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Author Topic: seeking an answer...  (Read 29209 times)

Procrustes

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Re: seeking an answer...
« Reply #15 on: November 15, 2006, 08:07:18 PM »
There has been mention of the great personalities of science and engineering.  What made these people great is not raw intelligence or the willingness to look at things differently then what is commonly known, both are fairly common by themselves, but the combination is not, also need a good deal of luck.

I don't disagree with what you say here, but I'd put persistence and dedication higher on the list.  Newton had an extraordinary capacity to concentrate.  Einstein made several comments to the effect that others could equal his accomplishments if they matched his dedicated.  Mozart is the archetypal prodigy, but what is lesser known is that his father pushed him very hard from early on.  By the time he wrote "Twinkle Twinkle Little Star" at age four he had something like 1500 hours of piano practice under his belt (also his father is the one who actually wrote down the composition...).  Edison said genius is 99% perspiration and 1% inspiration.  Steve Wozniak could work for four days straight without sleep.  I don't deny that luck, intelligence and perspective are factors, but persistence always accompanies genius, and geniuses regularly cite it as their edge.

mobile_bob

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Re: seeking an answer...
« Reply #16 on: November 16, 2006, 04:33:27 AM »
it has been widely stated that if one was to read one hour each and every day for 5 years on one subject, he would become the worlds leading expert in that one subject.

i digress :)

back to the topic at hand

Guy:

i can conceptualize how forces from a 6/1 are transmitted thru to a particular point within the concrete block, at a specific rpm, at a specific torque output, at a specific degree of crankshaft rotation etc.  theoretically we can calculate exactly where this point is within the block of concrete and in doing so determine the dimensions of the concrete block,  i don't need to do the math to accept this as fact, but that is where we part ways.

where i part with you in doing the math, is the results cannot be linear, as the point within the block will move based on degree of the crankshaft, timing of combustion, torque output and other factors. this would necessitate a chain of calculations or more likely an educated guess as to something close enough for satisfactory operation.

there are literally dozens if not hundreds of variables, so there is no way there can be a difinitive answer or one right dimension, but rather something close enough to work over the intended range of the engine.

variables to be considered are as follows

engine hp as a variable, if a 6/1 needs a ton, then what about an 8/1 at 850 rpm or a 10/1 at 1000rpm? i am not aware of there being a different concrete base for different hp ratings or rpm. my only mention of hp is in a generic sense, in that there certainly higher stresses, vibrations etc in a 8 or 10/1 than a 6/1, it would appear that these stresses are not part of the equation, and neither is a difference in rpm

when i stated earlier that i can conceptualize the vectors, and the forces being transferred into the block, i meant that i can see it in one plane of thought, at one point in operation, beit degree, power output level etc. this is based on a single engine bolted directly to the ton of concrete

what becomes unclear and seems to lead me away from your arguement is when the same engine is mounted to a som cast iron base and then the assy bolted to a concrete base, the vector arguement does not hold, at least to the point that the forces are transferred to a point in the block

lets step away from a lister vertical to some other horizonal single of similar size and output, now the vectors are changed 90 degrees and there is no way that these forces are directed to a point within the concrete, but rather contained within the crankcase proper, wierd harmonics not withstanding.

the bottom line as i see it Guy, and i want to be careful to state this in a non inflammatory way, so please take this with sincerity

"it is your contention that lister engineered the concrete base to fit their engine"  this is your statement of fact , theory, or position
it is therefore incumbent upon you to back up your statement with supporting facts that are directly related and pertinent to the position, further it is incumbent on you to produce your "work product", "supporting formulae", "references" etc.   so that anyone conversant in math can come to support your assertion

it is not incumbent upon me or anyone else to either prove or  disprove your assertion or position.


i would also like to note that if i was to make a statement that lister took a shortcut and did not design their intake manifold to optimize the VE, you would certainly call me to task, would you not? (yes you would and have)

it would then be incumbent on me to show some form of proof or at least some form of proof of concept, with related formulae, test results etc. i could and would provide copious amounts of information, documentation, formulae (that directly relates to manifold design), and with a bit of work some test results to back up the claim.
if i did not come up with anything concretely related to the assertion (such as formulae), you would rightly not accept my postion or assertion.

Guy i continue to press this issue not because of trying to prove or disprove either position, but rather to learn. what i learn often has broad application to other facets of what i do that often has no direct relation to the original problem.

respectfully

bob g
otherpower.com, microcogen.info, practicalmachinist.com
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Procrustes

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Re: seeking an answer...
« Reply #17 on: November 16, 2006, 04:47:20 AM »
Bob, when I want to be I can be a FUCKING good engineer, but I fall so far short of even lesser gods like henry ricardo and james watt and otto diesel and a string of other names whose boots I am not fit to lick it ain't even funny, and THEY worshipped people like newton and cavendish and maxwell etc.

Rudolf Diesel, not Otto, as I'm sure you know.

Doug

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Re: seeking an answer...
« Reply #18 on: November 16, 2006, 05:35:31 AM »
I need  to read this a little more later I just wanted to wish the best to Guy with regards to the baby on the way.

I had a hand in some clever engineering years ago and learned that my math skills suck.

I do recall some clever math relating to this sort of thing from college taught by a fat guy who used to work for NASA who mumbled and scribled and sweat at a chalk board and end every sentence with as you can see and very simple , a German woman who would scold me for looking in the back of the book and a Scottsman who could spend hours discussing " Nodular Iron " if you got him off topic...

What I have learned is Genius combines math with creativity. I walk on my knuckles and swing from the screen and ground support like a cave dwelling ape because. I don't use and lost most of my math skills, I replace rather than repair, I'm more interested in the technology of pre silicon era and shun what I don't like and last but not least I just am not paid to think and plan just do and react.....

Doug 

mobile_bob

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Re: seeking an answer...
« Reply #19 on: November 16, 2006, 06:45:39 AM »
Doug:

" I replace rather than repair, I'm more interested in the technology of pre silicon era and shun what I don't like and last but not least I just am not paid to think and plan just do and react....."

i have been fighting this fight for the last 15 years of better, it has prevaded my profession to such a point that it is rare you can find anyone that can fix anything.
parts changers have taken the place of mechanics,  but wait than seems derogatory so lets call them technicians. such bullshit.

i refuse to be known as a technician, i am a mechanic and strive to be a mechanic in the truest sense.

this is precisely why i question nearly everything these days, when it is presented to me that "its the way it is" or, "its the way its always been done" or " thats the way it was engineered" and having no documentation to back up the claim automatically raises red flags to me. (Guy, please take no offense here, i am using a different standard on our discussion)

in my profession we used to rebuild every component of a truck, everything! and if you were to be a good mechanic you learned how and became proficient at rebuilding every component on a truck from starters to alternators, waterpumps to injectors, cluches to differentials you name it.

today i would bet there are no more and likely far less than 1 in 10 so called technicians that could rebuild any single component let alone all of them.

don't get me started on diagnosis, that has become a joke.

complaint: truck won't start

a. replace batteries,, does it start now, no? go to b

b. replace starter, does it start now, no? go to c

c. replace ignition switch, does it start , no go to d

d. replace engine, does it start now, go to e

e. jack up radiator cap and drive under new truck, then go to f

f. replace radiator cap, does it start now? if not go to g

g. hide! take a sick day, leave it for someone else.


previous example is probably an over simplification, but you would be surprised just how close it is to reality.

another example, over the last few years i have had the misfortune of having to follow up dealers and other shops to work out issues with HUEI fuel systems on 3126 cat engines,

many times i have had phone calls, personal conferances, etc trying to get diagnostic procedures from the manufacture, with disastrous results.

each of the technicians at cat had been developing their own individual diagnostic procedures, because cat supposedly had not published procedures

about a month ago, in frustration i went out into the cat dealership shop, and asked to see their manuals, there on the top of the shelf was a complete diagnostic manual for a 3126e model, with diagnostic flow charts, spec's , procedures etc..... with at least a quarter inch of dust on it,
no one knew of its existance!
unbelievable!

ya technicians, parts changers, that is what they have become, sad thing was the lead guy was not even smart enough to use the book, look up anything in the book or even figure out where the index or contents pages were!

yup drop a couple of nukes and get some EMP, and down goes every single one of these engines, and no one will have a clue how to fix em
except for ordering all new electronics and replaceing everything, which should take about a year, because the delivery trucks won't run to deliver the parts anyway

i would suggest anyone that is at least a little handy with tools, mechanically inclined, do a bunch of independant study, learn how to fix it yourself.
and those of us that are in the fix it business, better slow down and take a good look where we have come from and where we are being dragged.

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

Doug

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Re: seeking an answer...
« Reply #20 on: November 17, 2006, 12:07:30 AM »
One day many years ago for a breif window of time my hands were made of gold....

No joke everthing I touched worked....

I could "feel" the difference between a  C3 clearence and bad shaft/bearing housing fit. I could tell by touch and smell, texture and yes paper pad and calculator what would work and what was trouble. Those were happy times, but I was also so poor I had to take the bus to work and often I walked becuase I had no bus money.

Now I make good money and I don't have the golden hands or the desire. Mother INCO beat it out of me, that kind of work is beyond the scope of a man who is expected to drop from the sky with a beat bag, chant burn some insence and make crap work. I doesn't matter what you do to make the crap work as long as it works....

A machine that cost 2 million bucks but does 25 million worth of work in a a week can be held together with snott, the string from used harpons, wishful thinking, ritual, therapudic massage, and tender romatic moments with a dead blow sledge hammer and no one cares as long as it keeps running....

I hate the fact I seem to be the only guy left that understands a U-215 frame motor and a T-215 are not the same and one has the potential to snap shafts and will trip overloads run hotter make more noise ect...

" DC BUS OVER VOLT "
I know that this means you clowns in general engineering, you had your chance to listen too me but no. Your smarter than me and better educated than me. I can fix this but your too proud to ask....

I'm realy tired of fighting, so I don't any more. I think you said once your in Oregon.....
There is an electric motor in the wheel of a Boewing nose wheel under test that has a little ME in it and my contribution netted me enough stock to buy a pack of smokes.

The world is messed up beause it doesn't pay to fix things and be creative anymore. Infact your making trouble if you rock the boat.

Doug

BTW I like engineers, the smart kind who know math and listen to other peoples ideas.



 

mobile_bob

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Re: seeking an answer...
« Reply #21 on: November 17, 2006, 06:53:40 AM »
Doug:

i can certainly relate to your plight

i have somehow mutated to being the last guy in the area it seems to call when all else has been tried and failed, usually miserably

today started at 6 am and i just got home at 10:30 pm

interesting day

2 days ago, one of my customers called with a hyd leak on a new (5 days old) drywall boom truck, got there and found a hyd swivel had lost its little
pin that retains the balls, and all the balls fell out, waaalaaa big leak, oil all over a million dollar home driveway, and somehow according to the homeowner it was
my fault! hey crap happens and stuff fails sometimes for no apparent reason. got the thing reattached and the truck off site. oh yes raining like hell and absolutely a
horrific access problem to boot.

last night i went out with a new american made steel swivel with an actual screw to retain the balls unlike the little rivet the italians seem to like, hooked it up and all is well

today bright and early another call, swivel broke!

got to the site and there was 6 inches of standing water over a foot of mud and i have to crawl under to inspect and repair, only to find out it is another of the five swivels that had lost a rivet and balls,
removed and replaced all five swivels with american units, found that another had lost its rivet and the last one was leaking badly... shit!
4 hours to change them,,
called the manufacture, talked to engineering, and they stated "oh yes we have had a few problems" we sent the customer new updated swivels, checked them out and found them to be the same swivels, same part number and date code!!!!  ya right..
i explained that the way they mounted them in the mast allowed them to hammer together as the hyd functions are activated and this likely was the cause of the rivets coming out..

their assinine responce "who are you to tell us what the problem is, you are just a mechanic" 

"well f@#$ u too buddy!" was my responce.

my job has morphed into one of fixing other engineers screw ups, and it has become a daily routine on all sorts of equipment, and i am sick and tired of it.

i am sure there are very fine folks that do engineering, i just don't happen to get to meet many of them anymore.

the rest of the day went much the same,

next call, "bob, help, we cant get this allen head bolt out so we drilled it and broke off an easy out in it" broke off down in the socket head where the allen wrench has to fit, and the head is recessed in the part to where you can't get at it with anything else.  no don't call me when you first encounter a problem, screw it up good first!
then stand over me and apply stress to me that you have to have it fixed yesterday...
oh ya.... bring it on

some peoples children!!

yup gone are the days of being able to just go out and repair stuff, overhaul worn equipment, the kind of thing you can feel good about.
today it is just get it going as fast as you can, and don't charge me for it, or if you are going to charge me, not too much...

no wonder the old guys i remember as a kid were so grouchy,

omg, i am an old guy now, i guess it is my turn to get grouchy

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

GuyFawkes

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Re: seeking an answer...
« Reply #22 on: November 17, 2006, 06:51:49 PM »
it has been widely stated that if one was to read one hour each and every day for 5 years on one subject, he would become the worlds leading expert in that one subject.

i digress :)

back to the topic at hand

Guy:

i can conceptualize how forces from a 6/1 are transmitted thru to a particular point within the concrete block, at a specific rpm, at a specific torque output, at a specific degree of crankshaft rotation etc.  theoretically we can calculate exactly where this point is within the block of concrete and in doing so determine the dimensions of the concrete block,  i don't need to do the math to accept this as fact, but that is where we part ways.

where i part with you in doing the math, is the results cannot be linear, as the point within the block will move based on degree of the crankshaft, timing of combustion, torque output and other factors. this would necessitate a chain of calculations or more likely an educated guess as to something close enough for satisfactory operation.

This is why you need to do the math.

If you take the moon example you will see it doesn't have a position (apart from an instantaneous one) but rather it can be found somewhere along a track, and the track is what you calculate.

You're right about the lister, there is no point, x y z co-ordinate defined, there is an area, this is why you need the math.

Have I mentioned you need the math? Good, cos you need the math.

Nobody likes the math, because it involves differentiation, dt over dy and all that stuff, and it is a real obstacle on the road of learning, I can still remember sitting in class looking at the board and being utterly lost and wondering what the fuck the teacher was on about, but it is the engineering equivalent of the micrometer, until you make it an everyday tool you flat out will not be doing any precision work to spec, the math is the same, until you master it you flat out will not be getting useful answers.

I don't like the math either, and nowadays I use it so infrequently I have to re-learn it, but I have learned it, I have used it, and I have used it (in collaboration with others) on a CS, and lister had it right.

the cast iron base doesn't magically change anything, it makes a difference that you factor into the math, it alters the end results but does not turn them on their heads.

=======================

here is a thought problem for you.
dissect it and tell me where it is wrong

Lister CS 6/1 is rated at about 47 ft/lb of torque

4.5 inch bore, 5.5 inch stroke.

5.5 inch stroke = crank radius of 2.25 inches

47 ft/lb = 564 inch/pounds

564 inch pounds / 2.25 crank radius = 250 lbs force on crank at 90 degrees after tdc firing stroke

4.5 inch bore = 2.25 inch bore radius

3.14 x (2.25 squared ) = 15.89 square inches piston area

250 lbs force / 15.89 inches piston area = 15.73 psi, just over 1 bar.

And yet 19:1 compression ratio (valve in) and 17:1 valve out gives us 19 x 14.7 = 279 psi, and 17 x 14.7 = 250 psi

If we assume 250 psi cylinder pressure at 90 degrees past TDC firing stroke we have 250 psi x 15.89 square inches piston area = 3970 off pounds force on the piston, 3970 pounds force at 2.25 inches crank radius = 8900 odd pound inches, /12 for 740 odd foot pounds.

So we calculate torque is 750 odd foot pounds, and yet we know torque is a shade under 50 foot pounds.

a/ tell me where the mistake(s) are in the above, and what they are.

b/ tell me how you get 47 ft/lb out of the correct equations. (don't evade the question by saying from a dyno, you can't dyno a blueprint and that is the stage where these things are calculated so you know if the design is viable)

--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

mobile_bob

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Re: seeking an answer...
« Reply #23 on: November 17, 2006, 07:48:05 PM »
Guy:

unless i am missing something, (likely) the flaw in your calculations is very basic

"If we assume 250 psi cylinder pressure at 90 degrees past TDC firing stroke "

your answer is based on an assumption? perhaps the flaw is not in the math, but in the assumption

also rated engine torque is something that is arrived at, at a constant rpm, without undue strain or temperature rise, undue smoking or other detrimental effect. rated torque is an average figure and not an instantaneous figure derived from a simple formulae based on on degree crank angle.

getting back to the point here

you insist that lister got it right by spec'ing out a yard of concrete or was it a ton of concrete, you further insist that they arrived at this spec thru careful engineering
if remember correctly you state that lister made only one recommendation and that was the ton of concrete. have i fairly restated your position?

if i remember correctly you have stated that they made no other recommendation as to spec for a concrete base

could you tell me what the fundamental difference between a 5/1 and a 6/1 as it relates only to the concrete base?

i dont have all the spec's/dimensions on a 6/1 but i do a 5/1, so would you consider them to be virtually the same engine, for purposes of determineing the proper concrete block, size, weight and dimension?

or can i calculate base on the 5/1 spec's to figure the concrete base to mount a 6/1 onto?

it is my understanding that both engines are basically the same, physically, i would assume there to be a slight difference in bore perhaps, or slight increase in rpm for a 6/1
but all else is virtually the same.

i think i am getting closer to an understanding, but could use your continued input

bob g

otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

Doug

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Re: seeking an answer...
« Reply #24 on: November 17, 2006, 11:11:46 PM »
Math is good, having some other person do the math for you correctly is better...

Thanks Guy for your input, and I'll spare you the engineering jokes I toss at people.

Doug

Bob....
I just don't care much anymore. That translates to just about time to hang up the beat bag and start pulling cable. Unless of course something cool comes up lol.


GuyFawkes

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Re: seeking an answer...
« Reply #25 on: November 17, 2006, 11:36:17 PM »
Guy:

unless i am missing something, (likely) the flaw in your calculations is very basic

"If we assume 250 psi cylinder pressure at 90 degrees past TDC firing stroke "

your answer is based on an assumption? perhaps the flaw is not in the math, but in the assumption

It was an assumption, but a fairly good one.

see http://www.kyma.no/sitefiles/site59/files/files/KDAreport.PDF 4 page pdf, some nice interesting data there.

then you need to do some of that math stuff to plot bearing load and torque at each degree of rotation, which will give you a bunch of other interesting answers.

few of which correlate with the dreaded "common sense"

Quote

also rated engine torque is something that is arrived at, at a constant rpm, without undue strain or temperature rise, undue smoking or other detrimental effect. rated torque is an average figure and not an instantaneous figure derived from a simple formulae based on on degree crank angle.


so your response is torque is not instantaneous, but the average figure over 720 crank degrees of the 4 stroke cycle.

good answer, it would require vastly higher instanataneous torque between TDC and TDC + 90 degrees, lower mechanical advantage of just past TDC compensated for by vastly higher cylinder pressures, as crank turns and mechanical advantage increases, cylinder pressure is dropping, so peak cylinder pressure is going to rise from 17:1 or  250 psi at injection to whatever the design peak is at around TDC firing stroke + 15/20 degrees, which will coincide with peak torque wear piston/barrel and big end / journal

Quote
getting back to the point here

oh, we never left the point.....

If you have peaks of maybe 1000 ft/lbs acting inside your engine you damn well need to know, because this directly affects where the centre of effort of these forces is going to be located.




you insist that lister got it right by spec'ing out a yard of concrete or was it a ton of concrete, you further insist that they arrived at this spec thru careful engineering
if remember correctly you state that lister made only one recommendation and that was the ton of concrete. have i fairly restated your position?

if i remember correctly you have stated that they made no other recommendation as to spec for a concrete base

could you tell me what the fundamental difference between a 5/1 and a 6/1 as it relates only to the concrete base?

[/quote}

A 6/1 is just a 5/1 running faster.

Each individual power stroke isn't generating any different loads, they are just happening faster, higher frequency, shorter wavelength, same amplitude.

the concrete block is about amplitude, not frequency per se, it keeps coming back to that math.

Quote
i dont have all the spec's/dimensions on a 6/1 but i do a 5/1, so would you consider them to be virtually the same engine, for purposes of determineing the proper concrete block, size, weight and dimension?

they are the same engine, apart from the frequency issue mentioned above.


Quote
or can i calculate base on the 5/1 spec's to figure the concrete base to mount a 6/1 onto?

it is my understanding that both engines are basically the same, physically, i would assume there to be a slight difference in bore perhaps, or slight increase in rpm for a 6/1
but all else is virtually the same.

6/1 is a 5/1 running at 650 rpm instead of 600 rpm

Quote
i think i am getting closer to an understanding, but could use your continued input

bob g



you gotta do the math.

you did not tell me what was wrong with my "question" and then tell me the right answer.

you hinted at it, but you didn't answer directly and lay it on the line

go work out the answer and ideally the reasoning in some detail and lay it out here, it will solve much of the question you keep asking.

=============================

everyone thinks 650 rpm = 650 rpm = 650 rpm

nope, it is a MEAN speed.

why else do your lights flicker?

you think your lights visibly flicker because the engine went from 650 rpm to 649 and back up to 650 again? a change of 0.15%???

get real, there are two full rotations in a 4 stroke, you only get (useful) power on one quarter of one rotation, the other one and three quarter rotations are drag, in varying amounts, the last compression stroke being the worst.

measure rotational speed degree by degree for each of those 720 degrees of rotation and you see some remarkable changes.

5% is nothing to talk about, 10% isn't even exceptional.

5% is 32 rpm, you think you can see it, you can't.

32 rpm acceleration in 90 degrees of crank travel.

with a 24 inch dia flywheel you have 75 inches of circumference, 32 extra rpm is 32 x 75 = 2400, 200 feet.

650 rpm is 10.83 revs per sec

1 rev is therefore 0.092 sec

90 degrees of crank rotation is a quarter of that, 0.092 / 4 = 0.023

200 extra feet of flywheel rim travel in 0.023 seconds, is 8695 feet per second

say you have 100 lbs of iron in each rim, 2 flywheels, 200 lbs of iron being accelerated an extra 200 feet in one fortieth of a second.

whats the tensile / shear / compression numbers of cast iron?

Why is the apparently incredibly conservative 60 mph rim speed always used?

what do you think actually causes the stress failures in flywheels that allow them to explode in overspeed conditions?

You weren't going to destructively test your flywheel on a smooth electric motor and then take those number as being good for a single cylinder engine were you?

why were early cast flywheels made with s shaped spokes?

what happens to torque output if you double flywheel mass, or halve it?

work the math
--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

Doug

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Re: seeking an answer...
« Reply #26 on: November 17, 2006, 11:43:21 PM »
The answere is 42..... It was a tough assignment.

My Petter calls for a yard a well. I just assume this is a carry over from the Listerany thoughts guy?

Doug

mobile_bob

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Re: seeking an answer...
« Reply #27 on: November 18, 2006, 03:41:58 AM »
well it comes down to me taking a stand and calling bullshit!

it has taken use many months of back and forth on this subject, then yesterday i was sent the recommendations and specifications for a 5/1 lister, the contributor sent me an copy of an original lister document for a 5/1

the problem is a difference in dimension of the block of concrete

the difference is so vast in what the recommendation from lister for a 5/1 and what you report for a 6/1 that it simply cannot be explained by any mathematical calculation

you reported on many occasions that lister spec'd a specific dimension of approx one yard of concrete, for a 6/1, and doing some quick math in my head is approx 2500#s give or take.

if there was some higher order engineering that took place there would be no possible explanation for lister to have recommended a base of ~600# lbs for the 5/1

unless you are prepared to take the position that the extra 50 rpm necessitated the need for another 2000 lbs of concrete?

if you wanna go there, i can't wait to see the non linear equation to arrive at anything less than a 10,000 # concrete block for a 8/1 running at 850 rpm

the only possible explanation basically comes down to this

a well balanced engine does not need a heavy base of concrete as evidenced by lister and the 5/1,  a less than well balanced engine needs a larger block of concrete as evidenced by the 6/1

a dollar to a dog turd says there simply was no high level engineering that went into the design of the concrete base.

this has been an interesting exchange of the theoretical, too bad we could not have arrived at the actual formulae or calculations for determining the dimensions of a concrete base.

obviously none existed or were applied at the time.

check
bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

mobile_bob

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Re: seeking an answer...
« Reply #28 on: November 18, 2006, 03:44:31 AM »
ps:

if you would like i can forward the lister print for a 5/1, which has clear dimensions of a block of around 600lbs

i dont know how to post the link of a pic, but i can forward the email attachment

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

Doug

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Re: seeking an answer...
« Reply #29 on: November 18, 2006, 04:02:45 AM »
I won't pretend to say I understand everything about mass dampening or moving the center of force blah blah.

But I can see in my minds eye some static force vectors as aplied to a crank. Is it then reasonable to assume that the addition of mass at the other end of the crank case will shift forces on crank, to me yes.

So where can I find "Rotational forces on cranks shafts and mass dampening of their effects for Dummies" to read up on this?

No way any engine with a litre of displacement will ever be so well ballanced that a good foundation or at least some dead weight isn't needed so how much do I need for a Petter?

Is more than a yard better?

Is just enough to keep it from hopping enough?

The force wasted making a block move is in fact wasted work. So how does one come to terms with all this information ?



Doug