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With all the work Ive been doing lately adjusting the wire feed speed circuitry on the control board and researching the operation of the mig power supply, I got to thinking, how much of an improvement all the modifications have made? The welding specifications for the Century 170 Mig are as follows:Primary input volts230 volts ACPrimary input amps20 ampsPhase SingleFrequency 60 HzSecondary output volts20.5 volts ACSecondary output amps [UL output]130 amps DCOpen circuit voltage [max]34 volts DCRated Duty Cycle 30%Other specifications in the manual:Power requirements198 to 245 Volts AC, nominal 230 volts ACCircuit breaker 50 ampsPrimary maximum current 40 amps AC, limit of the solid state relayMetal thickness 26 Gauge to 5/16 inchWire diameter 0.024, 0.030, 0.035, 0.045 inchWire feed speed 0.0 to 750 inch per minute Shielding gas steel 100% CO2, C25 Aluminum, 100% Argon Stainless Steel 90% Helium, 7.5% Argon, 2.5% CO275% Argon, 25% CO2Wire type ER70S-3 and ER70S-6Flux core ER71T-GS and ER71T-11Stainless steelmatch alloyAluminum match alloySilicon BronzeERCuSi-AThere was a nominal period of learning to use my new toy. I had a few projects that I had to run long beads and I noticed that the Ground clamp cable and gun cable would become hot welding at high current levels. Heat in an electric circuit represents an energy loss and I changed the cables from # 6 gauge to # 4 gauge, I also upgraded other cables in the power supply between components. I was not too happy with the connections from the secondary of the transformer to the rectifier; the connection was a loop of wire around a stud held in place with a nut, these connections also became hot. If you run a large current through a small diameter wire it gets hot, the same happens when a large current passes through a connection too small to handle the current. The remedy was to make new wire terminations on the rectifier studs and heat sink. I took the wire loop and closed it back on itself, placed it in a heavy copper eyelet and lightly crimped the collar to hold it in place, and then I filled the gap in the collar with solder and bolted everything back in place. Each upgrade in itself had little effect, taken as a whole the change was dramatic. While I had my fingers in the power supply, I very carefully disassembled the diode assembly marking all the diodes with White-Out. The individual diodes are the button type and the orientation to the heat sink is of utmost importance, one diode flipped over and BOOM goes the rectifier. I took a Scotch Bright pad and polished the heat sink plate and the copper contacts on the button diodes being careful of the White-Out. Reassembling the 24 diodes, I placed a drop of heat sink grease on each diode, between the diode and heat sink plate, the thermal grease fills any voids between the diode and the heat sink making the heat flow from the diode to the heat sink more efficient. In operation, the heat sink is warmer now because the diodes are dumping more heat into the sink, hence the diodes run cooler. This is the way manufactures make a Economy-Consumer model by skimping on the hardware and details, the Pro units have bus bars and other heavy duty components. The Devil is always in the details. I also added a second capacitor in parallel to the first, + to + and to , doubling the energy storage.The specifications for the unit are a bit misleading. If the power supply draws 20 amps, why use a 50 amp circuit breaker? The answer is in the way the specifications are written, 20 amps is the current draw at the 130 amps welding current. Remember the 40 amp maximum current? That number is printed on the solid state relay that switches the current to the main transformer. One may deduce that the maximum allowable current is 40 amps hence doubling the 20 amps at 130 amps welding current, 130 amps doubled is 260 amps max. You say that is a leap? Well, I can calculate the duty cycle and the corresponding current, this calculation is based on the maximum current the transformer may produce, which are 258 amps. Need more proof? Setting up for maximum current, I measured 255 amps. Close enough. Run some tests to evaluate the changes, the rated output is 130 amps at 30% duty cycle. 130 amps are close to 125 amps that would be used to weld 1/8 inch steel.Using my Miller Mig calculator as a guide to set the wire speed and current to the recommended values, I set the wire speed and heat and measured the current and voltage. The measured values were in range of the recommended settings, although the voltage was a little low.I also tested with 3/16 inch stock and the wire speed and current were within the miller calculators recommended range, again the voltage was low.Testing for the effect of the second capacitor:Using 3/16 inch stock the measured current with both capacitors in the circuit was 155 amps @ 18.5 volts DC.I disabled one capacitor by removing one led from the capacitor taking it out of the circuit. Not changing the wire speed and heat settings, the measured values were, 100 amps @ 18. 3 volts DC. Removing the second capacitor had little effect on the heat [voltage], but made a 55 amp difference in the weld current. The bead was also effected, much more penetration with the two capacitors and the additional 55 amps. The power supply will easily deliver 200-220 amps. I think I may have the low voltage figured out. The primary current draw was about 30-35 amps and when I measure the maximum open circuit voltage across the caps and the AC voltage output from the transformer they max out at #5 on the heat control dial, 6, 7, 8 have little effect, a buzzing sound comes from the transformer when the heat control is past 5. I believe that the solid state relay is limiting the input current too early, flat topping the voltage-current sign wave causing distortion and the buzz. Flat topping a sign wave has the same profile as a square wave, odd number harmonics. The third order harmonic [60Hz x 3] causes a current to flow in the opposite direction generating heat and detracting from performance, very, very bad for AC motors. I may very well turn this sows ear into a silk purse. There has been many postings about 110 volt Migs being under powered, what I learned may be applied to any power supply.
Reply:Thanks for the info. Most folks wouldn't tear apart a new welder, the fact that you did, and made your results public is a big plus. It gives us real facts rather than just seat of the pants observations.past work toys; lathes,mills, drills, saws, robots, lasers ironworker, shears, brake, press, grinders, tensile tester, torches, tigs, migs, sticks, platten table, positioner, plasmas , gleeble and spot. Retired June 30, 2009.
Reply:Originally Posted by transitThere has been many postings about 110 volt Migs being under powered, what I learned may be applied to any power supply.
Reply:Transit,To your comment about "this can be applied to any power source", I'd like to add:AND VOID ANY EXISTING WARRANTY ON SAID MACHINE.I'm not an electronics expert, just one speaking in general terms.Do you really think you know more about that particular machine than the manufacturers?If it was really that easy to "increase the output" and still maintain reliability don't you think the manufacturer's would have already done it. Couldn't they ask more for say a 150A machine than they could for a 120A machine.Generally speaking, manufacturers (not just welding machines) go thru a "systems design" process where the different components are "speced" to be compatible. Increasing output here/there will generally lead to another component failure down the line.It's your machine, so you can do with it what you choose. I just think it's sort of reckless to recommend this modification as something that can be "done to any power source".Sounds like a surefire way to "LET THE BLUE SMOKE OUT".Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I agree with Sundown on this one! While its nice to be able to share such info its not recommended.for safety sake. Unless the person is an authorized manufacturer service tech you will most certainly void your product warranty. Unless you have the technical know how you also have the liability issues if the modification was to fail as set fire to your house.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.& 2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Originally Posted by Broccoli1main problemo is the 120v receptacle power- either 15amps or 20amps @ 120v, possibly a 30amp @ 120v but still...15amps x 120v = 1800 watts20amps x 120v = 2400 watts30amps x 120v = 3600 wattsbump up to yer 50amps @ 240v and ... 12,000 watts.
Reply:Originally Posted by transitYoure basing these calculations on ideal conditions; consider yourself fortunate if you have 120 volts at the receptacle. The NEC allows for a 4% voltage drop, that is 120-4.8 = 115.2volts. Therefore 15 x 115.2 = 1728 watts that the circuit is capable of delivering. Its not the circuit breaker that influences the voltage, its the distance, wire gauge and current draw. Someone said in a post that he plugged his 110 volt mig into a circuit with a 30 amp breaker and things improved, that also means the wiring is now 10 gauge which translates into a maximum 2% voltage drop, and we dont know the condition of the original 15 amp circuit which may have had a larger loss. Ive seen voltages down to 104; it makes a huge difference with a toaster. Set the controls to light toast using 104 volts and move the toaster to a 120 volt outlet and burn the toast. Come 2 AM and you may see 125 or more at the outlet. Although the maximum current for my mig is not published, the power supply has a electronic relay that is rated at 40 amps. The 50 amp breaker is for protection and the mig should not draw more than 40 amps., 50 amps would most likely burnout the relay or transformer, hopefully the overheat switch would trip first.
Reply:Originally Posted by SundownIIITransit,To your comment about "this can be applied to any power source", I'd like to add:AND VOID ANY EXISTING WARRANTY ON SAID MACHINE.I'm not an electronics expert, just one speaking in general terms.Do you really think you know more about that particular machine than the manufacturers?If it was really that easy to "increase the output" and still maintain reliability don't you think the manufacturer's would have already done it. Couldn't they ask more for say a 150A machine than they could for a 120A machine.Generally speaking, manufacturers (not just welding machines) go thru a "systems design" process where the different components are "speced" to be compatible. Increasing output here/there will generally lead to another component failure down the line.It's your machine, so you can do with it what you choose. I just think it's sort of reckless to recommend this modification as something that can be "done to any power source".Sounds like a surefire way to "LET THE BLUE SMOKE OUT".
Reply:While I would not recommend we all go out and do this, it was evident in the first post that this man knows what he is doing here. Miller makes a 120, 150, 200 etc because not everyone wants or can afford a 350. It seems reasonable that someone, even with limited experience, can make modifications like this but not just anyone can make sense of it.I says thanks Transit
Reply:Wow Transit,Arn't we impressed with oneself.With that background and experience, I'm surprised you couldn't afford to buy a mig welder that did the job necessary, RIGHT OUT OF THE BOX.When you state that basically "anyone can do this" are you implying that all manufacturers have designed their machines poorly. Are you implying that Miller/Hobart/Lincoln all use "second year engineer students" to design their machines.I still say it's reckless to recommend that the average guy even attempt to make such modifications to their welders.BTW: Please do tell us more about Chernobyl. I just happened to have been there also, on or about 1 May 86. Except the Chenobyl (area) I visited was in the N. Ukraine (not Ukrainian). I'm not at liberty to discuss who "paid for that ticket". Maybe you could shed some more light on the "human error" that led to the accident at Reactor 4.PS (after rereading your reply) I really don't know if Hobart used heat sink grease on the HH187. Don't know if Miller used heat sink grease on the MM251, etc, etc. If they didn't, I suspect the .03 cost had nothing to do with it. Maybe they were concerned that it would attract and hold airborne air contaminants (metalic dust) thereby causing a short here or there. Welding machines do tend to get used in a dusty environment. Just a thought.Transit. Your qualifications to undertake such a modification are not what's being questioned here. It's the implication that "anyone can do it". After reading all the posts about "how do I make an extension cord for my 120v mig", this posting just concerns me about the expertise of some of our "do it yourselfers".Last edited by SundownIII; 07-28-2009 at 09:49 PM.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I would wonder how the transformer would hold up cause if you beef up all the week points of the machine (cheaper parts) you make the main parts like the transformer the weak link in the chain or other hard to replace or expensive parts I understand where your comin from I always make a heavy guage cord be it 120V or 220V and all welder outlets for me at home and work are directly on the breaker panel for optimal voltage but beefing the guts can make the wrong parts the week link especialy when the duty cycle is typically a heat operated switch. and all your changes affect the power loss through heat and could cause the duty cycle not to turn machine off in time..
Reply:Here is a pic of a mod that someone suggested how to carry it out and someone else's interpretation of how to physically do it. Attached Images
Reply:Ran some test today on 1/8 and 3/16 stock, settings were from the MilerMatic Calculator and the chart on the inside cover of the Century. The mig runs very different now; smother beads, easily controllable wire speed. There are signs of good penetration on the backside of the T joint... I’m still concerned about the maximum attainable heat; I need to find some ¼, 5/16 and ½ inch stock to test the beads at the upper settings. Now that I’ve fully recovered from cataract surgery I need to do something about a magnifier lens for the hood. Maybe magnifyring reading glasses?Last edited by transit; 08-01-2009 at 06:17 PM.
Reply:Originally Posted by transitRan some test today on 1/8 and 3/16 stock, settings were from the MilerMatic Calculator and the chart on the inside cover of the Century. The mig runs very different now; smother beads, easily controllable wire speed. There are signs of good penetration on the backside of the T joint... Im still concerned about the maximum attainable heat; I need to find some ¼, 5/16 and ½ inch stock to test the beads at the upper settings. Now that Ive fully recovered from cataract surgery I need to do something about a magnifier lens for the hood. Maybe magnifyring reading glasses?
Reply:you know boys I kinda like to hear the Mods and kicking his A#$ isn't very hospitable. You know if you dont like what he is say cool go read something else I want to read it.....We all arent as nasty and pissed off as you......Thank you BrandonLincoln Tombstone 225 A/C Steel StickerOld Victor O2/Acetylene setupMiller Syncrowave 250 Tig/PC-300 PulserMiller Millermatic 212 Mig HTP Invertatig 201 Giant Teck D50 Plasma cutterLots of HF grinders
Reply:Brandon thanks for the support. Ive encountered nay sayers before and take delight in proving them wrong. I also weigh valid arguments; thinking outside the box is how advancements are made. That power problem at the Jersey Ave station is in the hands of PSE&G, its on the utilities side of the meter on the local grid. It appears someone is putting power into the grid after hours in an unconventional manor and upsetting the voltage regulators. Now PSE&G is tracking them down after I made them an offer they cant refuse. Funny, Im not in the Power business and I have better tools, the tech working the problem was licking his chops when I e-mailed him the results from my Fluke 345 power analyzer. Been doing this since I was 8. My manager and I have crossed paths many times on projects and never met, funny. Im up this late because we have a police presents at a music concert at Liberty State park. We have an 18 wheeler Mobil Command Center at the park Buck Rogers would go nuts over. The side of the trailer pulls out to make a double-wide, diesel generator, land lines, satellite link, and LED video signs outside the trailer. Were still working the bugs out, what a pain. The doughnut wagon was two years behind schedule; the contractor in Maryland went belly up and
. We towed the cab and trailer up from Maryland, had to finish it ourselves. The Marines had the same problem. Must remember to stop in LWS, pass it on the way to-from our Newark Shops.
Reply:You getting a Fz problem or spikes, not sure if your power analyzer has an O-scope display but look at the waveform. We had a problem around here a few years ago that was caused by a foundry, they were doing something with an electric furnace in the middle of the night that destabilized the grid and caused very large fluctuations in both Frequency and voltage the interesting thing was it did not drag the grid down. It turned out to be a capacitance problem. The waveform became erratic after zero crossing then stabilized as it became more positive or negative, then had a nice parabolic shape. Cool stuff, I don't get to play with that kinda stuff any more. But modding a cheap welder might be fun, years ago when they used analogue power supplys in power amps we would mod the heck out of them, bigger caps, change the feedback loops, and sometimes they even sounded better.BrandonLincoln Tombstone 225 A/C Steel StickerOld Victor O2/Acetylene setupMiller Syncrowave 250 Tig/PC-300 PulserMiller Millermatic 212 Mig HTP Invertatig 201 Giant Teck D50 Plasma cutterLots of HF grinders
Reply:Brandon, I wish it was that simple, I’d have it bagged and on the shelf long ago. The problem starts about 9 to 10 PM and lasts to 6 to 7 AM the next morning, every day. The line voltage is a normal 120 volts with a little wiggle, 120-122 all day. At 9’ish the line voltage instantaneously goes to 140 volts or more [177] and stays there about 7 to 8 hours. At 6’ish the voltage instantaneously retunes to the normal 120 volts and everything is happy again. The data graphs show a perfect square wave lasting hours at a time, no spikes. The local substation half mile down the road is stable, there is a local transformer on the property and that is where we’ve traced the problem to. If something is malfunctioning, the event timing would be random, it’s like someone is turning a switch on and off. I’m gona grind their bones to bake my bread!Just noticed, lots interest in this thread.Last edited by transit; 08-02-2009 at 10:37 AM.
Reply:That is awsome you have improved the unit and only time and calculations will tell.....I had a coustomer at A Recording studio in Michigan... He was a tech and we did Mods to 8 Kenwood amplifiers straight out of the box and I was not fully understanding at the time but was a really great experience.... some of what was done is similar to your project,we replaced caps with superior ones doubled a fewand it sounded better...replaced all grease that wasn't there hardly at all failure point in that amp...some fet transistors for switching with better brand and a different amplifier chip being these were digital and to make the switch from analog the new amps sounded like crap and the mods are still in line today outlasting all the ones that didn't get it done.... Not everyone can do these mods but with direct advisement like you have put out there many Tech/Hacks I guess they will call em... can see how to do it and that is great if they have the want need and knowhow it is how we all learn different things but there is no coverage in case of fire!!!! use cinder block building lol.... Most everything manufactured today is as cheap as they can make it so any brand part you can cross reference, and replace with ECG,NTE or top of the line parts will definitely be an improvement from the china specially made parts that most you have to figure out because nobody can cross reference them for replacement...understanding what your looking at is the key here.... And with any design there is always room for improvement the manufactures use the cheapest and not always best parts, no matter the company to cut the cost of the build...... and some cheaper parts have a longer life span than their name brand replacement. so even with my HH180 and Hypertherm there is a few parts that could have been substituted for others and some are specially made only by them for the application.....but like anything else these days they are sadly disposable or repairable way before their time and not as dependable as what they have replaced... the old school units rock hands down but all the features are very nice on the new equipment and look much better in the shop for sure.... cost a lot to keep modern equipment running and looking good for your customers, but some of the best welding work I have ever seen has been out of Barns,sheds, and small shops oh ya and on here...... electronics thing out of basements and garages have been amazing what a tech can do with a piece of equipment IF HE knows what he's doing with it.... but for anyone to do it no way you are very educated in the field and what you could do to a piece of equipment has my attn. and respect because not everyone can do what you do ...as most of us all here are all different...and not without your direct supervision and they would learn how then and you could sign off I suppose would be legal if your a tech lol...Lincoln 225 Tombstone,Miller Big 20,Hobart 180,150' Argon,A/D hobart hood 22 Ton Log splitter,79 F350 dump eats 4.75 TONS and still turns cutters,grinders,And a Hypertherm POWERMAX 30
Reply:Probably someone with a Welding machine that they made some Modifications to is causing the PoCo problemsEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:Tony, about 15 years ago when Dolby surround sound became popular I spent some money on a Pioneer VSX-5900S. I didn’t like the speakers in the shops, they were over priced for their performance. I had to read two books on speaker design. Chose 12 inch Pyle Driver for the woofers [ 10-1600 Hz],6 inch for the midrange [1600-8k Hz] and piezoelectric tweeters [8k-30k Hz] in a ported cabinet that is optimized, Crossovers are 6 dB / octave.When I was testing the speakers one July 4th, they were playing the 1812 overture, the one with the cannon fire at the end, I broke a window.
Reply:Originally Posted by Broccoli1Probably someone with a Welding machine that they made some Modifications to is causing the PoCo problems
Reply:I'm with you, on working on welders,great fun.http://weldingweb.com/vbb/showthread.php...282#post279282There was a guy some years back that stole a bunch of power pole transformers and hooked them up backwards to make a time machine.Maybe he is out of jail and in your neighborhood.Robert
Reply:Face it the quality of ANY product has gone severely south. The majority of products now days is it works, sell it. I am a machinist and I can say confidently that most components we produce are horribly designed and engineered and if we were to follow their prints without question their would be many failures in aerospace, medical, and many consumer products like cars, atv's, welders, etc.
Reply:I'm all for making your stuff better if you know how and if you don't you learn by trying. If you have even a little sense you will not burn your house down or electrocute your self. Of course there are those with more stupid than brains but I do not think it is everybody's business to take care of all the dumb ones. Generally they will get burned or shocked and learn not to touch. I tried to instill in all my kids that the thrill in living was the investigation in the wilder side . they all made it and are all successful. But I notice that every forum has a few people that are worried all the time about very little. well it does take a village to make an idiot. Maci like the post and i do agree ppl need to layoff if you got something nasty to say just phuck off and read something else . ppl are awesome on the thing that they know from experience or learned knowledge so i think its phenomenal what ppl can do some are just naturals at what they do .. so i say awesome job keep us posted and more pics thanks assassinLincoln Power Arc 4000 Thermal Arc Fabricator 252 iThermal arc 186Thermal Arc 26 tigTweeko 200 amp spool gunHobart AirForce 400WP-17V-12R
Reply:With manufacturing in general; manufacturers take short cut with economy stuff (and even the premium stuff), and sometimes the "cheap" ones are the same as the "good" ones, just intentionally crippled! Don't ever buy into the "Its absolutely perfect from the factory" thinking. I bet even my new miller could be improved with some of these ideas with the OP's exact steps, I just don't have the guts to try them while its covered, I know they took shortcuts in assembly. If they had people hand polishing every contact, it would be prohibitively expensive, and even then I would care more about how my machine runs than the wage slaves. As it is I will probably upgrade my ground clamp and maybe the flow meter. They both look cheap, so I'll assume they are.Anyone here ever tried overclocking their computers? I have one CPU I can get about a 75% boost on with everything completely stable. Others were not so impressive, but I could always get at least a 10% boost out of everything I tried. Buying a 10% fast CPU from the factory can cost hundreds more at the high-end.I am all for putting in a little labor to make things better, and If you can learn a bit about how your machine works while doing it, all the better.Last edited by Groo; 10-10-2011 at 12:02 AM.
Reply:Any more info on what's going down with your local grid? |
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发表于 2021-9-1 00:08:04