Newbie needs help with Miller Roughneck 2E.
RSS | Subscribe | Contact Us | Advertise | About Us
Page 1 of 2 12 LastLast
Results 1 to 25 of 36
  1. #1
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Newbie needs help with Miller Roughneck 2E.

    Serial # JF852939

    So, I bought this thing with the understanding that it didn't make juice, and that turned out to be true.

    I replaced the rectifier bridge, and got a 1000 microfarad 75 VDC capacitor installed.

    No juice.

    Now, if it were wooden I could make it work, and that's a fact, but it's electronical, so I'm in uncharted territory.

    I did dig up a digital multimeter, and the outlets on the face are showing 1 or 2 VAC.

    The welding lugs show the same.

    I may not be using the meter correctly, either, but I sure would like to get this machine up and going.

    Any ideas?

    THANKS!

  2. #2
    Join Date
    Jul 2012
    Posts
    736

    Re: Newbie needs help with Miller Roughneck 2E.

    https://www.millerwelds.com/files/ow...s/O420H_MIL.pd

    Print a copy of ownwers manual and follow troubleshooting guide.

    Parts section lists specs for bridge rectifer(30 amp 600v) and cap (240 microfarad 200vdc).
    Last edited by guajilloweld03; 08-08-2019 at 03:51 PM.

  3. #3
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    Quote Originally Posted by guajilloweld03 View Post
    https://www.millerwelds.com/files/ow...s/O420H_MIL.pd

    Print a copy of ownwers manual and follow troubleshooting guide.

    Parts section lists specs for bridge rectifer(30 amp 600v) and cap (240 microfarad 200vdc).
    Thanks.

    That's a bad link, but I'll find it.

  4. #4
    Join Date
    Jul 2012
    Posts
    736

    Re: Newbie needs help with Miller Roughneck 2E.


  5. #5
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    Yep. The troubleshooting schedule is all complete, but no juice.

    Thanks for the heads up on the capacitor. I think I got that mixed up with the part number off the Bobcat.

    I replaced the rectifier, as I said before, but I checked the used one after the fact, and it seems OK.

    It will likely be a week before I get the right capacitor in hand.

    I'll give an update after it is installed.

    Thanks!

    John

  6. #6
    Join Date
    Jul 2012
    Posts
    736

    Re: Newbie needs help with Miller Roughneck 2E.

    Test both cap and bridge rectifier before installing them. One time tested the bridge rectifier and it was bad, but did not check cap and it was bad. Then only replaced the bridge rectifier and the bad cap killed the bridge rectifier.

  7. #7
    Join Date
    Jul 2012
    Posts
    736

    Re: Newbie needs help with Miller Roughneck 2E.

    Those parts are less $$$ from Allied Electronics and Mouser or a similar type Electronics store.

  8. #8
    Join Date
    Mar 2015
    Location
    Milwaukee, WI
    Posts
    318

    Re: Newbie needs help with Miller Roughneck 2E.

    Did you check that you're getting good contact between the carbon brushes and the rings? Also you should be able to read voltage between the wires feeding the brushes so that the rotor can produce a magnetic field.
    Last edited by Denis G; 08-10-2019 at 12:19 AM.

  9. #9
    Join Date
    Feb 2017
    Posts
    10

    Re: Newbie needs help with Miller Roughneck 2E.

    Check the wire running to the condenser on the machine. That turned out to be the issue on my unit when I got it.

    Sent from my Nexus 6P using Tapatalk
    Hobart betamig 1800
    Hobart handler 135
    Marquette (Miller) Roughneck 1E
    Century 295 AC/DC Arc welder/scratch start TIG rig
    The key to welding is to go slow and wing it.

  10. #10
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    Thanks, fellas!

    I'm thinking the correct capacitor should be in hand by Wednesday, and I'll put all these suggestions into practice at that time.

    Since I bought that machine, I have looked at many more. The face is in excellent shape, and even the paint is good.

    I figure it's seen little use, so I'm hoping this mystery doesn't go too many more chapters, and I end up with a durable machine.

    I'l let y'all know how it goes, and thanks again!

  11. #11
    Join Date
    Feb 2019
    Posts
    15

    Re: Newbie needs help with Miller Roughneck 2E.

    Also check the fine adjustment control.Mine had a open winding in it and one of the two micro switches was bad.

  12. #12
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    New capacitor is in.

    Everything still reads 1 volt.

    Quote Originally Posted by guajilloweld03 View Post
    Test both cap and bridge rectifier before installing them. One time tested the bridge rectifier and it was bad, but did not check cap and it was bad. Then only replaced the bridge rectifier and the bad cap killed the bridge rectifier.
    Yes, I have always to remember to double-check the triple-check.

    Quote Originally Posted by guajilloweld03 View Post
    Those parts are less $$$ from Allied Electronics and Mouser or a similar type Electronics store.
    I'll give your guys a try.

    Quote Originally Posted by Denis G View Post
    Did you check that you're getting good contact between the carbon brushes and the rings? Also you should be able to read voltage between the wires feeding the brushes so that the rotor can produce a magnetic field.
    Thanks for the suggestion. I did check, and I can report that there is continuity from Wire #25 to Wire #26 through the brushes/slip-rings and revolving field.

    The fuse is good.

    The capacitor is OK.

    The bridge rectifier. I take it that Wire #28 connects from the fuse holder to the Bridge Rectifier at the one corner that's cut off?

    Quote Originally Posted by Hypervisor View Post
    Check the wire running to the condenser on the machine. That turned out to be the issue on my unit when I got it.

    Sent from my Nexus 6P using Tapatalk
    I'm not sure what you mean. All the wire that I have seen in this machine is as new. Seriously.

    I have chased both wires that connect to the capacitor and I have found no faults, but I'm not sure what you are telling me to check for.

    Quote Originally Posted by cool air View Post
    Also check the fine adjustment control.Mine had a open winding in it and one of the two micro switches was bad.
    I am not aware of any micro-switches OR fine adjustment control.

    Please advise!

    I have been reading up on the idea that it needs to be 'flashed', which makes a lot of sense, as this thing has not made power in close to three years, if the previous owner is to be believed.

    I've tried the drill method, with no success.

    I wonder if there's anything I should know about the Roughneck 2E as regards placement of the battery leads or duration of the current?

    Thanks, fellas.

    I'm getting close, I just know it!

  13. #13
    Join Date
    Mar 2015
    Location
    Milwaukee, WI
    Posts
    318

    Re: Newbie needs help with Miller Roughneck 2E.

    Quote Originally Posted by johnnybanzai View Post
    <snip>

    I am not aware of any micro-switches OR fine adjustment control.
    See attached schematic from the Roughneck manual -Name:  Roughneck wiring diagram.jpg
Views: 168
Size:  70.5 KB

    S1 is an electrical toggle switch accessible from the front panel. It has two positions one for "WELD" and one for "POWER".
    S2 is a microswitch that is actuated by moving the throttle lever on the lower cowl of the engine. Full throttle sets S2 for "WELD" and flipping the throttle lever to the lower RPM sets S2 for "POWER" (115VAC). The machine is designed to either weld or work as a generator, but not do both. Both switches have to be set correctly to either weld or generate power.
    The fine tune adjustment control is R1 on the schematic and is a potentiometer accessible from the front panel. For generator power it should be set to 100%. For welding it can be adjusted to fine tune welding current. Coarse welding control is accomplished by selecting the right electrode socket on the front panel.
    Last edited by Denis G; 08-19-2019 at 05:53 PM.

  14. #14
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    Thank you, Denis.

    I'm pretty sure that is the wrong diagram for my machine.

    Serial Number starting with JF, built in 1985.


    Page 22 from that link.

    That's page 22 of the document, and page 24 of the PDF.

    I have no idea how to show a screen shot here.
    Last edited by johnnybanzai; 08-19-2019 at 06:26 PM.

  15. #15
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    This is a test:

    Name:  Roughneck wiring.jpg
Views: 235
Size:  124.4 KB

  16. #16
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    ¡Yes!

  17. #17
    Join Date
    Mar 2015
    Location
    Milwaukee, WI
    Posts
    318

    Re: Newbie needs help with Miller Roughneck 2E.

    Quote Originally Posted by johnnybanzai View Post
    Thank you, Denis.

    I'm pretty sure that is the wrong diagram for my machine.

    Serial Number starting with JF, built in 1985.


    Page 22 from that link.

    That's page 22 of the document, and page 24 of the PDF.

    I have no idea how to show a screen shot here.
    Ok. Sorry then, different version. I have one of the early Roughnecks.

  18. #18
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    Quote Originally Posted by Denis G View Post
    Ok. Sorry then, different version. I have one of the early Roughnecks.
    No need to apologize.

    You are clearly trying to help me, and I appreciate it!

  19. #19
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    I may have a problem.

    I mean, other than being a smooth-brained moron.

    I am no electronics whiz, and the drawing has only 2 electronic components, anyway (counting the four diodes in the rectifier bridge as one component).

    Because I am a smooth-brained moron, and because I always set the cover aside in its proper orientation - up side up, I never noticed that this machine has a copy of the circuit diagram taped to the underside!

    !!!!!


    This diagram, the same one I posted earlier:




    I do not know yet if this is significant or not, but the little symbol at the capacitor that looks like a '-' at 100% page size in my browser magically transforms into a "+" sign if I blow it up to 250%.

    The diagram taped to the machine shows this discrepancy clearly.

    I'm going to make that change, now.

    Wish me luck!

  20. #20
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    OK.

    No joy.

    I have had two occasions where I checked continuity across the rotational field and the meter read 26 ohms.

    I think I must have botched those measurements.

    I now have the machine up on the bench, and I managed to get the bell end off, removed the brush holder and checked continuity between the slip rings.

    No continuity.

    Each brush reads continuous through its respective lead up to the rectifier and capacitor (Yes, I disconnected the cap and rectifier before testing).

    Neither slip ring is continuous to ground.

    I am a determined little cuss, and I have read that this condition is usually due to a broken wire somewhere, and that if one can locate the break it can be silver-soldered back together.

    I really want this.

    I am having a really hard time figuring out how to get the rotational field the heck outta the machine, so I can examine it and fix it.

    I mean, it's pretty clear that I have to split the generator from the engine, and I am seeing no obvious way to do that.

    Any help?

  21. #21
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    OK!

    I placed one lead of the ohm meter on the slip ring nearest the end, and used the other lead to scrape away enough varnish to make contact on one side of the field, and yes, there is continuity. Then I moved the first lead to the other slip ring, no continuity.

    Then I moved the second lead to the other side of the field, and scraped a contact patch onto it. I still read continuity from the near slip ring to the second field winding.

    Then I picked up an inspection mirror and discovered a piece of Copper wire broken off flush with the back of the slip ring holder.

    If I can get this silly thing apart, I can fix it.

    I am so stoked!

    How do I get it apart?


  22. #22
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    So, I got it apart.

    The easy way, I guess.

    I pulled the armature out, still attached to the engine.

    Now, I get a dead-reliable 32 ohms across the slip rings.

    Is there something I should know, here?

    If I didn't know better, I would say this machine 'fixed itself'!

    Not completely unheard of, but still.

    If I don't hear some words of wisdom, I'm going to reassemble this thing and see if it works.

    Please advise!

  23. #23
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    Quote Originally Posted by johnnybanzai View Post
    OK!

    I placed one lead of the ohm meter on the slip ring nearest the end, and used the other lead to scrape away enough varnish to make contact on one side of the field, and yes, there is continuity. Then I moved the first lead to the other slip ring, no continuity.

    Then I moved the second lead to the other side of the field, and scraped a contact patch onto it. I still read continuity from the near slip ring to the second field winding.

    Then I picked up an inspection mirror and discovered a piece of Copper wire broken off flush with the back of the slip ring holder.


    If I can get this silly thing apart, I can fix it.

    I am so stoked!

    How do I get it apart?

    Apparently, all is not as it may seem in an inspection mirror.

    The 'Copper wire broken off' turned out to be a shiny spot of . . . something else.

  24. #24
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    So, I have arrived at a diagnosis.

    The block of resin (?) the slip rings are mounted onto is bored through the center and placed (pressed?) onto the armature shaft.

    The slip ring block is no longer tightly in position on the shaft.

    If you grab it and turn it back and forth, there's just a tiny bit of movement in relation to the shaft.

    If you twist one way, you have continuity across the slip rings.

    If you twist the other way, you have no continuity.

    I have run this test several dozen times, and that's where things go off the path.


    Clearly, I need to get the insulation out of the way, find the broken wire, repair that fault, then reset the slip ring so it won't move, re-insulate that mess, and put this machine back together.




    So tell me the truth, fellas.

    Is this something I should tackle myself, or should I take it down to Hamilton Electric and let them do it?

    It seems like the sort of thing a specially-equipped shop with knowledgeable, experienced repair professionals could knock out in about an hour, no?



    Hour and a half?

    My point is that by the time I buy the insulation material, the wire (if needed), the solder, the soldering equipment, etc. and learn how to do all that, I'll end up paying dearly for the experience.

  25. #25
    Join Date
    Jul 2019
    Location
    Austin, Texas
    Posts
    28

    Re: Newbie needs help with Miller Roughneck 2E.

    OK.

    I separated the engine from the generator so I could get at the slip ring assembly.

    I peeled back the insulation and exposed the connection between the winding and the slip ring. It was broken off.

    It was making contact intermittently.

    I drilled a hole between the slip rings in line with the bad connection and tapped that hole to accept an extra-long 1/4-20 set screw to eliminate any movement relative to the shaft.

    Once the set screw was in place, I dug out enough of the slip ring hub to expose the inner end of the hole that accepts the little plug from the winding, and managed to press the broken end of the plug right on through the hole.

    Once that was out of the way, I stripped the insulation off a piece of stranded Copper wire and threaded it through the hole.

    I let the strands extend past the inside of the slip ring by about a quarter of an inch.

    I then got a piece of 14 gauge solid copper wire, ground a one-inch taper on one end and cut the taper off to use as a wedge, and drove the wedge in between the strands of wire to lock it into the hole.

    Once the wedge was tightly in place, I used a pin punch to pack the strands tightly against the hole and further into the hole.

    Then, I twisted the stranded wire onto the lead from the winding, and soldered them together.

    I now measure ~18 ohms across the slip rings, with no intermittent failures.

    Reassembled the unit, fired it off, and I still have no juice.

    I'm beginning to get a little frustrated.

    It has been 9 days since anybody but me posted on this thread.

    I know y'all don't owe me anything, but I could use a clue.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement