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Messages - mikenash

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1
That may be OK, it looks like a modern one.  A picture from the other side would help.
I'd order a new one to have on hand, in case it's crap.  When your output voltage suddenly goes way low, that's the usual culpret (with Chinesium bridge diode).

Here's an example of what you want:
https://www.ebay.com/itm/224811975854?epid=25016784898&_trkparms=ispr%3D1&hash=item3457d684ae:g:LP0AAOSw07hh9D9b&amdata=enc%3AAQAGAAAA4DnkmsOqUD5Je7CXIp1vp20AWgEgoojiNCXA37jPM8BMpvjM1U4Yfupo7yaDHQ%2FWrT%2Fcg4npkrGOlp5z50wf8GCQFT68xqa89gdinHLtlG0vPIZUGluNz0ey9Ioc0pK3Egc8qiRPkpJjqCOqHKNYkftz9cvug0K4JLVudSv8c1EZzaWdRRSb8BoT9diH5euXC1Ihu0SFZuxvdHAKjrf9cCk4jDaSsDU2C8qjhiastbesKQfUKpD7COBS946hkpx6XRc%2FpBP24L9PhzmcE15wZsOrD8Tkccxa%2BJxCaq%2FUaYPc%7Ctkp%3ABFBMssOY95Vg

A bridge rectifier is just four diodes potted in a metal or plastic box.  Two AC inputs, usually opposite corners, and two DC outputs, usually marked + (plus)  and - (minus).  It turns AC (from the harmonic winding on the stator, which is very spikey and non-sine, and turns it into pulsed (spikey) DC for the rotor.  The rotor windings have a huge inductance, so they smooth the input current to create a more constant magnetic field at the 4 rotor poles. 

For this application, the metal body is better for heat sinking to some aluminum. A die cast aluminum case to replace the doghouse comes to mind. Use some thermal paste or a dab of silicone caulk It should be as thin as it can be, to just increase the surface contact area.

Hey Bruce - thanks again.  Just what I needed

See pics?

The very thing you left the email link to on EBay is available here on our TradeMe so cheap I bought two (one for a spare) and some heatsink compound.  I have some finned alloy sections off of VSDs that'll make good heat-sinks

These little fellows just have a " + " for DC positive I guess - and guess also as you say that DC neg is diagonally opposite.

They also have " AC" and I guess, again, that the other AC is diagonally opposite.  Do you think it matters which AC terminal is neutral and which is phase - or if it matters?  And how to tell which is which - if it does matter?

Cheers

2
Everything else / Re: Greetings from Tasmania
« on: June 01, 2022, 07:49:42 PM »
Hi Guys, it`s been a while. I`ve been a bit busy since we got burned out in the 2019 bush fires. I spent 12 months fixing chainsaws, water pumps, generators and any other piece of equipment needed by the local community to help with the recovery, all for free. I got an award from the New South Wales government for my efforts, shame they didn`t invite me to the awards ceremony. I guess they thought I was a loose canon after I got in the Governor Generals face twelve months earlier. I got my award several months later after they mailed it to a place I was no longer living in. Shameless b*stards the lot of them! Pleased to say that most of them lost their jobs in the recent elections. Good riddance to bad rubbish.
Two years ago we bought a 3 bedroom property in Tasmania, if I climb on the roof I can see the sea. Sadly, having got ourselves somewhere to live, Covid struck. My Wife eventually (6 months later) got permission to travel to our new home. I had to wait a further 18 months before I was allowed to travel. Two years living in a caravan changes ones perspective enormously, I now realise how lucky I am to have lost all the sh1t that I had accumulated over the previous 60+ years. Most of it I didn`t need or want, I was just storing it because I couldn`t part with it.

So, what does the future hold? Our new home is beautiful and has a double garage but no man space! I have put in an application, to the local council, to build an 13m x 12m shed. We recently got approval for the shed and are now progressing the final designs and hope to start construction in the next few months. I would like to share the shed design/construction and fit out with the LEF. I will do my best to share photos of the build along with costs and pitfalls. I hope this will be helpful to others planning to do something similar

Thank you all for the support you have given my Wife and me over the last few years.
Bob

Good on you, Bob

I had a forced down-size recently - having to very sudddenly leave the Valley where I had lived for over 40 years

Man, did I throw out some stuff.  Got the biggest skip-bin they would deliver parked in the drive, and took a ruthless approach . . .

The more stuff I lost - the free-er I felt tbh

I need to spend a couple of years living where I am now - a very small place, but an ideal situation - before retiring and moving to my country block

To be honest, it has been good for me to get rid of a lot of stuff i think i was just keeping because it "might come in handy one day"

Good luck for the next phase of your life - a new adventure!

3
Other Slow Speed Diesels / Re: Hatz E79 - Shop manual
« on: May 22, 2022, 06:33:40 AM »
A couple of thoughts - and others more knowledgeable here will correct me if I'm wrong:

I had an old Lister CS that came like that - long story short it had sat for a while and the rings had become stuck in the grooves, If you can get it running they may well come right by themselves

So - maybe a teaspoon or two of oil down the intake before cranking it over?  That'll just raise the compression temporarily - and smoke like a bugger if it fires

Second option is ether - "AeroStart" or "engine start" or whatever.  Just a puff into the intake as it is cranked.  A little is a lot with that stuff as it raises the compression enough to break rings if you over-use it

You could google the use of that

Good luck

4
Hi Ade

Good work, thanks

I like to visit the site every day - and contribute occasionally.  But some of the boards I just never look at?  I suspect others may be the same?

The stats will tell you.  Perhaps you could winnow out 30-40%-ish of the content - those that are little-used?

Folks who like to post in those subject areas might be Ok about using the "everything else" board - possibly you could change the name of that/modify it a bit to be more all-encompassing; and then ditch some of the lesser-used ones

Lots of us are getting older.  There will be younger folk out there with different, but related, interests?

Cheers

5
Lister Based Generators / Re: 6/1 driving ST clone 260 VAC
« on: May 18, 2022, 06:55:53 AM »

If you want to run the lister at 650 rpm (and the ST at 1800 rpm), you need a 2.77:1 ratio belt drive.
That would give you the correct voltage.
So if you have 23" flywheels, your generator should have an 8.3" pulley.
(Assuming you are driving the generator using a belt around the flywheel)

Hey, yes, thanks

We have 50Hz power down here - so 1500 RPM.  The flywheel is around 605mm diameter and my driven flat pulley is around 205mm (I'm working with what I have lying around here) from memory so a nominal 510-ish RPMs is probably about right

If it'll be happy making 4Hp at 500 RPM - say 2500 watts - that'd be (allowing for losses) a theoretical 150-ish amps I could get out of a battery charger attached to the gen-head.  In practise that's probably twice what I'd need or want . . . so if the Lister's happy to putter along doing that - well, there's potential there

I have to take the head off the old girl one weekend as there had been cooling water getting into the combustion chamber.  I had also thought that the COV was faulty and had taken it apart and swapped another one in - with no change; it still didn't like running on the low-compression setting.  But I'm leaning towards thinking the head gasket is causing me a loss of compression somewhere - and it's simply not getting enough compression to be happy with the COV "out"

We'll see what it has to say for itself once the head is off

Next up is a temp fit of my Markon head anyway to see how that works.  I have a 115mm nominal pulley there; so for 3150 RPM no-load it'll need a happy 600 RPMs - we;ll see what happens there

Cheers

6
Lister Based Generators / 6/1 driving ST clone 260 VAC
« on: May 17, 2022, 11:04:28 PM »
Hi guys

Thanks for your advice recently re the Chinese ST head

I temp-fitted it to the CS last weekend with a flat-belt drive

At 650-ish RPMs it was making something like a scary 380 VAC.  I lowered the engine speed in stages until at 528 RPM on the Lister it was producing a no-load 260 VAC.  No idea what the waveform will be like - that's a question for another day

See link attached for a short video of it running?

https://www.youtube.com/shorts/TC9fY1mfnfs

The Youtube guys have done a better-than-normal job of reducing the video quality to "awful" - but what the hell

I'm calling it the beginnings of a "win" and have taken that head off and put it aside for the moment to have a play with my Markon head which is a much nicer unit, to see what that will do

Whatever the relationship with these Chinese STs is between RPMs and VAC - it doesn't seem to be linear.

Once I have had a play with the Markon I can re-mount the ST-clone and find something with an oscilloscope and a Hz meter to give me some more to work with if I like

Thanks for all the various advice on this

I will have some stupid questions to ask re the Markon head, I'm sure; as it has just four identical unmarked black wires coming out of it lol.  I have it on the bench atm checking to see where there's continuity and what the resistance is between the various wires for some clues

Cheers

7
Everything else / Re: What engine?
« on: May 17, 2022, 06:52:30 AM »
Whereabouts in NZ?

8
Hey guys - thanks for the excellent advice - much appreciated

I have few chunks of finned, heat-sink alloy here out of 150kW-sized VSD/VFDs - a piece of one of them will work well.  The lads here try to throw them in the scrap every time we do a clean-up but I keep saying "I'll use these one day . . ." so there we go

I will mull over all this good advice & google a few bits so I understand - especially good explanation-to-lay-idiot of the bridge rectifier, Bruce, thanks

9
Ha, thanks Butch, my experience with the ST's is just one of practical necessity.   It was an educational "opportunity". 

MikeNash, good point on the need for removing the doghouse, I forgot to mention that abomination.  Adequate heat sinking of a modern, metal cased bridge rectifier is also essential. 

It really is a shame that the ST's aren't made in a more reliable and consistent manner with decent QC.  The best ones have acceptable waveform and voltage regulation by the stock harmonic system, though I expect THD is still about 15%.
For a smooth sine, you really need skewed rotor windings, it seems.

Hi Bruce.  Appreciate the input, thanks.  I know less about electronics than the Queen of England does about the poor . . . so I figure - see pic - the bridge rectifier is the alloy-bodied gizmo in the pic?  I might have a google and see what they do.  But I should replace it with a "good one"?  Cheers

10
Engines / Re: SR2 starter replacement
« on: May 10, 2022, 07:43:58 PM »
To be honest, I think that nut is still good enough to go again. Once torqued up using the C spanner you only need to fold a tab over to lock it in place. If you do not have a C spanner they are so easy to make by tracing the outline of the nut onto paper and thi gives you the pattern. Then enough 3/16" piece of sheet steel and a cutter and a file and then a length of pipe on the end of a short handle.

I had to use 2 24" pipe wrenches to get it off.. and was hard to turn until it came off ...
I need to find out what size/threat it was to get it to a point that i can finger thread it on .. and use the lock washer to keep it from coming off.

Pardon me for sticking my oar in . . .

But, unless I have mis-interpreted the photos, I'd say you have a threaded taper-sleeve-and-nut assembly on that shaft?  Perhaps I have that wrong?  If that is what it is, the sleeve and bearing will come off the shaft, and the sleeve, nut and locking-ring would be sold as a unit by any bearing supplier

Good luck either way

11
Interesting, Bruce

I have an ST-clone Chinese head I bought for a few hundred $$ years ago - basically thinking "copper windings + solid cast-iron construction = good bones"

I guess time will tell - but it's awfully rough:

Both bearings growled and grumbled from new so I replaced them with Timken/SKF ones.  One of the shafts was only about 70% machined as it was made uneven, out-of-round & partly undersized.

The brushes are "crumbly" and one just broke in half.  The springs behind them are the nastiest folded-tin I have seen anywhere.  They might work?

The fasteners right across the unit are just rusty muck-metal with heads so thin a spanner slips off them - so I have replaced them all

Normal stuff, really, I guess; and probably analogous to Indian Listeroid export units

But the electrics.  My god . . .

There was an isolator/on-off switch on the side.  The positive wire attached to it had no clearance at the bottom and a half-inch or so of bare wire was jammed against the tin base of the dog-box.  I don't know if the unit will generate power - but if it did, the casing would have been livened-up nicely.  I took it out, joined some good wire onto its terminals and ran the wire out through the outside of the box, using a gland and some insulated sleeves.  I guess I'll find a better isolator & mount it somewhere else.  Maybe something with some fuses  . . .

There's an output-box thingie with a couple of screw-on-knob terminals - but the phase & neutral wire terminations inside it were just made of folded thin copper plate.  I took them off, took the rusty steel terminal bolts out of the terminal holes and extended the wires, adding some shrink & insulation and running them out - I guess they'll end up on the terminal block for initial trials

Inside, everything was just floating around loose - I guess the big alloy thing does some sort of regulating job?  I'd be interested in suggestions as to what to do with it?

Once it's spinning - if it makes power, I guess I'll mount a tidy enclosure somewhere and block off the hole in the top where the dog-box sat

Apart from the fact the body was "live", I don't think you would have got ten hours out of either of those bearings?

I guess we'll see.  I have a nice Markon unit as Plan "B"; but I figure this unit has to be a good one for someone who knows nothing at all about gen heads to make mistakes on

12
Engines / Re: SR2 starter replacement
« on: May 07, 2022, 03:49:07 AM »
To be honest, I think that nut is still good enough to go again. Once torqued up using the C spanner you only need to fold a tab over to lock it in place. If you do not have a C spanner they are so easy to make by tracing the outline of the nut onto paper and thi gives you the pattern. Then enough 3/16" piece of sheet steel and a cutter and a file and then a length of pipe on the end of a short handle.

Also traditionally tightened with a cold-chisel and hammer - although perhaps I shouldn't admit . . .

However a new sleeve and nut will cost almost nothing and, being free of rust & having smooth surfaces, will take up an even, gradual tension to tighten up 'just nice" - just imho

13
Listeroid Engines / Re: My fix for Listeroid light flicker
« on: May 04, 2022, 08:05:05 AM »

mikenash,

Engine/Generator --> Battery Charger --> Battery Bank --> Inverter --> Clean Power

Should work.

I would hope so, yes.  I'm just playing with a few hundred watts of solar and a few a/h of lead-acid right now and I've been a bit precious about the LiFePos - but they're getting cheaper & they're coming as a unit with a smart BMS these days . . .  I guess we'll see.  Cheers

14
Engines / Re: SR2 starter replacement
« on: May 03, 2022, 08:22:28 AM »
I have the sheave and bearing already on the way ..

I'd rather have a roller bearing - bearing, but iv got what's called a deep Grove bearing on the way

I'd be surprised if your gen head was doing more than 3000 RPMs, so a deep-groove ball-bearing will be just fine.  If you have bought a ball bearing and a housing  - it may be that the dimension from the base of the bearing to the centre of the shaft - effectively your deck height - is not the same as the original unit as they will be a different kind of housing.  Anyway, sounds like progress.  I will watch with interest

15
Engines / Re: SR2 starter replacement
« on: May 02, 2022, 08:10:47 PM »
The lock ring ( the thing with the fingers ) is still playable

The Nut ( I still think it's a nut ) is still stuck ... I know I have 2 24" pipe wrench,  but currently can only find one.

So tried with a large set of vicegrips and one pipe wrench ... no movement yet. So I put some heat to the nut again and sprayed it with penetration oil ... then walked away.

I dont want to cut it off ... it might be a pain finding a replacement nut with the head still unknown to me as to who made the darn thing.

Fair call.  But I suspect you'll find that the taper sleeve, the nut, the locking ring and the bearing are all just "off the shelf" components.  If you took that photo to a bearing shop and asked them . . . .

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