Shop Kinks 1918 Style

Reid · Shop Kinks 1918 Style

roll your own smokestack, mister?

Reid

Source: Making the Small Shop Profitable
http://books.google.com/books?id=...i=qefiR6LxE5G0yQSdlZTRBA#PPP11,M1
(free downloadable book)

Reid

Oiling systems

I suggested in another thread that James Petts might consider centrifugal oiling.

This that is shown is nearly but not quite what I had in mind.
but it will get the principle across (or I'll find another image)

http://books.google.com/books?id=...ler&ei=l-riR9a6II-KzQS9qYzTBA
----
The shafts of the USS Orion, a WWII submarine tender I served on years ago,
were about 30 inches in diameter.
They were supported at intervals in great, oil-filled bearing boxes, and had ring oilers.

Such bearings and oiling systems are about eternal in life span.
Smaller shafts can do equally well with wick oilers, also automatic in operation.

Here is a wick oiler to be seen in this video:

jamespetts

An extremely interesting video - thank you for showing that

The oiling information is interesting, too, but I cannot immediately see how to apply that to a Stuart Score, which is both small and has double-sided cranks (the piston connecting rod being placed between two cranks each connected to the crankshaft, which runs the length of the engine, and protrudes on both sides). Perhaps I am just being dim...?

Reid

It may not be practical, James, but then again, centrifugal oiling of the crank throws could be a boon,
and sling oil far and wide automatically (grin).
Can you give me an image, drawing or something of the crankshaft?
Let's get on the same terms: I consider that a con rod big end is put on the crank, the throw
(crank and throw being the same thing, I mean),
and the crank/s is/are located located most usually along the length of a crank shaft.

Got a picture? I want to see more and then make a guess as to the feasibility of centrifugal oiling.

Reid

Wallace

Very interesting posts reid.

Thanks for sharing

Reid

Thank you Andrew!

me: Goal!

Say, let's all look for tips and tricks to share,
either our own, or from old books or old friends,
and put them here. Word to John/bogstandard
in most particular, of course!

---
Thanks again Andrew/Wallace.
Say, I can't go on saying that screen name of "Wallace"; see,

I had a pet hamster once
and it was named Wallace, Andrew.
Ergo I would much rather call you Andrew only.
I thank you to allow me this honour:
to address you as Andrew-Only sir!

Wallace

You can't call me Andrew. Makes me feel like I'm in trouble

Anyways, back to your thread as I don't want to head off topic

The thread is making great reading

jamespetts

Reid,

I'm having a slightly better idea of what you mean now (and the thought of doing something like that had already crossed my mind, but I had dismissed it at the time as impractical because of the solid cranks/throws). I am having difficulties in imagining just how to get the drilling out of the cranks right (and then the sealing up of the holes - I don't want big blobs of putty visible on the engine!), and also of how to connect the static oiler feed line to the rotating crankshaft, especially on such a small scale.

If it's of any help, here are some detailed pictures of the Score's crankshaft:

Does that assist at all?

johnreid

I noticed that there is an oiling port on my Fleischmann on the connecting rod at the crankshaft. Just an observation.

Reid

Your Fleishmann, John, shows how much nicer the detailing was on toy engines made many years ago.
The oil hole on the Fleishmann is also seen on the Wilesco products of today.
It's more decorative than useful, for a drop of oil applied anywhere on either side of any bearing area
will instantly wet the entire bearing.
These open oil holes are not of actual utility, therefore,
and only offer one more place for dust and dirt to settle,
and for fresh oil applied to those holes, to fly out from
(hardly important points considering the gross nature of things in reality).

Nick

My Marklin windmill even has one:

Reid

The exampled windmill makes a better illustration of the -useful- sort of oil hole;
the oil hole that is handy for the case where access to either of the two bearing ends is less than handy;
here, if there were no oil hole,
then the oil necessarily applied to the blade end
or to the pulley end, would be untidy and inconvenient to apply neatly.

In your Marklin there is even the opportunity to have designed a hollow (non-bearing) area
in the trunnion (center) of the bearing housing, and pack that loosely with cotton or wool waste,
and so retain oil for years and years at a time.
We can't do that with the sort of joint that JohnReid's Fleishmann shows.
We can do oil-retention to a practical degree with my own engine's recently installed silent cloth bushing system;
for the cloth which is the bearing is also the oil retainer.

However, I doubt that James hankers to ream out his bearing boxes for bits of woolen cloth bushings;
a system not yet proven perfect to the world,
though in my own mind the silent cloth bushing is quite without fault.

Old electric motors generally used some sort of oil reservoir area of that nature,
filled with loose waste, and so were "wick fed" and did retain oil well enough and for long terms.

Now to James's crank...
provisional thoughts about drilling for an oil supply dynamically sent to the throws by centrifugal pressure of the running.

(and here, because I am getting into 'can and should it be done' territory, expertise of actual experience is solicited)
Am quite sure it can be done. Holes are mandatory for the plan,
however, quite small holes, less than half a mm; a quarter mm or even less, would be just fine and sufficient,
and so the plugged ends of these holes, plugged with grey epoxy, would hardly constitute a noticeable marring

Reid

James' Stuart Shaft Wants Crank Oilers
a conundrum also entitled in 17th cent. style as:

How the Hollow Peg Leg'd Fellow Imbibes,
and So Seems to Hold His Liquor Well,
Excepting for those Leaks Designed
Into His Pipes By His Creator

Presentation of the stage play later to-day,
though it is the Author's fond wish that every Viewer
of this Broadside, should ,
instead of waiting for the Presentation,
instead crack the simple nut of the Plot in advance
without the Author's further ado.

Les

Was looking at the EKT accessories, and they have oilers as well.

jamespetts

Reid,

thank you again for your replies (and poem!). You might be right about the hole sizes, but the question remains: where exactly would I drill them such that the inner hollow of the middle part of the crankshaft (to which, presumably, via another hole, oil would be fed from the existing oiler cup designed to oil the bearing around that part of the crankshaft) would link with the holes drilled in the otherwise solid cranks? If the holes in the cranks were drilled in the middle of the cranks, they would not connect to the hollow in the crankshaft: conversely, if the holes were drilled at the very edges of the cranks such that it would touch the crankshaft's hollow, it would not be a hole so much as a semicircular indentation on the outside of the crank, which would, for obvious reasons, not serve its purpose. Or am I missing something obvious...?

Reid

All these toy oilers are fine and convenient and look well. That said,

James' need & want is for assured oiling of the crank throws of his costly new engine,
which he is setting up for non-stop running, to power a computer.

It is impossible to oil crank throws whilst they are whirring about.
It is possible to oil crankshaft main bearings whilst running.

It is possible to capitalize on the hollow Stuart crankshaft composite construction,
and by drilling just a few tiny holes, and by plugging the outboard ends of the crankshaft,
and by installing drip-feed oilers in place of the present oil cups at the two outboard ends,
to thereby send oil at a metered rate to both the outboard main bearings,
and also to the crank throws.
The left side drip oiler would feed the left crank throw.
The right side drip oiler would feed the right crank throw.
There will be oil leakage and oil throwing, but this will be limited to the metering rate: a drop a minute would be plenty of supply.
The main bearings will of course waste some oil, leakage out their sides,
leakage that won't go to feed the hard-working crank throws.

If the oil entry of the oiler into the upper half of the main bearing brass
intersects with a small hole drilled into the hollow Stuart shaft,
then oil will gradually fill that section of the shaft.
Now, from there, one small hole drilled into the solid crank throw, right angle to the shafting,,,
and then make a two more small holes as are needed
to make a communication,
and at last, plug the open ends of the Stuart cranks.

If I were making one of these engines up I would for my own preference,
simply fit woolen bushings and be done with the entire mess of
oilers and forever-thrown oil splatter.

James' third alternative is to do what he does not wish to do:
stop the engine at inconvenient intervals to re-oil manually the crank throws.
That's what the makers expect of the user:
they give oil cups for the bearings that need very little re-oiling,
but no oil cups are possible or practical for the bearings (the crank throws) which most need oiling!

So something should be done if such an engine is to be in constant operation.
That's what James is working for; it's why he wants a scheme of some sort.

jamespetts

Reid,

thank you for that - that explains things much more clearly. Unfortunately, I have just discovered that the crankshafts are not hollow after all, and that those holes at the end only go in a centimetre or so before the crankshaft is solid all the way through...

Reid

jamespetts

Reid

Cedge

Uhhh.... Reid...
Have you ever tried drilling .5 mm holes into cast iron or cold roll steel of any depth? It's not something the average bear would want to try. Very high RPM and a steady but very gentle touch are required... and you're still quite likely to wind up with a broken bit in the end of the crank shaft. Holes that small are known for putting even experienced machinists into cold sweats and fits of rage.

The "dimples" in the ends of the crankshaft are there because it was turned between centers on a lathe. The dimple was added to give the tail stock a purchase, allowing it to steady the one piece shaft during turning. Without the dimple, the thinned metal would flex under the pressure of the cut, giving it an unwanted taper.

Tricky bit of machining, but a single piece crankshaft is a pretty good indicator of a skilled builder and a quality build.

Steve

toxx

Les

Reid

jamespetts

Perhaps a solution involving drilling, not the crank, but the front end of the connecting rod assembly, and affixing to that some sort of lidded oiler cup? But where would I find a lidded oiler cup of the right thread and dimensions...?

johnreid

I think that the right oil is important too, I can see evidence that the oiler, not lidded, on the crank of my Fleischmann is doing its job.

Cedge

Reid
Lubricating the small hand made engines is more critical than the toy engines, as they tend to be made to tighter tolerances, however they are also good at retaining oil once you've given them a dose. The oiler cups, both drip and wick type are quite effective and they match the technology used in the portrayed era, which is the main point of building them to begin with.

Could your idea be done? Probably, although the journals would need to be quite tiny and natural oil viscosity could easily defeat their effectiveness. Would I do it to one of mine?... not likely. Keeping these engine true to their real world roots is where their value lies. The more accurate the rendition is to the original real world engine, the higher the value. You'd be amazed to see some of the engines where even the nuts and bolts have been hand turned and threaded to perfect scale, by old guys wearing multiple jeweler loupes.

Scale is pretty much king in the land of hand machined casting engines. Stock metal builders tend to get away with a bit more as long as everything looks proportional.

Steve

Cedge

Reid
Lubricating the small hand made engines is more critical than the toy engines, as they tend to be made to tighter tolerances, however they are also good at retaining oil once you've given them a dose. The oiler cups, both drip and wick type are quite effective and they match the technology used in the portrayed era, which is the main point of building them to begin with.

Could your idea be done? Probably, although the journals would need to be quite tiny and natural oil viscosity could easily defeat their effectiveness. Would I do it to one of mine?... not likely. Keeping these engine true to their real world roots is where their value lies. The more accurate the rendition is to the original real world engine, the higher the value. You'd be amazed to see some of the engines where even the nuts and bolts have been hand turned and threaded to perfect scale, by old guys wearing multiple jeweler loupes.

Scale is pretty much king in the land of hand machined casting engines. Stock metal builders tend to get away with a bit more as long as everything looks proportional.

Steve

Reid

I copy you on that Steve and do not disagree at all.

In the real world of scale speeds James could fit an oil cup feed to the crank throws.

But these won't work on a model engine as his, running the crank throws
at the entirely non-scale speed of 2,000 rpm; centrifugal forces would empty any oil cup and disable the action of any sight glass oiler.

And he's going to be working the engine at that 2,000 rpm.
So he needs truly positive lubrication.

If I had such a project at hand that would be run continuously at high speed, I'd not only have precision fitting bearings of course,
but a constant feed oiler (a drop a minute would suffice)
becomes a need, perhaps.

James might worry about this somewhat likely need for positive oiling later on after the plant runs.

True, some oil will keep in the bearing for a long long while.
But will it be clean oil by fifteen minutes in?
Or will it be oil blackened by the brass rubbings, which become wear-inducers in themselves, and will lap not only the brass, but the steel.

It's that he's running this model engine at IC engine speeds and scale loads, that begs for a steady oiling of the crank throws.
The mains, of course are no worry at all. They don't get the punishment nor do they suffer the centrifugal forces throwing oil off into space.

The solution then if James does not want to drill the crank is to fit miniature grease cups or simply inject grease of suitable quality into the present oil holes, and do that upon every running.

Think of small IC engines of the open crankcase, say, hit and miss type:
they run at low rpms but the actual surface speeds of the bearings are probably higher by far than James' engine at 2k rpm.
Those engines have crank throws lubed by grease cups;
babbitt liners or bronze and grease cups.
And they last well if given proper attention.

Cedge

As a practical matter you've effectively solved a non existent problem. A small steam engine is not going to run for such sustained periods at 2K RPM as to do it damage, unless someone actually wants to do it damage. Either the fuel source or the water supply will run out before the engine runs the cups or journals dry. With viscosity comes adherence which means the two moving parts will retain some oil. An operator who knowingly runs an engine dry shouldn't have access to one anyway.

As an aside... a wick style oiler will ignore the forces of motion and continue to draw oil to the joint, as needed, via the natural capillary action of the wicking material.

Theory is a fine thing, as far as it goes, but advocating a theory as fact when it's only proven in your own fertile mind is just plain wrong. New guys can read this fluff and puffery and make the mistake of thinking you've proven your hypothesis under real world conditions and might do damage to an engine. When you've spent a bit of hands on time with these more complex and rather expensive engines, you can then share the benefit of your practical experience. It's a huge technical jump from Wilesco D class engines to the smallest of Stuarts.

Steve

Reid

Cedge

Two words... "sealed bearings". Forced oil at 2K rpm is going to become one very messy aerosol mist ,due to the same forces you're trying to overcome. Low friction, high speed sealed bearings are the way to go.

Steve

Reid

jamespetts

Thank you both for your replies

This is indeed a somewhat complicated topic, and I note that you disagree somewhat about how to proceed. Steve, I do intend to run the engine at high speeds for relatively extended intervals (the idea is to turn a dynamo to power a small, low-power computer), but, obviously, I do not want the oiler cups to run dry, and would have to suspend the computer and stop the engine if and when they did.

The official Stuart specifications list the Score as having a maximum power output of 75W when running at 60psi (the maximum pressure of my boiler, a Stuart 504) and 2,000rpm. My calculations as to the amount of electricity that I will be able to generate are based on that as a maximum output, and then adjusted downwards to take account of the fact that the dynamo is far less than 100% efficient, and the fact that the engine will not be running quite at peak speed all the time (my calculations are based on 80-85% of peak engine power output, a dynamo with 65% efficiency, and a computer power supply with the rated 94% efficiency).

There seem to have been a total of three lubrication suggestions so far: (1) centrifugal oiling by drilling the crankshaft and cranks; (2) wick lubricators; and (3) grease-cups.

As to (1), efficient as the idea would be if it worked, it seems that, especially as the hard steel crankshaft is not already hollow, it would probably be far too difficult for me with my limited model engineering skills to drill it accurately.

As to (2) and (3), both of those ideas seem plausible (requiring only a little drilling of the brass connecting rod part of the big end bearing: I have seen Stuarts with this done to them running happily, or in photographs), but they both depend on me being able to find the requisite lidded cups of either type (grease or oil).

I will not need that sort of lubrication straight away, as I do not have the dynamo yet, and, once I install a new sight-glass in the boiler to replace the previous one that was too short and leaked, and connect all the drain cocks to my sump tank with pipes, I will be testing the engine in steam, but under somewhat less demanding conditions.

Thank you again both for your replies

Do either of you know where I might find lidded wicked oiler cups or grease cups with a thread small enough to fit in a hole that I could readily drill and tap in the brass connecting rod ends?

Reid

I wish you'd told me at the very beginning when I asked for any and all about the crank,
that it is hardened steel. Gosh, that changes everything.
Are you sure it's hardened?
I would intuit that it is not hardened, that crank; is it silver soldered together?

James, sir: if you're spinning at 2k rpm you really don't want to add oil cups of any size nor weight nor grease cups even, unless they are truly doll-sized toy things.

Calculate the added centrifugal forces? I don't know how to do that.

Wick oilers accomplish what cloth bushings do as a matter of course.
I would have no reason to re-oil my D21 bearings in the course of many hours of running;
in fact, I do not have to re-oil them at all even after hours of long running.

If someday this technology becomes seen for what it is:
a problem solver, then perhaps someday someone else who is bold
will do an engine with properly fitted flange cloth bearings and see the fact:

when we scale down to doll-house sized stuff we do not need the brute and nasty resistance of conventional steel and bronze bearings.

In fact, I could make these woolen bushings work identically well in large, full-size machines.

The soundest conservative smartest easiest thing is to not fit grease cups.
You'd have to stop the engine to turn the cup caps anyway.
Might as well have a fitting grease gun.
This grease approach would run you for some time (tbd) and not add yet more imbalanced weight the engine, not if you forget the notion of what would only be a seeming convenience of grease cups
that won't extend your run times one bit, only sort of ease, maybe,
the between-run greasings, and add that weight and complication,

eh.

And I would like to learn more about "capped oil cups".
If wicked, yes, interesting, and they do actually feed at two thousand rpm on those rotating centers: capillarity vs. centrifugal force of that magnitude?

?

I'm so intrigued by all these things, have no practical experience,
but put two and three together and get 1.74. or 1.75.

Cedge

James
An open crank engine is not going to be the ideal choice for your project. Lubrication is going to be a problem on any open crank design. The best of all worlds would find you using a wet sump engine like the Stuart "Sun" or "Sirrus" engines. They are enclosed crank engines with an oil sump. These were used in WWII to power radios parachuted to the underground resistance groups.

These little engines are high RPM rated and became quite popular for powering small model hydroplanes at high speeds. I have a bar stock version that will rev up to some pretty incredible levels. I've been planning to let the engine go at some point. PM me if you have an interest.

Steve