No announcement yet.

Roughneck 1 Low Excitation DC Voltage, No Output At All - HELP!

  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Yup, that right there is a Standard Kohler K-34? engine.
    Before anything else, be real careful what oil you put in them. I have 4 blown up K-341s sitting on the pile, and when the rod lets go it takes out the timing gears and anything else it can find in the crankcase.

    WHY did they design it that way? How about because they could and more because it worked, and because the Miller Brothers weren't held back by twerps in ties & suits. There was enough power available from the wire going to the points to trigger the rotor to produce more power and excite the machine without killing spark to the engine, why not use it? Ain't all that different from Ryan plugging a drill motor in and spinning the chuck to excite a machine, it works so why not?

    Pretty much like how Miller Bros came up with the FIRST successful way to weld copper leads to aluminum windings, they got lucky before Lincoln got lucky. That was in the 1960s.

    That's how things were done in the 60s and 70s before ALL the college kids arrived and took over.

    BTW, as I said, clean up the coil lamination faces, and the magnet faces and also the terminal on the wire from coil to the block. Do NOT move the coil in the process or use power tools. All that rust has cut your coil output by half.

    The way you pulled the flywheel is pretty much Kohler procedure. Only move you didn't know was to slap the end of the puller screw indexed into the crankshaft square on with a delicate touch from a 4# hammer to shock the flywheel off.

    Apply half a drop of Franz© Miracle Rust Abater to the faces of the laminations and magnets along with the shaft prior to reassembly, massage into the laminations, and wipe off with a clean paper towel. Contact Takit Distribution for the product.
    Last edited by Franz©; 09-09-2019, 03:24 PM.


    • #47
      just a quick update.. ive been busy at work so not done a lot of troubleshooting...
      I did try the drill trick and nothing, so I tested the output possibility of my old drill on my meter and when I spin it I get sod all anyway, so that was pointless.
      I need to find something that does put something out when spun by hand and try it again.
      I checked a couple of diodes D12, D5 and D8 and those three checked out ok. So im going to now try the 8 rectifier arranged diodes and see if any of those are at fault.


      • #48
        You'll see results faster if you disconnect the leads going to the slip rings and apply 1.5 volts from a flashlight battery to the brushes feeding the slip rings.


        • #49
          Originally posted by Franz© View Post
          You'll see results faster if you disconnect the leads going to the slip rings and apply 1.5 volts from a flashlight battery to the brushes feeding the slip rings.
          UPDATE!!! Ordered a set of 10x diodes and just replaced the lot on the board,i started removing one at a time and testing and i had one bad diode no D1.
          Fired it up and im getting 2v DC at the slip rings but no output on the 240v generator side or the Welding DC side when switched.
          So your saying try a direct DC battery source of arround 1.5v or 2v. Ive tested the large 20uf capacitor and the smaller one and they both show there ratings of 20uf on the large capacitor and 1uf on the smaller capacitor.
          What is the large yellow thing on the board?


          • #50
            In complete honesty I haven't touched a Roughneck in 20 years.

            Secondly, I am NOT a fan of PC boards or throwing parts at machines till they run or burn down.

            From recall the roughneck is a single Ø alternator with only 1 set of windings that generate both welding current and AC power, NOT at the same time.
            What the windings are generating is a function of speed of rotation and magnetic flux delivered to the Stator (generating coil) from the rotor via slip rings.

            There are few places you can test the machine, primary being the slip rings.
            Disconnect both wires from the brushes and after winding the machine up, put DC voltage to the brushes. For minimization of disaster potential I'd feed that DC through a backup light bulb, filament type.

            A AC voltmeter across the output leads from the stator will tell you if that part of the machine is good or not.
            Varying the DC voltage to the slip rings via brushes will also tell you more about the condition of windings.
            You also need to test brush to slip ring conductivity clear back to where the wires attach to the brushes.

            The generating section of the machine is simple and straight forward. Unless and until it is completely tested there is no point to speculating on the machine.