Resources/Information for Crank Lubrication?

A special section just for steam engines and boilers, as without these you may as well fit a sail.
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Re: Resources/Information for Crank Lubrication?

Post by cyberbadger » Fri Mar 23, 2018 3:11 am

For what it is worth, the Toledo is an interesting bridging technology steam engine that was designed to operate with 2 closed crank cases filled with straight mineral SAE30. My 1902 Toledo did not come with the covers and I run it open with Green Velvet PB&J 220. And I will say, at this point I'm not 100% happy with my current situation with the crank lubrication on my Toledo as I mentioned it's very sticky and it gathers grime.

My Toledo definitely has that preference for running direction - don't know if left the factory that way. I made Ahead the preference for my right handed prop. I only use the Astern engine direction sparingly during docking manuvers - so I don't care if it runs rough in that direction.

The Toledo literature details some design choices that they made (or some might say were promoting) that might be an interesting comparison for some...
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Toledo Engine
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-CB
Lionel Connell
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Re: Resources/Information for Crank Lubrication?

Post by Lionel Connell » Fri Mar 23, 2018 4:01 am

Where might I go from here?
Mike. For a boat, only forward really matters.

Put the engine in full forward gear and check that the inlet steam is opening at the same point for both ends of the cylinder. This can be done by using compressed air. Open the drains, apply low pressure air to the steam chest, rotate the engine by hand and note the point that air starts to come out of the drains. Continue to rotate the engine and note the point when air stops coming out of the drains. Do this for both ends of the cylinder. You now know the inlet and cut off timing. If you have a piston valve engine the same test can be done for the exhaust timing by blowing air into the exhaust outlet and you will know the exhaust opening and closing time. Compare the results for each end of cylinder and you will see how well the events are in balance. Then close the expansion link to say 50% and take all of the measurements again. If you find that the balance between one end of the cylinder and the other is out by more than 10% of the stroke length for any of the events then there is free power to be found by improving things. Railway practice in the later years was to work toward a tolerance of 1% of stroke length for valve event accuracy, efficiency statistics over known journeys proved that 2% of inaccuracy could be detected in the quantities of fuel and water used for those journeys.

Holding a lit candle next to the drains can assist in checking the timing, as sometimes hearing or feeling the air coming out of the drains can be difficult. Be careful not to use too great an air supply or your engine may decide to start up.

I forgot to add that it is better to work in stroke length rather that degrees of crankshaft rotation, this way that angularity change between one end of the stoke and the other do not complicate the results.

Lionel
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Re: Resources/Information for Crank Lubrication?

Post by Lionel Connell » Fri Mar 23, 2018 6:00 am

Code: Select all

Just remember she's your baby and it doesn't bother you when she cries."
Too True. My problem is that it bothers me if she cries, it bothers me even more if other people hear her cry, and most of all it bothers me if my one is crying while others are humming. We are all different.

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Re: Resources/Information for Crank Lubrication?

Post by fredrosse » Fri Mar 23, 2018 10:20 am

"Who would have thought... Anything you post on an internet forum really is just an opinion and a conversation and nothing more.... "

CB, sorry I have to differ with you on that statement. There are opinions for many things, and in some cases there are technical facts, and in many cases, especially around machinery, identification of facts vs. opinions often occurs in engineering, and is very relevant!

In my opinion, a most easy way to directly post a picture, I think it needs to be in a file size under 100k, but most of my boat/machinery postings look OK when saved on my picture software at this low resolution.

If you want to directly post a picture on this forum without any hosting, you scroll down to the "Upload attachment" section, "Choose File", add a caption if you wish, then "Add the file". You can preview your post to see how it looks, and resample it to a smaller physical size if it is too big for the computer monitor. Finally click "Submit", and there it is.
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Re: Resources/Information for Crank Lubrication?

Post by cyberbadger » Fri Mar 23, 2018 3:11 pm

fredrosse wrote:CB, sorry I have to differ with you on that statement. There are opinions for many things, and in some cases there are technical facts, and in many cases, especially around machinery, identification of facts vs. opinions often occurs in engineering, and is very relevant!
Of course you would disagree because you are an authority to some and don't want to give up any authority you think you already have. :D

It's great when we can talk about facts and not opinions - but this forum is not quite always a venue of100% engineering facts. Someone can post on this forum with facts and simulations, but if Fred doesn't agree it can't possibly be true....

-CB
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Re: Resources/Information for Crank Lubrication?

Post by fredrosse » Fri Mar 23, 2018 5:28 pm

"Of course you would disagree because you are an authority to some and don't want to give up any authority you think you already have."

What are you saying, what does "...don't want to give up any authority you think you already have." mean? I deal in engineering facts first and foremost, they are frequently not a matter of opinion, just engineering applied with an established knowledge of thermodynamics, heat and mass transfer, stress analysis, mathematics, etc. Many of these things are long established facts, not up for discussion as to their validity. When I can contribute to the forum in this vein, it can build knowledge. What on earth does "not wanting to give up any authority" have to do with this?

"....but this forum is not quite always a venue of100% engineering facts. Someone can post on this forum with facts and simulations, but if Fred doesn't agree it can't possibly be true...."

You have misunderstood many of my inputs to this forum if that is what you think. Many technical points involve my opinions, and I try to identify them as such, not as absolute truths. But very often I do not agree because I know that certain facts are not up for discussion as to their validity, or truth. 1 + 1 = 2, that is what I know to be truth, not up for discussion on that one.
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Re: Resources/Information for Crank Lubrication?

Post by cyberbadger » Fri Mar 23, 2018 9:00 pm

fredrosse wrote: You have misunderstood many of my inputs to this forum if that is what you think.

I'll buy that. :)
fredrosse wrote: Many technical points involve my opinions, and I try to identify them as such, not as absolute truths. But very often I do not agree because I know that certain facts are not up for discussion as to their validity, or truth. 1 + 1 = 2, that is what I know to be truth, not up for discussion on that one.
The more transparent that line is the better because you often seem to be filling a role of moderator.

When Lionell brought up all the work on his simulations and then there was disagreement I was quick to draw comparisons to when I have presented simulations and basically got told - your simulation is wrong. I get really grumpy when I see folks present what appears to be reasonable evidence and they just get told that their evidence is wrong.

-CB
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Re: Resources/Information for Crank Lubrication?

Post by DetroiTug » Fri Mar 23, 2018 11:14 pm

When someone posts their personal empirical evidence and claims any other way it's being done is "wrong" because their simulation says so, it's going to prompt spirited conversation. I'm not convinced that the placement of the suspension arms other than on center is necessarily wrong, because it was done that way by designers over the years and if it was imperative that it be on center, not so many well trained engineers and designers would have deviated from that. And too, it's a well known fact that most patent drawings submitted are not exactly as the finished product, they are merely to secure license on a concept, they aren't working drawings, several old patent drawings covering steam controls etc wouldn't even work as drawn. I think was done to prevent people stealing their ideas by unscrupulous patent attorneys.

As a machinist of many years, starting out working with hand-drawn three-views made by professional engineers and draftsman that knew what they were doing (worked their way up the ranks to designer) all the way through to the modern day, fresh out of community college "Cad operators", I can attest it hasn't gotten better. I'm a bit prejudice against computer generated evidence, it's only as accurate as the information provided. The old adage "on paper, an elephant can fly" applies.

Timing a steam engine on the bench on air or in a computer simulation and freewheeling will get it close, but it's not going to be optimal. The only way to truly set engine timing is on a prony brake under load and under steam. Case in point, my Locomobile engine with factory set and keyed eccentrics does not run well on the bench, it's really choppy, wants to kick back at the top of the stroke - because the eccentrics are set advanced for load. It runs as smooth as silk under the car. Find one of those engines and play with it, you'll see what I'm talking about, I think there are YouTube videos of those engines that show it. And it isn't because it doesn't have a flywheel, I set the twin in the boat with no flywheel to run smooth and it did, I have it set advanced now in forward and not so aggressive in reverse. As I stated earlier, the difference in torque is stark.

-Ron
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Re: Resources/Information for Crank Lubrication?

Post by marinesteam » Sat Mar 24, 2018 1:59 am

In theory, there is no difference between practice and theory. In practice, there is.”
Yogi Berra

It's quite true. CAD and simulations are quite good for many things. I do CAD simulations on high speed machinery and there are still areas that we need to apply our own experience, a bit of fudge factor and sometimes just luck as there are some things that CAD just doesn't get quite get right. It's not so much that there is any problem or inaccuracy with the digital data, it's more that it doesn't truly represent the inaccuracies found in the real world.

You can go crazy chasing "Perfect" with CAD/simulations just to find out the due to the vagaries of the real world you're no better off than if you had stopped at "good enough"

Cheers

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Re: Resources/Information for Crank Lubrication?

Post by Lionel Connell » Sat Mar 24, 2018 3:09 am

When someone posts their personal empirical evidence and claims any other way it's being done is "wrong" because their simulation says so, it's going to prompt spirited conversation. I'm not convinced that the placement of the suspension arms other than on center is necessarily wrong, because it was done that way by designers over the years and if it was imperative that it be on center, not so many well trained engineers and designers would have deviated from that. And too, it's a well known fact that most patent drawings submitted are not exactly as the finished product, they are merely to secure license on a concept, they aren't working drawings, several old patent drawings covering steam controls etc wouldn't even work as drawn. I think was done to prevent people stealing their ideas by unscrupulous patent attorneys.
I am sorry, but the method that is prescribed in the patent is the protected IP, period. Yes the drawings are not the finished drawing because the inventor needs to apply for the patent before too many people find out, at which point it becomes in jeopardy of being claimed as "prior public knowledge" But the wording of the patent is set in concrete. It is that wording and sketched detail that is used in court to fight off would be offenders. Yes, it is a fact that some companies created (create) patents to use as a smoke screen for their competitors, but it is a very expensive process of deception, and rather frowned upon in industy.

Firstly it should be noted that less than 1% of patented ideas ever make enough profit to pay for the filing and licensing fees. This is because an idea does NOT need to be a good idea in order to qualify for a patent, it just needs to be an ORIGINAL idea. When a company not only makes a profit from using the patented idea in their own product or service, but many other companies around the world pay big money to the patent owner for license to use that same technology on their product or service as well, then that is a technology who's method is not easily surpassed. It is a technology that has been studied by many other engineers and mathematicians, scientists etc. who have confirmed that the technology not only works, but that it is worth the investment of their company's owners, rather than the company investing to find a way around the patent. Stephenson's gear is one such technology, that is why we all know the name.

It is not just a bunch of links that work together regardless of their position and length!

The components of Stephenson's gear work together to make an extraordinary motion take place. If you take a look at the mathematics that it takes to explain the motion you will realize that what you are saying about suspending the link form the end being an option that can be changed without destroying the way the motion works is just ( I am sorry to say it) fantasy. It is rather like saying that you can have a circle where the radius can be varied in various places around the circle but the line never changes in distance from the center. A circle by any other equation is just not a circle.

The mathematical equations that I have for Stephenson's gear is the work of D.L.Ashton and I can't quote it here as it is not my work, you have to purchase his book. For anybody who wishes to truly understand and not guess in the dark about how Stephenson's gear actually works, it is a great investment.

If you do purchase the book, and you do have the patience to work through it, you will understand that what I am saying cannot be argued, it is pure mathematics. For Stephenson's gear to work in the magical way that it does, the expansion link must absolutely be suspended in the center and the suspension pin offset distance must be precise and matched to the eccentric timing, laps of the valve, rod lengths etc. For which there is a mathematical formula that works precisely. If the expansion link is suspended from the end, there will be errors in the valve timing and those errors will be physically measurable and have a measurable effect on the overall performance, economy and longevity of the engine. This is not an opinion, it is a mathematical fact that has been well discussed and explained on a number of other forums, including ones that deal with the restoration of full sized locomotives.

It is a free world, you have the choice of believing what you like, and if you choose to believe that the mathematics tells lies or is somehow confused that is your prerogative. Engineers often disagree, but the disagreements between engineers that are working together to solve a common problem are usually resolved by the mathematics. I have offered you a source of information that would enable you to calculate for yourself which of us is correct. I too found during my research that Stephenson's method or similar had been applied differently between quite a few manufacturers and I made a concerted effort to determine the truth using mathematics, not by trying to balance a collection of opinions. That We are not enemies, just people of like interest and our research has bought us to different sides of this particular debate, which I think is unfortunate for us both.

Lionel
Last edited by Lionel Connell on Sat Mar 24, 2018 6:48 am, edited 1 time in total.
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