This is why I said to build the 3D printed arm. You gain a lot of experience with a table top sized robot even if it is not the $100K metal arm you dreamed of.
Lots of people can assemble metal parts and buy expensive motors. But purposeful behavior and REALLY hard. What you don't want is a $100K robot that can't do anything. Start with a $150 arm that is made of plastic and uses $10 stepper motors. Get that arm to pick up a pencil from wherever you place it on the table and then put the pencil in a plastic coffee mug. I would say if you can't do this, don't even think about building a robot that can manufacture children's toys or make cars. Too many people try and bypass the design process and jump to the final product. I think it is Youtube that drives this. You can't get a million views if all you do is left a pencil 1 inch off the table, drop it, then pick it up and drop it again 20 times in a row and say "next month I hope to be able to move the pencil to the space over the coffee cup." Doing that would only impress engineers, not the public. On Thu, Jan 6, 2022 at 12:33 AM John Dammeyer <jo...@autoartisans.com> wrote: > Anyone looked at this guy and his robot arm etc. Nice to see someone else > makes almost as many mistakes as I do. > https://www.youtube.com/watch?v=T3fl1FIKEQo > > > > -----Original Message----- > > From: Chris Albertson [mailto:albertson.ch...@gmail.com] > > Sent: January-05-22 5:58 PM > > To: Enhanced Machine Controller (EMC) > > Subject: Re: [Emc-users] Tormach writing open sorce ROS2/Machiekit/LCNC > bridge. > > > > The current repository is "machinekit-hal". They only work on HAL. > There > > are no CNC apps in the current repository. All the stuff for running CNC > > equipment is removed now. When the developers moved from "machinekit" > to > > "machinekit-hal" they abandoned all the CNC-related stuff. It is all on > > GitHub, go look. > > > > But it does seem to be actively developed although the last update was > > almost two weeks ago. I think someone took a Christmas break. > > > > If I had to guess what Tormach does, it would be to use their own > > closed-source "Path Pilot" app along with HAL from Machine kit. But I'm > > guessing. They are funding the ROS2 work. > > > > Someone asked, "What is ROS2?" It is the planner and motion > controller > > that is now probably the most-used. The part of ROS used for > > manipulators (arms) is called "MoveIt" and a Google search will turn up > > information on MoveIt. Motion planning is harder with a robot arm > > because they don't usually run pre-programmed code. In the CNC world > the > > motion path is designed when the g-code is written. But robot controls > > have to do this in real time as the world around them changes. > > > > When the palletizing robot lifts a box to be placed on a pallet the box > > might be in a different location and of course the pallets are placed > more > > or less randomly wherever the human forklift driver left it. Even a pick > > and place robot has to find the parts which might be loose-packed in a > open > > bin. Moveit is open source and integrated with ROS. ROS is larger > > "Robot Operating System" that includes things for communications, driving > > wheeled robots and other stuff like MoveIt. > > > > Not using MoveIt to move a robot arm is like saying "LCNC is too > complex, > > I'll just write my own code on an Arduino to read g-code and generate > steps > > for my 4-axis mill." You could, maybe, but it would take more than a few > > days. > > > > For those who like looking at interesting robots here is a video from > 2019, > > these have been improved but are not moving boxes in warehouses. You can > > see that the task they are doing can't be pre-programmed. Really this > is > > not much more than a CNC mill. The wheels but the machine in (X,Y and > the > > orange suction cup-thing is like a spindle that moves in Z, it just > > operates in a larger space than a mill table > > https://youtu.be/5iV_hB08Uns > > > > > > > > > > On Wed, Jan 5, 2022 at 11:49 AM Ralph Stirling < > > ralph.stirl...@wallawalla.edu> wrote: > > > > > The newest version of Machinekit separates "emc" from hal, > > > and permits their hal to compile with standard Linuxcnc 2.8 > > > if I recall correctly. Their focus has always been on the > > > hal end of things rather than gui's and cnc machining. > > > > > > I can't find the email post that explained this, and the machinekit > > > documentation is rather sparse, so how one actually installs > > > things with current LinuxCNC high level code and Machinekit > > > hal code, I couldn't tell you. > > > > > > -- Ralph > > > ________________________________________ > > > From: Rob C [rclandro...@gmail.com] > > > Sent: Wednesday, January 5, 2022 10:53 AM > > > To: Enhanced Machine Controller (EMC) > > > Subject: Re: [Emc-users] Tormach writing open sorce ROS2/Machiekit/LCNC > > > bridge. > > > > > > CAUTION: This email originated from outside the Walla Walla University > > > email system. > > > > > > > > > I was also confused by machine kit reference from tormach. I thought > > > tormach was based on linuxcnc and not the machine kit branch/fork > > > > > > although I guess if Tormach are running a 2.7 linuxcnc version I guess > you > > > could say they have their own branch/fork > > > > > > I would have thought that since the change to python 3 with linuxcnc > that > > > will be quite a divergent change to linuxcnc that will make it > difficult to > > > integrate any items pushed back to 2.7 > > > > > > On Wed, 5 Jan 2022, 18:38 John Dammeyer, <jo...@autoartisans.com> > wrote: > > > > > > > > From: Chris Albertson [mailto:albertson.ch...@gmail.com] > > > > > > > > > > On Wed, Jan 5, 2022 at 3:29 AM Gregg Eshelman via Emc-users < > > > > > emc-users@lists.sourceforge.net> wrote: > > > > > > > > > > > That repeatability is plenty good enough to drop work into an > > > automatic > > > > > > holding fixture (which does the final precision positioning) then > > > pick > > > > the > > > > > > pieces out for transfer to another manufacturing stage or into a > box. > > > > > > > > > > > > > > > > > > > > As it turns out, for all the really hard tasks, +/- a quarter-inch > > > > (0.25") > > > > > is accurate enough. You only need 0.001 inches for the simple > no-brain > > > > > jobs. So my point is that you can do a LOT with the cheaper 3D > > > printed > > > > > plastic version of this robot. > > > > > > > > > > I'm surprised there are not more people here working on robots. > hey > > > are > > > > > very much like CNC tools but more interesting. > > > > > > > > > > > > > I'm headed in that direction once I get the power drawbar working to > my > > > > satisfaction. I had considered using one of the Size24 Steppers with > > > 50:1 > > > > planetary drives to replace the butterfly impact wrench. Easy > enough to > > > > track turns with an encoder on the back of the motor and let it stall > > > when > > > > target torque is reached with software control of motor torque. > Then to > > > > remove use full torque for required number of turns. > > > > > > > > Then the tool changer. To me a robot arm seemed more useful since > I'm > > > > using TTS and R8 tooling. Lining up the R8 is possible because the > > > spindle > > > > has step/dir so the spindle could be rotated until the R8 tool slips > up > > > the > > > > key. > > > > > > > > Anyway, my Ball Bearing Jacobs Chuck with R8 weighs in at 1.7kg > without > > > > tooling so I think a 3D printed version of this arm is probably just > a > > > bit > > > > undersize along with the planetary gearboxes not being 0 backlash. > > > > > > > > You're right. His software is minimal but still the entire project > as > > > > open source is impressive. Few people are doing it to that level > even if > > > > he's earning income off the metalwork and part sets which comes to > over > > > $1k > > > > if you buy his metal and bearing and parts sets along with the > > > > StepperOnline motors and gearboxes. > > > > > > > > But still it's interesting other than I'd much rather dedicated a > Pi4 and > > > > LCNC to it. With no idea where to start since I don�t' even know > what > > > > ROS2 is and am confused as to why Tormach is using the MachineKit > version > > > > instead of LCNC. I thought MachineKit had stalled and was no longer > > > used. > > > > > > > > John > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > > > > > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc- > > users&data=04%7C01%7Cralph.stirling%40wallawalla.edu > %7C927f98bdb466429393e908d9d07ca945%7Cd958f048e43142779c > > > 8debfb75e7aa64%7C0%7C0%7C637770056117520462%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL > > > CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=lZrq9WQkB8RdlXePS6pA7hkoankChBqt%2FC19vyoBSfA%3D&reserve > > d=0 > > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > > > > > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc- > > users&data=04%7C01%7Cralph.stirling%40wallawalla.edu > %7C927f98bdb466429393e908d9d07ca945%7Cd958f048e43142779c > > > 8debfb75e7aa64%7C0%7C0%7C637770056117520462%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL > > > CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=lZrq9WQkB8RdlXePS6pA7hkoankChBqt%2FC19vyoBSfA%3D&reserve > > d=0 > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
