Anyone else into resistance welding?

[gravitar 3]

Just curious.. Does anyone else here work with resistance welding controls?

[Big Country 3]

yeah we use dengensha, panasonic, medar, and kimura spot welders. Lots of spot welders.

[Chris Elston 78]

Yup doing it right now. Using seven Unitek Welders with pincher style weld heads.

[Guest low on the pole]

oh yeah, about 25 robots with medar controls, and lots of old robotron 400 spot welders. had a medar guy in yesterday, he was touting their new 4000 series. stand alone medar controller. present time we are using medweld 3005 with allen bradley interface. nothing like a few hot sparks in your face and slag down your shirt

[bluebyu 4]

Many Entron in use here on the East Coast. Very reliable controller.

[Jay Anthony 118]

bluebyu: Remember when we used to fight the Weldtronics controls?

[Big Country 3]

Yeah we had to weltronics but are know replaced with a medar in the 3 years that they were in service we replaced the controller 4 times. One of them was on an old GE robot I can't remeber the series but it was a real dinosaur I replaced it with a Kawasaki.

[gravitar 3]

We've got a couple machines with the new 4000 series Medar controller. I was surprised to see that they had gone this route.. I really liked having the weld controller integrated right into the SLC rack. What did the salesman say was "better" about this design? The only thing I can figure this would be good for is if you were using a CLX or some other platform other than SLC 500. They did come out with something I do think is pretty slick though.. They've got three SCR packs sitting close together in parallel, mounted on a big copper chill plate. The line side of the SCRs are all bolted to a buss bar. One firing board controls all three SCRs. Makes cascaded welding pretty simple and compact. Robotron 400/415 controllers are a pretty good product as well, but trying to enter ladder logic through the pendant is an exercise in futility Does anyone have the robotron or medar programming software? I've seen mention of it in the books but have never been lucky enough to see it in operation. I asked the WTC sales dept. about it and they argued with me over its existance! They finally found a guy that was vaguely familiar with it, but apparently it isn't something they sell much of! Edited 19 Sep 2005 by gravitar

[gravitar 3]

Yeah I have to agree.. We've had pretty good luck with Entron. They're hard to beat, especially for simple line-frequency standalone pedestals. I haven't seen their prices but I'll bet they are a good bit cheaper than a similar WTC offering, too.. Do you guys have any of the "mailbox-sized" Entron timers? It is amazing that they have crammed so much you-know-what into such a small package. Not the easiest thing in the world to work on, though!

[Guest low on the pole]

gravitar, what the medar salesman really told me aout their new 4000 controllers is that they make more money on them as opposed to a/b interface. we have robotron on 485 net, 2 channels 6 timers per channel, robonet. medar on ethernet

[gravitar 3]

Well at least the guy was honest about it! I imagine WTC has to pay A-B a royalty for every 3005 card they sell. The last plant I worked at used exclusively Robotron 415 controllers, and we looked at networking them over Robo-net. I can't remember the exact figure but I think WTC wanted $30K for the software! Needless to say we abandoned that idea pretty quick :) Have you found that the data you get over the network is useful enough to justify the cost? How sophisticated is it? I.e. can you store all the weld schedules in a central server and download them as needed? We have a lot of low-volume jobs that are constantly getting changed over. My maint. guys struggle to remember what worked well the last time "X" fixture was set in "Y" welder, etc.. Did you split your network in to 2 channels for increased speed or does the link really only support 6 nodes? To me it sure looks like Robonet is based on DH485 and Medlan is DH+. I wonder how hard it would be to figure out the protocol and write something to take advantage of it... The other thing I've been toying around with is making a panelview app to more or less take the place of the Medar teach pendant. I've been going through the "integrator's pack" and it looks like just about every parameter in the 3005 card is accessable through the SLC data table. Given enough time, I'll whip something up..

[gravitar 3]

Heh.. you're talking about the Weltronic, right? I've never worked with them.. Very rarely do we lose a medar card though!

[Guest low on the pole]

gravitar, robonet is pretty handy, you can upload and download weld programs from it and collect data and faults and reset steppers from it. but it's pretty dated 485 net. at one time wtc was talking about an ethernet network but I think they dropped that idea. hey as far as doing a medar info panelview screen we have a couple like that on 1400e rio, all the data is passed via block transfers and taken right from the timer cards. if you have a medweld plc/weld control logic integrators guide and dug into it, you could figure out all the data tables for weld info. its has all the bwords and nwords in it and what they use them for.

[gravitar 3]

Here's a Medar question that should be pretty simple for you guys! What is the difference between the 917-0042 and 917-0050 cards? They LOOK identical, and I have used them interchangably in many of our spotwelders. There must be SOME additional capability of the 50 though.. What is it?

[TimWilborne 108]

Looks like everyone here is talking about robotic welders but does anyone have experience with flash("butt") welders

[gravitar 3]

Maybe we call that technique something different here.. what is a flash("butt") welder?

[TimWilborne 108]

Similar to spot welding, but you do not use the copper electrodes. You will see this done to weld two full stocks of steel. One side of the transformer is applied to one piece of steel and the other side is applied to another piece of steel. Welding is controlled by an scr. If it is a "butt" welder, you just push the steel together till its glowing red just like a spot welder. A flash welder uses a hyraulic servo valve to bring the steel together at a controlled rate. As it gets close it arcs and burns off the ends of the steel. The arcs shoot pieces of steel out so the name Flash welder. This flashing both cleans the ends of the steel and heats them up. Once they are hot, you push the molten pieces together. It may not matter because what I am wondering about is the SCR. Mainly what does it really take to fire it. One of ours has a custom made board firing board that is very hard to get. Besides this one board, the whole welding process is controlled by Controllogix

[gravitar 3]

Well I guess I've had a Medar-related epiphany (sp?) today. Until a couple months ago, all of our Medar panels were isolated, non-networked single-board machines. The guys got rough with one of them and broke the teach pendant AMP connector off, so we haven't been able to get into the schedule. I've been clearing weld faults from the SLC, but I'm pretty sure you can't access any weld schedule data from the SLC's data tables so we've been kinda hosed in that regard. We recently got a machine that has two Medar cards in the rack, both daisy-chained through the phoenix plugs to a small black box that has an AMP receptacle for plugging in a standard teach pendant. Now, until I took a look at this, it never dawned on me that "MedLAN" was RS485-based and directly compatible with the pendant. I guess when I see blue hose and 3-pin phoenix plugs I'm conditioned to think DH+! I was curious, so I took apart the black box, and I'll be darned.. All it is is a DC power supply. Looks like the signal pins from the phoenix are tied DIRECTLY into a couple of the pins on the AMP plug. And just to eliminate all doubt, the relevant pins have RS485 and RS485(bar) silkscreened right onto the board :) The end result of this is that I'll be able to finally get into the schedule on the machine with the broken card.. And maybe the next step would be to tie all of our Medar boards into a centrally-located teach pendant (or two or three pendants on subnetworks atleast.. We probably have 30-40 Medar units here). Man, it would sure be nice to have the Medar programming software!

[Guest budw]

From: New Fallujah, home of the NBA insurgency Hey, I thought Rush Limbaugh was not going to call Detroit or the Palace "New Fallujaf" any more!!

[gravitar 3]

Haha.. I had forgotten about all that until Rush came on the Paul W Smith show last week and it all got brought back up again! Everyone in Detroit is breathing a huge sigh of relief that we made it through the Superbowl without any major embarrassing incidents!

[DBacon 0]

I have been exclusively devoted to resistance welding since becoming the Welding Engineer at Chevy Gear & Axle, Detroit, in 1976. I am very familiar with the controls and practices used in US auto manufacturing, and I like to help others. Too bad it took me 7 years to reply...