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Welding robot by Joel Sullivan. 9:18 video:
https://www.youtube.com/watch?v=YOt0LxMMp2M
Previously:
https://www.homemadetools.net/forum/...841#post100173
https://www.homemadetools.net/forum/...438#post107444
https://www.homemadetools.net/forum/...218#post109858
https://www.homemadetools.net/forum/...2114#post75761
https://www.homemadetools.net/forum/...2565#post76591
https://www.homemadetools.net/forum/...4074#post79294
Quick call NASA this guy has a means to repair the hole in the ISS.
Quite a shop build...engineering top notch. Wonder about the screw life with splatter welding, and the AL wheels with no rubber for traction, but quite impressive multi-functionality overall...and from a cell phone, hopefully not a distracted driver.
Thanks Jon...definitely worth 10min of my time to watch!
Like you said Pj, I would imagine there will be several refinements over time. One of which I suspect will be shielding around the mig gun to prevent sparks from flying everywhere. Rubber wheels for traction should not be required as the weight of the robotic tractor looks to be sufficient. sparks or splatter grains would easily be embedded in rubber or polyurethane. Adding a convex culture to them would help in guidance and control I would think. As the point of contact would concentrate the weight of the tractor. The wheel contact area could be knurled just as that of a track torch which I have used frequently in the past as a means for making long straight seam and filet welds. Not computer or Cell phony device required. Set the travel speed the height and watch it weld. We used to make square and hex Kelley bars for drill rigs this way Had a 90 ft long torch tract another way was when joining large cylinders to make long pipes was to place them on powered rollers wiht the mig gun stationary at the top. or send it on a tractor down the inside of a rolled sheet to make the cylinders
I agree Frank, this will probably go through some revisions and about a convex shape to the wheels and perhaps knurling for traction. The aluminum seems to be robust if they are 7075-t6 but anything in the 20 or 60 series would take a beating quickly, perhaps 6063-t6 might work. It seems a slippery slope for vertical/angular or upside down placement even with the weight. Guessing the weight is a few hundred pounds and the terrain it travels on is not very clean, steering would be an issue even with 4 wheel independent drives and slag and debris (let alone grinder dust) would be a long term problems for longevity and control.
I also suspect this machine has a specific set of design/ops criteria that we are unaware of, like the use of the pneumatic cylinders for locking it in place. They have to be no more throw than the height of the frame to lock it down, especially in a vertical position. Still quite the "Home Shop Build" especially with all the automation, vision systems, firmware and software, imho.
PJ
Hey everyone, I'm Joel and I built this as well as a few other industrial robots. Thanks for your kind words. I'll give a few more details with respect to the project. The robot crawls into big hot presses and fills in dents and dings. The presses operate at 220C (428F) and the temperature poses an issue.
I've tried many types of high temperature polymer wheels and they've all been really bad. The friction is horrible. The robot slid around like it was on ice. Aluminum directly on the press surface actually bites in really well and has good grip, and the aluminum can certainly tolerate the heat. The knurling and the convex idea are both great, and I may try one or the other the next time I have the wheels off.
The actuators have dust seals that seem to do a good job of keeping spatter out. A light coat of Lincoln anti spatter compound seems to do the trick. Also the actuators were chosen because they're essentially a consumable and easily replaceable with off the shelf replacements. They're going to die, just prolong them as much as possible and swap out when needed.
I'm making lots of changes, including adding some shipping/parking brackets for the arms, and air jets to blow away dust. There are also lots of changes to the programming that need to happen.
Here's a video of the robot inside a press making a repair. https://www.youtube.com/watch?v=dPqJkUGOP8Y
Hi Joel, Thanks for chiming in here with some details and the additional footage in use. All makes much more sense now! Nasty environment for a robot for sure and can imagine the heat being interesting challenges for the electronics and vision system for sure. When I first saw it the wheels didn't make sense and felt like they might be slip and slide power glides. :p
I get it about the screws being necessary expendables, again in that environment. I am curious what kind of dents and dings occur that would need filling and fixing and if the press is re-run after your welding and clean up? Years ago I did some of the design work on a 50t forge press for making jet engine impellers, interesting and challenging from a design/environment standpoint, and also several automated machines over the years, mostly PLC and HMI operated.
What you've done in your shop is pretty amazing for a specialty robot like this. Did you do all the code work also?
Thanks for sharing and look forward to seeing and hearing more.
PJ
P.S. I sub'd your YT channel. :cool:
They run rocks through, nuts, bolts, hammers, any tool really. Any time that happens it takes a big chunk out of the surface and that ruins the board. They have fairly long operating cycles and it can be the better part of a year before somebody can get in there and fix it. My robot can go in at any time.Quote:
Originally Posted by PJs
I coded about 90% of it. My friend Neil coded the web interface in Python.
I have some small drilling robots and a scanning robot as well. There are a lot more coming including a cleaning robot and one for fire watch. Keep checking the Youtube channel for updates. :D
Edit: And yes, the press was up and running again right after the repair.
As Paul Harvy used to say and now the rest of the story.
Thank's Joel. Your comment about repairing dents or divots in the press die reminds me of some sheet steel we bought one time that was made entirely from recycled automobiles the problem was when this is done some of the metals are quite hard like bearings for instance once the cars are run through a shredder there is hardly anyway to insure no bearings are in the mix. Forming shearing machining or even just drilling these sheets were a challenge. I can see these as causing problems in press dies
Do you have a way to re harden the surface area of the repairs? perhaps localized induction heating cooled with a spray of liquid nitrogen could do the trick
> perhaps localized induction heating cooled with a spray of liquid nitrogen could do the trick
Wouldn't that cause waves in the sheet? (I ask in ignorance.)
I was referring to the possibility of the need to re surface harden the repairs on a press dieQuote:
Originally Posted by Elizabeth Greene
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I have used heat and cold to flatten thin sheet metal such as hail dents in the roofs of cars.sometimes in reverse by super cooling a very small depression then warming the area around it will do the trick other times vacuum and vibrations in the ultrasonic range will pull a small dent from an auto body other times when ever possible to work from behind the dents can be massaged out.
But as I was saying in the case of a press die a weld repair will leave the area softer than the rest of the die that was why my suggestion of heat and rapid cooling.
I never really thought about hardening the surface. It would be difficult to do anything thermally. These presses are HUGE and they're filled with thermal oil for heating. Maybe some sort of hard coating? Maybe change up my mig wire for something designed for hard coating? It's certainly something to think about. Thanks!Quote:
Originally Posted by Frank S
Do you know what RC the surface was supposed to be originally?
There are many grades of hard surface wires. Study products is a famous brand, however as you may already know when making a repair on a flat surface it is often difficult to blend the repair into the rest of the surface. If in a short arc mode the weld has very little penetration due to the low voltage and amperage. Globular transfer is the most popular method of welding for joining structural members together and is also the method by which 90% of all welding is performed. due to the balance in voltage and amperage this yields a nice fluid puddle altering the type of gas used IE straight CO2 versus 75/25 Argon mix greatly changes the penetration puddle freezing and material deposit flow. Mig wires are formulated differently as well some work better on straight CO2 than a mix gas.
If at all possible to actually get into a spray arc mode then the deposit will have much lower splatter deeper penetration and a flatter weld deposit But spray arc will require using an even more exotic gas like 98/2 or a tri mix of gas 98/2 is 98% Argon and 2% oxygen Tri mix gas might contain many different mixtures which is most often a custom mixture right at the welding facility this may include Argon nitrogen Helium or even in some cases a percentage of oxygen as well.
any and all of these a fore mentioned processes can alter the surface hardness of the weld deposit as well as tensile strength wear properties and penetration.
Since most of my builds and repairs require the best possible strength I mostly use a duel shielded flux cored mig wire with CO2 as my filler material and gas. for real thin metal I use ER70 S6 copper coated bare wire with 75/25 gas. But I have had to go with a non coated solid wire with 98/2 gas back when I was welding up derricks for foundation drilling rigs. the Spray arc mode was to make the welds appear to look like joint and welds on the tubing were molded in and to spread the heat effected zone further into the core of the structure like fluc core gas shielded wire does but without the clean up.
My suggestion would be if your local welding supply company has a welding analysis engineer on staff would be to ask them for their recommendations and procedure It never hurts to seek the advice of a 3rd party if they have familiarity with the situation you are encountering.
I see that you have done testing on scrap samples already and this is probably the single most important way of learning which process works best for you.
Wow. Okay. That's a lot of information. I'm obviously far too ignorant when it comes to welding processes. I'll have to do some reading. If I do some experimentation and get it dialed in maybe it could be a value adder for the client. Thanks!