Frisbie

[PaulR]

A couple of decades ago I came across this toy engine and a descendant of the designer very kindly sent me copies of the incomplete original drawings. I've always fancied building something with a similar mechanism (without potential for shrapnel wounds from the safety-valve-free boiler!) but I have to admit I don't quite understand it. I think the double acting cylinder is fixed, taking steam directly from the boiler below, and the 'valve plate' rocks to exhaust steam - sort of a negative version of a wobbler!

What's confusing me is the valve rod guide, surely that can't be a close-fitting hole... can it??

I've collected photos of several examples from auction sites which I can post but I can't post the original drawings.

[crueby]

Neat looking engine!  I would say that guide hole is loose fit since the rod rocks, so does the plate at its end.

[Kim]

That IS a fascinating (if somewhat scary) engine.  Very interesting!

Kim

[CI]

My dad built that Frisbie replica in the top photo.
Dad's was a barstock build.
Unfortunately he gave it away to some unknown party, so I just have a few photos.

There was an article in Live Steam magazine about a cast Frisbie.
I will see if I can find that.
Perhaps I can post a piece of that article.

I recall looking at the photos, and not really understanding how it worked myself.

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[CI]

1st Part was in Live Steam, March/April, 1999, by Birk Peterson.
Part 4 was Nov/Dec, 1999.

Here is a sample from that article.

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[CI]

I discovered that they also made vertical Frisbies ("vertical" probably not being the correct term").

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[CI]

Here are the sketches that my dad came up with for his Frisbie.
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[CI]

A few more of dad's photos.
I guess the cylinder is bolted solid, and the plate rotates.
Steam must come up from the boiler somehow to the steam ports.

Edit:
Looks like there is a steam passage drilled upwards from the boiler into the cylinder support, and a horizontal passage connecting the two lower ports.
So the upper ports would be exhaust ports.

The boiler needs a safety valve on it somewhere, even if it is just a toy boiler (in my opinion).

It does seem like the hole in the guide for the valve rod would need to be relieved; sort of like drill the hole, and then tilt the drill bit up and down.
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[PaulR]

My dad built that Frisbie replica in the top photo.
Dad's was a barstock build.
Unfortunately he gave it away to some unknown party, so I just have a few photos.

There was an article in Live Steam magazine about a cast Frisbie.
I will see if I can find that.
Perhaps I can post a piece of that article.

I recall looking at the photos, and not really understanding how it worked myself.

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Thanks for all the photos, drawings and info, that's much clearer now! Yes, there was a Frisbie #1 and #2.

Seems it's as I thought, a wobbler with a moving valve plate instead of an oscillating cylinder. I suppose a slot would serve to guide the rod rather than an oddly shaped hole? EDIT: No, that obviously wouldn't work as it's acting as a fulcrum 

I built a miniature wobbler mounted on top of a tiny boiler and that has no safety valve but after seeing this photo of what looks like a Frisbie blown up, I think I'll just admire it as a static display piece in future!!

[CI]

When I was growing up, I had basically no parental supervision, and so when I was five, I fired up my brother's Wilesco steam plant, and ran it until it went dry.
The solder gave way first at the whistle, which I guess is what saved me.
I somehow saw the steam coming at me, and closed my eyes just before it hit.
I got scalded, but was otherwise ok.

My brother's Wilescos had a safety valve, but nothing to prevent low water, and no water gauge.
One of the later Wilescos I saw had a glass end on the boiler.

I did all sorts of dangerous things as a kid, and I am not sure why I am still on this earth.
We broke open light switches to get the mercury, and would play around with it all day.
We played with the asbestos sheet that my dad had in the shop; cutting it and making things from it.
We would wander up to the railroad tracks, and play around as the trains passed, putting pennies on the tracks.
They were building an expressway nearby, and we would climb down into unsupported excavations that were at least 20 feet deep, with a vertical wall.
We climbed down into the deep holes that were excavated in the street to repair pipes, and they were never supported.
We climbed down in the stormwater pipes around the neighborhood, and built forts, and also used them for transportation, since they crossed under roadways, etc.
The list goes on.....as I mentioned, I have no idea why I survived my childhood.
The parents would call us home when the sun went down, and always asked "were you safe today?".
LOL, they would have had a heart attack if they only knew.  We were professional liars.

I complain a lot about what I consider excessive OSHA rules these days, mainly because some of the safety gear is so combersome as to be dangerous, but OSHA has saved a lot of people, especially with those large plastic mushroom caps that are required on the ends of rebar in trenches, and similar things.

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[PaulR]

I did all sorts of dangerous things as a kid, and I am not sure why I am still on this earth...

I did pretty much all of those too and others...

Jumping on and off flat wagons as trains pulled away from signals, shooting television CRTs and railway detonators, lots of what they now call 'wild swimming' in dirty and dangerous waters, plugging home made electrical circuits into the mains, building tree-houses at ridiculous heights, playing on the nearby motorway during construction and taking dumper trucks for a spin, and electrocuting myself on a lamp-post into which a car had crashed on the first day of the school holidays! I guess the biggest fib I told my parents was as an 11 year old when I said I'd been down the lane playing all day when I'd actually been in the engine shed at Bristol railway station about 100 miles from home!

[Admiral_dk]

The Wobler (Cylinder + Spring) is the Safety-Valve in itself !!!

Any chance this arrangement work somewhat similar ?

But it should have the Soft-Solder Safety too - for when running dry ...!!!

Would LOVE to see a proper drawing of the Valve-system, where you can see the Steampassages too ....

Per             

[PaulR]

I found this picture showing the large channel for steam to leave the boiler.

Maybe it joins the threaded part that secures the engine to the boiler 'lid'?

[Jasonb]

I'll have to have a closer look a bit later.

But on a couple of engines I have made where a rod needs to be able to pivot it a hole then it is first drilled to close to the rod size and then either side tapered, this can be done with a taper reamer (angle to suit how much rod movement there is) or for something like this quite possibly just come in from each side with a ctr drill.

As Admiral says if the pressure gets too high in the boiler then th evalve simply lifts off teh port face, same as the cylinder lifts off on a wobbler.

[CI]

My mother-in-law had a pressure cooker she used frequently, and the safety valve clogged with a bit of meat.
Blew the lid off, and blew stew all over the ceiling.
Luckily she was not standing immediately next to it when the lid came off, and luckily the side did not give out like Mt. St. Helen.

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[PaulR]

Blew the lid off, and blew stew all over the ceiling.

Turned meat into dripping!
(Not sure how well that joke travels, maybe 'dripping' is a UK-only thing?)

[CI]

As they use to say in the 60's, "It was a bad scene man......".

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[CI]

This is my guess on how it is arranged.
I would think that the pivoting valve would have vertical slots on the cylinder side, with the height of the slots being the distance between the lower steam port and the port that goes into the cylinder.

The port on the top of the valve is a thru-hole, which is the exhaust, and it would also have a vertical slot facing the cylinder.
Steam ports (on the port face) are the ones at the bottom.

There would have to be some careful drilling horizontally, vertically, and at an angle, through the cylinder support member, to get the steam passage routed back to the boiler.
The ends of these drilled holes, except at the boiler, would have to be plugged.

Edit:
Looking at the port face with the pivoting valve removed, you would see two holes going into the cylinder, and two round steam ports.
Looking into the inside face of the pivoting valve, you would see two upper through-holes, with slots protruding down from these two holes, and then on the lower side of the valve, two more slots that don't connect to anything, and are on the inside face of the valve only.

Edit2:
Looks like my dad silver-soldered a plate on top the boiler, and drilled the lower horizontal steam passage in it, and then drilled/extended the passage at an angle into the boiler.
The cylinder appears to bolt on, I guess so it can be final machined prior to being installed, without having to turn it while it is attached to the boiler.
The vertical steam passage upwards from the silver-soldered plate into the cylinder wall would have to be sealed (the joint between the cylinder and the plate sealed).
Another horizontal steam passage is drilled into the wall of the cylinder, and then the two lower ports drilled into this passage at 90 degrees.
The end of this upper passage would be plugged.
Then drill holes into either end of the cylinder.

For the port face of the valve, machine four shallow slots, and then drill through on the top two slots.

Can anybody follow this explanation?
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[CI]

Looks like the holes in the cylinder don't go straight in, but rather there are passaged drilled from either end, with a cut into the end of the cylinder.

Looks like the slots on the inside of the pivoting valve were milled on the rotary table.

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[Jasonb]

Pat, where are you seeing these steam ports mentioned in your first edit?

Looking at the broken engine I can see three holes and a central pivot pin.

Assuming the two holes higher up go to each end of the cylinder then the third would have to be the steam supply

Most photos of these engines show the pivoting valve plate to be quite thick so that would allow for some slots to be cut into it's face, the exception being the second photo in the first post.

I think I have it working in a hand sketch, will check it later in CAD to be sure, easier if teh third steam supply hole was central

[Jasonb]

So here is my thinking based on the three holes that can be seen in the port face of the broken engine's cylinder.

The cylinder is grey

The three holes Red

The valve the green/blue I have shown the lower "passage slot" going all the way through for clarity, in reality it would be only half depth. needs a bit of tweaking to get the holes lined up better but shows the principal.

First image is when the valve is in the mid position, two ports to the cylinder ends closed and steam from below only going into the void of the slot.

Second photo The valve at full travel. Steam can now travel along the recess to the left end of the cylinder pushing the piston to the right where the used steam can exit through the right hand hole in the valve.

Third Photo. The valve at it's other extream of travel steam going in on the right and out on the left

[uuu]

This is my guess on how it is arranged....

Can anybody follow this explanation?
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Yes - that arrangement was my reading of the position.

[Admiral_dk]

Thank you both - very logical solution .... and as Jasons would be the cheapest to make - that one is probably the one used 

Per         

[CI]

I am throwing out guesses.
I don't have a good understanding of it.
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[Admiral_dk]

Does it help if I say that in Jasons illustrations there is only hole all the way through @ the two small holes on top - the rest is an internal passage milled / cast into the Valve.

The top Pic shows no connection from the big Inlet hole (Steam into the Valve) to any of the Ports - nor from the Ports to the Exhaust holes (the two small ones).

Second Pic shows the Steam Inlet connected to the Left Port and the Right Port to the Right Exhaust hole => Piston moving to the Right side.

Third Pic shows the Steam Inlet connected to the Right Port and the Left Port to the Left Exhaust hole => Piston moving Left.

[PaulR]

Thanks for all the replies, glad it's proving of interest - I need time to digest the answers! However, if it requires fancy drilling or slot cutting it'll probably be off the menu for my next engine.

[Jasonb]

Assuming you will not be trying to recreate an exact replica of the engine and just want to try a different valve system then it is not hard to simplify the basic geometry. That was why I just did straight slots and a hole that could be done with just a lathe and an endmill held in the chuck (yes I did that when I started out)

The passages in the cylinder would be no more than holes drilled straight into the face and joining ones drilled straight in from the end and edge. Even bring the air in from above so it is easy to connect the compressor to and leaves the bottom face for mounting to the frame.

If the third inlet hole was placed centrally then the recess on the inside face of the valve can be simplified even more.

[Jasonb]

In an idle moment yesterday evening I had a bit more of a play with this one, looks like it would work.

[PaulR]

In an idle moment yesterday evening I had a bit more of a play with this one, looks like it would work.

Thanks for this. I'll try to understand how it works over the next few days!