Frequently asked questions
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Frequently Asked Questions
Push-Pull Systems
Q. What is Push-Pull and how does it work?
A. The Cobramatic® wire feed system is based on a push-pull principle with a “slave” motor in the wire feed cabinet and a drive motor in the welding gun. The slave motor is an AC motor which runs at a higher speed, but lower torque.
Cobramatic wire feed cabinets
Q. Which wire feeder best suits my needs?
A. The Cobramatic® Pro Series wire feeders are designed for the hands-on manual welder, And easily lends itself to automatic operation.
Q. Will any of my Cobramatic MIG welding guns fit any Cobramatic wire feeder?
A. Yes. All welding guns currently manufactured by MK Products, Inc. will work with any currently manufactured Cobramatic wire feeder.
To connect the Python or CobraMAX torches to the older model wire feeders P/N 150-003 and 150-005, an “UPGRADE KIT” (P/N 005-0713) must be installed into the Cobramatic wire feeder.
Q. What sort of adjustments does the wire feeder need?
A. There are no adjustments required in the wire feeder: only select Aluminum or Steel on the center spindle nut for spool drag and the same on the slave motor drive. Both of these settings can be found in the wire feeder owners manual or inside the lid of the wire feeder.
Q. Does the wire feeder require special drive and idler rolls for different sized wires?
A. No. The wire feeder comes ready to use with any size wire from 0.030″ to 1/16″. There are no special drive or idler rolls needed.
Q. How do I connect my wire feeder to my existing power supply?
A. There is an interface relationship between what the wire feeder requires from the power supply, and what the power supply requires from the wire feeder. Optional Power Supply Interface Cable Kits connect the Cobramatic Wire Feeder to most Lincoln Electric, Miller, ESAB, Thermal Arc and OTC welding power supplies. Because of the many different power supplies that can have a wire feeder connected, the “Weld Control Selector Guide” available on our Owner’s Manuals web page gives instructions on connecting not only the wire feeders, but MK spool guns, external contactors, and other weld control components. It is available at no cost from http://www.mkproducts.com. The Optional Power Supply Interface Cable Kits are listed below.
Q. What options are available for my Cobramatic?
A. Cobramatic Pro Series: Model 150-007:
150-007-M (MK Connections) input power capabilities: 30/42/115/230 VAC, 50/60 Hz
150-007-E (Euro Connections) input power capabilities: 30/42/115/230 VAC, 50/60 Hz.
Mk Products engineers have thought of all connection options and included them in the “PRO SERIES” Wire Feeder at no extra cost. More information about the “PRO SERIES” cabinet here.
Q. Can I load any size wire spool into the wire feeder?
A. Any 12″ standard spool will fit the wire feeder.
Q. What is PosaStart? When do I need to use it
A. PosaStart is the slow run-in wire speed needed to counteract the high amperage arc start when the wire touches the work. Once the arc has been established, the wire speed is automatically changed from the slow run-in speed to the preset welding speed. PosaStart MUST be used with a CC power supply to provide arc initiation and may be used with a CV power supply to help eliminate burn-back at arc strike.
Q. What are Closing Contacts?
A. Most, if not all, welding power supplies used for MIG welding utilize closing contacts to energize the welding wire. In order to “close” the contacts in the welding power supply, the circuitry in the wire feeder control simply ‘completes the loop’ and closes the contactor.
Q. Can I use my old “S” clocked gun on the wire feeder?
A. Yes, but it is advisable to modify the 7-pin connector on the end of the welding gun to match that of the wire feeder. All wire feeders and welding guns currently manufactured by MK Products, Inc. are 7-pin “W” clocked. The kit for this conversion is P/N 005-0163.
Q. After using the wire feeder for a while the slave motor gets hot, is this normal?
A. Yes. The slave motor is designed to stand heat build-up, especially if it stalls. This type of motor is also called a stall motor.
Q. Why do the fuses (F1 & F3) on the Main Board keep blowing?
A. F1 is related to the 24VDC motor circuit. Check motor leads, wires and relevant connections. Replace motor and/or gun if necessary. The higher torque-lower voltage motors in the new Prince guns, use more amperage at start up. This increased amperage may or may not cause the fuse to blow. It is recommended to change the existing AGC 2A 250V fuse (P/N 151-0001) with fuse 3AG 4A 250V (P/N 151-0043). F3 is related to the 120VAC circuit. Isolate slave motor, brake solenoid, 120VAC contactor and relevant connections. Repair and/or replace faulty components as necessary.
Q. What is the 120VAC external contactor?
A. When do I need it? The MK200 attaches easily to any Cobramatic wire feeder or WC-1 control box. It’s a secondary contactor that is used in conjunction with welding power supplies that are not equipped with contactors. The MK200 may also be used with other wire feeders that provide a 120VAC contactor signal.blow. It is recommended to change the existing AGC 2A 250V fuse (P/N 151-0001) with fuse 3AG 4A 250V (P/N 151-0043). F3 is related to the 120VAC circuit. Isolate slave motor, brake solenoid, 120VAC contactor and relevant connections. Repair and/or replace faulty components as necessary.
Q. Why doesn’t the brake solenoid come back down after the trigger is released?
A. There may be some residual magnetism left in the solenoid coil assembly once the trigger has been released. This magnetism is just enough to hold the solenoid plunger up against the pull of the spring. Replacement of the solenoid assembly is recommended.
Q. When using 030 or 035 aluminum wire, I have to put the Wire Selector switch in the all other wires position, is this right?
A. No. The slave motor in the wire feeder should have enough torque to push the wire up any length gun conduit, without stalling.
Guns - Python
Q. Why is there is groove in my knurled drive roll?
A. That is from micro arcing do to bad contact on the tip.
Q. Can I use the Python on ANY Cobramatic wire feeder?
A. Yes if the gun is a MK compatible model and provided the feeder has the ability to control the purge gas with a solenoid. The Python gun does not have a mechanical valve which controls the flow of the shielding gas, it relies on a gas solenoid for control.
Q. What is the proper idler roll tension for the Python?
A. As received and adjusted from the factory. The Python uses a cam-lever design, pre-set at the factory, to deliver the proper amount of pressure between the idler and drive rolls. Changing this factory setting will result in erratic wire control.
Q. How do I replace the potentiometer?
A. The replacement and calibration of the Python potentiometer must be performed in accordance with proper MK Products Assembly Techniques. Contact MK Products Technical Support for proper instruction on replacing and calibrating the Python potentiometer.
Q. How do I replace the micro-switch?
A. The replacement of the Python trigger micro-switch must be performed in accordance with proper MK Products Assembly Techniques. Contact MK Products Technical Support for proper instruction on replacing the Python trigger micro-switch.
Q. What is the difference between the Finned Copper and the Heavy Duty brass gas cups?
A. Because of their finned design and specific material thermal coefficients, the Finned Copper cups provide greater variability in duty cycle performance over the Heavy Duty brass cups. The Heavy Duty brass cups were all designed using one wall thickness, the Finned Copper cups utilize two different wall thickness options for better performance.
GUNS - PRINCE XL & PRINCE XL SPOOL
Q. Why is there is groove in my knurled drive roll?
A. That is from micro arcing do to bad contact on the tip.
Q. How do I tell the difference between a Prince and a Prince XL?
A. At first glance the Prince and Prince XL look identical however, there are telltale signs that indicate a difference. The quickest way to notice is to look at the way the barrel is held to the gun body, all Prince XL barrels use a hand-tightening nut to hold it to the front of the gun body. Whereas Prince guns use two set screws to clamp inside the gun body.
Q. If I have a barrel for a Prince, will it fit the Prince XL?
A. No. The method in which the barrel is held in the gun body is completely different between the two guns, and is not common between the two gun styles.
Q. Will my Prince gas cup fit on the Prince XL?
A. Yes. All Prince guns are air cooled and use the standard gas cup.
Q. Can I convert my Prince to a Prince XL?
A. No. The main components that need to be changed include: gun body, barrel, handles, power cable… It is easier and cheaper to purchase a new Prince XL.
Q. What do I need to convert my Air Cooled Prince XL to Water cooled?
A. Three items:
Water Cooled Barrel Assembly
Water Cooled Power Cable
Water Hose.
Q. Is there a way to recalibrate the potentiometer?
A. Yes. Turn the pot knob in one direction until it stops. Then turn the knob in the opposite direction until it stops, then back again to the first stop. With power applied to the motor, you will hear the motor change speeds while turning the knob.
Q. Why does the wire keep “walking” out of the drive rolls?
A. This is usually caused by misalignment of the welding wire traveling from the rear wire guide, through the drive rolls, then into the front wire guide. In most cases, the grooved drive roll is either the wrong size for the wire being welded, or it is upside down, or it does not have the proper spacer underneath. Other occurrences are related to guide tube and/or wire guide placement.
Q. How do I test the potentiometer?
A. Measure resistance across the wiper and the both ends of the potentiometer.
Using an ohmmeter, measure resistance across pin “D” (wiper) and pin “C”. The resistance should vary from 0-5K ohms while turning the potentiometer. Measure the resistance across pin “D” (wiper) and pin “G”. The resistance should vary from 5K-0 ohms while turning the potentiometer.
Q. How do I test the micro switch?
A. Place a continuity tester across pins “E” and “F”. When the trigger is pulled, the signal should close.
Q. How can I tell if the motor is bad?
A. Using an ohmmeter measure the resistance across pins “A” and “B”. A good motor will have a resistance between 5-10 ohms.
Q. How do I connect my Spool Gun to my existing power supply?
A. There is an interface relationship between what the gun requires from the power supply, and what the power supply requires from the gun. Because of the many different power supplies that can have a spool gun connected, please reference the MK Weld Control Selector Guide. This guide gives instructions on connecting not only spool guns, but MK wire feed cabinets, external contactors, and other weld control components. It is available at no cost from Customer Support (800) 787-9707.
Q. Why does the motor fuse in my speed control unit keep blowing when I use my new Prince XL/Spool Gun?
A. The higher torque-lower voltage motors in the new Prince guns use more amperage at start up. This increased amperage may or may not cause the 2A fuse to blow. It is recommended to change the existing AGC 2A 250V fuse (P/N 151-0001) with fuse 3AG 4A 250V (P/N 151-0043).
GUNS - COBRA
Q. Why is there is groove in my knurled drive roll?
A. That is from micro arcing do to bad contact on the tip.
Q. How do I know if I have an old Cobra Gooseneck? Or System III? Or Cobra Gold?
A. Even though they all look the same, there are noticeable differences that distinguish each Model. The older Cobra Gooseneck utilizes a large nut that holds the conduit onto the end of the front body. The System III and the Cobra Gold both use a small set screw from the top of the handles. The majority of these older Cobra goosenecks have “S” clocked Amphenols.
The System III and the Cobra Gold goosenecks are very similar in appearance however the Cobra Gold does live up to its name. By looking down into the hole where the drive rolls are, the knurled drive roll, the idler arm and the gearbox all have a gold plated color. The System III has a gray colored idler arm and gearbox. These two guns have “W” clocked Amphenols.
Q. How can I tell if my 7 pin Amphenol is “S” or “W” clocked?
A. Both of these Amphenols are the same, except the rotational location of the pins, with respect to the keyway slot is different.
The “S” clocked has pins “A” and “F” on each side of the slot. While the “W” clocked Amphenol has pin “E” almost directly underneath the slot.
Q. Can I use the conduit from my Cobra Gooseneck on my Cobra Gold?
A. Yes. The conduit from the Cobra Gooseneck may have a Nut Kit attached. This kit can be removed and the conduit can be used on any MK welding gun.
Q. How do I test the potentiometer? “S” clocked:
A. Using an Ohm meter, measure resistance across pin “”D” (wiper) and pin “C”. The resistance should vary from 0-5K ohms while turning the potentiometer.
Measure the resistance across pin “D” (wiper) and pin “A”. The resistance should vary from 5K-0 ohms while turning the potentiometer.
Q. How do I test the potentiometer? “W” clocked:
A. Using an ohmmeter, measure resistance across pin “D” (wiper) and pin “C”. The resistance should vary from 0-5K ohms while turning the potentiometer.
Measure the resistance across pin “D” (wiper) and pin “G”. The resistance should vary from 5K-0 ohms while turning the potentiometer.
Q. How do I test the micro switch?
A. Place a continuity tester across pins “E” and “F”. When the trigger is pulled, the signal should close.
Q. How can I tell if the Motor is bad?
A. Using an ohmmeter measure the resistance across pins “A” and “B”. A good motor will have a resistance between 5-10 ohms.
Q. How do I know if my gooseneck is water cooled?
A. Coming out the back of the gun handle are five connections: 1) Conduit, 2) Electric Cable, 3) Welding Power Cable, 4) Gas Hose, and 5) Water Hose.
Q. What is the proper idler roll pressure?
A. Proper tension is achieved when wire does not slip if a small amount of pressure is added to the wire as it exists the tip. Too little tension and the drive roll slips on the wire not pushing it out easily. Too much tension cuts into the wire causing excessive wire residue buildup, it also flatten and deforms the shape of the wire.
Q. What do I need to convert my Air Cooled gun to Water Cooled?
A. Remove and replace the weld power cable with a water cooled weld power cable (copper cable inside a water hose). Install a water hose to the extra barbed-end fitting.
GUNS - COBRA MX
Q. If I want to weld aluminum most or all of the time what do you recommend for the Cobra MX? Is there an aluminum kit available?
A. If you are planning on welding aluminum most or all of the time, upgrade your Cobra® MX with the insulated groove drive roll kit. Part numbers for wire size specific kits are listed in your owners manual, or call MK for details. Keep the standard knurled drive roll for spare part or switching back to steel or flux cored welding.
Q. What should I consider regarding consumables, when ordering the Cobra MX?
A. When ordering a new Cobra® MX be sure to order the model that uses the same consumables as any existing guns in your shop. You may already have many cups and tips that will work on the Cobra® MX Gun!
Q. To make better use of the Pre and Post Purge function of the Cobramatic® cabinet while using the Cobra MX, what should I do?
A. Unlike the Python or CobraMAX, the Cobra® MX guns all have the original MK valve body and stem installed. To make better use of the Pre and Post Purge function of the Cobramatic® cabinet, replace the standard valve stem with a Modified Valve Stem, P/N 431-1080.
COBRACOOLER
Q. Can I use automotive anti-freeze in my Cobra Cooler?
A. No. Automotive anti-freeze is corrosive to the internal parts of both the CobraCooler and any MK Weldheads being used. Use Cobra Coolant, or contact factory for further information.
Q. I have everything hooked up properly and the Cobra Cooler powered on, but the coolant is not flowing through the lines and back to the reservoir. What is happening??
A. There could be a bubble in one of the lines, unplug the hose connection at the cooler, and then reconnect. Also tilt the Cobra Cooler by lifting front end, this can aid in getting flow started if there is an air bubble in one of the lines.
Q. How often should I change the coolant?
A. Cobra Coolant should be changed at least every three months under normal use. If you are going to store your Cobra Cooler for weeks or months without use, it should be drained before storage. Fill it up with fresh coolant after storage. Using clean Cobra Coolant will improve the longevity of both the Cobra Cooler and the weldheads being used.
Q. Can I convert my Cobra Cooler to run on 220 V input power?Can I convert my Cobra Cooler to run on 220 V input power?
A. Yes. Like your CobraTig, the Cobra Cooler can be switched over to accept 220 V input power. Please consult your owner’s manual, or give MK Products customer service a call.
COPPERHEAD 5003
Q. Do I always have to run coolant through my 5003 when I am welding?
A. No, you can run the 5003, 5002, and 5001 Copperheads without coolant, provided that you do not make too many welds in a short time. One weld every 5 minutes is suggested when running the weldhead without coolant. However, running coolant with a Cobra Cooler through your 5003 will improve the longevity of your weldhead, as well as giving you the option to make weld after weld without concern of overheating your Copperhead. Running a weldhead without coolant can also endanger the warranty, if the current is too high, or if too many welds are made in a short time.
Q. What do I set my arc gap distance at?
A. It depends on the material you are welding, stainless vs. titanium, etc. A good basic formula is 1/2 the thickness of the tube being welded, plus .010. For example, if you were welding .065 wall stainless tubing, formula would be .033 plus .010, arc gap would be .043. This can be increased or reduced by a few thousandths, once welds have been made and parameters are set in power supply. Keep a record of your settings and parameters once best results have been achieved and tested.
Q. Why does my 5003 not strike an arc when start button has been pressed and pre purge has completed?
A. There are a number of causes for arc fault, or no arc strike. First, verify that the tungsten is new or in good condition, and check your arc gap. Also, make sure that the tube or ferrule being welded has a good ground, this can be achieved by tightening down the plungers in the collets and weldhead with the allen wrench that is used for the collet screws. Be careful not to over tighten the plungers, make contact with tube, then ¼ to ½ turn will be tight enough. Make sure that you are using the correct coolant, Cobra Coolant, as this will help keep arc strikes consistent. Do not use too much argon gas pressure, as too much pressure can keep the arc from initiating. For a 5003, 25 to 30 CFH would be maximum gas flow that is needed. Give MK Products Customer Service a call for assistance in helping you with your application.
Q. What part numbers do I need for Tungsten Extenders and Offset Holders?
A. You can download the Tungsten Layout Configuration Chart here. See Chart to determine which parts you need.
T (Tungsten P/N: 635-063-SERIES)
X (Tungsten Extender Assembly P/N: 002-0770)
H-90 (Tungsten Holder Assembly 90 DEG P/N: 002-0771)
H-20/30 (Tungsten Holder Assembly 20 & 30 DEG P/N: 002-0772)
NOTE: Possible combinations are not limited by what is shown on this chart, other configurations can be arranged accordingly.
DIAMONDBACK
Q. I cannot find the Cobra Cooler connections on the cable assembly for my 5006 DiamondBack weldhead. Why is this?
A. The 5006 DiamondBack is not a watercooled weldhead. The reason for this is that the 5006 is a much larger weldhead than the CopperHead series and 4000 Mini Micro weldheads. The heat dissipates quicker with the 5006 DiamondBack, eliminating the need to run coolant through this weldhead. Typically, set up and fit up times are longer for larger diameter tube and pipe, so the time in between orbital welds is longer also, giving the 5006 even more time to cool down.
Q. I cannot calibrate my 5006 at the same motor speeds as the CopperHead series weldheads, or the 4000 Mini Micro weldhead. Why is this?
A. The motor speed and tach feedback values for the DiamondBack are different than that of smaller weldheads. The 5006 runs slower as it is a much larger weldhead. The default speed for motor calibration is automatically set when the control cable for the 5006 is installed to your CobraTig 150 power supply. The calibration speeds for the 5006 are .50 RPM low speed, and 1.50 RPM at high speed.
Q. Can I use my 25 foot extension cable for my CopperHead on a 5006 DiamondBack weldhead?
A. Yes, hook up everything as you would for your CopperHead, but leave the waterlines disconnected as the 5006 is not a watercooled weldhead. Disconnect any fittings from your Cobra Cooler also while running the 5006 DiamondBack. The fittings on the water lines will not allow any dirt or debris to enter the coolant flow lines for your CopperHead. There is also no need to power up your Cobra Cooler when running a 5006 DiamondBack.
Q. After completing welds on a job for larger diameter tube, I switched back to my CopperHead to complete another smaller diameter orbital tube welding job. Why are the calibration values still set up for the DiamondBack when I installed the control cable for a CopperHead weldhead?
A. The software in the CobraTig 150 needs to have the motor calibration values reset manually when switching from a DiamondBack weldhead to a CopperHead series weldhead. This can be done by simply going to the calibration menu on the CobraTig 150, and changing the calibration speed default values back to 2.00 RPM low and 6.00 RPM high for the CopperHead. Please reference your owners manual or give MK customer service a call if you have any problems.
Q. What part numbers do I need for Tungsten Extenders and Offset Holders?
A. You can download the Tungsten Layout Configuration Chart here. See Chart to determine which parts you need.
T (Tungsten P/N: 635-063-SERIES)
X (Tungsten Extender Assembly P/N: 002-0770)
H-90 (Tungsten Holder Assembly 90 DEG P/N: 002-0771)
H-20/30 (Tungsten Holder Assembly 20 & 30 DEG P/N: 002-0772)
NOTE: Possible combinations are not limited by what is shown on this chart, other configurations can be arranged accordingly.