|
Post by linus69 on Apr 24, 2008 15:01:04 GMT -5
Hey Larry, My gas engine powered DC job-site welder wants the rod on the negative pole, I`ve always had good results using it that way. Good luck with your new machine.
Paul
|
|
|
Post by bradblazer on Apr 24, 2008 23:21:47 GMT -5
|
|
|
Post by gerifalte on Apr 25, 2008 16:19:30 GMT -5
OK Stick welding with DC, I have a question - what polarity should the rod be? I find myself using negative polarity most times because it lets me do very smooth passes. Here is a very nice "cheat-sheet" for stick welding www.hobartwelders.com/elearning/pdfs/Stick_Welding_Tips.pdf I use 6013 for most jobs, and sometimes 7018 when I need a stronger weld (i.e. the darn cracked tiller I posted in another thread in the TPH section). I am by no means a very proficient welder, I am just sharing my bit of experience here I hope this helps! By the way where do you choose the polarity for stick welding in your machine? Your pics only show the MIG settings (I think) G
|
|
|
Post by bradblazer on Apr 25, 2008 20:32:43 GMT -5
"By the way where do you choose the polarity for stick welding in your machine? Your pics only show the MIG settings (I think)"
It has DINSE type cable connections - I think you just swap them.
|
|
GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
|
Post by GuglioLS on Apr 25, 2008 21:29:34 GMT -5
G: "By the way where do you choose the polarity for stick welding in your machine?"In the upper left of the wire compartment, notice the + and - marked wires, remove two nuts, then swap the wires. Electrode + for Shield gas, electrode - for flux core wire: Reading that nice chart Brad posted a link to, unless I am missing something, it tells me most of the rods can be used either DC + or -. Something tell me I'll probably not be using too much stick welding, since I'm spoiled rotten using MIG. Larry
|
|
GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
|
Post by GuglioLS on Apr 25, 2008 21:37:42 GMT -5
Brad: "It has DINSE type cable connections - I think you just swap them"Correct for Stick welding, it's a simple matter of just swapping the cables: For MIG polarity, it's as described in my post above. Larry
|
|
3RRL
Administrator
Huge Kama
Posts: 2,027
|
Post by 3RRL on Apr 25, 2008 23:31:58 GMT -5
Larry, great find and nice mods to get it working good. 250 amps is a lot of power, that big weld is awesome. Of all the welders I've had and/or run, I've never tried a MIG. Don't think I'll be getting one soon since the last stick welder I bought is still in the box. But next visit to your place, I'd like to try that welder out. Rob-
|
|
|
Post by beaualex on Nov 9, 2010 16:35:09 GMT -5
Hey Larry, what's the chance I could get you to post a PDF of the manual for the Chicago Electric/HF 250 AMP Mig/Arc Welder? I can get my hands on a unit, but it does not have an owner's manual.
Any help would be greatly appreciate.
Beau
|
|
GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
|
Post by GuglioLS on Nov 10, 2010 11:47:08 GMT -5
Hi Beau, Welcome to CTW. Your in luck I found the link to the manual online. Click on the link below it should open up a new tab in your browser and go directly to the online PDF manual. After it opens choose "File", "Save" and viola you should have a pdf copy. www.harborfreight.com/manuals/95000-95999/95424.pdfPlease let me know if that works for you. If you don't mind me asking what kind of a deal are you getting? Oh and what are some of the projects you plan on? We would love to see some new pics and projects. Larry
|
|
|
Post by beaualex on Dec 9, 2010 14:54:14 GMT -5
Hey Larry,
Where did you get the secondary fan? I have been searching all over for one with the wire guard and cannot find one.
I just picked up the Chicago 250 amp mig/arc welder used for $265. It looks new, very little wear.
Thanks for all of the very useful tips and photos to make this a really great welder.
Beau
|
|
|
Post by beaualex on Dec 9, 2010 15:03:03 GMT -5
Thanks Larry for the tip. I had already call HF and had Hugo Ramos send me the PDF. I posted a questiion to you a few minutes ago regarding the source of the secondary cooling fan with the wire guard. I just picked up a slightly used Chicago/HF 250 amp mig/arc welder for $265. Just got to get the gas argon/co2 bottle, flow meter and I'll be ready to go. I'll will be using the argon/co2 mix since I like the results. I used to weld for GE and that is what we used and it works really well even on mild steel. I sure appreciate all of the great tips and photos you supplied.
Beau
|
|
|
Post by Rich Waugh on Dec 9, 2010 15:30:06 GMT -5
Beau,
You can sometimes find those fans in salvaged computer server racks. Those usually run on 120v as opposed to the 12v ones that desktop computers generally use. Anther source is from copy machines - the bigger laser copiers often use several of them. If you can't find one with the wire grille cover you can always make one from a wire kitchen cooling rack.
The 80/20 Argon/CO2 mix is a good shield gas for use on mild steel and medium carbon steels. It gives a bit more penetration than straight argon and is a little cheaper, too. You can actually use straight CO2 for steel, but you'll get a bit more spatter - not a lot, but some. For silicon bronze, stainless steel and high alloy steels you'll need pure argon to get good results.
If you need maximum penetration and filler deposition for work on heavier stock one good way to achieve this is to use DualShield wire with the 80/20 shield gas. The DualShield wire is a flux-core wire intended for use with a supplemental shield gas and it allows you to both work very thin stock and very thick. It isn't cheap, but for work where strength and penetration are mandatory (like heavy equipment) it's my filler of choice. With a250 amp machine you really lay down a lot of wire with the DualShield and know you're getting solid penetration - 1/2" single-pass welds should be no problem at all. With a machine that can be dialed down to consistent low voltage and smooth feed rate you can even weld sheet metal as thin as 18 gauge with the DualShield, too. Pretty slick stuff.
Rich
|
|
GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
|
Post by GuglioLS on Dec 10, 2010 0:15:03 GMT -5
Hey Larry, Where did you get the secondary fan? I have been searching all over for one with the wire guard and cannot find one. I just picked up the Chicago 250 amp mig/arc welder used for $265. It looks new, very little wear. Thanks for all of the very useful tips and photos to make this a really great welder. Beau Beau, That sure was a smoking good deal on the welder. I just updated the rectifier diodes in mine. I took out all 96 of the 3 amp diodes and replaced them with two 300 amp full wave bridge rectifiers I got off e-bay. The performance and duty cycle are much improved. The OEM diodes were breaking down pretty fast on the 250 amp setting. Now with the upgraded diodes it welds as smooth as silk for as long as I can pull the trigger. The fan and screen I got from - well I got if from my old parts stock I carry in the performance of my job to repair instruments. It's a 240 volt AC fan, pushes about 100 CFM. Granger sells them. www.grainger.com/Grainger/DAYTON-Square-AC-Axial-Fan-3LE74?Pid=searchGuard: www.grainger.com/Grainger/DAYTON-Fan-Guard-4YD87Larry
|
|
|
Post by Rich Waugh on Dec 10, 2010 0:48:13 GMT -5
That was a good call replacing those diodes, Larry. I'm surprised they would use a bunch of little ones like that - the potential for a cascading failure would seem pretty high. They must have gotten a deal on them surplus. :-) Were they set up in a full-wave circuit or just a half-wave?
That pair of big bridge rectifiers will do a much better job at the higher amperages for sure, and you've got a great safety margin with them, too. Have you found that they are still stable at the low end of the output range? I've wondered about that in the past when I was building electro-forming power supplies but never found any real information that answered my uncertainty. That was back before the answer to everything was available on the 'net, of course. I can hardly remember how I managed before Google - couldn't have been pretty, I'm sure.
That welder of yours is going to be unrecognizable as a HF unit before much longer. You might have to re-paint it gold or something. (grin)
Rich
|
|
|
Post by beaualex on Jan 2, 2011 17:57:08 GMT -5
Larry, I am not sure how this thread is supposed to work. I had sent you a comment and you replied, but now I cannot locate any thing except your original entry.
You had inquired about any projects I would be using the Chicago 250 amp mig on. I'll be building a steel fence and gate for my side yard. Tomorrow I'll be looking for a machine shop to modify the drive wheels as you recommended. Seems like a pretty good idea based on the whimpy knurl job on the originals.
I was able to pick up my Chicago 250 amp mig/arc for $265 here in Tucson. I now have a 55 cft argon/co2 tank and regulator.
I found an adapter to enable the use of 1-2 lb spools. If you have not already found that source, I'll send you the supplier.
Beau
|
|