Micro CoGen.

Keith:
yes i still have pretty much everything i came to kansas with
i would have to figure out how to get it out of my shop and loaded, but other than that?

been a long time since i checked in on the forum, so hopefully you will get this reply

i bet a dollar to a dog turd that the story regarding missing a mortgage payment and the bank kaboshing the deal is bogus.

if the seller was truly having issues with his/her/its lender, then it would stand to reason that a sale would be just what would be needed to clear the debt and help the bank and the seller, along with the buyer.

my thinking is they got a higher offer and figured they would float this story to see if they could get out of your deal on the property.

its been about 40 odd years since i was last in SE colorado, and from my memory it was about as desolate an area as one might find short of the dark side of the moon.  lots of land rush small stone and mud brick cabins where folks tried and failed to thrive there back about 150 years ago now.

SW colorado might well be a different story and be more desirable?  i don't know, never been there.

don't get discouraged, there is still a lot of property off the beaten path all across the country, just keep looking and you will find something to your liking.

bob g

just in case there are members of our sister forum, yes it is down, but payment has been made to re-up the dues for the domain name.

so it should be up soon, i will be checking to make sure it does come back.

i have been very busy and the domain dues came up and of course i missed paying them.

i will try to do better next year   

bob g

the best method that i know of is the following

remove the cylinder head, and make a bracket and stop bolt that the piston can contact when rotated toward top dead center

rotate slowly until contact is made, and note the pointer mark at the flywheel

rotate the opposite direction until the piston comes around and makes contact again,  and note the pointer mark on the flywheel.

then divide the two marks in half, that is the actual top dead center.

if it were me, i would do as above, with a pointer of my choosing, then when i find tdc i would mark the flywheel to correspond with my pointer.

then using a tape measure, measure the circumference of the flywheel. divide that number in inches (i prefer those units) by 360 and you then have the amount 1 degree is in inch units or fractions thereof.

then it is a simple matter of multiplying by 18 degrees and measure advance of the tdc mark by that amount and mark the flywheel.

if i wanted more marks i would simply mark for each degree, maybe  a couple degrees one way or another.

with a direct injection engine you can do the same thing you just have to make a top stop for the piston that fits  down the injector bore and contacts the piston.

from memory (which i have slept a night or to since '07-'09 when i was working on my s195idi engine) my flywheel had all sorts of marks that may well make sense to some fellow in china. having removed the water hopper i put a piece of hanger wire to make a pointer and sorted it out from there, and marked tdc to my liking.

fwiw

bob g

it also depends on what the motor is connected to.

a 1hp motor connected to a compressor that is asked to start at perhaps 120psi and cut out at 150psi may have a difficult time starting up, that is if it doesn't have some sort of unloader system.

blower motors also have a harder time starting,

high efficiency motors also have higher starting amps requirements.

what do you have in mind for the load for this new motor?

bg

my bet?

1/4 mile,  18.99 sec @ 79.3mph

are you going to bleach the tires?



bob g

edit: make that 73.9 mph

dumpster diving is known as "shopping at the big store" around these parts.

sort of a twist on what mobile mechanics refer to working outside as "working in the big shop"

our little town lost its hardware store years ago, and it is 30 miles to get to where you can find nuts/bolts/fittings, so just about every old guy saves everything imaginable. and it kills us to throw away anything.

soon as you do is the day you have to drive 30 miles or more to replace it.

i imagine living in alaska would be even moreso

bob g

sounds like an interesting plan you have there.
and i look foward to hearing more about it.

having a hydro source would be wonderful in my opinion
not much chance for that here in central kansas, the only time
we get enough water moving fast enough it is biblical in proportions (read that spring floods).

there was a time about 25 years ago, when i was about to be single again, i had thought seriously about a small cabin, and the very real possibility that i would be driving 60miles to work each day.  my plan was to build a special vehicle that had additional battery capacity, and a hot water storage tank so when i got home i could plug the vehicle into the cabin and have power for the evening, and enough hot water to provide for my domestic needs.

figured while driving for an hour, why not have the vehicle do something else useful too.

sounds like you live in a nice part of the world.

bob g

you're a bad bad man, Tom Reed!


(ducking and covering)
bob g

Bill Rogers wrote the book, and he was a frequent contributor over on the lef years ago, up until things got stupid with all sorts of arguing and other b/s

i am in frequent contact with him in an email group, a few of the og's from years ago.

i have asked for others about the book, and Bill has no desire to do an upgrade, or print more of that edition.

his book is still quite useful, in that there is a lot more to a system than just the solar/wind/generator/inverter/ etc. his book dealt with the ST gen head, and a lot of stuff on power factor, power factor correction, which was a godsend in my opinion.

i can't tell you how many electrical engineers i went to trying to get answers about power factor and its correction, only to be met with "why do you care, you as a residential consumer are not charged for poor power factor"

apparently the fact that an off grid installation makes "you" the power company was lost on them.

Bill not only explained power factor and why it is important to an offgrid installation, but also all sorts of other things that are not easily found, and he explains things so that mortals can get their head wrapped around it.

i will send him an email and see if he has any extra left over copies laying about, and come back here.

if you can get a copy for 5 bucks it is well worth it in my opinion.  if you learn but one thing for 5 bucks, it is worth the money.

we need more books to be written which incorporate the newer technologies/strategies/etc.

my collection goes back to 1893 and i scour everywhere looking for books relating to power production, whether utility scale or diy offgrid, and everything in between.

bob g

i got it a bit wrong on the temp thing

the 555jho alternators are able to stand 125 centigrade
that works out to 257F

so they can stand some pretty high temperatures
the older versions were 105C or 221F

either way, they can stand some pretty high temperatures, and i would expect all automotive alternators are built to the higher end of this range, given the underhood temperatures being quite high it is hard for the alternator to shed its heat so i would sure have it spinning upwards of 4k rpm or more so that its fan could pump as much relatively cooler air as possible.

the 110-555jho as used in the white paper i wrote 13 years ago, (has it been that long?) i got the alternator to charging 28.8 volts at 100amps in 70F ambient continuous duty and the stator never exceeded 175F and everything else i could get the heat laser to access was under 175F that included the rectifier diodes.

running at 130amps and 28.8vdc the heat only rose about 10deg
which was still well under the alternators 120c design

the temperature was measured at 5 minute intervals and after 30 minutes of testing i quit as the temperatures did not rise further.

fwiw

bob g

most automotive alternators, made for the trucking industry have a design limit of at least 205F and many newer versions (last 15-20 years) are made to handle 220F iirc.

i thought of doing just what you are talking about doing, with the case and all, but also drive an A/C compressor to use as a heat pump to draw the internal heat from the enclosure and move it to the house where it would be put to use.

i think that could be done with the 175, with a control scheme to cycle the compressor and while it was pumping freon the alternator could be cut back to a lower output to not overload the engine.  keeping it near max output would make for maximum efficiency, whether at 80% or whatever you design for.

the heat exchanger i designed and built for exhaust heat recovery on the s195 trigen, was designed to be a batch fire system. in that the unit was only designed to operate for an hour or so, twice a day. it used the condensation to self clean after each startup.  running only an hour or so the unit did not build up enough carbon so that the condensation available could not keep it clean. not sure how it would fair with longer run times, i never tested for that. and i never tested for other than max output of the engine where the amount of soot is minimal to deal with.

i think maybe the little stainless steel egr coolers might be worth working with. it would be interesting to find out how much heat could be recovered using one, and how well the clean themselves over time.

a good indicator of how well they recover heat, is the difference between the temp going in, and the temp coming out of the exhaust.

i got lucky with my design, the heat going in at max output on a 70F day was 640F and the heat coming out was 240F which is above the boiling point of water, keeping the exhaust hot enough to not condense and cause issue with the remaining exhaust system.

the system could raise 60 gallons of water from 70F to 140F in an hour of operation, that on 70F ambient temp days which was typical in tacoma during the month or so i was doing all the testing.

i ran over 50 test runs and all the temps remained stable, which told me the unit was not only functioning well, but also able to self clean.  had the unit over time not been able to raise the 60 gallons of water by 70F and the temps coming out of the exchanger started to rise, i would have expected things were starting to carbon up internally.

bob g
bob g

the schematic shows two stator winding, unless the st 3 is a 3600rpm head, which would have only two stator windinds, the schematic does not show that the two windings are actually internally connected four windings, grouped as coils 1 and 2 as one in the schematic along with 3 and 4 as the other group shown as one in the schematic.

so basically what i am saying is this, one would have to take the head apart and find the jumper in the windings, where one coil is wound and then jumps over to the next coil which is 90 degree from the first (something the chinese do, most everyone else spaces them 180 degrees apart.)  that jumper is likely buried in the lacing and should have some sort of insulating sleeve which will make it easier to find.

once found that jumper would be split so that each coil is then independent of the other, leads attached to each end and brought out to the junction box. one would then have 4 separate coils and  8 leads, rectify each coil and then parallel connect the DC output of each rectifier for the maximum power output.

in theory the stator should then be capable of twice the output power of the original design, as a maximum output.  reason being each of the original coils as connected in series internally is limited to 1.5kw and pairing both externally in parallel gives you 3kw output.  however breaking each coil and paralleling all 4 coils would give you 6kw AC if you didn't rectify them (and phased them properly of course), but at only ~60vac output.

so you could in theory parallel connect all 4 coils, bring them out as AC at 60 volts and rectify the sum with one rectifier bridge for DC output.  however the bridge would have to be large enought to handle the total output of 6kwatts of DC power and i would suspect one would want to design and use ~200 piv (peak inverse voltage) diodes to form the rectifier bridge.

you could possibly use something like these to rectify the sum of all 4 coils, these are used, but you get the idea of what to look for.  i have in years past found nos heavy duty diodes such as these at really good prices on ebay, and maybe the chinese also have something that could be used for reasonable prices too.

https://www.ebay.com/itm/304415057563?hash=item46e08d269b:g:dKwAAOSwI-RiP-o4&amdata=enc%3AAQAHAAAA4IalDKOIBhm1Sd0LRV1HPAdUR0U5Q2gCd3hexRxiDq70OWVths073eebowxA5ROPEMismhPYa2WgiXSPnzCAnz37AWohsgoj34bLzzvkcnmTt%2Fry8%2BSj%2FKRwiFU%2BUkcuEAQSxMeji0ilJRkWu3Aly4vvnLHdP0cNUDpjnUNeqSxxkZvIWekwLTz70wXAiMqteaJzA1weCXBqXJEXwN6pZEAIUHoISW4Oiz%2FyE2nW%2BKiA4Z8MmpExAPymWeydDNwjjuVJTIJ%2BZQQ5R5%2FxT8eBTuhZiOCjqTgcevxZrnFNbVC2%7Ctkp%3ABk9SR86ujeWrYQ

let me know if the link does not work.

also i thank you for this topic
as looking for the diodes above, i came across high frequency rated rectifiers, made for the modern inverter welders from chinese suppliers on ebay.  these would likely solve the problem with rectifying modified automotive alternators running in 48vdc nominal operation, where the AC stator frequency can be ~600hz or more, making the higher piv welder diodes which are designed to operate at around 60hz useless as the avalanche and cannot recover.  so having the ability to get fast recovery high current  rectifiers at low cost is something i could only dream about 13 or 14 years ago.  try as i might i could not find anything that would fit the bill back then, but now??? they are readily available on ebay, and likely alibaba, aliexpress, bangood and the corner convenience store in china.

this topic has opened more doors

thanks
bob g

we don't need 3 phase from the st3 to rectify each of the 4 coils on the stator, and then parallel them for higher current DC charging.  the ripple will be decidedly higher than a three phase stator, but that might be smoothed a bit with a large bank of capacitors, many DC welders have large banks of electrolytics.

the sd heads are single phase, but were setup to be welders, with a reostat to control the field current and by extension the output of the genhead.

i don't have a schematic for the sd heads, they are lost to time, but might be available online?

the stc genheads are three phase, and as such would make for a better charger, likely more efficient too.

i have a 12kva stc-12, but have no plans to modify it for charger use,

my thinking is this, the project might be quite interesting to work out, especially if it were to be switchable from charger to AC output, might make for something useful

having said that, the overall efficiency of the head as a charger  might be as high as the low 70's. the st7.5 in my testing works out to be about 80% efficient making 120 vac power being direct driven. the rectifier losses for a charger would have to be accounted for and would lower the overall efficiency.

the best efficiency would like be with a 48volt nominal system, as that voltage would be close to what each of the coil output would be, under load.

if you try to pull it down to 24 or 12 volt charging, one would either have to dramatically reduce the engine speed and/or the field current, and the rectifier losses would have a larger portion of the losses, otherwise the stator losses will be higher  than if used in a 48volt system, or so i would think.

fwiw
bob g

i assume the st3 is just a smaller version of the st5 and others?

that being 120/240 output?

if so...

there will be 4 coils on the stator, and for whatever reason they are spaced in pairs 90 degrees apart and then either parallel connected for 120 output, or in series for 240vac operation.

if one is crafty he/she could separate each of these coils, which
at rated output would put out ~60vac each, that at 1800rpm and rated field current (whatever that is).

each of these coils could then be rectified with preferrably a full wave rectifier, and then parallel the resultant DC output for around 3kwatts of DC output, the voltage of which would be whatever the field drive current would be and/or whatever the drive rpm and of course load would be.

i don't think this would be difficult at all, and i have postulated this possibility for at least 15 years now, but have never done it.

i have been working to clear out my shop, a huge task any time of the year, and only made worse with the low temps of late.  one of the projects i want to finish is the tear down and final welding of the frame of the trigenerator i built 13 plus years ago now.

it was only tack welded together to prove out the concept and i never got around to taking it all apart to finish the welding, so i want to finish that.

in my collection of stuff i have 2 sd-5 welding heads which have 240vac output and welding output, i am pretty sure they have the same stator layout as the regular st-5.  i have no real use for them as welding heads, so i might well find the time to take one and do the above mentioned modifications to convert it to a dc charger,  and set it up to charge a 48v battery bank.

i think one of these st or in my case sd heads would make a nice heavy duty battery charger, and with a bit of relay control, maybe a dual purpose unit that could do both dc charging and ac 120/240vac output, just not at the same time.

then i am going to throw this out for consideration

the apc ups systems use some really nice heavy transformers, and these units can be found sometimes pretty cheap to free, with dead batteries.  95% of which can be brought back to life with new batteries, and of which in my experience all can be powered by much larger capacity battery banks. most also are pure sine wave units and are really clean output with low distortion.

so you could couple one or more of these to a system and have battery charging, and AC sine wave output, or...

you can strip them down and use the transformers as step down and rectify for 24vdc nominal battery charging, drive them with 120vac off the st3 and off you go.

of course there is the hit in efficiency for the added level of conversion, so maybe the modification of the st3 to rectify the stator coils for dc output would be preferrable?

babbling on here.

bob g