AHP AlphaMig 250 / Big issue with wire feed speeds

[notserpe]

Is anyone familiar with the AlphaMig 250 by AHP? I have one with almost no hours on it.

I was getting **** beads when trying to weld at 19V at 250ipm, I expected the knob/reality to be off a little bit but
I'm manually measuring the actual wire feed speed as subpar... as follows

~100ipm when the knob and display is "set" to 315 ipm setting (lowest)and
~240ipm when the knob and display is "set" to 629 ipm setting (the theoretical max), and
~550ipm when I push the QuickFeed button inside the spool area

I was thinking the motor is shot but I'm getting near max "setting" when pushing the quickfeed button.

When I put the voltmeter on the two pins for the spool gun on the front of the machine, I read

1.8V for 78 ipm setting (lowest) and
5.52V for 314ipm setting (middle) and
10.62V for 629ipm (highest) setting

A spool gun typically runs at 24V, no? It seems like the machine is putting out 0-10.5V (0-12V) range instead of 0-24V range for the wire feed voltages.

Thoughts?

[SweetMK]

With "Almost No Hours" on the machine,, I would be calling the manufacturer,,, for such answers.

They might want the machine returned,,

[M J D]

With "Almost No Hours" on the machine,, I would be calling the manufacturer,,, for such answers.

They might want the machine returned,,

Good luck with that.

[metalmeltr]

I believe that machine has been out of production for a few years. I wouldn't suspect any warranty help from AHP. I presume low hours just means it hasn't been used much even though he has had it for a while.

[notserpe]

"I would be calling the manufacturer" for such answers.

Great idea. Thanks for your help.

I presume low hours just means it hasn't been used much even though he has had it for a while.

You are correct. It's got maybe <100 hours on it, probably <50 hours.

I've contacted them directly and am awaiting a callback while trying to stay optimistic. So far I've been told briefly on the phone that measuring the speed "dry" (aka with no arc) is known to be slower than with arc, but I'm awaiting details/explanation why it's 3x slower and why the front panel spool feed seems to be 1/2 the voltage one would expect at any given speed. It's not the motor since the Quick Feed drives the wire near the max speed albeit ~75 ipm too slow.

My current hypothesis is a design issue with the controller or an issue with the logic board, favoring the former since the machine has been sitting in a climate controlled shop the entire time I've had it next to other machines that function flawlessly.

Since I'm now sure that the wire speed is way slow (as evidenced by process and dry measure) I'll be more radical in my selection of feed speed while await, hopefully, some input from the manufacturer.

[notserpe]

Alright, some time has passed and for educational purposes and a general update I'm going to post some photos and additional findings:

First off, I sent a support request on the AHP website and then about a day later I telephoned AHP just at the end of the day EST thinking the number which is California PST should be open for a bit but tech support is 9-5 EST on a PST number. I spoke briefly with someone at tech support who said they would get back to me because it was end of day but that "dry fire wire feed" is known to be slower than "actual arc wire speed". It's been over a week now and I haven't received any follow up from AHP in fashion.

So I decide to dig further into things for myself. I have now confirmed that dry wire feed speed is same as arc wire feed speed.
With front panel set to 314 IPM (half total possible wire feed speed), when laying down a bead, the front panel indicates wire feed speed drops and hovers around 120-130 IPM. This is consistent with the measures I have taken with manual dry feed measurements. Furthermore, with the front panel set to 629 IPM (max wire feed speed possible), when laying down a bead, the front panel indicates the wire feed speed drops and hovers around 230IPM. This too is consistent with the measures I have taken with manual dry feed. (~240IPM max) So this seems to dispell the myth that there is a different between dry and hot wire feed speeds. See previous message regarding manual wire feed measurements.

Disappointed at both no support return call or email for more than a week and that the small amount of information I did receive turned out not to be accurate.

[notserpe]

I'm posting the following information for educational purposes only. I discourage anyone from opening up any sort of electrical or electronic devices and I am posting this information for your edification only. Any welder contains extremely dangerous internal voltage and current that can easily kill you. Do not open up your welder!!!

That said, with both of us having a background in electronics, embedded and reverse engineering, a colleague and I decided to take a peak under the hood and here because neither of us had ever done an actual tear down of a solid state welder before.

Here are some photos of the welder internals:

Wire Feed Motor



Control Board



Feed Motor / Spool Gun Power




Quick Feed Button / Gun Trigger



Front Panel Connectors

[notserpe]

Motor Driver Section



Motor Driver Rectifier & MOSFET



Unknown purpose POT



Chassis Ground

[notserpe]

Unknown ST MICRO Motor Driver IC



Main Power Switch



Selenoid Gas Valve



Power / Drivers DANGER DANGER DANGER



DO NOT DISASSEMBLE YOUR WELDER YOU MIGHT DIE. DO NOT DO IT.

[notserpe]

I've saved the best / worst for last. This is the sort of thing that seriously discourages me from buying another AHP product and most likely Everlast product in the future. I own a couple of 2016/2017 AlphaTIGs that I've been extremely happy with but opening up this 2017 AlphaMIG and finding this sort of thing makes anyone with a background in electronics cringe:

Two solder blobs instead of 10 cents worth of jumpers.



Solder Block Nightmare #1



Solder Blob Nightmare #2



Furthermore the solder job on the rectifier and MOSFET for the wire feed motor doesn't look great:

[notserpe]

So, this leads to a few trouble shooting questions regarding this particular unit.

Given the confirmed hot/dry wire speeds, are one of these solder blobs configuring the PCB to drive the 24V motor in a 12V motor range?
The multimeter readings for motor voltage suggest something like that could well be the case both for the wire feed motor and the spool gun motor voltages.
The voltage readings for both are consistent.

Is AHP willing to address this probable manufacturing defect issue or provide me with the PCB schematic so I can continue troubleshooting? Doubtful. The unit is clearly out of warranty. Like I've previously stated, There are probably less than 50 hours on this particular unit and despite being a repeat customer, I have yet to hear back from AHP at all. Insert sad emojis here.

An additional solution is possible but only because of my requisite skill sets. Build additional PCB to drive the 24V motor properly with 24V power vampire'd off the gas selenoid circuit for example with an external speed control knob. This isn't a particularly difficult thing to accomplish but is ultimately a waste of my time and resources given that this unit isn't and hasn't appeared to work properly since I purchased it.

The unit isn't 100% a waste and write off since it does appear to operate < 240IPM but that isn't terribly useful for the current project I want to use it for...

[notserpe]

I guess my next step is to get motivated enough to want to take the case apart again and get the soldering iron in there to remove the two jumper solder blobs
and replace them with proper jumpers and hope that one of them is a 12V/24V feeder motor selection jumper with a cold solder joint blob at one of the nightmare points.

Less hopefully but also perhaps as well as attempting to call AHP again and see if they can just give me a simple answer.

[notserpe]

Positive news to report, I had some time today so I called AHP again and happily received a very fast call back from their tech support.
Fingers crossed from here forward.

[duramax-rob]

Positive news to report, I had some time today so I called AHP again and happily received a very fast call back from their tech support.
Fingers crossed from here forward.

please keep us informed. i have the AHP 200 TIG unit!!!!! mine no problems yet.

[lugweld]

Few things to consider. Most inverter migs have a slow run in to improve start. That means measured wire feed speed will not be accurate.
Also most MIGs with displays change from reading in IPM in static mode to actual Amp output.
Wire diameter also plays a factor in amp output and wire feed speed correlation.

[notserpe]

please keep us informed. i have the AHP 200 TIG unit!!!!! mine no problems yet.

I have too for about 5 years and I love it, never had any problems with it, though I did toss all the accessories, added SSC foot pedal/victor reg/flow meter/western quick interconnects/CK torches and most recently an HTP Artic Chill water cooler to that setup. Runs like a charm and I'm happy to have been able to put the money into quality accessories instead of pouring it into marketing on a "big brand".

[notserpe]

Also most MIGs with displays change from reading in IPM in static mode to actual Amp output.

Right. I made an error in my previous post about under arc wire feed numbers from above because of a brain fart for that exact reason.
I caught myself doing it today again when glancing at the front panel, I'll admit I'm no MIG veteran.
I will be doing a setup to measure the roller speed next either by IR tacho or dot + 120fps camera.

Thanks for the reply.

[notserpe]

Couple of updates, I've heard back from AHP tech support again which gives the warm fuzzies. Confirmed that dry wire feed speed is normally slower than front panel reading and that is also confirmed as a normal situation by other poster.

Also I had some time today to get back on the MIG for a little bit and had no problem laying down decent beads while trying to dial in the sweet spot on some filthy 1/8"





Yeah, the beads could be nicer/better penetration but I'm operating on low sleep and food today.

And so it's as though everything that seemed to not be working before is now working flawlessly and the previous issues I had had were a fever dream.
I did change the gas bottle in the interim from a few weeks ago but that doesn't make much sense to me tbh.

I'm going to try to find some time and cut up some 3/8" coupons to fillet and cut and etch and see if I can't either have similar success or wander back into the fever dream of issues I thought I was having.

I think I have an old contactless IR tacho Arduino project thing sitting around someplace and will see about setting it up on the actual rollers and collecting some measurements.

I'm honestly really scratching my head at this at the moment.
If one thing has come about from this, it's that I've fallen in love again with my Tamron macro lens.