1966 Round Top Idealarc 250

[FlyFishn]

Things are coming together. I cleaned up the faceplates today and the work/electrode studs/bolts/washers.


















Another tidbit is I painted the on/off letters. I think it is one of those subtle details that "pops" when you run it. That is a control that will always be used. Its hard to imagine not knowing if it is on or off, but the white makes it look nicer than just the engraved/recessed letters.

[Sparkie1957]

Your 3 wheel cart is actually the one specifically designed for the Idealarc250. You can tell by the flat plate the machine sits on. Other Lincoln tricycles were for the bigger gray TM series. If you mount an Idealarc on it the back of the machine is about 1” low. I have the one like that, easy to shim it up level.


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[FlyFishn]

Your 3 wheel cart is actually the one specifically designed for the Idealarc250. You can tell by the flat plate the machine sits on.

Thanks for the info. The fact it had a cart was a bonus to me, I thought. I am actually thinking about taking it off the cart, though. The reason being I intend to put it in a fixed location where it won't move. I have to do the numbers on the leads again and see what kind of reach I have. The leads that came with it are pretty long. If that works out the cart would be in the way as the machine would be pretty close to a wall where the cart would get in the way of it.

That isn't to say I would ever part with the cart, I wont. It might be really nice to have in the future with a shop/barn.

As to it being OEM - from the pictures I saw looking online when I was researching these that is what I figured. However, I have seen other styles. What sets this one apart, to me, is it has the 2 arched frame bars that come up to the front castor. The other styles I've seen have a solid bar (one piece, not 2). I believe, I am not 100% sure, but the 1 piece frame carts are newer designs.

Cool stuff. The more I think about this and browse others' projects and the used market for these machines the more I am glad I moved on this one when I did. Yeah, a lot of people might look at it as still being a 50+year old junk tombstone. However, at the end of the day a good stick welder is what I was after and even when I upgrade to a TIG/Stick machine this one will be around to stick metal together with if there is ever a problem with another machine. It might even take care of all my heavy welding duties and leave my options to a TIG machine to lighter stuff without the higher end amperage or duty cycle being a factor. Lots to think about. Any way I slice the cake, the Idealarc is a great idea. I think anyone that sticks metal together should have an old-school transformer machine around, even if it collects dust, because it would make for a great back-up machine when something just has to get stuck together and other machines don't work or are on loan etc.

[Sparkie1957]

Something to consider in regards to using the cart or not is cost of more lead vs longer power cord to increase reach. We put 6-4 SO power cord on our units. As high as that is it’s cheaper than 1/0 welding cable. I have 35’ of power cord on my Idealarc and 60’ of 1/0 on stinger and 40’ in the ground


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[FlyFishn]

Something to consider in regards to using the cart or not is cost of more lead vs longer power cord to increase reach. We put 6-4 SO power cord on our units. As high as that is it’s cheaper than 1/0 welding cable. I have 35’ of power cord on my Idealarc and 60’ of 1/0 on stinger and 40’ in the ground

Good point.

I don't have the power supply entirely worked out yet. 6/4 SO is a consideration.

The ground is 28' and the electrode is 48'. I took pictures of them. I am thinking the cables are 1/0 but I could be off.

At the moment all I have to work with is a 30 amp circuit. As soon as I can burn some rods I am going to test it and see how much weld current I can get before it pops the breaker. It might get me by with the amount of welding I'll likely do with it in the near future. Though, I have a thought about running a separate temporary circuit with 6/4 from the breaker box if I need it. I hope I don't but its an option. I need a mix of lead in cables for generator power at times as well so the 6/4 (or what ever I figure up going with) would have a lot of varying purposes, but none as a regular permanent install. That won't happen at this location. Down the road is another story - but too early to try to plan anything. All that is planned is the machine at this point - and a few other machines in my collection.

[FlyFishn]

Your 3 wheel cart is actually the one specifically designed for the Idealarc250. You can tell by the flat plate the machine sits on. Other Lincoln tricycles were for the bigger gray TM series. If you mount an Idealarc on it the back of the machine is about 1” low. I have the one like that, easy to shim it up level.


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Is that the cart that the machine in the link here is sitting on?

The one in the link is said to be a 1971 machine. If that is the cart - is that an "after-thought" that someone added later? And if so - were the carts like what mine is on not available after purchase/ordering the machine from Lincoln?

https://weldtalk.hobartwelders.com/f...7&d=1383863262

[Welder Dave]

I wonder if what you're using for thinner isn't compatible with the paint and is causing the rough finish? I know with automotive paint sometimes you have to add fish eye eliminator and depending on the paint the proper thinner is very important. I'd look at updating your electrical before trying it on a 30 amp circuit. I that's way too low. People in the know don't look at older Idealarc's as old machines. They are just damn good time tested machines like the older SA200's. How many inverters will still be working in 50 years? Chances are an Idealarc 250 will still be working in another 50 years.

[Sparkie1957]

Is that the cart that the machine in the link here is sitting on?

The one in the link is said to be a 1971 machine. If that is the cart - is that an "after-thought" that someone added later? And if so - were the carts like what mine is on not available after purchase/ordering the machine from Lincoln?

https://weldtalk.hobartwelders.com/f...7&d=1383863262

I’m not sure but I don’t think age was the difference but the size (weight) of the machine to be carried. If you look at both carts it appears that the one I have has bigger wheels and the frame is made from larger material. It would be interesting to know from Lincoln sales literature. My source is a gentleman that had worked at Stumpf’s Welding since 1971, they have been Lincoln dealers since 1952.


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[FlyFishn]

Todays work - mainly cleaning the polarity switch. I was hoping to not have to disassemble the whole thing but that was the only way to get to the metal base plate to repaint it. So I bit the bullet and took it all apart. That was several hours worth of work. While the paint was drying I took my breakfast break - at about 2:00 this afternoon. Multitasking - eating while paint dries.





Once the switch was reassembled I started rewiring the machine. I did have to take the rear panel back off to get access to the rectifier block and the pass-through for the straps. In fact, I had to remove the baffle/bulkhead also as I needed clearance between the panel and the transformer stack to get the pass-through back in with the straps in it.

There are still a few things I would like to clean a bit with the wiring and straps. I am thinking painting a few things would be a good idea. However, I am not sure how much more detail work I want to do on the inside.

Truth be told, I am anticipating rebuilding the rectifier. It works as of right now but that is one component that I am anticipating having issues with as time goes on. When that happens I will have to change a few things. So details inside probably aren't worth a whole lot to do.



A couple other tidbits -

The black wire on the stabilizer cap (big oval silver can on the bulkhead/baffle panel) is 3k ohms (3,000 ohms). That is the "resistor" that is in the circuit.

I also added a set of spade connectors on the red wire. That way it is easy to pull back out if need-be.

[Sparkie1957]

Those selinium diode rectifiers might surprise you and last for many years. Are you using 30 amp drier power cord?


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[FlyFishn]

Before I put the panels on I test-powered the machine. I was careful with the wiring of the polarity switch etc and I labeled the straps before I took them off (you can see some of the labels still on them that I haven't taken off yet). The fan ran and nothing sounded odd. I did not hook the leads up and burn any rod. That will have to wait.



















There is a rubber piece that goes over the lifting eye on top. I will put that back on, I just didn't have it out to put on tonight.

[Sparkie1957]

Looks good. At least no blue spark when you powered it up


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[FlyFishn]

Those selinium diode rectifiers might surprise you and last for many years. Are you using 30 amp drier power cord?

That cord came with it. It is a 50 amp range/stove cord. NMEA 10-50. It obviously isn't factory from Lincoln.

[Sparkie1957]

Ok good. We use regular 6-3 SO for power cord


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[FlyFishn]

Here’s one of the interior of the machine

Any chance you can get a few more pictures of the rectifier brick from different angles?

That is the closest picture I've come across (and I was just scanning through the thread pics again here and caught it) to what I was envisioning with the flange mount diodes. I think the plates I have will be good donors when/if the time comes to upgrade, but they are too close together. I saw a video where the flange type units were retrofitted to the generation rectifier brick on my machine, but there was very little spacing between the panels. I had in the back of my mind to use all thread for the bolts and mount the plates further apart. It looks like your machine is very much set up the same way with the newer diodes and further plate spacing. I am curious how the strapping works with the connections.

[Sparkie1957]

Idealarc 250 AC/DC round top - diode upgrade.
https://r.tapatalk.com/shareLink/top...ink_source=app


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[N2 Welding]

Flyfishn,

I like your ambition.

[John T]

Looks good.

If it was me, Ida painted the inside of the panels also.....

.

Is that primer paint on the transformer?? (or whatever it's called)

.

[FlyFishn]

Looks good.

If it was me, Ida painted the inside of the panels also.....

I thought about it, but I didn't think it necessary. The most inside the paint should really be is inside the vent fins on the visible sides.

The original paint was pretty much red oxide primer anyway so even Lincoln didn't paint this "Lincoln Red" through and through.

Another reason was I was trying to conserve on the top coat red paint as I was trying to get by with a single quart. That sort of worked, but with all the fixing I have tried to do on the top coat I ran pretty thin and ordered a 2nd quart anyway. Its not here yet - supposedly wednesday. I am going to give the whole outside (minus the cart and base) another round of uniform top coat so I can cover up the last round of blemish fixes - the blemishes are covered, but the paint now is a different consistency which shows when the light hits it. So to fix it I need to do a uniform coat over the whole panels.

.

Is that primer paint on the transformer?? (or whatever it's called)

Yes - everything not red is red oxide primer.

[FlyFishn]

Idealarc 250 AC/DC round top - diode upgrade.
https://r.tapatalk.com/shareLink/top...ink_source=app

The picture in post number 5 of that thread is what I have seen before, not sure if that same exact picture, but the same method - where the rectifier panels are drilled or milled out to make room for the bolt-on diodes.

That isn't what I want to do. The reason being that I want to preserve the panels as much as I can. The outside one (most to the rear of the machine, positive/red mark on top) has the serial number written on it in permanent marker. I don't want to deface that. As to drilling more holes - only in places that won't mess up the writing and as minimal as I can make it. That's why I want to do the allthread method to space the panels away from each other so clearance isn't an issue. Then the only holes should be for the diode studs.

There are 2 polarities for the diodes. I'd need 2 of each so that the studs bolt on to their respective panels correctly. The stud side of the diode is also the heat sink. So for anyone else reading through with the idea of upgrading them - you can't simply take 4 of the same polarity diodes and bolt 2 of them "backwards" where the pigtail connection is attached to a panel and the stud end is free floating. There is no heat sink on the stud end that way - only the strap it is bolted to. That is why you need reverse polarity diodes - so that you can sink the studs on both polarities on the 2 plats that are there. Otherwise, you would need a 3ord plate/heat sink - which is not stock on the machines.

[shortfuse]

Beautiful job on the restoration!!

[FlyFishn]

I cleaned up the leads today and gave it a test run. All is good. I did check the output with a multimeter before I ran any rods just to be sure.

For what it is worth - on AC I am getting 74 volts and DC 102 volts (both polarities), all open circuit volts of course, not burning rods.




And a couple side-by-side comparisons of before and after:

[Sparkie1957]

Looks good. Great job. I believe your open circuit volts are out of spec for DC


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[FlyFishn]

I believe your open circuit volts are out of spec for DC

Studying this one today...


AC

For what it is worth, the DC trace is very clean and with the power removed it fades off with the supressor cap bleeding off noting that the cap is holding a charge. I haven't measured the cap yet but the voltage is dependent on the supply voltage - which is from the rectified AC. So it would appear to be functioning correctly. The RMS voltage on AC is 74v, which is spec. Vtop is the upper peak = 104v. That is the same as the rectified and filtered DC.


Electrode positive*



Electrode negative*


*The 'scope ground is on the electrode and the signal is on the work. That's why the polarity may appear opposite in the traces above. Doesn't really matter, it measures the same both ways. DC coupled, of course.



Green is work, red is electrode.

[FlyFishn]

And the idle power specs:





~6.3 amps idle 244v in.