PatJ | 03/05/2022 06:31:47 |
![]() 367 forum posts 410 photos | I had someone send me some scans of side lever engine drawings (originals from 1840), and they were dreadful drawings, in dreadful condition. I worked on this engine last year when I had more time, and made some good progress with making accurate 3D models of many of the parts. The columns actually taper as they go up, like an ancient temple column, and so that was a challenge to get the flutes to act correctly.
Edited By PatJ on 03/05/2022 06:32:35 Edited By JasonB on 03/05/2022 07:35:07 |
PatJ | 03/05/2022 06:55:23 |
![]() 367 forum posts 410 photos | Some of the drawings were missing, and some of the drawings had incorrect information on them, so I had to fill in the missing pieces (still working on that), and correct the things that were wrong. The engine is from the Gunboat Mississippi, 1840, which had two of these engines, and sidewheels. Luckily the Mississippi engine is very close to the Pacific engine, and designed by the same individual.
Edited By PatJ on 03/05/2022 06:56:21 |
PatJ | 03/05/2022 07:12:23 |
![]() 367 forum posts 410 photos | My intent was/is to make 3D models that match the original design exactly (minus the errors that were in the original drawings). That has taken a lot of time, and a lot of discovery, and there are many subtle features in an old beam design, such as the crank pin only being fixed on one side, and have a ball on the other side that is not fixes (in case a wave hit a paddlewheel on one side, it would not shear the crank pin). I have made pretty good progress on this engine, but still have much to do.
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JasonB | 03/05/2022 07:20:43 |
![]() Moderator 22751 forum posts 2653 photos 1 articles | That layout of engine is usually called a "side lever" with beam being kept for engines where the beam is at the top. |
PatJ | 03/05/2022 07:21:27 |
![]() 367 forum posts 410 photos | A few more screen captures.
Edited By PatJ on 03/05/2022 07:28:20 |
PatJ | 03/05/2022 07:26:34 |
![]() 367 forum posts 410 photos | The first engine I recall modeling in 3D a few years ago was a barstock build of my dad's, and I recall struggling to create 3D parts for this engine. At the time, these models seemed pretty complex and challenging. With each engine that I modeled, I got better at modeling, and so you can see where things can go if you work at learning 3D. That is the challenge; make something in 3D, no matter how simple, then increase the complexity with each part that you model. Each step mastered becomes another tool in your 3D modeling toolkit. Before you know it, it is Beam Engine time !
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PatJ | 03/05/2022 07:30:40 |
![]() 367 forum posts 410 photos | Posted by JasonB on 03/05/2022 07:20:43:
That layout of engine is usually called a "side lever" with beam being kept for engines where the beam is at the top. Yes, I completely forgot about that. Such is my brain fog these days from too many work projects and too little time. Perhaps you could change the heading to "Side Lever"; I don't see an option to change that. . Edited By PatJ on 03/05/2022 07:31:47 |
Michael Gilligan | 03/05/2022 08:32:19 |
![]() 20183 forum posts 1053 photos | Posted by PatJ on 03/05/2022 06:31:47:
[…] The columns actually taper as they go up, like an ancient temple column, and so that was a challenge to get the flutes to act correctly. . Wonderful work, Pat … but your observation prompts a question Do the original columns only taper, or do they have entasis ? On a small model it would probably not be relevant [or even detectable], but at full size it might put the engine in a class above the rest. MichaelG. |
PatJ | 03/05/2022 09:04:53 |
![]() 367 forum posts 410 photos | I had to pull out the dictionary on that one. I inserted the sheet below into CAD, and made sure it was level, and then drew lines up either side of the columns. It appears that the columns have a linear taper; at least that is what it looks like to me. This is the original 1840 sheet. There is a great deal of artwork in the old engine designs.
Edited By PatJ on 03/05/2022 09:05:37 |
Michael Gilligan | 03/05/2022 09:33:58 |
![]() 20183 forum posts 1053 photos | Thanks for checking, Pat MichaelG. |
SillyOldDuffer | 03/05/2022 10:41:50 |
Moderator 8694 forum posts 1967 photos | Posted by PatJ on 03/05/2022 09:04:53:...
It appears that the columns have a linear taper; at least that is what it looks like to me. This is the original 1840 sheet. There is a great deal of artwork in the old engine designs.
Pat's thread was read as a breakfast treat here! I do enjoy engineering drawings, whether the draughtsman uses CAD or pen and paper! Pat's 1840 engine clearly imitates the architectural style of the day which was Gothic. The drawing above could almost be part of a cathedral or the Palace of Westminster, rebuilt after the original burned down in 1834: The architectural influence in Pat's 1840 drawing made me wonder where early draughtsmen came from. Before mechanical engineering drawing became a big thing, I guess technical drawing methods and skills came from architects, who would tend to transfer what they knew worked OK on buildings to engines. In the same way, early railway carriages were clearly copied from a stage-coach: Later draughtsmen would have specialised in engineering drawings from the outset and become much more savvy about practical design: efficient function, reliability, and keeping manufacturing and maintenance costs down. Pioneers have to do seriously clever stuff. We really do stand on the shoulders of giants. Dave
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PatJ | 03/05/2022 22:39:36 |
![]() 367 forum posts 410 photos | An interesting backstory on this engine design is that it was designed by Charles Copeland, who was either a contractor, or worked for the US Navy. In looking at the Mississippi drawings, I noticed an incredible gaffe, which was that the crank arms were drawn both facing the same direction. No competent engineering designer would ever make such an obvious blunder. So I assumed that this must be Copeland's first attempt at a steam engine for a Naval vessel (I think this was the first steam powered Naval vessel design for the US), and I assumed (falsely) that this would also be Copeland's last engine design, since he clearly did not know what he was doing with the Mississippi design. I found other errors in the Copeland drawings, and in general, they are good examples of very poor drafting and engineering design. Further research indicated that Copeland went on to design other ship engines, apparently very successfully, and sophisticated designs, and so I guess it was a learning process for him. And as a comparison, I found a set of French side-level engine drawings, also created in 1840, and the French drawings indicate a very refined and complete design, with exceptionally clear and concise drawings. The Mississippi engines are so close the French design that I have to suspect that Copeland researched other engine designs, and basically copied them to the best of his ability (which was very poor ability). I tend to forget how primitive engineering design and manufacturing was in the US in 1840. England was king of the world as far as industrial design in the 1800's, although the French design from 1840 is very respectable. Charles Porter mentions in his book "Engineering Reminisces" that the only way to make a decent steam engine in the US was to order all of the tooling and measuring instruments from England. To this day I still find and buy some superb products from England, such as a large paper cutter I bought recently. Manufacturing seems to have vacated the US these days, but that is another story that we won't get into. I am not up on architectural terms, but gothic seems to describe the Mississippi engine design well. It is amazing how much effort went into the cosmetics of these old engines. Later engine designs are devoid of these striking and remarkable visual features, and one has to lament that something has been lost over time. .
Edited By PatJ on 03/05/2022 22:43:04 |
PatJ | 03/05/2022 22:48:43 |
![]() 367 forum posts 410 photos | The proportions on the Mississippi engines are enormous. As I recall, the cylinder bore was 8 or 10 feet. The engines were said to be slow moving and reliable, and would function well even when in worn condition. The Mississippi had a very successful sailing career, and I guess set the stage for steam Naval power in the US. As I understand it, Copeland basically took a large sailing vessel, and shoehorned two large engines and associated boilers and coal bunkers into it. The fit is rather tight. As I understand it, many in the US Navy were against steam power, because while they did not object to being shot and killed by cannon fire, being scalded/burned alive by boiling water and steam was a bridge too far. . Edited By PatJ on 03/05/2022 22:52:31 |
SillyOldDuffer | 04/05/2022 08:32:21 |
Moderator 8694 forum posts 1967 photos | Posted by PatJ on 03/05/2022 22:48:43: ... As I understand it, many in the US Navy were against steam power, because while they did not object to being shot and killed by cannon fire, being scalded/burned alive by boiling water and steam was a bridge too far. ... My bedtime reading at the moment is the 'Personal Memoirs of U S Grant', who mentions: 'My regiment lost four commissioned officers, all senior to me, by steamboat explosions during the Mexican war. The Mexicans were not so discriminating. They sometimes picked off my juniors.' After the Mexican War of 1846-1848 the US acquired California, New Mexico and Texas. Dave |
Tim Stevens | 05/05/2022 20:50:37 |
![]() 1598 forum posts | Interesting. I think there is another reason for the first railway carriages to look just like road carriages. This is the problem of public acceptance. People will not travel on or in, or purchase, or have in the drives (etc) a vehicle which is totally unfamiliar. Look at the electric cars we are blessed with today. Even those which are not spitting images of standard models have dummy radiators. Perhaps the best example I know is the Suzuki wankel-engined motorcycle of the late 1970s. The designers had fun with it, making it obviously new, and related to a rotary engine, with spherical lamps and flashers etc. As a style exercise, bang on - but Joe Public did not like it at all. In six months it was toned down to look much more like the bikes were knew, and people bought them. Remember that the first railway carriages had to appeal, not 'merely' to the travelling public, but to the railway shareholders - not the most adventurous folk ... Cheers, Tim |
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