A system allowing orbital TIG welding of small tube components and swagelok valves. Orbital TIG welding system holds TIG torch and rotates weld components.

Orbital TIG Welding System (9/3/2018)

Valve body and tube adapter held in chuck. TIG torch held over weld area.

Orbital TIG Welding System (9/3/2018)

Torch holder is mounted on a sliding linear bearing for easy positioning. Frame is made out of 8020 extruded aluminum.

Orbital TIG Welding System (9/3/2018)

Tailstock has a gas feed to purge the interior of the tube with Argon.

Orbital TIG Welding System (9/3/2018)

Mounting plate machined out of aluminum holds gearbox and frame.

Orbital TIG Welding System (9/3/2018)

Torch holder is a Bicycle handlebar mount for a Gopro Hero (after market).

Orbital TIG Welding System (9/3/2018)

Gearbox mounts to aluminum base plate.

VEXTA STEPPER MOTOR:
- NEMA 23
- 4-WIRE
- 5V 1.4A
- 2 Phase

RHINO DRIVE:
- WORM-GEAR
- 90Deg GEARHEAD
- 30:1 RATIO
- ZERO BACKLASH
- 8mm bore, 2mm keyway

Orbital TIG Welding System (9/3/2018)

The stepper controller is a Pololu TIC T825
www.pololu.com

Orbital TIG Welding System (9/3/2018)

The current flows down the drawbar (a 1/4-20 bolt) which is insulated from the gearbox so current doesn't flow through the worm gear or bearings.

Orbital TIG Welding System (9/3/2018)

The current flows down the drawbar (a 1/4-20 bolt) which is insulated from the gearbox so current doesn't flow through the worm gear or bearings.

Orbital TIG Welding System (9/3/2018)

The current is grounded by a spring loaded copper brush that is presses against the back of the drawbar.

Orbital TIG Welding System (9/3/2018)

The current is grounded by a spring loaded copper brush that is presses against the back of the drawbar.

Orbital TIG Welding System (9/3/2018)

The chuck is capable of continuous rotation, the wire on the jaw connects to the chuck body so weld current dosen't flow through the jaw ways or scroll.

Orbital TIG Welding System (9/3/2018)

Tailstock has a gas feed to purge the interior of the tube with Argon.

Orbital TIG Welding System (9/3/2018)

Tailstock has a gas feed to purge the interior of the tube with Argon.

Orbital TIG Welding System (9/3/2018)

Orbital TIG Welding System (9/3/2018)

Orbital TIG Welding System (9/3/2018)

Orbital TIG Welding System (9/3/2018)

Torch can be positioned vertically for welding conflat flanges

Orbital TIG Welding System (9/3/2018)

Torch can be positioned vertically for welding conflat flanges

Orbital TIG Welding System (9/3/2018)

Testing clearance from valve body

Orbital TIG Welding System (9/3/2018)

Welded valve assembly

Orbital TIG Welding System (9/3/2018)

Welded valve assembly

Calculations used for the but weld onto the valve were adapted from:
www.pro-fusiononline.com/
For a ~0.1" wall tube of 3/8 diameter, the welder settings were:
Electrode tip ground to a 90 deg angle
Rotation rate of 4.1RPM => ~5inch/min surface speed
Electrode to tube gap = 0.05"
Pulsed TIG on
3:1 peak to avg current
5 pulse per second pulse rate
35% pulse width
HF continuous
Peak I = 80A
current was decreased to ~80 of starting value manually via TIG pedal during the weld process

Orbital TIG Welding System (9/3/2018)

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