This video is an answer to a viewer's question about welding on the lathe. It also features some machine gore and discussion on whether or not it's necessary to baby machines at all times.
As a machine tech. Best logical and factual breakdown of the subject, and how risk vs reward always enters an intelligent persons decision making. Would I ever do it on a 100+K CNC? NO! On a junk lathe? Absolutely! The precision spindle bearings are where this ends up being very damaging as they so precision. They do make brushes that hook to the back of the spindle to transfer the current. In hydraulic shops adding a MIG welder to the tool post and a slow motor to the head stock just to build up a shaft is common. Nice shop BTW.
I've never heard the phrase " union marks" but my old machines came with many. Being a hobby shop, I guess I'll just call them character. You appear to be pretty mellow about stuff around the shop, I guess there really isn't much else you can be and stay sane. Thanks for the interesting video.
We weld repair shafts everyday. Two lathes, an 18 x 50 and 34 x 120. Usually motor rotors from 1 hp to 1000 hp. Also pump shafts and large mixer shafts. We also lengthen shafts for custom applications. We repaired a 17 foot shaft @ 4500 lbs with bad bearing surfaces. 50 lbs of Mig wire was required. Both lathes have spindle drive systems adjustable from 1 to 10 rpm. Also ground systems that commutate on the chuck OD. And Mig gun holders for the quick change tool post. No helmet required, no lathe protection needed. Setup time 3 min. Everyday. After 5 years nothing from the customer has been returned.
That grounding system stops most any potential damage. And it's the machine that's going to get messed up, not the parts. Very common practice in places that must build up shafts.
We had work done on a fuel truck, they needed to weld on it. The welding caused thousands in damage because the current flowed through electronic components in the meters.
Yep.... My dad arched a welding rod to our combine cylinder when he dropped the stinger and it fell past the cylinder shaft. JUST a quick MOMENT! The closest bearing bearing lasted 40 minutes of use.
Thanks for the content! I’m a mineral exploration drill builder in Whitehorse. If you’re ever passing through, let me know. I have a small machine shop and a lot of our stuff looks the same as you guys. Can tell you guys cater to the mining industry.
We had a job, large steel domes that needed 2” holes, all drilled vertical. We cut varied angled blocks to weld on, so the drill would enter on a flat surface. The Night Shift used the drill spindle to hold the blocks in place so the welder could tack them. When I came in the next morning, the 6” dia. spindle of our Bickford Master Service radial drill had dozens of arc-strikes. The spindle ball thrust bearing was about destroyed. Parts no longer available. We had new custom bearing races ground and bought 7/8” balls to fill the bearing. We had it torn down for about a month. Oops!
Nice to see someone honest about their own mistakes, many crafts people have such big egos they never admit mistakes. I have a 2 foot and 3 foot heavy cable in my shop with clamps on both ends in case in case I want to double ground. My work bench is also grounded and I use the short cables to run ground from the table to the piece being welded at times. I'm really more of a sheet metal and fabrication shop but thanks for your chip making tips.
Yo, in regards to grounding, grab a 18-24 inch length of 1/0 copper stranded electrical wire and strip all the insulation off, grab a short piece of copper pipe or tubing that you can slip both ends of the wire through as a sleeve to tighten the loop of the wire. Loop the copper wire around whatever you're fixing to weld, just figure a clever way of a-fixing the ground clamp to the ends of the wire and now your work can turn freely and it's always in contact with the ground lead.
I used to leave my initials on my boo boo's... being the supervisor at the time, I felt it was important to demonstrate humbleness, 10 years or so later I've been moonlighting at that shop trying to help them out, and its kind of weird to see my own initials on stuff
You could isolate both parts. Well, a bit hard between centers. But also even harder to try to join two parts between centers. 🙂Voltage of a welder is normaly below 50 V. So even an isolation tape should do the job. Admittedly, I didn't try it. Albeit, with TIG welding, you should be cautious! HF and high voltage to start the arc. And you know what gaps the ignition can jump.
Some high speed machine spindles have earthing contacts built in because of current generated either from machining of the rotation (I think it's the machining), I think they got around the problem by using ceramic balls in the ball races.
The brush set You are referring to, is generally good for around 20 amps, the welder will be 90 or more amps. While it would help, if you are doing things mostly correctly. I could see someone deciding to use this as the ground, and causing great damage.
Most welders suck at welding near a welder, nevermind welding with/on/near a lathe. Just don't ground any moving parts like bearings or bushings and don't get spatter on anything you don't want it on. For competent people it's fine. For everyone else slightly above average or lower; just don't.
Just clamp a U bolt on there. Flatten couple inches on each side of U bolt. Easier to clamp down. Then once you got some of the welding done you can take it away.
If you touch your bumber at a wall while parking, is that also s union mark? As said, if you don't want Union Marks/scratches on you things, put them in a museum, and never turn them on...
What do you think of welding while the machine is running? I've seen Abom79 spatter-weld a shaft while it was turning to build up material at least once.
You can set-up a set of brushes on a ring to make contact for welding, this is a common modification, along with slowing the motor speed to a crawl, so an old lathe can be used to do weld build-up, similar can be done for plasma spray transfer, but the speed can remain higher, if it is flame spray then the brush ring is not needed as no electricity is involved.
There is a difference between modifying a machine and abusing a machine. And you're never going to make money if you're buying a machine for every single job.
Wouldnt oxy welding just eliminate the issue alltogether ? I get it would also present its own issues and not always be ideal but in alot of cases wouldnt it just make it much simpler to. Not have a ground to worry about ?
25K for a lathe this size? I guess we're talking Chinesium here... No way I a welder will come close to any of my lathes. Quality German and Swiss machines deserve the utmost respect and I know the craftsmen that created them would be turning in their graves by doing stuff like welding or cutting our pieces of the machine. I once saw a Heid Sensitast lathe butchered this way, very very sad.
For some reason I can't comment from the main but thanks for taking the time to help it has been with me for many years and watching people who do it on RU-vid has always been a big issue with me 😅😂😮
I did try friction welding on a lathe, but it didn't work well, I think some kind of flux would be required, but I've got the feeling that flux is nasty, and wouldn't want it being flung off a spinning part.
5:12 lodge and Shipley lathe? Shop I used to work at had an super old lathe that someone had done that to. We also welded on lathes I wasn’t a welder but I would set the machines up for it since our welders weren’t really up to speed on the important parts of the lathes. Still had one kid catch a lathe on fire used old oil soaked rags to cover the ways after I indicated a cylinder eye and a rod in our big moriseiki. Didn’t burn it up just game me a scare.
How about the welding current going through the electrical motor and the earth on the electrical supply. Should one pull the fuses , turn the power to the machine to off. Also clearer metal items (scrap) that’s touching the machine and touching the next machine and the chance of the welding current running to earth via the second machine.
@@ke6gwf I’ve had power lead to handheld disc grinders burn out & melt due to welding current going through the machine earthing cable. It certainly was not a lol moment!
@@LifetimeinWelding sounds like you didn't have the ground clamp on the workpiece, but it was on something connected to the building grounding system lol And pulling the fuses won't stop that sort of thing, because the ground wire on a lathe would be hard wired in, no switches or fuses. Basically make sure that the ground clamp is on the piece you are welding on, and if possible don't ground the welder ground to the building ground lol
Insane to use your lathe as a welding table. A welding clamp setup is way..way..way..way cheaper than a lathe. Great you covered the ways...what about everything else? Chuck jaws, tool post, compound ways. So much safer and easier to just pull it from the chuck and go to a table and weld. If you need it perfectly aligned, use a rotary table setup on the welding table. Rotary tables are a lot cheaper than a lathe. Just saying. Im fairly sure the electrons can travel through the bolt head connection unless there is a gap Im not seeing on the vid. Strike an arc on the other bolt head and the electrons will always choose the shortest route to ground, which would be through the bolt heads. Striking an arc means arc welding which spatters everywhere. If you are going to weld on your lathe...use a tig....or at least a gas mig. Have a good day. Make chips that don't need dips!
I am an auto mechanic. I have a six step voltage drop test i use on every car and light truck. Engine running. Headlights on. Positive to Negative battery posts. 14.1 to14.8vdc Two. Negative post to the engine block. No more than 0.04vdc 4/100th of a volt Three. Negative post to the body. 0.04vdc max Four. Engine to body. 0.04 vdc max Five. Positive to all the fuses in the underhood fusebox 0.04vdc max Six. Positive to alternator output studs. 0.3 volts or less. 3/10th If tests 2, 3, 4 are high especially 4. The electrons coming off the alternator are trying to get to the body where eveything is grounded. The electrons will take the shortest path. Thru the transmission. Cv joints. Wheel bearings. Strut mounts. The repeat failure of front wheel drive wheel bearings can be traced in some cases to loose electrical connections. If i had to weld on a lathe. A twin lead ground cable assembly with braided copper cables to use over both chuck bodies to reduce the chance of electrons playing. Frogger across the spindle bearings.
