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Messages - BruceM

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1
If this is a Listeroid, with a cylinder liner, I highly recommend measuring the protrusion relative to the head surface.  This has a big effect on which gaskets work and don't.  If you have more than say 0.003", your best bet is the Rajkot gaskets, with the asbestos soaked in Permatex gasket sealer to eliminate coolant weeping. 

If you have more than 3 mils of protrusion, you should get it fixed by a competent machinist.  Take the whole assembly.  I did mine by the file and sanding disk method, which is not for the average joe.  Excessive protrusion will lead to head casting concavity/warping and head gasket leakage.

The Lister clones that Gary at DES imports don't have liners and have no protrusion issues as the Listeroids usually do. 

2
General Discussion / Re: Welding on clean DC
« on: May 25, 2019, 10:40:43 PM »
Hey MikeN, Yes, I'm sure the modern welding machine will compensate for welding lead losses up to a point, to maintain the set amperage regardless of losses in fittings and cable.  I'm guessing that I should conserve voltage as well as I can within reason for <150 amp operation.  I'll try baking the 7018 rods and let you know how that works.

The batteries were not run down much at all from my practice welds, so I'm guessing the amperage must be fairly low.  I'll have to get some help to measure voltage and current.  No point in measuring now until I get the new cables and connectors. 

Can you show me a link for the type of ground clamp you like?



3
General Discussion / Re: Welding on clean DC
« on: May 25, 2019, 03:49:57 PM »
The choke resists a change in current in a passive manner; no electronics needed as in the modern DC welder which electronically attempts to maintain a set current by adjusting voltage.  I have the choke in the ground lead right at the battery, but I will move it to the electrode lead for the final setup. Anywhere in the welding current path will work.

It helps stabilize the arc as follows: as the current of the arc is starting to be interrupted, the choke will increase the voltage and thus help keep the arc going.  Likewise, voltage and current will be reduced by the choke in case of starting an arc.

The modern DC welder is capable of doing this electronically, using high frequency PWM from an excessively high voltage.  This keeps things compact and lightweight, but generates massive high frequency EMI from the high current, high speed switching.  Just like a typical switch mode power supply, but at 10-100x the current.  Emission strength is related to current times frequency times current loop area.  The welding cables radiate this EMI, and the welder is very close.  Ignoring what this does to the welder, the electronic regulation of current is a technically marvelous; no massive, expensive 40 lb choke is needed.

If you have a voltage monitor on your DC welder, you will find that welding is taking place around 20 volts plus a bit at 100amps of current.  Current will increase dramatically as voltage is raised.  I think that solar panels have insufficient voltage regulation, so while a bunch of 24V panels in series might work with a choke, I think the voltage may be too wild; open circuit is 44V.  If your peak welding current is 125 amps this would still require 3000 watts of PV or better in parallel.  I don't have enough PV to try it.

Welding cable size is determined by your max welding current. Small units with 140A limit may use 4 awg., 250A typically use 2 awg., 300a use 1/0.  The point is to limit voltage drop in the cable and cable heating.  I've ordered some 2 AWG cable, and will have short, 12 foot cables since the batteries with choke are going to be wheeled and portable. 

Here's a link to the article which encouraged me to try a choke on a 2 battery setup:
https://weldingweb.com/showthread.php?8996-Welding-With-Car-Batteries-%96-2-ARC-STABILIZER

The one thing he didn't get right was his choke core; ferrites are never used for high current chokes as they saturate easily so that testing by LCR meter (testing with tiny current) will read way higher than the actual loaded inductance.  But since he related his methods and materials well, it was a most valuable and well presented piece of research. I have experience re-purposing toroidal transformer cores as DC chokes, since I used two in my inverter project (for keeping ripple off the 120VDC), and could compare them to a commercial E-I core choke made by Hammond.  Gapped laminated toroid cores have the advantage of being the most compact and lowest loss for high current, relatively high inductance DC chokes.  Still, not cheap or lightweight.

The choke, with 22 turns (16 feet) of 6 strands of 12awg is shown in the attached photo wit the 2 group 29 marine deep cycle batteries.  It's a 1000 watt transformer core, with a gap cut via abrasive blade, epoxy filled.  I think it would work as well with only 8 feet or 10 turns and would be less likely to saturate at higher currents.  Battery jumper cables were used for initial testing and will be replaced with proper welding cables and connectors next week.  I will be increasing all the battery connections to some old 1/0 wire I have, with lugs added. The welding cable with use the standard Dinse 10-25 connectors at the to be designed battery& choke rack/cart. 






4
General Discussion / Re: Welding on clean DC
« on: May 25, 2019, 08:06:07 AM »
Thanks MikeNash,  Yes, similar to your 16TC's, I read about the good welding properties of the 7018's and was very disappointed to not be able to use them.  As my skills improve, maybe I'll figure them out. Right now, they stick on striking an arc, or the arc goes out immediately.  I have not made even the smallest puddle or bead.  So perhaps I should put them in my propane oven and heat them up for a few hours?






5
General Discussion / Re: Welding on clean DC
« on: May 25, 2019, 07:29:33 AM »
Next is a small but tall plow blade attachment for a subsoiler/ripper I got for the Kubota tractor.  I have ideas about doing trenching for pipes and such by ripping a few passes on the sides and middle of the trench, then plowing it.  The ripper pulls easily with the Kubota L2250 and can go down the 18 inches needed, even with rocks. 

6
General Discussion / Welding on clean DC
« on: May 25, 2019, 12:42:31 AM »
I bought a new group 29 "marine deep cycle" battery to give the clean DC, 24V welding thing a go. They are rated 385 cranking amps so a good match for 100+ amp welding current, and they are what I have in my 120V battery bank now.

I made a 600 uH choke from a gapped 1000watt laminated toroid core; 22 turns, 16 feet, of 6 strands of 12 awg. I gapped the core with a 10" abrasive chop saw blade in my table saw. I only lost 1/4" of blade on the job, but it took 4-500 gallon tanks of air to make the cut.  I filled the gap with steel filled epoxy. To save some $ on the trial, I used some heavy jumper cables for welding cables. 

The exciting news for me is that yes, I can do it. While regular welders have me running for the hills from EMI headache, this was doable for me.

Welding on 2-12V batteries does work, and as the article I found by a welding enthusiast stated, the choke makes it possible. When I bypass the choke, it's just not possible to maintain an arc and get the puddle going. Alas, I seem to be a bit lower voltage than I'd like- no such thing as long arcing with this setup!  7018 (3/32) rods were a bust, could not maintain an arc and liked to stick and melt the rod. 6013 (3/32) worked, best with positive on the electrode.  I'll have to set up some meters on volts and amps and get my neighbor to watch them while I do a practice bead.  I'm ordering some 1/8 rods- more current may have better arc length and stability.

I suspect the losses in the jumper cable are not helping, so I will pop for some fat and short welding cables.  I may also reduce the turns on the choke.  No need for that much inductance, but I goofed on calculations when shooting for 250-300uH.  Battery and all cables were cool immediately after a 6 inch test bead. 

I'm very rusty, my last stick welding was in 1974.  I think with some practice and some fine tuning of the setup, I can do my own welding again.

Yippee!


7
General Discussion / Re: Tesla and Towing.
« on: May 24, 2019, 10:17:34 PM »
Trucks and hauling are more compatible with hydrogen fuel cell vehicles.  It's well refined now, Toyota spent a bundle developing it. 

Battery storage is much simpler...but our civilization may have crashed before long haul trucking via battery is viable.


8
Changfa Engines / Re: Do it Changfa Style
« on: May 19, 2019, 05:19:02 PM »
2 hrs and his wife told him to shut it down or move out? 
Great little engines for the nearly deaf.

Slow speed engines rule for often used home generator power!

My custom keyboard (analog passive matrix so no emissions) started having shift key problems after about 25 years of use.  It's based on a Keytronic silicone membrane keyboard, with printed conductive ink, with some mods to the ink and processor removed. Finally had to clean the contacts on my little connector board and the ink. It's working great again, and all the bits got a bath with the parts brush so it looks like new. Amazing how the molded silicone sheet works so well for a nice feel.

Success always makes me cocky.  :D

9
General Discussion / Re: MIG Welder, what to look for?
« on: May 18, 2019, 04:01:48 PM »
Thanks Glort, they will be relatively small values and not high enough current for welding.  a 3000 watt inverter with 230vac output will have filtering chokes for 15-30 amps. The needed 150amp or better for a 24vdc welder is going to make for big wire and a big core.  Expensive commercially because of size and weight in electrical steel and copper.  Since there will be a strong stray magentic field from an E-I core, with changes in current, I'll stick to the tedious gapped toroid, wound in two layers for better self cancelling.  If I ordered one to be made, I'd be out near $1000.  I can make it with a surplus core for about $70 worth of copper. I might be able to get a puny 250 uh without saturation at 150a.

I have doubts about the project- no telling if the welding fumes will be more than I can handle, or if the variations in welding current which the researcher noted are rapid and will cause substantial AC magnetic field.  I hate failed expensive projects, though often much more is learned. 



10
General Discussion / Re: MIG Welder, what to look for?
« on: May 18, 2019, 04:28:43 AM »
I spent quite a bit of time researching direct battery powered DC welding.  Clean DC the way i like it; I'm a charter member of the Church of Edison.  ;)

Seems 2 good batteries plus a big DC choke does an acceptable job up to 1/4 steel at around 120 amps.  The choke, around 300 uH or better is essential as a current limiter/regulator and keeping the arc going.

A guy on a welding forum in 2007 did a lot of experimenting and documented his work pretty well.  Alas, he didn't have an electronics background and didn't realize that he was saturating his ferrite and other cores at his welding current of 90-125 amps, and his test values were  using with an LCR meter that only gives the unloaded inductance.  His choke weighed 40 lbs, largely from copper windings.

I may give it a shot, but it does mean unwinding and gapping a 1000w or bigger toroidal transformer core for the choke.  I'll have to crack some books to estimate the number of turns to avoid saturation at 140 amps. 




11
Everything else / Re: Finally, some use for excess solar power.
« on: May 17, 2019, 12:00:56 AM »
Mike was right about plastics- HDPE is often used for barrels, and it's going to very slowly start to deform at boiling, just give it time, it's strength is greatly reduced at higher temps. It will just ooze. You will see that buried rotomolded HDPE tanks will rarely be rated for over 130F.   

Polypropylene is much stronger, especially at higher temperatures, the buried tanks are often rated to 150F or better.

So if you're bargain shopping for tanks for hot water, look for a PP stamp, though even that isn't going to take 100C for extended periods without some deformation unless it was overbuilt.


12
Lister Market Place (things for Sale) / Re: New Listeroids for sale
« on: May 16, 2019, 11:48:04 PM »
If you think Rajkot can put consistently ready to run engines in a crate for you with typical China tractor quality...you are heading for a rude lesson.

Rajkot has not been in the same ballpark as China in consistency; we all wish you'd find someone in China to build Lister CS clones.  Rajkot is even infamous within India, as we learned here from a native many years ago. 

Sample pieces for evaluation will always be the finest they can manage...but not much like the following containers.  Competent and technically skilled people I respect have spent a great deal of time and money hoping to pull up Rajkot standards, and largely failed in getting those new stardards consistently.  Things like cam lobe placement, cam straightness, tappet alignment/binding, casting quality and material, weight of con rod and piston , flywheel key location and mass of counterbalance, finish of machined parts, valve placement/spacing in the head/rocker arm placement, voids in the head casting, idler gear location/lash, finish of cast parts, and cylinder liner protrusion all vary WIDELY.  These are all things the skilled builders here have to check and fix, and I've missed some other common ones.

The CS is a great engine and I'm glad for my Rajkot kit of mostly usable parts with rework, machining and some replacement.  With a reputable dealer like Gary at DES, bad parts are not a risk.  I would have gladly paid more for a China quality product, but that doesn't exist.


 

13
Everything else / Re: Compressor oil grade
« on: May 16, 2019, 12:43:52 AM »
I'm sure sheeple are global.

14
Lister Market Place (things for Sale) / Re: New Listeroids for sale
« on: May 13, 2019, 11:09:43 PM »
Others have gone to Rajkot as well. Best wishes for your success.

15
General Discussion / Re: MIG Welder, what to look for?
« on: May 13, 2019, 08:13:21 PM »
My head is a significant target for strong magnetic fields (near field in EMC parlance) - so back before I learned that air tools would solve it, I used to try and use a drill keeping my head as far away as possible...it increased my working time but wasn't very practical.  For electric fields, it seems anywhere goes.  I've tried see through metalized fabrics and even an aluminum foil helmet with holes for eyes...they don't do much...too many openings and slits.

Some of the earliest reports of electrical sensitivity in Sweden were cell phone design engineers.  One of them had a full bee keeper's suit with metalized fabrics and silver thread fabrics.  Hardly conducive to an improved social life, but I understand the desperation. I haven't gone that route as I find the metalized synthetic fabrics stink bad enough to bother me, and can't imagine wearing it for a long time. 

My only interesting finding of late is that the blood thinners for my DVT have markedly improved my latency and decreased the severity of symptoms- which where always pressure headaches followed by cognitive impairment and eventually complex partial seizure or absence seizure.  Perhaps venous blood flow from the brain is being effected.
 
SPECT scans of people with electrical sensitivity look much like a closed head injury...only they didn't have the physical injury...just the identical pattern of areas not getting blood flow.


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