First post / MIG question

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Hey     ****  first post We have a Miller 251 Mig  machine with 33 lbs spool at work . My question is can I connect the cheap Hobart spool gun quickly . The 3035 spool gun is the same model for hobart and miller .Do you just cut the wire after the feed roller , and disconnect the MIG gun cable lock screw .There is supposed to be a switch spool gun / mig cable gun . So I need to go straight Argon for Aluminum , Is polarity the same for steel and aluminum on MIG machines ( DCEP  ) ?. Once I clamp my power / gas cable in and connect the 4 pin plug am I good to go ? Thanks  ahead of time .Last edited by heli-tech; 08-30-2009 at 03:29 PM.
Reply:Aluminum mig is DCEP and straight argon gas.The 251 is not compatible with the Spoolmate 3xxx series spool guns.  The gun you need is the Spoolmatic 15A or 30A.  The 251 spool gun connector puts out 24vdc for the Spoolmatic gun's drive motor to operate.  The Spoolmate series operate on some other voltage.The gas line for the spool gun connects directly to the regulator on the argon tank.  The Spoolmatic has it's own gas valve inside the gun, so the gas valve inside the 251 is not used and the gas line does not connect to the 251.    That is the way my Spoolmatic hooks up to my 350P.  I have one tank of mix gas that connects to the back of the machine and goes to the mig gun and another tank of argon that connects directly to the spool gun.   The power cable for the spool gun connects inside the machine on the positive weld output terminal and the 10-pin remote connector connects to the 10-pin plug on the front of the machine.  This allows for use of the 'gun on demand' feature of the 251/252/350/350P migs, where you keep both guns connected to the machine and can swap between welding steel and aluminum simply by picking up the right gun and pulling the trigger (after opening the valve on the gas tank) and not have to physically  swap guns back and forth and change out spools of wire.   The machine automatically knows which gun you're using as soon as you pull the trigger and the machine automatically loads the last settings you used with that gun and is ready weld in that process as soon as you pick up the gun and pull the trigger.   Pretty neat stuff!   I have welded 2 projects at once, one in steel and one in aluminum, alternating welding between the two different projects every other weld, just for the fun of it, just because I could.  LOL If you get a Spoolmatic with a power pin connector, then you will have to remove the mig gun and insert spool gun in it's place.  That will provide the weld power connection.  I'm not sure how the gas connection is handled in that situation as I have not owned a Spoolmatic with a power  pin connector.   You're better off buying the regular Spoolmatic with seperate lines and no power pin connector though cause you can use the Spoolmatic in other applications without having to remove the power pin connector or buy the adaptor to change from power pin to seperate connections.EDIT:  I don't think the Spoolmatic is sold with a power pin connector option at all.  I was thinking of the XR15/30A  push-pull guns, which are available with the power pin connector.   The Spoolmatic15/30A and XR15/30A are the same gun, except the XR has a wire conduit and the Spoolmatic has a spool holder.   My Spoolmatic was originally an XR push-pull gun, untill I converted it with the spool holder parts for a Spoolmatic.  Last edited by DesertRider33; 08-30-2009 at 05:31 PM.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Thanks for the replyI need to double check the model of the machine . Maybe it was 210 212 ? two knobs a red voltage digital readouts .  It has the combo power / argon cable , connected to the 4 pin plug ( feed motor / switch / gas solenoid ) ?Maybe I'll hike over to air / gas when its under 100 degrees . The voltage difference between the two looks like the deal breaker .Last edited by heli-tech; 08-30-2009 at 06:17 PM.
Reply:If it has digital meters, it's a 251 or above.  The 210/212 don't have digital meters, or at least the 212 didn't at the beginning of this year.  I don't think they've changed it since then.  If the mig gun cable connects straight into the machine on the horizontal and there is one tubular handle accross the top of the machine, you have a 251.  If the cable connects at about a 45* angle down and there are 2 seperate handles oriented vertically on each side of the machine, you have a 252.'Combo power/agon cable' connected to the 4-pin plug ???The M25 gun that comes on the 210/212/251/252 machines has a power pin connector that slides into the cast aluminum wire drive mechanism inside the machine and provides for connection of the weld power and the shielding gas.  The 4-pin connector on the front of the machine is for the control cable for the mig gun trigger.  The 251/252/350/350P also have a 10-pin control cable connector in addtion to the 4-pin.  The two plugs are right next to eachother on the front of the machine next to where the mig gun connects to the feed mechanism.  The 10-pin connector is for use with the spool gun and push-pull motor drive guns.Last edited by DesertRider33; 08-30-2009 at 06:46 PM.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:We don't use it much its about 4- 6 years old . I eye balled the MIG gun cable connection . The power pin is cross drilled for cover gas input , so the gas runs internal with the power lead . The connections on the  3035 has the same cross drilled gas feed and 4 pin plug , like the stock Mig cable head on the machine .I don't want to fry it on a " Hey watch this run " .
Reply:If it's any consolation, I've seen used Spoolmatic spool guns sell for as little as $500 on Craig's List.  That's about what a Spoolmate 3xxx series gun costs new.   A new Spoolmatic is about $1000.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by heli-techWe don't use it much its about 4- 6 years old . I eye balled the MIG gun cable connection . The power pin is cross drilled for cover gas input , so the gas runs internal with the power lead . The connections on the  3035 has the same cross drilled gas feed and 4 pin plug , like the stock Mig cable head on the machine .I don't want to fry it on a " Hey watch this run " .
Reply:Here it the Hobart 3035 connector photo . I  think the hobart is a 24V motor as well .But like you wrote compatibility issues of the 3 types .http://img.photobucket.com/albums/v4...h/KFD_5842.jpg
Reply:To further clarify the difference in spool guns, the 251 has a 4-pin mig gun connector,  however, only 2 of the pins are used and those are for trigger.   The other 2 pins are duds.  On the machines made to use the Spoolmate series spool guns that connect to the 4-pin connector on the machine, which is all the machines from the 212-down, the other 2 pins in the 4-pin connector are to power the motor in the spool gun.  The wire feed speed is set at the front of the machine.   The machine varies the voltage range supplied to the spool gun's wire drive motor to change the wire speed.On a 251 or above machine, the 10-pin connector supplies the Spoolmatic spool gun with it's trigger and wire drive motor connections.  7 of the 10 pins in the connector are used, 3 of those are for the potentiometer, 2 are for the trigger and to 2 are for the wire drive motor, the other 3 are duds.  The 4-pin connector is not used with the Spoolmatic.  The wire feed speed is set on the gun.  There is a dial control in the bottom of the gun handle for wire speed.  The machine does not directly provide the variable voltage to the wire drive motor in the spool gun.  The voltage is changed by the potentiometer inside the gun.  The wire speed control on the face of the machine is useless when the spool gun is being used.If you connect a Spoolmate gun's 4-pin connector to a 251 or above machine, as far as I know, nothing will happen.  There is no power on the other 2 pins in the 4-pin connector.   That also means that the spool gun motor will not have any power at all, so the gun is useless on that machine.Last edited by DesertRider33; 08-30-2009 at 07:33 PM.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by heli-techHere it the Hobart 3035 connector photo . I  think the hobart is a 24V motor as well .But like you wrote compatibility issues of the 3 types .http://img.photobucket.com/albums/v4...h/KFD_5842.jpg
Reply:The wiring diagram for the 3035 shows a motor , trigger switch on the 4 pins . But I agree you may get no or full wire speed . As the speed control varies the machine feed speed not the spool gun . Thanks for the ideas / info .
Reply:I think you have it down now, for practical purposes.  If you want to discuss the engineering details of this further, you may want to contact Miller tech service directly, at 1-800-4-A-Miller, ask for the Millermatic service dept.   They can tell you in more detail how and why their equipment is or is not compatible with eachother.  I know from a user standpoint what works or doesn't work, however I'm not a service tech, so can't really answer anything much more technical than what we've already discussed.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op