Author Topic: Welding from a Listeroid/ST generator rig  (Read 3465 times)

Martin

  • Newbie
  • *
  • Posts: 15
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #15 on: March 04, 2021, 12:07:24 AM »
In this picture the crank is at 9 o'clock when viewed from the front of the engine. So looking in through the crank case door gives a view of the bottom of the two kidney shaped counterweights.

Martin

  • Newbie
  • *
  • Posts: 15
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #16 on: March 04, 2021, 12:12:03 AM »
This is a view through the crank case door with the crank at TDC, so we can see the sides of the two counter weights.

Martin

  • Newbie
  • *
  • Posts: 15
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #17 on: March 04, 2021, 12:16:12 AM »
This one shows the crank at TDC, but the picture is taken at an oblique angle to show the kidney shaped profile of the counter weights.

Martin

  • Newbie
  • *
  • Posts: 15
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #18 on: March 04, 2021, 12:21:16 AM »
Crank at BDC showing the counter weights at the top.

38ac

  • Hero Member
  • *****
  • Posts: 2203
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #19 on: March 04, 2021, 01:16:31 AM »
Martin, that type flywheel was used on the internally balanced engines with counter weights on the crankshaft. That flywheel should sit still on a balance stand in any position.
« Last Edit: March 04, 2021, 01:18:07 AM by 38ac »
Collector and horder of about anything diesel

highroad281

  • Newbie
  • *
  • Posts: 16
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #20 on: March 23, 2022, 02:00:50 AM »
It was unfortunate that all my pictures were lost when the photo host shut down this the reason for the vanishing posts here.  No pics equals rest of post worthless. That being said an enterprizing individual happened to save all of my rants so there is hope at some point they will be available with pictures.

Iím aware that this is a cold topic but since I havenít seen anyone else offering this up I figured I would. Maybe someone has and I missed it.  In that case please disregard the following.

Some years back I collected a both 6/1 and 12/2 clones with intent to go through them and build a back up gen.  I thought at the time that Iíd like to have a hard copy of 38acís Indian build thread to work from, so I saved it to a doc.  Now that the kids no longer require constant supervision Iím hoping to pick back up on these projects and was quite dismayed to find the content gone, and myself unable to locate the doc that I had saved! 

Well, after a few days of searching usb drives I have finally just found it. 

With permission from the original author Iíd be happy to share, drop me a pm.  Better yet if there is a way for a moderator to restore the content to the WOK from the doc that would be better still.

Iím positive that I also saved the twin build, and others (possibly timing, and balancing) threads too but unfortunately I think those are now lost to me.  If anyone happens to have the twin thread content to share Iíd be especially grateful.

Best,
Neal


cobbadog

  • Hero Member
  • *****
  • Posts: 957
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #21 on: March 23, 2022, 04:38:50 AM »
G'Day Neil,
That is a very kind offer and hopefully those who need it will contact you.

Something I would suggest providing the Admin approve is a new topic for listing all these manuals so they are easily found and looked up. Then anytime needs the information simply go to this new thread and find them there.

Is this possible to do please Admin?
Coopernook - the centre of our Universe.

olNick

  • Newbie
  • *
  • Posts: 24
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #22 on: April 13, 2022, 11:19:41 AM »
Hi,

After cooking an expensive inverter welder connected to "cheesy" generators, I found that what kills them, at least in my case is the sudden voltage drop that occurs when striking a real arc (120-150A), tacking is ok...

This AC drop is enough to momentarily lose the 12V logic voltage so the welder is running w/o the control circuit, i.e. no PWM of the current.

I believe that it's a tossup as to which IGBT side clamps ON, thus full current, thus meltdown.

Maybe this could be remedied w/ a supercap or something in the control voltage PS.

Never, ever had a problem w/ my "real" 2 cyl DEUTZ, 6KVA, avr controlled generator. If anything it runs a lot sweeter when I'm wleding away....

Anyway, my 2c,

nick

cobbadog

  • Hero Member
  • *****
  • Posts: 957
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #23 on: April 13, 2022, 12:34:05 PM »
Tghis site and another one I know of have a dedicated generator section with some very clever people to offer help with the right answers. Sorry I have no idea about generators but enjoy reading the problems and ways to fix.
Possibly duplicate the thread in the generator section or ask in that section to have a look at this and post a link of this in that section. If that makes any sense.
Coopernook - the centre of our Universe.

BruceM

  • Hero Member
  • *****
  • Posts: 3029
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #24 on: April 13, 2022, 03:48:40 PM »
Oldnick, I think your assessment of the failure is interesting and quite possibly spot on.  Adding  large electrolytic capacitors on the 12V might be the simple solution.  But it is a very poor inverter-welder design that doesn't protect it's critical IGBT or Mosfet gate control from voltage sag.  Even if it did work admirably with a stronger AC supply.  All power electronics designers are not created equal; it's like any other professional, a brilliant minority and the rest barely getting by. 

I'm in the latter group.  I popped a couple MOSFETs in my own home-hobby inverter design last week when I accidentally applied a hard short to the 120V (transformer stepped down) while testing a current/voltage/power smart sensor for a water chiller project. The 230V AC breaker didn't pop in time, and the DC fast blow fuse for that H-bridge blew but not quite fast enough, apparently.  This is the first failure ever of my inverter.  I never tested it for an overload/ short on the 120V side, only 230V.  Luckily it's all my own design so the repair was $8. in parts and a lost day.

I'm adding a fuse on the 120V side to protect me from future senior moments.  If it was a commercial design,  I'd add a microcontroller and circuitry watching the real time current to shut down the waveform generator in real time, safely as soon as a peak load exceeded the safe limit for peak current and/or time at peak.  Fuses are too crude. 




olNick

  • Newbie
  • *
  • Posts: 24
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #25 on: April 14, 2022, 11:21:27 AM »
Bruce,

Bit further on this, FWIW, my first shotgun repair attempt (simply replacing the IGBT's), lasted about 5 seconds before blowing up, since I did not check that I had pwm drive, before enabling the HV (SMPS-101 lessons here)

I bit the bullet, and read up to understand how inverters/SMPS work. Poking around I found that GDT had shorted/opened I don't remember.
Replacing that transformer brought back the PWM, and the thing started working again, with new transistors

The welder is/was quite advanced for a early 90's design, with a very high duty cycle. Specifically stated 8KVA generator minimum, my bad..
The "6KVA" chinese honda that did the damage, essentially almost stalled at that time...

anyway, I don't qualify for even 2nd group above, ha...
nick

BruceM

  • Hero Member
  • *****
  • Posts: 3029
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #26 on: April 14, 2022, 04:02:23 PM »
olNick,
Bravo on that repair. 
I expect a 90's design with IGBT's would not be power factor correcting, so it would need a much higher rating on the generator head to cope.

Inverter-welders have always been at the cutting edge of power designs.  I can't imagine a more difficult power design application; high current arcing and shorts are normal. 

 



mikenash

  • Hero Member
  • *****
  • Posts: 945
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #27 on: April 18, 2022, 08:04:27 PM »
Fwiw we use a couple of $400 180A inverter welders at work (one of which belongs to me, personally) off of a Chinese generator and have done so for over a decade at the cost of just one welder, which was very second-hand at the time, anyway.  We use an 11kVA generator and it doesn't really notice when the load comes on - no real drop in revs or whatever.  I have been told that is the secret to looking after both generator and welder.  Our local hire company won't hire you anything smaller than about 15kW if you tell them you're welding - they say it "blows up" the generators sometimes too.   Cheers

mauro

  • Newbie
  • *
  • Posts: 2
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #28 on: October 19, 2022, 09:32:47 AM »
Hello everyone. I have read various treads in this forum, written over the years, about flywheel balancing. There are some things I don't understand and I would be grateful to those who have already done this if he could help me. I got an axle with bearings where I will place the flywheel. The first question: if I put weight on the opposite side of the flywheel counterweight to cancel it, won't the engine start jumping even more? I think I understand that the flywheels have a counterweight to counteract the force of the piston and try to balance the crankshaft. It's correct? After having found the weight to add I read from 38ac "once you have the weight in the correct position and with respect to the key and equally weighted both flywheels, you attach them to the engine and adjust the offset weight to make the operation easier". How do I know how much counterweight and where should I put it when the flywheels are reassembled?
Thanks for any help.

« Last Edit: October 19, 2022, 10:06:52 AM by mauro »

cobbadog

  • Hero Member
  • *****
  • Posts: 957
    • View Profile
Re: Welding from a Listeroid/ST generator rig
« Reply #29 on: October 19, 2022, 11:19:56 AM »
From what I understand about any flywheel is that the engine will run without one. By adding a flywheel you are adding 'inertia'' which aids in  the smoother running of an engine and also helps the engine to maintain speed when loaded until the governor opens up and lifts the RPM.
I fell there is no need to run 2 flywheels unless you want to add extra weight to make it run smoother for longer before need more RPM. I have a few stationary hit n miss engines. Some have one flywheel and others have 2. There are 2 engines with the same cubic capacity, fuel mixers and head and stroke and bore but have a single flywheel and the other a twin. O ne engine is rated at 1.5HP and the other at 2HP, only difference is the extra flywheel and one is air cooled the other hopper cooled.
In my opinion one flywheel would be sufficient remembering that flywheels are balanced before being fitted to an engine. As a comparision your tyre gets balanced on the wheel before it is fitted to the car which has many different choices to mount it. Hopw that makes sense for you.
Coopernook - the centre of our Universe.