The Bucket Foundry

[ken seeber]

[QUOTE=Frits Overmars;1130944909]M6 sounds a bit feeble to me.

The situation is that the M6 will, in fact, be screwed permanently into the boss of the cylinder so the actuation will be external of the waterways.
As the cylinder head (spigotted into the cylinder and the same diameter as the piston) will be stationary, supported by the water jacket, the sliding cylinder will not see any direct combustion forces. However it will see:
1. The axial component of the piston face and ring friction forces
2. Crankcase pressure variations acting on the relatively large cylinder base diameter
3. Cooling water pressure
Hopefully these are all small and time averaged to be close to zero.

As to the actuation, there are a couple of sources of friction to consider:
1. 3 off O rings surrounding the exh passage outlets
2. The large cylinder base O ring
3. The O ring and piston ring in the cyl head

Will just have to wait until it is all assembled for the first time to see what axial force is required to overcome all the above. However, for the first runs it can be simply be done with spanners over nuts on a long thread connected to the M6. There is a thought that, when operating, all the relatively high frequency fluctuating and reversing forces might act favourably to break the stiction allow the cylinder to be easily moved in either direction.

I know the M6 is possibly feeble (not so in a Swiss watch though) so time will tell with all the unknowns yet to rear their heads. Space is tight in this design format.
If the mechanism shits itself, then we'll just lock it up into fixed positions and still be able to conduct some meaningful testing.

Currently, 37 C with Monday/Tuesday going to 42+. Just can't wait. Makes the 40C coolant temp into the engine from the radiator seem a tad difficult.

[Frits Overmars]

With no backlash allowable,(using an adjustable double nut) - how about ballscrews?
Hang on a minute, this is all beginning to sound positively sadistic - that was unintentional by the way!

Your sudden sensitivity fits in nicely with a certain quote in another Kiwi-thread:

I can still get a leg over, unfortunately not over the seat of a racing bike!

Currently, 37 C with Monday/Tuesday going to 42+. Just can't wait.

You sadist. It just stopped snowing here.

[F5 Dave]

Crumbs, we're getting close to 30 during the days, met it the day before, can't sleep. Maybe I'll stop bitching.

[Flettner]

Frit's, you must be a little bit excited to see what happens with this experiment, I know I am. Throttleable transfers!

[Frits Overmars]

Frit's, you must be a little bit excited to see what happens with this experiment, I know I am. Throttleable transfers!

We both are. I had a hunch you were up to something like this after our 'comma-transfers' discussion went quiet and it dawned on me when I saw your castings in October. But do you think your cylinder will be able to move up and down quickly enough to make a throttle redundant? It might turn out to be fly-off by wire .

[ken seeber]

But do you think your cylinder will be able to move up and down quickly enough to make a throttle redundant?.

Frits, speed of actuation would be an issue in real life, but not so for a slave test cylinder such as this. Obviously there are lots of things going on with this version, axial scavenging, tri exh ports, large crankcase volume, etc, etc. If it can go from a 2 stroke 2 stroke idle up to a reasonable output then good, with a wide powerband in between then sweet. Like lots of things, if some basic principle shows promise, then one will try hard to get around the shortcomings, in this case, a responsive actuation system.
Obviously, one does not need to limit oneself to the existing scavenging design, so a much lower friction level for a more conventional sliding cylinder sealing system could be introduced.
Who knows? Jeez, if one thinks too hard about making a perfect design, nothing would ever get made.

[Frits Overmars]

Jeez, if one thinks too hard about making a perfect design, nothing would ever get made.

This deserves a place on the wall of fame.

[seattle smitty]

Academic economists have a running joke on themselves about this process: "Oh sure, that's how it works in real life . . . but how does it work in theory??"

[Frits Overmars]

..........

[seattle smitty]

(Darn, not again! However you, and others, are posting that, I never can get this computer (Win 10.1) to read it).

Henry Kissinger said the same thing as the economists, but from another angle (you have to remember his deep growling voice): "It was such a beautiful theory . . . and in this case it had the added advantage of being true!"

[Frits Overmars]

Darn, not again! However you, and others, are posting that, I never can get this computer (Win 10.1) to read it.

I have a hunch as to what the problem could be Smitty. Below are three picture formats: PNG, JPG and GIF. Can you see all of them?

[husaberg]

(Darn, not again! However you, and others, are posting that, I never can get this computer (Win 10.1) to read it).

Henry Kissinger said the same thing as the economists, but from another angle (you have to remember his deep growling voice): "It was such a beautiful theory . . . and in this case it had the added advantage of being true!"

Yes Smitty windows 10 is the same for me I just right click on the PNG and open it. Or conversely save it and look at it there.

Maybe frits has another work around?

[seattle smitty]

I can see all three, Frits, but left-clicking doesn't open any of them. However Husaberg's right-click did the trick with your previously unopenable post, AAHHHH!!!

Increasing age is supposed to mellow us out, but personal computers have increased my profanity to levels that would have horrified my poor mother. There was an expression in this country, easily a hundred years old but now disappearing in our regrettable modern age, in which something reliable "Runs like a Swiss watch!!" Every computer I've owned runs like a cheap Chinese knock-off. Hiccups and farts, endless glitches, hours of work vaporized beyond recall. Is it supposed to be irrelevant that a Swiss watch was AN ENTIRELY MECHANICAL DEVICE??? The nerds love to load these miserable computers with hundreds of FEATURES!, lah-di-dah, which they assume are as exciting to us as to them, where what I want would be stripped and SIMPLE. Now these same nerds want to fill our roads with computer-driven cars (and our airspace with drones). They imagine they reassure us by saying that the car-driving computers are comparatively simple. Right. A fly-by-wire throttle is even simpler, yet one that was put into production by one of the world's best carmakers killed several people before being recalled, while the carmaker scratched its head in searching for a cause.

Computers!!! I never really appreciated the expression, "a love/hate relationship" until I got a computer.

(Sorry, TeeZee, and I promise I'm going to come back and delete this gratuitous rant, but for the moment I want to vent!)

[TZ350]

(Sorry, TeeZee, and I promise I'm going to come back and delete this gratuitous rant, but for the moment I want to vent!)

Vent away, fill your boots, I am happy, this is the Foundry thread started by Yow Ling ......

[Flettner]

I can see all three, Frits, but left-clicking doesn't open any of them. However Husaberg's right-click did the trick with your previously unopenable post, AAHHHH!!!

Increasing age is supposed to mellow us out, but personal computers have increased my profanity to levels that would have horrified my poor mother. There was an expression in this country, easily a hundred years old but now disappearing in our regrettable modern age, in which something reliable "Runs like a Swiss watch!!" Every computer I've owned runs like a cheap Chinese knock-off. Hiccups and farts, endless glitches, hours of work vaporized beyond recall. Is it supposed to be irrelevant that a Swiss watch was AN ENTIRELY MECHANICAL DEVICE??? The nerds love to load these miserable computers with hundreds of FEATURES!, lah-di-dah, which they assume are as exciting to us as to them, where what I want would be stripped and SIMPLE. Now these same nerds want to fill our roads with computer-driven cars (and our airspace with drones). They imagine they reassure us by saying that the car-driving computers are comparatively simple. Right. A fly-by-wire throttle is even simpler, yet one that was put into production by one of the world's best carmakers killed several people before being recalled, while the carmaker scratched its head in searching for a cause.

Computers!!! I never really appreciated the expression, "a love/hate relationship" until I got a computer.

(Sorry, TeeZee, and I promise I'm going to come back and delete this gratuitous rant, but for the moment I want to vent!)

Computers, HA HA, work of the devil I say (waving my pitch fork around), I hate the bloddy things, but I need them CNC and all that, you know.