Welding around a circumferance

Stupid question from a dauber...sigh..
Lets say I want to tig an upright cylinder to a flat plate. What is the
best way to do this in an unbroken, cosmetically pleasing fashion?
Im having some difficulties getting a good looking weldment whenever I
try to do round Stuff. I can do..say a quarter way around or less, have
to stop, turn it, weld more..turn etc.
I see all these really pretty weldments and cannot duplicate them. Same
of course with MIG and Stick..but now with TIG..its become more
important as Im working with thinner materials with more cosmetic need.
Its to the point Im considering making up a slow, variable speed welding
fixture to turn the work via motor drive..though the grounding issue has
yet to be figured out.. and this cant be used on stuff like say..exhaust
manifolds and whatnot
Hints? Tips?
Gunner
"If thy pride is sorely vexed when others disparage your offering, be
as lamb's wool is to cold rain and the Gore-tex of Odin's raiment
is to gullshit in the gale, for thy angst shall vex them not at
all. Yea, they shall scorn thee all the more. Rejoice in
sharing what you have to share without expectation of adoration,
knowing that sharing your treasure does not diminish your treasure
but enriches it."
- Onni 1:33
Reply to
Gunner
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You need a rotating table. Here;s how I built one: The table part was a disc that was left over from burning a 12 inch hole through 5/8 plate. It had a slot burned in it where the torch started. I welded this up. I welded a 1 1/4" inch diameter, 6 inch long rod to one side of the plate. This rod was perpendicular to the plate and close to being on center. Then I turned and faced the opposite side of the plate and chamfered the edges. I used the same tool that was used for chamfering to put concentric grooves into the face of the plate. The tool is ground to a point, like a threading tool, except that the included angle is 90 degrees, not 60. When chamfering this part the tool was parallel to the face of the part and perpendicular to the face when grooving. The grooves were 1 inch apart. Then I turned the plate around and turned the rod to 1 1/8" dia so that it was concentric to the plate OD and very perpendicular to the machined face. Then I bored a piece of pipe to accept two bronze bushings that were 1.127" ID and 1.375 OD. The bushing for the bottom was not bored through. After pressing the bushings in I welded a washer on the bottom to keep the bushing from being pushed out. This pipe was then welded to the left front weld bench corner. I dropped a large ball salvaged from a big bearing down the hole where it centered itself in the cone the drill point left when drilling the bottom bushing. Finally I put the rod that was welded to the plate into the bushed pipe and that was that. It wasn't motorized and eventually I would have done that too but I quit working at that shop to become self-employed. Still, it was easy to spin it with one hand while welding. and it would coast a while too. ERS
Reply to
Eric R Snow
The grounding should not be a big problem. You only need it to turn one revolution. So just attach your ground cable and then wind it back one revolution. Ditto on the motor drive. Forget a motor. Use a weight to rotate it. You only need one turn, remember. So a cable with a pulley to change the direction from vertical to horizontal. The pulley needs some kind of brake you can operate with your foot, so you can control the speed.
Dan Gunner wrote:
Reply to
dcaster
I'm sure you will get input from folks with lots more skill than I have, but my welder son would tell ME to practice "blending" a LOT!
I see that another poster has described his rotary table; here's mine: On the rotary table side, I built one for my other son a couple of years ago that uses 2 blocks of carbon, 2" X 2" X 4" clamped together and drilled to match the fixture's shaft with a flat rectangular spring to act as a grounding element, below the fixture's table. I have some simple drawings if you want them. This rotary table is turned by hand, also, only because my son didn't need it motorized. I built up a control device out of Surplus Center and Radio Shack parts. It drives a used wire drive motor from a scrapped MIG welder. If he ever needs a variable speed controller, I am ready.
Pete Stanaitis -------------------------
Gunner wrote:
Reply to
spaco
Gunner, you know my meager amount of experience, but with TIG, I would weld a few "circle arcs" at a time, staying within comfort zone for the hand movement, and then I would go back to where they meet each other and remelt those areas to give consistent appearance. In fact, I did just that yesterday, when I made a "bulkhead fitting".
i
Reply to
Ignoramus4106
ROFLMAO!!! Thats to the Right.
Gunner
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33
Reply to
Gunner
YOur problem is that you can only weld to the right......
John
Reply to
John
"Ignoramus4106" wrote: (clip) I would weld a few "circle arcs" at a time, staying within comfort zone for the hand movement (clip) ^^^^^^^^^^^^^^^^^ I don't see how, using a turntable, and all that implies, how you will avoid having the weld pull out of true as it cools. So, I think what Iggy says makes the most sense. I would do a tack, and then go around to the other side and do another tack. Then I would do a couple at 90 degrees. By now the remaining gaps should be short enough to do without the turntable. If a turntable makes the job easier, then go for it, but I don't think it's necessary. IOW, I wouldn't bother building a turntable unless you are going to use it a lot.
Reply to
Leo Lichtman
Funny that you should mention this, I am in the middle of building a weld positioner now. I am using big pillow block bearings. I want to be able to weld long straight tubes, so a pass through is needed. The pillow block will be mounted to a frame that can sit horizontally or vertically, so I can use it for pass thru or as a table. The ID will be 2 3/4". I got two of the pillow blocks and some DOM tube (1" wall, I guess it's still tubing). I will turn a shoulder on the tube to pass through the bearing and weld a sprocket to. There will be tapped holes in the large end to center tubing or bold a table to the end.
I got a big fat step motor and driver board at a junk sale to power it. The center tube will be grounded with springloaded copper brushes.
In order to weld long straight stuff, I am making two of these, one driven and one just as a support.
This thing may be overdesigned, but I have kludged this too many times and I want a nice one.
Bob
Reply to
MetalHead
On Mon, 03 Jul 2006 02:02:21 GMT, with neither quill nor qualm, Gunner quickly quoth:
Need some -good- heart exercise? Here's one way:
Water down a 6' area.
Dig a hole large enough for a differential.
Take one spare differential and remove spider gears so axle floats.
Drop said diff into hole with one axle sticking out a few inches.
Center and drill a bolthole pattern and mount a round piece of steel plate to the top. Grind off the excess lugs 'til flat.
Now place your weldable round stock on that and TIG away, rotating it with a spare foot.
If your heart can't take that , just grab a full floating front axle knuckle and cut off the pointy parts so it fits flat on a welding table. Mount the steel plate to that.
You probably have all the parts mentioned in stock.
To automate it, mount a suitable gearmotor nearby and run a band around the spinny parts. ;)
G'luck!
-- Sex is Evil, Evil is Sin, Sin is Forgiven. Gee, ain't religion GREAT? ---------------------------------------------
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Sin-free Website Design
Reply to
Larry Jaques
I watched a professional welder do this on some work he did for our team (donated much of his time at a reduced rate). The parts were drive shafts attached vertically to entire gearboxes for steering purposes. They had to be perfectly vertical and well attached. The shafts had a shoulder which was then fillet welded to the plate. The welder put the shafts on a professional electric rotary table (about $3000 IIRC) which is connected to a foot pedal. He tack welded in about 3 places and then rotary tabled it all the way around. I have a video of him actually doing the welding somewhere. If I can find it I'll post a link.
Gunner wrote:
Reply to
woodworker88
As a variation of that, I used to be caisson certified. That is a 36" diameter pipe with 1.5" wall thickness. A band with standoffs was clamped to the pipe. Then a motorized FCAW welding head was attached. The operator watches the puddle through a lens and adapts the angles and speed. It takes about 36 passes with .072" wire to fill up the vee. The test takes about eight hours.
So, in that case, the weldment stayed stationary, and the welding head moved by mechanics.
Steve
Reply to
Steve B
Aside from the recomendations to build a positioner, the way to become slick on pipe/tube/anything round is to practice two things with dilligence. 1.) the smooth (to the point of not disturbing the puddle) movement required to travel around the "round" thing. 2.) the smooth (to the point of not or almost not being able to tell where one stopped and one started) tieing in of one weld to another. This is easier to get for most people that the first one, but you do have to work at it. Both come to some people with practice, some people never get it. If as a self proclaimed "dauber" you need to use crutches (temporarily) like grinding a starting spot in your last starting spot then you should do so.
JTMcC.
Reply to
JTMcC
If as a
That should of course say "grind a starting spot in your last STOPPING spot.
Beginers often can't start a new weld without piling up a big old knot, if you grind a divit your blob has a place to live without standing out too bad.
JTMcC.
Reply to
JTMcC
Then it would be ok to take one of the gearmotor/speed controller combinations I have already and make up a turning table?
Gunner
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33
Reply to
Gunner
I built my rotary table out of two old flywheels and a throwout bearing. Use what you have. Brake rotors will probably work, but iron might do funny things at the contact point..
Reply to
Stupendous Man
You could cobble up a rotary table out of almost anything. But don't try to run the welding ground current through ball or roller bearings especially if you want them to still turn freely when you are done. The drive motor will be isolated if you use a rubber V-belt.
Float the bearings in insulators of some sort - wood will work, and rig up a slip-ring and a carbon pickup brush or three between the shaft and the welder ground. A ground strap would work if you were restricting motion to one or two revolutions before reversing.
-->--
Reply to
Bruce L. Bergman
A variation of this method is used in welding together segments of nuclear submarines. The segments are fabricated at the Quonset Point RI facility of General Dynamics. Giant rings about 36 feet in diameter and four inches wal thickness, as much equipment is installed as possible and the the segments are barged to Groton CT to the Electric Boat division of GD.
The segments are VERY carefully aligned and tracks are tacked to the hull and the welding machine rides the track around the hull. I believe that several welding units are used at the same time.
The equipment in the second segment is plumbed, electrically connected etc. to the first segment and so on. The sub is built up like gluing rings together end to end.
The last time I had a tour of the ship yard I was super impressed to see the innards of the sub. The sub under construction at that time might have been the Jimmy Carter or the Virginia. I don't remember as both were in the build shed but one was much further along than the other.
BTW, since today is the 4th of July, Happy Birthday America!
Errol Groff
Instructor, Manufacturing Technology H.H. Ellis Technical High School 613 Upper Maple Street Danielson, CT 06239
New England Model Engineering Society
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Reply to
Errol Groff
Many many thanks everybody. Ill post what I cobbled together when its done.
Gunner
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33
Reply to
Gunner
Hi all
I saw a picture of a rotary table where the shaft continued through the table and there was a second "wheel" near the floor which enabled the welder to turn the workpiece as desired using their feet.
Richard Smith
Reply to
Richard Smith

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