New to me "JUNK $75.00 '97 ESAB Migmaster 250 " Let's get it working again... HELP!!!

[Jawslandshark]

I am just skimming this thread and was looking at the pictures. Since I had a migmaster 250 for many years I will say it welds like butter, it will never drive the wire like your Rebel, turn the inductance all the way up on the Rebel to make the machines similar in thier arc characteristics. My migmaster always liked .035 wire and put down excellent looking/penetrating welds. I don't like welding over mill scale, your cut and etch does not look bad but keep in mind the Rebel will compensate voltage/WFS (Smig) as you weld, the migmaster won't, it's a tapped transformer, how you weld is a big part of it. Better make sure it has a 6/3 stranded power cable feeding it also with the proper 50 amp plug, it makes a differnce. I know of another MM250 a guy replaced the capacitors that he said were weak, I don't know how he knew this but said it made it weld like new? Maybe somebody has mentioned all this, but I did not read the entire thread, just wanted to throw that out there.

[soutthpaw]

I looked for the documentation on the capacitors, couldn't find it I would call esab and ask them about the service bulletin for the MM250 caps. You can tell by the screws on top if they are the newer version or not. I think it was flathead vs Phillips but there is definitely a bulletin from ESAB because I used to have it. Probably gave it away with the machine.

[MinnesotaDave]

Ok got this info from another thread about the Lincoln Welder I purchased a while back. Dave is this the kind of meter you are talking about ?



This meter is pretty cheap but I don't think it does DC Amps.

https://www.homedepot.com/p/Commerci...033C/206288136

Yes, but you need the ac/dc version.

[N2 Welding]

Jaws thank you for dropping in and helping out. it's funny you mention the inductance on the Migmaster 250 vs. the Rebel. An old timer at the local welding supply " California Welding Supply " told me that he sold a lot of these units back in the day and that they had a lot of inductance which is why they welded so nicely. I will put the REBEL in Manual mode and turn the inductance up to 100% on the REBEL so that I can attempt to find settings that work comparable to the Migmaster 250.

For now I just put a NEMA 6-50 plug on the short power cable coming out the back of the machine. I am running it with about a 40' 12/3 cord atm. The plan is to keep the plug short on the Migmaster 250 and buy about 25' of 6/3 and make an extension cord that can be used on this as well as all my machines. You don't think a long 6/3 extension cord with all the plugs on it would create any problems do you? I don't have any Mig experience outside of the Rebel. I have been comparing the Migmaster 250 to the Rebel and been quite disappointed and in doing so I have been thinking there maybe something wrong with this machine based on the way it's welding. I totally understand the way I weld will come into play as it will not spoil me like the REBEL.

I still have to get a AC/DC Amp meter as suggested by Dave to check for voltage and amperage while welding. I need to establish a base line known set of parameters to determine if there is any thing wrong with the machine or if it is just me.

I read something about the Capacitors and some other stuff when the spot timer was installed. Something about the wire will hold a small amount of spark after welding and can be seen when you touch the wire to any grounded material. I see that spark from the wire after I am finished welding if I let it touch any material that is grounded to the work clamp.

I looked for the documentation on the capacitors, couldn't find it I would call esab and ask them about the service bulletin for the MM250 caps. You can tell by the screws on top if they are the newer version or not. I think it was flathead vs Phillips but there is definitely a bulletin from ESAB because I used to have it. Probably gave it away with the machine.

So the newer caps are preferred over the older style or vice versa? I'll give them a call.

Dave do you or any one have any cheap amp meter suggestions that will get the job done?

[N2 Welding]

I am looking at this meter for $85 atm. https://www.lowes.com/pd/Southwire-D...Meter/50125831

https://www.lowes.com/pd/Southwire-D...eter/50125831#

[soutthpaw]

I have this one, works good to 400 amps DC, $40 shipped or pickup at Sears store. http://www.sears.com/craftsman-digit...FUPewAod0wgE-A

[N2 Welding]

One review of that meter says the following

DOES NOT measure DC current
WARNING, this does not do what the product description claims!! If you zoom in on the picture, you can clearly see that it does not measure DC current. I bought this based on the description during a car battery emergency, and it was completely useless. It seems to have good reviews for the functions that it DOES provide, but to advertise the product with a function that can be found on the +20 dollar mark-up is a serious mistake.

view less
Willibomb | Churubusco, IN | Wed, Jan 20, 2016 via craftsman.com

[soutthpaw]

One review of that meter says the following

Mine does DC, but they updated the part number.

[Jawslandshark]

Jaws thank you for dropping in and helping out. it's funny you mention the inductance on the Migmaster 250 vs. the Rebel. An old timer at the local welding supply " California Welding Supply " told me that he sold a lot of these units back in the day and that they had a lot of inductance which is why they welded so nicely. I will put the REBEL in Manual mode and turn the inductance up to 100% on the REBEL so that I can attempt to find settings that work comparable to the Migmaster 250.

For now I just put a NEMA 6-50 plug on the short power cable coming out the back of the machine. I am running it with about a 40' 12/3 cord atm. The plan is to keep the plug short on the Migmaster 250 and buy about 25' of 6/3 and make an extension cord that can be used on this as well as all my machines. You don't think a long 6/3 extension cord with all the plugs on it would create any problems do you? I don't have any Mig experience outside of the Rebel. I have been comparing the Migmaster 250 to the Rebel and been quite disappointed and in doing so I have been thinking there maybe something wrong with this machine based on the way it's welding. I totally understand the way I weld will come into play as it will not spoil me like the REBEL.

I still have to get a AC/DC Amp meter as suggested by Dave to check for voltage and amperage while welding. I need to establish a base line known set of parameters to determine if there is any thing wrong with the machine or if it is just me.

I read something about the Capacitors and some other stuff when the spot timer was installed. Something about the wire will hold a small amount of spark after welding and can be seen when you touch the wire to any grounded material. I see that spark from the wire after I am finished welding if I let it touch any material that is grounded to the work clamp.

So the newer caps are preferred over the older style or vice versa? I'll give them a call.

Dave do you or any one have any cheap amp meter suggestions that will get the job done?

You can use 25 feet of 6/2 SOOW or SJOOW with NEMA 50 plugs. I can tell you 40ft of 12/3 is not going to be good, it's going to choke that transformer welder. I would put a 60 amp breaker in your box and run a new outlet from there for your 6/2 extension, you would be surprised the inrush amperage that machine will pull.

On the inductance start at 100% with clean 10 gauge material and run one inch welds on both using same wire, you should be able to tune the Rebel somewhere close after a few runs, if I had to guess it will be in the high 80% range on the Rebel to match the MM 250. I doubt ESAB will know anything on the caps unless you get a tech that knows what it is, that machine dates back a ways, you can probably source some from eBay or other electronic places, just match up specs. Did you discharge and take them all out to clean up the cap connection straps? On older transformer machines all the current connections will need to be gone through as well as possibly a new ground cable and lugs, seen several that welded funny from just a little corrosion and old copper, ground clamps are always suspect also.

If you can't make that v350 gun work I have a like new euro back 250 15' tweco spray master that we could do some trading on. It takes standard Tweco consumables though.

[N2 Welding]

I got the V350 for use with Spray transfer and not having to worry about the duty cycle on the gun. I have not touched the capacitors other than to probe with DMM leads trying to measure voltages with machine off. I really don't have a clue what I am doing there but with a little help can get it done. I am scared the caps may knock me on my but if I touch them incorrectly with out discharging them and I do not know the best way to do so with out hurting my self or the machine.

[N2 Welding]

I just scored 25' of new unused SOOW 6/3 for $78.00 at an electrical supply house.

[Jawslandshark]

That's great now you can get rid of the 12 ga, no way that can handle the amperage of the inrush. Just cut the white wire back so it can't short out anything in the plug since it's not going to be used. I might be stating the obvious but use red +/black +/ green ground. Don't know what you are pluging into but remember most dryer plugs etc in houses are only 10 ga, that welder needs to have a 6 ga from the breaker to the plug with a 60 amp breaker. I did not look it up but as I recall is pulls near 52 amps full tilt. Maybe this has all been stated before, sorry if it has or if you already know it.

I think that machine has a capacitor drain down resistor, so if its unplugged for a few hours the caps lose charge and safe to touch, please double check this it's been too many years since I had the top off one. It should be easy to find it if it does, it's probably brown and about 3 inches long, souttpaw probably knows or pm brand X for the info, he knows ESAB stuff really well.

[N2 Welding]

I installed a 6/3 from my panel with a short run about 3' to 4' from a 50 amp breaker to outlet the outlet on the other side of the wall. That should be fine for my purposes. I did as you explained and snipped the white wire back. Eventually I want to add a 100 amp sub panel in the garage to run two 50 amp circuits for plasma cutting.

[N2 Welding]

Ok I made the new extension cord and as I was going to test the MM250 with the new cord I noticed the cable at the ground clamp was a little loose. The Tweco Junior GC300 ground clamp was tight when I installed it but I did not double the cable up onto itself so it wiggled loose after some use. So after both of those issues were addressed the machine woke up and breathed a new breath of fresh air. I think it is working the way it should be now. I was able to get those near spatter free welds with very little effort Now I have to find and fix the gas leaks. I have been going through my C25 gas like crazy. I started with a full 80CF bottle and it's about half way if not a little less than half full. I know one of the issues is a leak coming from the regulator and I noticed when I was working on the Drive System that the gas hose near the Euro socket was a little rough like it has been gouged previously or something else happened. I'll have to get some towels out and stuff them under where I will be spraying the gas line with a Dawn dish soap and water solution to check for additional leaks. Yes I will unplug the machine and wait probably over night to test for leaks. Now I can see what all the fuss is about

[N2 Welding]

Here I was attempting to spray on 1/4" using .035 with C25. It was spraying for the most part but I was getting a few globs every once in a while. Now that I know the machine looks like it is going to be a very nice asset to my Mig arsenal I will invest in some 90/10 gas for Spray. I did not clean the slag off the material for what it's worth. It may of made a little difference but from what you were showing me Dave earlier in this thread, you get a very nice bead profile with out cleaning the slag.

[N2 Welding]

Here is 1/8" material using C25 and .035 SC wire. I used a wire wheel here to clean the mill scale before welding. No fine tuning and tweaking the settings, just a quick adjustment to get it close to spatter free. I started out pushing then starting weaving backwards e's

No more poppy starts like before either

[N2 Welding]

What are you using for an etching solution?.

. Sorry Dan I forgot to answer this. I believe it is Phosfuric Acid but I will have to take a look for you in the morning.

[tylerd]

I have the L-Tec version of this welder, I am pretty sure that the power cable was swapped out on it. Does anyone know what gauge came on it from the factory? I have about 10-12ft of 10/3 soow on it now. I think I am going to do like N2 did and run 6\3 to the wall plug as I am pretty sure that is 10\3 also. My unit welds great as it is but want to provide it all the juice it needs for optimum performance.

Thanks

[N2 Welding]

tylerd I got the following information from the user manual on page 22 I put a red rectangle around the power requirements for my situation.

[N2 Welding]

What are you using for an etching solution?

Here you go Dan

[tylerd]

Awesome! thanks for the quick response, I got some upgrading to do now!

[N2 Welding]

No Problem tylerd. I did not use the 6 gauge power cable on the machine. I just made an extension cord that runs to the machine. Keep in mind that 6 gauge power cable is not cheap I just got lucky and found a deal. You may want to change the machine to use 6' - 10' of 8 gauge then use a 6 gauge extension chord past that to the wall plug.

[Jawslandshark]

Glad you got the machine working like it should!

Getting 90/10 will take you into real spray not the globular spray you are getting with c25. The euro connection has a little o-ring that always gets messed up on backend, check that for gas leaks as well, a trick I use to keep o-rings nice and not tear when putting them in the drive is to spray some anti-spatter on it. Also negative cable ground clamp is key to good spray, I never use ground clamps that have springs.

[N2 Welding]

Thank you for all the tips Jaws.

[N2 Welding]

Ok I just compared both Gunmaster 250 and the Spraymaster V350 back ends to see what if anything I can do to use the parts I already have. I am under the impression that I have what is needed already to convert the Spraymster V350 to a Euro connection if I use the parts on the Gunmaster 250. I don't want to damage the Gunmaster 250 though by trying to swap the parts. You can see where I circled the back ends in red how similar they are.