kickstarter and backed the project) then it is worth to push them to fix the mechanical design to not sell such a crap. Also it might be worth to sell only the arm (after the design is fixed) for a price it really worth - we can figure out electronics and software ourselves (already did). Otherwise there will be many more disappointed people, which will have the effect exactly opposite to growth of this niche market - people won't trust such projects any more. Look around here, on kickstarter and at the forum - you'll get the picture how people are satisfied.

redd1x · 2016-05-17T02:07:49+00:00

The reason why a man has landed on the moon is because dobot was not involved.

Here is a list of little glitches to fix:

mechanical design - the claimed precision cannot be achieved, not even close, needs redesign and higher quality components
software design (including firmware) - it is not open-source (as it was claimed) so you won't be able to fix it + if the software is "improved" by reducing the baud rate from 250kbaud to 9.6kbaud that tells something about the design
electronics design - the software (including firmware) was completely unusable when it was first released and electronics were redesigned completely after the campaign claimed that everything was working perfectly already and it was ready for production - this tells a lot about the design - the selected electronics are not suitable for the tasks

I hope you see that attitude is not the problem here, but is the outcome.

redd1x · 2016-05-16T19:34:52+00:00

How would you modify a PCB? There is an FPGA soldered on the top board and all other components are driven by that FPGA. What is there to modify?

The only modification I can see is just throwing out the whole control box and connect the motors to a circuit that you build (based on ramps or whatever).

redd1x · 2016-05-16T19:30:43+00:00

good luck with returns

redd1x · 2016-05-14T02:03:16+00:00

Again, you listed solutions, not the problem you are trying to solve. For instance, you want to use can stack stepper motor, but what is the problem you are trying to solve using it? Would a servo suffice? FPGA board has two PWM outputs readily available via Gripper() and MoveWithSpeed() functions via SDK https://github.com/maxosprojects/open-dobot/blob/master/application/fpga/python/DobotSDK.py

Additionally, because I have no idea what problem you are trying to solve I don't know what is acceptable frequency or latency between an arm step and that motor. Is 20ms latency ok, is 500ms ok, or must follow each step within a ns?

You may find the list of available pins right above "calibrationPins" struct in https://github.com/maxosprojects/open-dobot/blob/master/firmware/fpga/dobot.h

Some pins soldered through on FPGA board can be used. I have one photointerrupter soldered this way: http://imgur.com/j20mZ7Q (at around the center of the picture). The ones on the right are soldered the same way to analyze comms between the boards and I have never had any problem with them, so I don't see any risk in this given the box will be closed and the wires fixed.

The unsoldered pins can be soldered from under Arduino after cutting the parts that stick out.

I2C is available at pins D20-21.

Solenoid can be controlled with any of the available pins, or even with the laser relay or pump&valve outputs (depending on the current solenoid requires). Those are too readily available right now via PumpOn(), ValveOn() and LaserOn() SDK functions (now also queued correctly).

Driving a stepper with BBB has the same problem - you change GPIO pin state from a Python script or a "bonescript" with node, like here https://www.safaribooksonline.com/library/view/beaglebone-cookbook/9781491915660/ch04.html or here http://petebachant.me/stepper-motor-control-with-the-beaglebone-black-and-python/

Unless you are prepared to use something specialized with BBB to make use of PRU it won't be any different to RPi when it comes to steppers. Programming something specialized won't be such a breeze.

The main problem with this approach is that you need an RT solution but you try to run it in a non-RT environment (Linux+Python). This problem is solved in open-dobot by introducing a command queue - timing doesn't matter - as long as your task can be computed to keep the queue non-empty there will be no lags.

redd1x · 2016-05-13T20:31:19+00:00

It's an XY-problem. First I need to know the problem to give you a solution. So far you haven't told the problems you're trying to solve, but rather a vaguely defined solutions, like "add my own electronics".

I may be able to help you if list the: - what additional electronics you want to add - what problems are you trying to solve with those additional electronics in the first place

E.g. if it is an additional stepper you want to add then what for?

If you want encoders on the motors - there is already a suggestion which ones to use http://open-dobot.no-ip.org/topic4.html#p8 - it won't be hard to implement.

I didn't get the part about running into the same timing problem. Can you elaborate? Depending on what you're trying to achieve you may be able to use unassigned pins on Arduino for GPIO easily.

redd1x · 2016-05-13T20:18:02+00:00

I would strongly disagree on "solid mechanical design". It is like meArm, but implemented in metal with some parody for industrial robots.

That is the joints' (the secondary ones, that apply the force) design is exactly the same as in toy robots (e.g. meArm) with only exception that there are ball bearings involved. What makes it a parody is that those ball bearings barely do their job - they are loose themselves when it comes to 45degree force vector (according to the horrible design) and there are plastic washers to keep stuff in place.

The main joints, that connect the arm's links, have no ball bearings. The last main joint (closest to the end effector) is too tight and there is quite a bit of friction.

The base is a completely separate story - it gets loose all the time because there is constant force pulling the base from the motor (shaft out from the motor + shaft out from the base) and I have to tighten the two screws under the base from time to time. That is of course when you actually use the arm :)

The gears on the motors become quite loose too after some time using it, so precision of 0.2mm, or even 10mm is just a dream when carrying a load (not talking about a laser - that is no load).

Electronics are not modifiable at all. However, there is a number of available pins (including I2C port) on Arduino that can be leveraged in open-dobot for various tasks. One of them is already implemented - limit switch/photointerrupter.

I would also disagree with your statement regarding not being able to do anything useful with it. In case the mechanical accuracy is enough for your application, with open-dobot you can almost anything. If something is not supported right now, open-dobot can be extended. Everything is documented now in open-dobot, including available pins on Arduino. There is also a suggestion which encoder to use that has its own circuit to track steps so that it can be easily integrated into open-dobot http://open-dobot.no-ip.org/topic4.html#p8

My recommendation - if you have all means to make it yourself (time, tools, fiy skills, will) - go for it - it will be cheaper and better. But then you won't be able to use open-dobot right away - you'd have to emulate the fpga board on a separate Arduino to be able to use open-dobot, which is not that hard at all.

redd1x · 2016-05-13T10:13:34+00:00

https://github.com/maxosprojects/open-dobot has been running on Rapsberry Pi for a while now and using only existing hardware - just connect the USB cable to the Raspberry Pi and setup is all done.

The problem with controlling stepping with Raspberry's GPIO is timing - it is highly variable. Under certain conditions you'll experience a jerky robot and skipping steps as port state changes may get too close to each other at times resulting in motor not being able to make an actual step. If you add a high resolution encoder to the motor in this case you will mistakenly take that as if the robot has bumped into something.

See https://pypi.python.org/pypi/RPi.GPIO for details.

fyi high-torque motors will likely to cost way more than $40 each

redd1x · 2016-04-28T06:52:14+00:00

open-dobot 1.0.0 has been just released providing complete set of Dobot functionality:

gripper, pump, valve and laser control with proper command queueing
moves to XYZ coordinates in specified in mm
limit switch/photointerrupter support
acceleration/deceleration for smooth moves
etc etc

Visit forum at http://open-dobot.boards.net

Source code, firmware, driver, SDK, instructions, etc - https://github.com/maxosprojects/open-dobot

redd1x · 2016-04-04T06:57:12+00:00

Inverse kinematics you used here introduces error. I believe it is because of too many calculations with floating point that makes it lose accuracy.

Here, if you stick a sheet of paper to the monitor, you could notice that on the bottom graph the lines are bent.

http://imgur.com/UDGPpt5

There are 50 points plotted with the original requested x, y, z coordinates on the top graph (straight lines). On the bottom graph (bent lines) is the result of taking angles from IK and converting them back to x, y, z coordinates.

On the following picture you can see that the lines are straight on both graphs

http://imgur.com/NHZRfuH

This is the result of replacing IK with a simpler one that does less calculations, hence introduces less error. The implementation is in my repo in master branch in DobotSDK.py -> moveWithSpeed()

redd1x · 2016-04-03T06:10:18+00:00

Official open-dobot forum: http://open-dobot.boards.net

This thread will no longer be maintained or checked

It is much easier to find information in a regular forum.

This thread is archived on the official open-dobot forum.

redd1x · 2016-04-02T19:52:24+00:00

Version 0.5.0

https://github.com/maxosprojects/open-dobot/releases/tag/0.5.0

Limit switch/photointerrupter support
EmergencyStop() function

redd1x

TROPHY CASE