Might consider adding one of these delay timers, starting the bead is much smoother.

Charl

 

What does the delay timer for?

 

With the cap mod, voltage drops at the electrode while the capacitor charges. That makes the arc unstable. The timer delays the wire feed motor. That lets the capacitor get fully charged before feeding wire and the arc is stable from the get-go.

 

Oh I have something kind of like that.
My bleed down resistorsis only a fan now, so residual welding system voltage stays around a lot longer and it is easy to build up voltage now. Now before I start welding I position the wire just above the work and pull the trigger. The electrode charges up to 30 volts almost instantly, then dropps to normal arc voltage. It used to take a few seconds for input current and out put voltage to stabilize and for arc volts to come up and stabilize. The firsr quarter inch or so of weld would show it by be noticeable cooler than the rest.

The 2 things that helped were my power factor correction capacitor and doing away with the bleed down resistors. And I went from touching the electrode to the work and pulling the trigger to standing off and pulling thee trigger.

 

doing away with the bleed down resistor. Bleed resistor will make
your torch a little more safer. As you can get an arc from that capacitor, even when mig is shut off, So bleed
resistor on my 180 is still there.

All the metal screws have been changed out on the case. Strip so easily. Tried some 1/4 x 20 socket head bolts, those stripped out also. Sort of holding the box together, cause there an inch long.

Charl

 

I cut power to the bleed down resistors because they were on the main circuit board. I figured the heat they were putting off was not doing the other electronics any favors. I still have something that bleeds down tne resistors, I wired in a 28v computer fan that blows air straight out the top of the machine. It still bleeds down the capacitor, just takes longer, now that left over capacitor energy actually gets used to reject heat from the enclosure rather than generate it.

 

i was thinking of picking one of these up someday if i found a good deal on craigslist or something. i was looking at the user manual online, and they claim it will weld 5/16"? i assume thats with flux core wire. does this machine weld 1/4" with gas?

 

xmancharl - will the controller you used in your HF180 wire feed circuit work in a HF171? If you could, explain the wiring connections when installing the new controller. Just ran across this thread and hope it is applicable to upgrading my HF171. Thank you and take care. Burt

 

Here is some info:

find which wires for 230 power, you need to splice these
to the relay.

normally open relay contact used was between screws ‘4’ and ‘6’. (Note: These are NOT the same numbers as printed on the side of the time-delay relay). Polarity does not matter. Simply cut the ground wire to the wire feed motor and connect the normally open contact in series as shown in my schematic, above.

Both the 230 volt and dc motor wires carry less than about 1 amp. 16,18 or 20 gage will be OK. Good insulation on the 230 volt wires is important. For those connections I used a piece of old ac heater cord.

There are two 230 volt connections:

one is that black thingy, it clicks when you press the mig trigger.

Second 230 volt connection is from pc board, I just spliced the wires, no need to un solder anything.

The two 230 volt wires just added are then connected to the time-delay relay. Referring to picture, above, with numbers, connect them to screws ‘7’ and ‘8’.(Note: These are NOT the same numbers as printed on the side of the time-delay relay). Polarity does not matter

Was a breeze to install, much smoother.

Charl

 

Charl: Thanks for the response. Already have the information for the TDR, I was looking for information on the PWM motor controller discussed in post #8 of this thread. Cannot make out where the DC comes from (new bridge rectifier?) and the Output connections go (replace existing wires to motor from stock controller?). Can see the 4 black wires but cannot trace them in the pictures. Hope this is clear to you. Thanks again and hope to hear from you. Take care. Burt

 

i believe this the the controller: http://www.amazon.com/DROK-12V-40V-...s/dp/B00CGXJSNY/ref=sr_1_3?ie=UTF8&qid=1411429467&sr=8-3&keywords=dc+controller

it looks like you just pop the knob off the old controller and move it out of the way (it still has all the stuff on it for the gun switch and what not so you still need it.) take the white 4 pin connector off the top of the old board and break the wires out. the ones label dc+ and dc- (on the left side of the connector when it's still in the old controller) go to the input+ and input- on the new controller. the ones on the right side are for the motor connect them as you would normally, red to plus and black to minus. hope that helps.

 

Thank you. I was hoping it was something simple like that. Now I have a chance to get it right. Have a list of mods to do to my HF171 over the winter. Take care. Burt

 

Deleted duplicate post

 

Are pins 1234 only for powering/controlling the dc motor or do they serve other functions on the pcb?

I've attached a mockup of how I'm thinking it should hook up.

 

Are pins 1234 only for powering/controlling the dc motor or do they serve other functions on the pcb?

I've attached a mockup of how I'm thinking it should hook up.
View attachment 885521

Bump..... anyone have any input on this?

 

The one problem I noticed, on your drawing, is that, as far as I know, it makes no difference wether your using gas or not, it should be electrode positive.


Sent from my iPhone using Tapatalk

 

Anyone have any current part number or location to purchase this? -D

 

Any idea where I can buy these today? Ebay? Part number?

 

No idea where to buy that. There are several old threads on here discussing modifications to the MIG-170 and MIG-180, one might have what you need.

Just checking in here to say my MIG-180 with the mods described in this thread is still going strong after 10 years of occasional use, doing farm repairs and minor fabrication.

The capacitor mod provides more output than the original maximum setting. When I occasionally have to crank it up all the way for heavy material, I maintain a very short duty cycle just to be cautious and let it cool. I think that mod is a worthwhile for the smooth arc, while the extra capacity is a nice bonus.

Now a comment on how time changes things: The MIG-180 and MIG-170 were fair value back in the day when they were introduced. Now today the cheap, $150 welders sold on Amazon with a 3 year warranty available, are in my opinion a better choice compared to upgrading these old transformer welders. The latest welders with 2 digital readouts, voltage and current, and 'synergy' (automatic setup) are a third the weight of the transformer welders, easier for a novice to learn on, and should weld just as well. I would also specify dual voltage - such a portable welder should be capable of use anywhere.

Ok, end of rant. I'm old, rasseling the MIG-180 out of locked storage to use in my open-air shop got old. I bought a $139 Amico-130 dual voltage smaller welder and use it most of the time now. It stores in a file cabinet and sets up faster than rolling the MIG-180 to where I will use it. Now 2 years after buying that, the current offerings on Amazon are notably better. Just be sure to also get the $29 extended warranty offered alongside the welder listing, it offers no-hassle replacement if needed. Or buy a thousand dollar welder if your interest is more than a hobby.