After quite a while looking, I finally picked up a Millermatic 250 Mig welder at an auction the other day. This will replace a Harbor Freight/Chicago Electric "175" (in quotes) Amp Mig welder I've had for a number of years. The HF unit was a piece of junk. As delivered, the wire feed drive wheel was oval, which really didn't help the welds at all. I ended up reengineering the wire feed entirely, but that still left one problem: the duty cycle. At the high end, the duty cycle is about 10% (1 minute out of ten), otherwise the transformer starts toasting and the thermal overload pops. I've been building a Caddigger and welding a lot of plate from 1/4 to 1/2 and this was getting annoying, thus the Millermatic.
I had the Miller apart for cleaning and correction of a few minor problems, and had a chance to compare the units. I think the duty cycle for 250A on this unit is 40%. The transformer looks like it uses 1/4 inch square copper, compared to 10 or 12 ga on the HF. The voltage control uses a couple of SCRs feeding into a cap/inductor/cap filter (60,000 uf on each bank). The HF unit uses a tapped transformer, some automotive alternator diodes and an inductor. I can pick up the HF unit with some difficulty, the Miller weighs about 250 pounds. The Miller also has a thermostaticly controlled fan.
I had reengineered the HF unit to use a Tweeco gun, the orginal was pretty bad. The Miller had a Tweeco as well so I could swap guns (the Miller one was pretty beat up). The HF has a spot weld timer (and I kept that when I reengineered the drive), the Miller doesn't but that was a plug in option. I never used that option anyway. I added a gas purge and wire feed only switch on the HF which were pretty handy. I hate wasting gas when loading wire, or having wire run out when purging the lines. Those should be easy to add, though.
I mercifully do not remember what I paid for the HF unit, but it was probably more than what I paid for the Miller, particularly after rebuilding the wire feed unit. The cheap units are OK for light work, I suppose, but there's no replacement for quality. At least with the Miller, if I screw up a weld, I know it's me and not the equipment :-)
My experience with NEW welding machines:
You get what you pay for.
Now, USED is a different story. You can get something dirt cheap that is an outstanding machine.
Paul, how are the Caddigger plans? I've noticed a few different plans out on the market. A friend and I both want to build one.
dschwalm a t earthlink d o t net
Hi All, Here's my Caddigger experience: www.metalwebnews.com/howto/caddigger/caddigger.html I have 325 hours on the machine and it has performed very well. Happy Holidays, Jim
brought forth from the murky depths:
Those little things are tres cool. What all have you used yours for? Did you get a ripper with it? Are they handy?
Your steel costs seem similar to MetKit's prices. What made you buy locally and cut your own vs. buying MetKit's prefab parts?
What would a similar (smallish) backhoe have cost you?
The extension boom looks mighty handy. How much can it lift and do you have a winch on there or just use the hydraulics to move the boom around to get height?
Safe and sane holidays to you, too.
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I have used the machine for digging foundations, removing trees, planting trees, grading, lifting heavy objects, driving metal 'T' posts (made an adapter), clearing brush, screening rock, trenching, and probably a couple more things I can't remember right now. If I had more tree stumps to remove, I would probably make a ripper attachment with large aggressive teeth on it.
I wanted more quality control of the parts. Also, I enjoyed the challenge of making the parts. If I were to build a digger today, I could save about one third of the metal cost by purchasing from a new (to me) source. I would also use 3/8" hydraulic hose instead of 1/2". The 1/2" works well, but is a bit bulky.
The backhoes that I looked at were all attached to tractors and to get the same size backhoe, the tractor would have been larger than I needed. I have since purchased a Kubota B7500 and am glad that the two machines are separate. I can go places with the digger that a tractor with a backhoe attachment would not even think of. As for price, gosh, $20,000?? That's new - probably could find something used for a better price.
Yes, the boom extention is handy. I am guessing that it could lift about 400 lbs. I do know that the glulams that I lifted without the extention weighed about 600 lbs. I have not put a winch on the digger so getting the height right took some adjusting. It was not easy sometimes because with the boom installed it was difficult to move the machine into position. I am currently building a house and bought a used truck mounted crane so the Caddigger boom has not been used recently. Good luck to all! Jim
brought forth from the murky depths:
Yes, they sound even more handy. I'm looking at a dozen rootballs out in my front yard this spring and really need a backhoe. My neighbor's little Kubota w/ bucket just isn't heavy enough, even with the large mowing deck on the back.
To cut the roots or cut the stump into smaller pieces? Both?
I can understand the challenge but the parts on the website looked mighty well cut. Are they less sweet in real arn?
How quick is the response compared to a backhoe? Would 3/8" lines diminish that?
Yes, I was thinking used. Very few things are better new.
Only about 1/4 ton, eh? It looked heavier.
I saw a helluva lot of 1/2/5T avo picker trucks in SoCal when I lived there. Is that the type you got, with a hydraulic arm?
Thanks for the followup.
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Just to cut the roots for easier removal.
I have not seen the Metkit parts in 'real life' so I don't know what quality they are. Five years ago when Metkit was Metco, a couple of RCMers said that the parts were cut a bit rough.
The hydraulics of the Caddigger are not fast compared to commercially made machines. I rented a Komatsu PC128UU (28,000 lbs.) to dig our basement and was very impressed with it's speed as compared to the Caddigger. Still nothing wrong with the Caddigger's speed if you own the machine! I don't believe 3/8" lines would affect the response at all. I just went with 1/2" lines because that's what NAPA had in stock.
It could probably lift more, but the rear wheels will eventually come off the ground.
No, I have a Ford LT9000 with a 12 ton National telescoping crane.
The plans are pretty good, with a few minor exceptions. I have a web page that details my construction process, but the web server's been down until I get a UPS back on it (there are currently 2 UPSs on my bench to fix and I've been running 15 hrs/day on a new house project), but I'll see if I can get it up soon. You'll likely find it interesting, if not useful.
I'm not sure I'd do it over again. I ran out of time to work on it and I still don't have a backhoe. I should get it finished over the winter, however. If I did it over, I'd probably get a beat up backhoe for $5k. I might have to fix it, but at least I'd get some digging done. On the other hand, it's really a neat project and you get quite a sense of accomplishment out of building it.
There's no doubt the Miller is miles above the HF unit in quality and performance. There's also little doubt the HF unit is at least serviceable. I increased the high-end duty cycle substantially on my cheapy SIP wire feed simply by installing a 5" muffin fan in the case, so it blows on and around the TR and diodes. JR Dweller in the cellar
Paul Amaranth wrote: