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Weld build up feed per revolution?

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
Anyone have a setup they've made for build up welding of shafts? I'm putting something together to semi-automate driveline welding and I'd like it to have the ability to build up a shaft when needed.

I was going to use a chain and sprockets off a DC gearmotor to move the MIG torch, varying the feedrate with a variable DC drive. But the more I think about it it seems like it should somehow be geared off the rotation of the shaft being welded. Having two axis controlled with variable speed motors seems like it could be a nightmare to get dialed in.

What are your guy's thoughts on this? Would a fixed ratio, say .200 per rev or thereabout be right for mig buildup or do you need a few different feedrates for different applications?
 
I would avoid making it geardriven for the simple reason that there is no adjustment down the road.
Depends on your budget, but 2 fractional hp VFDs would do a great job, one for rotation and one for feeding.
They could be synced to within a fraction of a hertz.
Automation Direct ones are about $100 each for a 1/4 hp 110V input.
 
But the more I think about it it seems like it should somehow be geared off the rotation of the shaft being welded. Having two axis controlled with variable speed motors seems like it could be a nightmare to get dialed in.

What are your guy's thoughts on this? Would a fixed ratio, say .200 per rev or thereabout be right for mig buildup or do you need a few different feedrates for different applications?

How much the torch travels per RPM of the part will depend on the size of your weld bead. RPM of leadscrew is driven at is dependant on its thread pitch.
I would want the gun travel to be locked to spindle rpm.
Just get a worn out lathe and dont re invent the wheel here. QCGB would be nice to change travel speed, as well as 1/2 nuts to open and set gun location quickly.
 
2 entirely different process

unless you plan on a production shaft buildup time you eliminate coldlap wagontracks

and inclusions you prolly se why the crankshaft folks use subarc

feed will be the least of your prolems

if you still want to make wire work look at what profax has to offer oscelateing heads

linear feeds

also going to need to use multipass wire
 
2 entirely different process

unless you plan on a production shaft buildup time you eliminate coldlap wagontracks

and inclusions you prolly se why the crankshaft folks use subarc

feed will be the least of your prolems

if you still want to make wire work look at what profax has to offer oscelateing heads

linear feeds

also going to need to use multipass wire
Huh ?

Oscillating ? then you will get cold laps.
Adding complexity will have you chasing your tail to find cold lap problems.

Many shops doing "non crankshaft" work use open arc.

FWIW, if you want to go with sub-arc (local crank shop uses .030 wire and sub-arc) and don't want to totally trash lathe bed, mount lathe behind, and on wall.
Like a modern slant bed, but go a full 90 degrees, crap will fall into pan below.

The K.I.S.S. principle applies here.
 
Saw this done at a shop. Old Poreba lathe, wire feed mounted to the compound, submerged arc, VFD for surface speed control, QCGB to make it more versatile. Then there was the whole induction setup for preheating. You probably wouldn't need that though. This guy was building up large shafts and added the process to his services offered so what he made had to be adaptable to what came through the door. A place I worked at did crankshaft welding. Wire feed mounted on a holder to maintain control and prevent fatigue. Worked pretty good. This was back in the 80's in think they used a motor on a rheostat for surface speed control. DIY machine, these guys were knew what they needed, made a prototype and went from there. They even added a belt sander to it to rough grind the weld. Tearing up a belt was cheaper then a crankshaft grinding wheel.
 
How much the torch travels per RPM of the part will depend on the size of your weld bead. RPM of leadscrew is driven at is dependant on its thread pitch.
I would want the gun travel to be locked to spindle rpm.
Just get a worn out lathe and dont re invent the wheel here. QCGB would be nice to change travel speed, as well as 1/2 nuts to open and set gun location quickly.

I don't really want a shitty old lathe. It's heavy, ugly, and will just collect shit on it if I don't use it for a month.

I'm hoping to use up "cool stuff" I have collected for the mechanical stuff. Looking for a tasteful, clean design that doesn't clutter up the welding area when I'm not using it.

I like digger's idea of mounting the works behind or above with just a pan below the work.
 
2 entirely different process

unless you plan on a production shaft buildup time you eliminate coldlap wagontracks

and inclusions you prolly se why the crankshaft folks use subarc

feed will be the least of your prolems

if you still want to make wire work look at what profax has to offer oscelateing heads

linear feeds

also going to need to use multipass wire

I've welded up and machined a lot of non-critical dumb old ag shafts. Have not experienced any issues that weren't self inflicted. I have a nice roto-star positioner. I guess my problem is I'm not the welder I used to be (eye's don't see great through a hood anymore I suspect) and don't do enough of it to always be in practice. Seems like I frequently need to lay a perfect bead on a driveline and I'd like to just purge the gas, check the settings and hit go for a perfect weld.
 
Good idea that just don't work all that well, First the mig gets all spited up, gas flow fails and little holes end up in the build up. Wire sticks in tips, tips get hot and jams up, and many other hic ups...Best to power turn the work and hold the torch by hand and weld it up...Phil
 
Good idea that just don't work all that well, First the mig gets all spited up, gas flow fails and little holes end up in the build up. Wire sticks in tips, tips get hot and jams up, and many other hic ups...Best to power turn the work and hold the torch by hand and weld it up...Phil

It CAN work if you're a welder and not just a "wire-burner"....:D

I would use spray transfer with 90/10 gas. Nice even flat beads.
 
Your .200 per rev is right in the ballpark.

We frequently build up bearing journels and seal surfaces on a 30" LeBlond.

Generally .035 carbon steel or 316 SS wire.

Our "go to" feed rate is .187.

Occasionally, depending on how the weld is laying, we will jump up to .215
or down a gear to .166. Seldom up two gears to .230 or down to .150.

The advantage of using a lathe is that we can straighten and finish the journal
in the same set up.

The old LeBlond has a lot of miles on her since 1941; but we can still coax a bearing
journal within a couple tenths or put a flawless stainless build on a corroded gear
reducer seal surface.
 
Your .200 per rev is right in the ballpark.

We frequently build up bearing journels and seal surfaces on a 30" LeBlond.

Generally .035 carbon steel or 316 SS wire.

Our "go to" feed rate is .187.

Occasionally, depending on how the weld is laying, we will jump up to .215
or down a gear to .166. Seldom up two gears to .230 or down to .150.

The advantage of using a lathe is that we can straighten and finish the journal
in the same set up.

The old LeBlond has a lot of miles on her since 1941; but we can still coax a bearing
journal within a couple tenths or put a flawless stainless build on a corroded gear
reducer seal surface.
We have an old South bend that is set up to weld shaft or what ever round. we fabricated a frame that used 4 Large carbon brushes for a Lincoln SAE 400 and even used Lincoln spring loaded brush holders mounted at 12,3,6 and 9 o-clock that travel on the smooth surface of the chuck just inboard of the chuck key there lugged to the power source work lug (ground).
We used a Tweco 400 amp GMAW machine welding gun in an adjustable fixture on the lathe that works great. We just set feeds to get a acceptable weld profile. we even installed micro switches to set horizontal travel distance that also controls the power sources contactor to stop/start arc. Power source is a Hobart Mega arc 450. there is a hand held trigger for bypass control but most of the time it is switched to a sensor that only allows arc/contactor control when the shaft to be welded is turning.
We have welded short circuit with it but most of the time it's spray transfer.
 
I have a Hobart CV750 on a very heavy duty rolling cart. I never use this monster. Not worth anything to sell. What do you guys think about mounting the works of a driveline/buildup welder right to the top of this beast?

This welder is 4' long and I'm leaning towards a design that uses a spindle/chuck on one end of a 4' W14x48 beam, the beam set with the flanges vertical/web horizontal to form a trough. No tailstock, just adjustable height rollers that slide along the beam on camfollowers- End of whatever I'm welding just hangs out past the end. The machine feeder/mig torch I have will roll along the rear flange of the beam on camfollowers. Small roller chain and a slip clutch to position the welder where it's needed.
 
When I started at this job there was a rig made up just like that.The spindle was mounted on a pair of pillow blocks,chuck on one end and some surplus sliprings and brushes from an old wound rotor motor on the other.

The feed was 3/4" all thread. Quarter hp dc with a Dart drive. I never got to use it since someone needed the motor for a break down and never replaced it.

A friend worked at the local paper mill and building up and grinding large rolls was common.They had an old lathe set up with a mig.
Welding-Torch-Holder-Support-Mig-Gun-Holder-Clamp-Mountings-for-MIG-MAG-CO2-TIG-Welding.jpg
I had made up something similar to that holder but when I saw it on E-Bay for $75. I bought it.No way to make one that nice for $75. and time.

I use it with an Aircrafter rotary.You have to weld one bead at a time but gives good control and goes pretty quick. The adjusters are rack and pinion for height and feed.
 








 
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