Author Topic: seeking an answer...  (Read 38206 times)

Tugger

  • Full Member
  • ***
  • Posts: 104
    • View Profile
Re: seeking an answer...
« Reply #45 on: November 21, 2006, 02:04:51 AM »
Im bolting mine too a big block of concrete so i dont have to lend it to friends and nieghbours....

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #46 on: November 21, 2006, 05:01:56 AM »
Tugger:

probably the most compelling arguement i have heard yet for the use of a ton of concrete  :)

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

Procrustes

  • Sr. Member
  • ****
  • Posts: 332
    • View Profile
Re: seeking an answer...
« Reply #47 on: November 21, 2006, 06:41:22 AM »
"You didn't address one part of my post: does the fact that the block size changed prove that the block is not part of the engine design?  Yes or no?"
...

... the block changed dimensions radically, so "yes" that would prove it was not part of the design of the engine.

To me that is an extraordinary claim.  An engineer could simply have decided, "That's not big enough!", and increased the spec without altering the fact that RA Lister designed the CS for use with a block.  We'll just have to agree to disagree here.

further i can find no mention of any manufacture ever using the concrete base as an intregal part of an engine design.

the use of the concrete block as an intregal part of the design flies in the face of all that has been published on sound engine design and engineering (at least for purposes of moving a center of mass, center of gravity is another story)

From my admittedly small knowledge of such things, I flatly disagree.  I've not seen any industrial stationary engines mounted on anything but concrete.  Rtgii posted a bunch of pictures here:

http://listerengine.com/smf/index.php?topic=1033.msg13851#msg13851

conversely I know of zero industrial stationary engines mounted on anything else.

proper engine design (and i have no reason to believe that the good folks at lister were incapable of proper design) dictates that all internal forces/stresses etc are to be contained and managed within the structure of the engine proper, eg. the crankcase.

the lister crankcase is typical of design and shows no sign of deficiency that would dictate that a concrete base would improve upon. further...

Yet again, I flatly disagree, on the basis of what I said above and also because the concrete block is plainly a part of the schematics that I've seen.

if by design the lister needed the concrete base to stablize, increase strength, move centers of mass etc. the print would have included an iron or steel bedplate that would have been grouted to the concrete providing a broader contact with the concrete rather than the relative point loading that would lead to abrasion at the mounting bolts over time. for there to be a tranfer of forces to the concrete this connection would have to be very solid and if abrasion occured the engine would exhibit catastrophic failure which has not proven to be the case.

listers overall design is very good, solid and time proven, and was based on popular design as far as basic structure and crankcase design are concerned. for the power density envolved it is hell for stout and has no need for outside strengthening from a concrete base.

Same comments.

from a standpoint of simple, cheap, stable and expedient clearly the concrete base is a good method of mounting, i got no problem with that or its use.

the bottom line here is not whether or not concrete is good, bad or indifferent, or if resilient is good, bad or indifferent.
i just want to see some formulae or reference to the claim that the block has to be, or was a part of the structural design of the engine to begin with.

still looking, still waiting, perhaps i will find it but like granny used to say "maybe so, but i kinda friggin doubt it"

the more i research the further i get from accepting that the yard of concrete is the only way to mount a lister/oid and have an engine that will live longer than if mounted in an alternative (and properly engineered) manner.

bob g

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #48 on: November 21, 2006, 10:31:03 AM »
Pro:

"An engineer could simply have decided, "That's not big enough!", and increased the spec without altering the fact that RA Lister designed the CS for use with a block.  We'll just have to agree to disagree here."

This whole thread was based on the premise that lister used a formula to determine the base dimension, now some engineer just decide it wasnt big enough?
based on what? his feelings? or the fact that the block was not big enough by a factor of 4? ... give me a break!

"From my admittedly small knowledge of such things, I flatly disagree.  I've not seen any industrial stationary engines mounted on anything but concrete."

i know of none either, but this does not prove the existance of some higher mathematical formula, but rather should make you wonder why there is no reference to one forthcoming if one did exist!

"Yet again, I flatly disagree, on the basis of what I said above and also because the concrete block is plainly a part of the schematics that I've seen."

fine, then you explain mathematically the huge disparity in the 5/1 prints showing 600 lbs and the 6/1 showing the need for 2000+ lbs, given the fact that the 5/1 and the 6/1 are the same engine, and for that matter the same as the 3/1.  show me the formula to reconcile the difference!

so far all you have done is regurgitate all the same stuff, you have not come up with any new or sound engineering answers, the fact that concrete has been used forever for the mounting of heavy stationary equipment does not necessarily mean that it is an intregal part of any design.

again i will state based on much research, that all of the internal stresses and vibrations of an engine are addressed and handled within proper crankcase design, lister engines are not atypical in design and show no signs of being deficient in such a way that a concrete base adds anything to their function other than a place to bolt it down to.

it is ok by me if you want to blindly accept whatever is said to you, and it is ok that we disagree on this topic, and i have no interest in changing yours or anyone elses mind.

what would be interesting though is for those that hold your side of the arguement to come up with something solid to support the claim that lister used a formula to arrive at the spec, and some proof that from an engineering standpoint the block was an intregal part of the design.  for that matter any engine, by any manufacture, same criteria!

for now i am still waiting, still reading, still looking for proof.
to date, still nada, zip, zilch, just a bunch of restatement and shuffling, and kicking sand

bob g

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

biobill

  • Sr. Member
  • ****
  • Posts: 408
  • 'riods make good houseguests if fed right
    • View Profile
Re: seeking an answer...
« Reply #49 on: November 21, 2006, 02:03:52 PM »
 I'm a fence sitter in this discussion. To me it's all application. If it's ok for vibration to be transmitted to the surroundings then start mixing. If it's not, then you better think resiliant. I'm not known for following instructions and, if I think I've got a better way, I'll try it. Occasionally to my detriment, but not often. I think most DIYers are the same. And natural selection will take care of those who should not be experimenting.

       But....that's not what I'm here to talk about

  I have been chosen as a messenger from the 'other side'.  R.A. visited me in my dreams last night (he's shorter than I thought)   and told me to give Bob his "friggin" formula. So simple and elegant I'm surprised it wasn't discovered earlier.


                                                      LV = 908,000               
                                                                     MF

                        where:     LV = Lister Vibrations
                                       MF = Mass of Foundation(in grams)

  I was hoping to ask him a couple questions about my 'roid' but he was replaced by a 19 yr old belly dancer with a tiger and a dwarf before i had the chance.


                                           Gotta Run (and hide)   Bill
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #50 on: November 21, 2006, 11:47:44 PM »
Bill:

your killing me! :)

i gotta tell ya, you have some strange dreams there buddy.

too damn funny

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

Procrustes

  • Sr. Member
  • ****
  • Posts: 332
    • View Profile
Re: seeking an answer...
« Reply #51 on: November 21, 2006, 11:50:13 PM »
"An engineer could simply have decided, "That's not big enough!", and increased the spec without altering the fact that RA Lister designed the CS for use with a block.  We'll just have to agree to disagree here."

This whole thread was based on the premise that lister used a formula to determine the base dimension, now some engineer just decide it wasnt big enough?
based on what? his feelings? or the fact that the block was not big enough by a factor of 4? ... give me a break!

I never made any assertions about whether Lister used a formula.  My point has always been that you can't infer from the change in block size that the block is not part of the spec.   You stated baldly that your inference is in fact proof, but it simply isn't.

"From my admittedly small knowledge of such things, I flatly disagree.  I've not seen any industrial stationary engines mounted on anything but concrete."

i know of none either, but this does not prove the existance of some higher mathematical formula, but rather should make you wonder why there is no reference to one forthcoming if one did exist!

To my knowledge no one is looking for such a formula.  You are the one who wants it.  I have nothing to prove by presenting this to you.  RA Lister could change their block spec because of what they observed in the field, or because they changed a parameter in their formula or switched to a different formula.  None of these would alter the fact that the block is part of the spec.

"Yet again, I flatly disagree, on the basis of what I said above and also because the concrete block is plainly a part of the schematics that I've seen."

fine, then you explain mathematically the huge disparity in the 5/1 prints showing 600 lbs and the 6/1 showing the need for 2000+ lbs, given the fact that the 5/1 and the 6/1 are the same engine, and for that matter the same as the 3/1.  show me the formula to reconcile the difference!

As above, I just don't care what the formula is.

so far all you have done is regurgitate all the same stuff, you have not come up with any new or sound engineering answers, the fact that concrete has been used forever for the mounting of heavy stationary equipment does not necessarily mean that it is an intregal part of any design.

I'm not making any engineering arguments, Bob.  All I've tried to convince you of is that Lister designed the CS to work with a concrete block.  My reasoning, as you know, is not based on engineering knowledge, it's based in the schematic that RA Lister published, and the fact that all stationary engines seem to use concrete.  IMO "the fact that concrete has been used forever for the mounting of heavy stationary equipment" most certainly does mean that concrete is part of the design.

again i will state based on much research, that all of the internal stresses and vibrations of an engine are addressed and handled within proper crankcase design, lister engines are not atypical in design and show no signs of being deficient in such a way that a concrete base adds anything to their function other than a place to bolt it down to.

I'm not dissing you Bob, but I haven't a clue about your research, so I'd be naive to attach this much weight.

it is ok by me if you want to blindly accept whatever is said to you, and it is ok that we disagree on this topic, and i have no interest in changing yours or anyone elses mind.

what would be interesting though is for those that hold your side of the arguement to come up with something solid to support the claim that lister used a formula to arrive at the spec, and some proof that from an engineering standpoint the block was an intregal part of the design.  for that matter any engine, by any manufacture, same criteria!

for now i am still waiting, still reading, still looking for proof.
to date, still nada, zip, zilch, just a bunch of restatement and shuffling, and kicking sand

My side?  Maybe you think I'm in cahoots with Fawkes and that's why you keep asking me for a formula?  You'll have to ask him.  I'm agnostic about whether there's a formula.  I just don't care much about it.  My position is that RA Lister could have changed the concrete spec for any reason: formula, formula parameter, business, caprice, idiocy, you name it, and the block would still be part of the spec.  As I respect the engine, I respect the block spec.  You can call this blind trust, but that seems harsh to me.  We're all agreed on the merits of the engine design, so I have no qualms about accepting the merits of the mount designed along with the engine.

I'm not trying to prove to you what you seem to think I'm trying to prove.  My argument is this and this alone:

   1) the block is part of the spec
   2) a change in block size does not imply that the block is not part of the spec

I'm baffled that you keep asking me for a formula, and believe you've scored points because I haven't produced it.  I haven't lifted a finger trying to find this formula.

You say that concrete is a part of basically all stationary engine mounts, so IMO that means concrete is a part of the design.  Maybe it's a difference in semantics.

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #52 on: November 22, 2006, 02:08:05 AM »
Pro:

for the record, i have the utmost respect for you and for everyother soul on this board.
while i may not agree with everyone with everything, i am also cognisant of the fact that not everyone is going to agree
with me on everything, and that is a good thing.

i am not pounding on you for a formula, i am however pounding on GuyF to produce the formula as he has been the one that has stated that there was only "one" specification from lister, which clearly is not the case.

i should also state that i have deep respect for GuyF, and as he has been a time served engineer i take a harder stance with him to provide proof.

as you have stated perhaps lister used a different formula or changed the formula from the 600 lb  spec to the ton spec, and if so then there should be reference to not one formula but two. This would tend to lend credence to the fact that there was no formula by reason that both formula's seem to be lost to time, which i find a bit hard to accept.

i might also add that i too will likely mount a lister to concrete or some spec that fits my needs, as well as likely one that is mounted resiliently. in either case i will buck up and spend the bucks to get either engine balanced properly to start with.

Again i am not trying to beat you or anyone into submission, but i did start this thread asking for proof of the formula or proof of concept or any other reference to the use of a formula by lister or anyother stationary engine manufacture.

i would ask you to think of the benefit of having the "formula", with it one could put together his machine, beit a lister/generator, a lister/pump or whatever and then work out the formula to determine precisely what he needed to accomplish his ends with a measure of assurance that he is at least in the ballpark enough to have a successful installation, without having to overkill the project or worry that he hasn't done enough.

maybe i am just a wierd asshole that is fixated on details? but i have been around the block a few times and have learned that the devil truely is in the details.

i don't know about you or others, but i know me and my acheing back enough to know full well that i don't want to poor an ounce more concrete than is needed, or conversely an ounce less than what is needed and have to chop it out and do it over again.

btw,,, still waiting for a formula !
(sorry i couldn't help myself)  :)

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

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: seeking an answer...
« Reply #53 on: November 22, 2006, 02:30:16 AM »
Hi I certainly am no expert. In the old days when a hi speed engine might turn1-200rpm The builders would put the engines on something that could stand the weight. And the pull from a flatbelt drive.

Have you ever looked at a steam donkey engine mounted on a skid?

I have seen an oilfeild engine mounted on blockes of mortered stone.

Have you seen a side shaft engine with a seperate bearing support? Then you need to have a stabile mount or the engine would wear prematurely.

A faster engine (600-1000rpm) needs to have more mass to hold it down. Drive pull has to be compensated for too.

I really don't think there was a formula except for the school of hard knocks!  Then the builder might say from experience 2x the weight of the engine or what ever works.

Modern engineering practice would call for a subsoil exploration bore to determine if the ground was stabile and how much structure it would provide.  In soft marshy ground you increase the size of the concrete base  to suport even static loads. What I mean by static loads is building etc. no movement or viberation.

Dennis
« Last Edit: November 22, 2006, 02:53:36 AM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #54 on: November 22, 2006, 03:45:22 AM »
 and don't forget the environmental impact statement !

i really suspect there is a rule of thumb to arrive at sizing of a concrete base, or a range to work from based on historical or empirical results.

i could accept that,

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

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #55 on: November 22, 2006, 03:53:10 AM »
Dennis:

your assessment that the design of the concrete block having to not only support the engine but provide for side thrust for a flat belt drive makes good sense to me

and it reconciles quite nicely with the dimensions of the concrete block in the lister 5/1 drawings, and teh 3/1 drawings, in that the block in the drawing has room to mount the engine but no room to make provisions to mount anything else, so the assumption is the driven accessory being remotely mounted and belt driven would need a fairly substantial/heavy concrete base to keep the engine from creeping under belt tension.

seems plausible to me, also seems a likely explanation for a specific size and shape of the concrete block in the drawing.

from a practical standpoint that is easy to understand or conceptualize.

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

Procrustes

  • Sr. Member
  • ****
  • Posts: 332
    • View Profile
Re: seeking an answer...
« Reply #56 on: November 22, 2006, 06:41:39 AM »
Bob: shall I go home and get my fucking shine box then?

http://www.youtube.com/watch?v=W5S-H4uE0y0

I don't know if you've seen that movie, but there's another funny line: "Looks a little like somebody we know!"

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #57 on: November 22, 2006, 03:46:53 PM »
GuyF, Pro and others of the proformula camp:

Mr. Bill had a dream, and last night so did I

and it all came clear to me, there isnt a formula but there appears to be a geometric explanation to the spec's of the concrete block.

it appears to hold true for the 3/1, 5/1 and the 10/2

i need to see prints for the newer 6/1 etc where the spec changed to more concrete, to see if the same theory holds true, and then check it against other manufactures to see if it holds up.

can anyone post a similar link for the 6/1 and the 12/1?

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

Procrustes

  • Sr. Member
  • ****
  • Posts: 332
    • View Profile
Re: seeking an answer...
« Reply #58 on: November 22, 2006, 05:37:44 PM »
GuyF, Pro and others of the proformula camp:

I'll run home and fetch that shine box now, Bob.

You are joking, right?

mobile_bob

  • Administrator
  • Hero Member
  • *****
  • Posts: 2940
    • View Profile
Re: seeking an answer...
« Reply #59 on: November 22, 2006, 06:14:07 PM »
Pro:

i am serious as a heart attack!

it was never my intention to deny any possibility of a formula.  i just havent seen one

but i have a geometric answer that is plausible, and perhaps if it holds up with the prints of the later 6/1's and 12/2, (which i would not be surprised if it did) then i think i would have my answer, or at least an answer to the basic question.

don't get too excited yet, because from a geometric expression the block was not figured at the time of design or the engine,  but as an afterthought or consequence of the designof the engine.

but of course feel free to disagree :)

if you don't i am sure someone will, hell tomorrow i may even disagree with myself!

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