Model Engine Maker
Help! => Specific Engine Help => Topic started by: sbwhart on March 24, 2013, 10:47:32 AM
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Whilst serfing the net came across a free down load of a book called Steam and the Steam Engine printed in 1873, I like to check these old books for any unusual engines and came across a reference to a Ramsbottom Intermedial Engine this is all the book said about it
(http://i431.photobucket.com/albums/qq32/sbwhart/Untitled_zpseb2c9b71.jpg)
The only other reference is a description of the rotary valve, no etching, no mention of one being made nothing.
I've done a few preliminary sketches, and would like to try and find out more about this engine as Ramsbottom is a bit of a hero of mine,
so:---- IS THERE ANY ONE OUT THERE WITH ANY INFORMATION THEY CAN SHARE WITH ME.
Thanks
Stew
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Stew,
I'm throwing this out there just as an extra data point. It seems your interest here is primarily with Ramsbottom, but some time ago, I ran across an engine with a similar configuration invented by a Texan by the name of Pinkham (1885). It doesn't use a rotary valve.
Anyway, here's a link to the US patent that might be interesting to look at.
http://www.google.com/patents?id=fkhfAAAAEBAJ&pg=PA1&dq=321313&source=gbs_selected_pages&cad=2#v=onepage&q=321313&f=false (http://www.google.com/patents?id=fkhfAAAAEBAJ&pg=PA1&dq=321313&source=gbs_selected_pages&cad=2#v=onepage&q=321313&f=false)
Regards,
--Tim
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Thanks Tim
That has certainly added to my understanding of the Ramsbottm engine, its alway amazes me the wide range of different types of engines that were invented, this Pinkerton engine looks a very interesting engine just how sucessful a design it was we can only guess at.
Thanks Again
Stew
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Decided to have a go at drawing something up and came up with this
(http://i431.photobucket.com/albums/qq32/sbwhart/assydrawing_zps3bff89af.jpg)
When you break it down its quite a simple engine, the hardest part will be in fabricating the cylinder.
Stew
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Stew,
no help i'm afraid - I know there's nothing like this in daniel Kinear clark's 'a treatise on the steam engine in 4 volumes', but I did come across this similar engine, but using a slide valve here:-
http://www.gracesguide.co.uk/images/8/84/Er18600330.
on page 200
good luck with the design
peter
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Interesting designs. I see no reason why either or some combination of the two shouldn't make for a fine working model. Will look forward to following along.
Bill
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Stew
I followed your Simpson & Shipton and your Dake engine builds. This is an interesting design as well. There seems to be a trend here. If this turns out like the others, we will soon be seeing another unique model with new and challenging problems to solve. Is it a coincidence that they all have double acting pistons with the crank connected in the middle with no piston rod gland?
Jerry
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Thanks for your interest chaps.
Jerry the only coincidence is that they are all odd balls, I told my wife that I had a liking for odd balls, she replied that's not very flatering :Lol:
I've attached some pdf drawings of the design, the rotary valve in the book looked like a butterfly type design, that i think would be a SOB to make and fit, so I've come up with my own design that i think will be easyer to do.
I still have a couple of other projects ahead of the queue so it will be some time before i get to this one, but i have bought a length of thick wall tube for its cylinder.
Stew
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I like that Stew and the rotary valve per your design should simplify things as well. Just a quick question, the slot in the side of the piston seems to be 90 degrees off or am I missing something. Would seem that it should run parallel to the long axis of the piston?
Bill
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Apparently it uses a 'scotch yoke' drive for the piston rod. The drawings are not clear on this detail. A square block would be fitted to the crank pin sliding in the yoke perpendicular to the piston motion. A disadvantage to the scotch yoke is there is no way to adjust the block for wear. It appears that it would be difficult to assemble the crank and yoke system if the drive shaft extends out both sides of the engine.
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Her's a animation of a scotish yoke http://en.wikipedia.org/wiki/Scotch_yoke it shuld make thing a little clearer. I wasn't going to fit the crank in a sliding block, as i didn't think a model would need it, and it will be hiden away inside the cylinder anyway so who would know :Lol:
I keep reading scotish yoke as scotish joke:- so her's a scotish joke as told by Chick Murry, who insidently was a model engineer.
I went to see Dumbarton Rock, I wathced it all day it it never moved:- boom, boom
:lolb: :lolb: :lolb: :lolb:
Dumbarton Rock, is a large island in the river Clyde.
Stew
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Yes i understand the scotch yoke mechanism and i assume now that is the slot shown in the piston on the 2nd page of the pdf. Wouldn't there need to also be a slot running lengthwise on each side of the piston also to allow it to slip over the "shaft" ends of the crankshaft?
Bill
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Yes i understand the scotch yoke mechanism and i assume now that is the slot shown in the piston on the 2nd page of the pdf. Wouldn't there need to also be a slot running lengthwise on each side of the piston also to allow it to slip over the "shaft" ends of the crankshaft?
Bill
No the crank webs will stradle either side of the webb with the yoke slot that connects the two ends of the piston.
Stew
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Thanks Stew....sorry...it just dawned on me. I had been visualizing the piston as a cylinder with the central web as shown which isn't the case at all, just the two round ends joined by that same web....makes perfect sense now...duh :embarassed:
Bill