View Full Version : Miller shopmaster

Planet X
04-02-2003, 01:22 AM
Hi, I would like to know more about this machine esp. real world use.
How do the mig characteristics compare to say the millermatic 251, I see on paper it has some extra volts and I like the extra elbow room, but can somebody draw some bang for the buck conclusions for me. Yes I can sometimes think for myself, but I enjoy talking to others with similiar (welding) likes.
I am limited to 1-phase power and my preference is for 'traditional' power sources. The Inverter type of machines out on the market look to have excellent $$$ to power ratio, but I can anticipate major "brain-pain" trying to use all the arc 'tuning' features.:D
Thanks in advance for any and all opinions.

Scott V
04-02-2003, 04:24 AM
Do you know what a 3n1 machine is?Mill,Drillpress,Lathe.It's in the same league.It can't do anything real well.It will cost more to setup than seperate machines.The ac/dc inverters are easier to use by far,so don't let that scare you.Here is a little bit Brad said about them.


Hobart Expert
04-02-2003, 10:55 AM
The Shopmaster actually is a very good MIG welding unit and the extra output can come in handy. Scott is right though you do have to compromise some to get the multi-process capability, but on this unit the compromise is primarily on the TIG side (no built in HF, no AC balance control). Don't get me wrong, it is a decent TIG welder but just does not have the control that a true TIG machine does. Be sure to compare the price of separate dedicated units to the Shopmaster with all the required acsessories. Remember it's your money and your decision


Planet X
04-03-2003, 08:12 PM
Kevin & Scott , thanks for your replys.
Scott V you mentioned the MK2000A and I am wondering if the output/duty cycles you mentioned are for when the machine is plugged into 3-phase power ? Surely the 1-phase output would be somewhat less or am I missing something?

Kevin I am wondering since it appears that 1-phase will support >300 amp machines ala Shopmaster & powermig 300 type units that a strictly1-phase cv power source no stick/ no tig mig unit could be made.
To clarify the millermatic 251 & powermig 255 on paper seem to be essentially the same machines- why? Why not blow the powermig 255 out've the water by offering those extra top end volts?
Most of my mig welding involves >1/8 steel and I pretty much use spray parameters, sure my power source seems to 'do it' but I'm only using .035 wire, sure would like to have one machine loaded with .045 wire for my spray apps and then just use a smaller mig like the 175 for short circuit apps.
So it looks like it will be powermig 300 vs. shopmaster both machines essentially offering features I do not want which cost $$ that I would rather spend on a High-end goose-neck. ...

Scott V
04-03-2003, 10:40 PM
The MK2000a is 300 amps 100% duty-cycle single or three phase.You just have to make sure your electrical service is big enough.Like wire size,and so on.It pulls fifty amps on single phase at 300 amps 33 volts output.They were ahead of the game when they came out,and still pretty impressive in the quality of them.I have to laugh when I look at Miller,and Lincoln on the inside of the machine,and open up a MK to compare.They know how to run wires.Plus it welds very nice,and is a spraying fool.Plus it goes down to six volts.It also peaks at 360 amps.It is also a stick machine if you jack the slope to 100%,and dc tig with a hot start control.For straight mig welding you only use one knob for power,real easy.There is only one other one thats close the single phase 275 amp 100% duty-cycle,and its the Lincoln Invertec V350.It can go up to 425 amps on single phase power though.Both these companys are working on something thats going to be interesting,judging from the powermig 300 deal.

Look at the MK site for the manual for the MK2000A,and read up on it.They have a few 2000a left so for a cheap awsome machine you better jump.With my new old stock Hobart feeder I got for $300 dollars,and a new gun for $50 I am into it less than about any 250 amp mig out there.It flat just blows them into the weeds in about every type of welding there is.:D


Hobart Expert
04-04-2003, 01:40 PM
Yes a single phase 300 amp machine can be built. The limiting factors are the input power requirements. Transfomer based machines such as the Shopmaster require large input currents on a 230 vac input line to produce the the 300 amp ratings. Few home/small shops have that amount of power available and the large industrial guys that do have it usually buy heavy industrial equipment of the three phase variety. According to the owners manual, the MK unit requires a 25KVA input power supply to acheive the 300 amp 100% duty cycle rating on single phase power. As technology keeps advancing I'm sure someone will find a way to clear that hurdle but until then we'll have make do. One thing to consider here is that the Shopmaster is the only unit of the 3 mentioned that has AC tig capabilities. Good luck with your choice. :)



Scott V
04-04-2003, 02:25 PM
What is telling you is that for 100% duty-cycle you need a electrical service of about 125 amps,and half that for 50%duty-cycle.It still only draws about 50 amp wide open.To put in a 125 amp setup is well within the the skill level of the average home shop guy.I really don't see the need for 100% duty-cycle for the average home shop or even 300 amps,33 volts.Also the shopmaster can't compare to the pulse mig of the MK or the pulse on pulse of the Lincoln.

04-04-2003, 02:40 PM
I've been browsing this board for a few weeks now and I just had to jump in. This mk machine is way to good to be true..
come on a $6,200 welder for 1,500 :confused: :confused: We all know the old adage "YOU GET WHAT YOU PAY FOR!!" There has to be some reason they selling them so cheap. Hey Scott V I was wondering how you find the time to weld with just about every welder made and surf the web day and night :rolleyes: Don't you ever sleep??

Scott V
04-04-2003, 08:41 PM
I been welding longer than 2 weeks,as far as the info on welders.
People have called MK,and have got that answer.That machine was never made for the average idiot,only people that know what they are doing.Mostly hi quality boat builders,and the like.The MK is older tech,and not up to the new ones in ease of use.To say that it's not worth it is just showing your limited knowledge on that subject.I also have welded about 3 hours a night in the last two weeks.Not really making very much,but getting used to my new machines.

Arcman,I sure would like to know what machine you would recommend to PlanetX?:confused:

Planet X
04-05-2003, 12:11 AM
Thanks to all who replied, but purchasing a new welder has been shelved by my 'better' half, she rightly pointed out that my current welders (only two) will weld pretty much everything the Mk will do at least in the material thickness range I most often work with.
But all is not lost because of my plots within plots strategys she actually said " why don't you get a tool you don't have" So that means 1500 guilt free bucks:D .
I also picked up the latest Miller catalog and the Shopmaster is missing + info won't load up on that machine on Millers website-so I guess they shelved it.
Ok I must rant one more time- If Miller would just carve away the FAT (tig/stick) from the Shopmaster leaving only the lean mean mig snorting machine.....:eek:
Hobart Expert & Scott V, about the shop power if were just talking upgrading the service panel with a 200amp drop thats easy getting 3-phase hopeless.

Thanks again everyone.

Hobart Expert Rock
04-07-2003, 08:27 AM
PLANET-X...........YES THE SHOPMASTER WAS CANCELLED........ TECHNOLOGY DOES MARCH ON.............. IT WAS A GOOD DISCUSSION THOUGH........... 1500.00 USA BUCKS........ TO SPEND...........WELL DO YOU NEED A PLASMA CUTTER........ THAT IS ALWAYS A GOOD DISCUSSION....................:D .........ROCK.........:cool: