MaxArc Mig 200- need to change to single phase

[NotANormalCoder]

Al
You are welcome. The old Max Arc was a good solid machine and will probably last years yet but probably will need a new contactor sometime as the Arrow unit fitted tended to burn out the contact as you have found.
I personally would use 0.8mm wire for your rollcage as it'll give you more control. If you want to use 1.0mm, try it on the existing rollers first and you may find it works fine.
Yes Woodfield Welding Services is me.
Dave

 

[Alan]

Dave , I'll get a 15kg roll of 0.8 wire and test it out properly ( I had a big roll of 0.6 but it wouldn't grip it only had a small roll of 0.8 to hand so I put that on a spindle , which I think someone had fitted , to test if it arced - it wouldn't tension properly so I couldn't test it on faster wire speeds on higher settings ) Any idea what it's minimum amps setting is ?

In appreciation of your help Dave , your welcome to some free sponsorship for Woodfield Welding Services on the car when completed . Thanks again , regards Al.

 

[NotANormalCoder]

Good luck with your project. All free advertising is welcome - if you put our name and web address on the car, I will not object!
Dave

 

[Alan]

I'll let you know when it's done and you can tell me what you want it to say , it should be racing next season. It should be in at least one magazine , one has already asked to run an article on it . Regards Al.

 

[hermetic]

message for @NotANormalCoder if he is still around this forum, you posted a link to the Maxarc mig 200 wiring diagram which is no longer working, I have the opposite problem to above, my welder is set for single phase, and I want to convert it to three phase, and also need to know which terminals the cooling fan connects to! Any help appreciated, especially a wiring diagram or links to a pdf manual!
Phil, East Yorkshire

 

[cumbriasteve]

message for @NotANormalCoder if he is still around this forum, you posted a link to the Maxarc mig 200 wiring diagram which is no longer working, I have the opposite problem to above, my welder is set for single phase, and I want to convert it to three phase, and also need to know which terminals the cooling fan connects to! Any help appreciated, especially a wiring diagram or links to a pdf manual!
Phil, East Yorkshire

Yes he is still here, I have edited your post so he gets a notificiation you are asking.

 

[NotANormalCoder]

Oh yesss, very much still alive but very busy, with little time to visit the forum: PM's always welcome if I can help.
Moving on - When I get back in the office on monday, I will check the Max-Arc files and see if I still have the info and if you PM me your email, I'll pass it on. Meanwhile, the fan is 240V but I can't remember where it connects to. Probably across the 240V terminals on the auxiliary transformer but wait until I confirm that!
Dave

 

[hermetic]

Thanks Cumbriasteve!

 

[hermetic]

Oh yesss, very much still alive but very busy, with little time to visit the forum: PM's always welcome if I can help.
Moving on - When I get back in the office on monday, I will check the Max-Arc files and see if I still have the info and if you PM me your email, I'll pass it on. Meanwhile, the fan is 240V but I can't remember where it connects to. Probably across the 240V terminals on the auxiliary transformer but wait until I confirm that!
Dave

PM sent, or at least "conversation started" is that the EQ of pm on this forum?
Phil

 

[hermetic]

THE MAXARC LiVES!! The speed control variac was faulty, among other minor fixes, but I have replaced it with a £3 chinee speed control, its a bit choppy at the lowest speeds, but it has enabled me to prove the rest of the machine, when I get a eurotorch and check it under load, I will bite the bullet and buy a new one, and then do the conversion to 3 phase, which means I need a 30amp slydloc fuse carrier as well.

 

[NotANormalCoder]

Good news indeed. I am not too surprised that the wire feed is a bit 'choppy' at low speeds as the PCB illustrated seems to be very basic and has only one thyristor. This type of speed contrl was/is often used in cheaper MIGs and they all exhibited the same problem. You pays your money and makes your choice.....
Dave

 

[hermetic]

Yes (he said replying to last months post which he missed) I suspected these speed controls would not do the job, but they were ridiculously cheap, and enabled me to prove the rest of the machine was ok. after I had done that, I bought one of these https://www.ebay.co.uk/itm/RAVI-2F-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649. Made in India (very well made too!) and does the job really well. The Maxarc 200 has now got a new torch, as it had already been changed to Eurotorch, but the old torch was shot, it arrived today, and the good news is, she welds very well, although I am still going to swap it over to three phase. I had to get another slydloc fuse and carrier, as I could not get a G30 slydloc fuse, but I will use it single phase for now untill I get my 3 phase socket wired in the new welding shop. Thanks for all your help, and if anyone has a pdf instruction manual, I would like one! For anyone using an older mig with the variac type speed control, the above was about half the price of a comparable replacement, and is 2 amp rated, whereas the original was 0.6 amps. Heres a question! I note that this welder has a capacitor bank in it, and appears to have been used on single phase all its life, is there any need to remove this when I swap to three phase?
Phil

 

[NotANormalCoder]

Leave the capacitors in. Generally makes for a better welding condition and from memory, the circuit design requires them.
Dave

 

[hermetic]

Thanks again Dave!!

 

[hermetic]

today I bit the bullet, fitted the new slydloc fuse ( the carrier was missing from the middle fuse as the welder had been supplied set for single phase) swapped the connections over as per instructions, and changed over to 3 phase! Bootifull!! so good that I have stopped blowing holes! one thing puzzles me though, I have a fine and coarse voltage adjustment, and also a low medium and high earth lead connections? I assume that this gives a low/med/high amperage choice for each different volts setting, anyone have any advice?
Phil

 

[NotANormalCoder]

These are 'Choke' connections. A choke is like a transformer but with only one wire wound round an iron core, with one or more points of exit at different lengths from the start of the winding. In your case, you have 3 connections (or tappings). The Choke is a form of smoothing for the output current. When the incoming AC is rectified into DC by the welding transformer and rectifier, it comes out as rather lumpy DC. As the current passes through the choke, imagine it being straightened out into a smoother, straighter line of DC. The different tappings allow you to choose how much 'smoothness' works for you. Some machines used the lowest setting for thin stuff and the highest for thick, but you need to work out whats best for you and your machine.

Easiest way to set up your machine, is to start with the earth in one position, do a test weld, adjusting wire speed/volts to get the best condition. Try with the next choke setting, varying wire speed and possibly fine voltage, to get the best condition. Do choke position 3 and see which suits you best.

The choke has pretty much dissapeared from switched MIGs now, as rectifier technology has improved and capacitors (do a similar job) are cheaper than heavy chokes. However, a lot of Inverter type MIGs have a choke control knob fitted that electronically changes the arc characteristics. Don't think I've tried one that made any noticable difference though!

I should also point out that sometime a little 'lumpiness' in the output current will help welds in different positions and with different wire sizes. It's not all about the total smoothness, otherwise they would not have fitted 3 tappings at the factory.

 

[hermetic]

As Elvis used to say "thangyuverymuch" That explains a lot I will experiment and report back. Your help has been invaluable Dave!
Phil

 

[hermetic]

Only done a bit of tacking up today, but ran a few test welds on some scrap, and it does make a difference. I have quite a bit to do next week, so I will have a play and let you know the results I am building a workshop wood fired warm air heater and I need to build the flange to attach the squirrel cage fan to the heater chamber Not easy making patterns with damp cardboard!

 

[NotANormalCoder]

Nice to see the end results of a conversation. Don't often manage to help somebody over 't internet and see this, unlike my day job, when I fix a machine and get told 'It hasn't run that well since it was new'. Good to get feedback.
Happy New Year
Dave

 

[hermetic]

Here is the firebox on the heater, all built with the Maxarc Mig 200 with many thanks to Notanormalcoder Dave. Unfortunately I had a fight with a 9" angle grinder and wire cup brush, which resulted in 12 stiches in my leg, a minor op and an overnight in Scarborough hospital. I am recovering well and will be out of the full leg splint and stiches out next thursday, to say I an going stir crazy is an understatement!! I have now had some time on the Maxarc, and done some experiments with the choke settings and feed speeds/ amp and volt settings, and come to the conclusion that it is a really excellent bit of kit. I grin from ear to ear every time I use it! I should say I started with an ancient BOC autolynx mig about the size of a phone box, and bought a Clarke 165 in the eighties, which has done an enormous amount of work, and recently got a service and refurb. The maxarc is far superior to both of them! next job on the heater is a duct from the top of the round silver barrel to let the heat out, and then it is light it and hope time! Thanks Dave, couldnt have done it without you!
Phil