phil_barber
Member
Hi, I'm a retired engineer from Yorkshire.
See also...
philbarber2.wordpress.com
See also...
philbarber2.wordpress.com
Hello from Yorkshire
- Thread starter phil_barber
- Start date
Help Support Home Model Engine Machinist Forum:
Welcome Phil, glad to have you here.
I browsed your website.
So many interesting topics; control loop analysis, pattern making, castings, electrical, etc.
Just chocked full of good experimentation.
I have studied the Porter governor, and I believe it was one of the first isochronous steam engine governors (check me on that).
An interesting study with its free-spinning central weight, and small spinning weights at a high rpm; said to be dead-on accurate.
I remember well the lesson in controls class about the importance of keeping your roots on the correct side of the S-plane to keep the feedback loop stable.
LOL, I forget now which side of the S-plane you want to avoid, but I recall the importance if it.
What are your model engine building plans for 2024 ?
Pat J
.
I browsed your website.
So many interesting topics; control loop analysis, pattern making, castings, electrical, etc.
Just chocked full of good experimentation.
I have studied the Porter governor, and I believe it was one of the first isochronous steam engine governors (check me on that).
An interesting study with its free-spinning central weight, and small spinning weights at a high rpm; said to be dead-on accurate.
I remember well the lesson in controls class about the importance of keeping your roots on the correct side of the S-plane to keep the feedback loop stable.
LOL, I forget now which side of the S-plane you want to avoid, but I recall the importance if it.
What are your model engine building plans for 2024 ?
Pat J
.
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phil_barber
Member
... hmmm, never heard of a Porter governor, seems like a development of Watt's with an extra weight, which would further compound the failure mode! Any solely proportional feedback controller will have a negative speed vs load characteristic so will not be 'dead on accurate'. ... In Manchester science museum, there used to be a mechanical PID on the mill engine, but that has gone now. ... and its the real roots you want to avoid, on the RHS
Yes, it was indeed an accurate governor design (the Porter governor).
I guess the term "accurate" is subjective, depending on what you compare it to.
My term "dead-on accurate" unfortunately has no meaning, so poor choice of words there.
At any rate, welcome to the forum.
Some steam engine governor information at this link:
https://www.homemodelenginemachinist.com/threads/steam-engine-governor-types.36393/#post-416287
.
I guess the term "accurate" is subjective, depending on what you compare it to.
My term "dead-on accurate" unfortunately has no meaning, so poor choice of words there.
At any rate, welcome to the forum.
Some steam engine governor information at this link:
https://www.homemodelenginemachinist.com/threads/steam-engine-governor-types.36393/#post-416287
.
Last edited:
Welcome to the forum!
Hi Phil
I’m also in Yorkshire (Ripon) but less retired engineer more learning as I go! I do have a tech background though and like you (I looked at your website) enjoy fixing things and diving into projects.
Cheers
Chris
kf2qd
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I would think that the function of the governor would also be heavily affected by the mass of the engine and it's load. A lighter engine with a lighter load would be much more responsive to changes in the governor setting, and thus more prone to more noticeable oscilations in speed. A heavier engine and load would have more resistance (inertia) and thus would be easier to govern. On the other hand, a motor with a variable load would present a whole different set of problems, and a motor connected to a load that goes from driven to driving would present a whole new batch of issues.
I would think that the valve design would be a major part of the design of any governor, and a non-linear taper would yield better results.
I would think that the valve design would be a major part of the design of any governor, and a non-linear taper would yield better results.
phil_barber
Member
Indeed, the mathematics of the dynamic response of an inertive engine are well understood. A science in itself. You may be interested in a demo of this :
https://philbarber2.wordpress.com/2024/04/10/the-destabilising-effects-of-feedback/
As for regenerative braking,
phil_barber
Member
Ripon is a fine place. I take it you are familiar with the 2' gauge by the canal.
I am indeed
rklopp
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There's excellent Mexican food in Ripon. Oh wait, that's Ripon, California, USA. I wonder whether the California Ripon is named after the Yorkshire Ripon. What is Ripon, UK famous for? Ripon, California is an old Central Valley farming town turning into sprawling housing developments along Highway 99.
