Author Topic: SPEED CONTROL  (Read 20267 times)

Copybell

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SPEED CONTROL
« on: April 08, 2006, 01:33:41 AM »
Guys,
   I have a Satyajeet brand 20/1 engine running at 510 R.P.M. coupled to a 15KW ST type generator head.  I would like to have better speed control than I am able to get using the stock governor.  I am thinking about something along these lines:  A sensor to sense the flywheel speed coupled to a computer which would adjust a linear actuator or servo mechanism coupled to the fuel rack.  Does anyone know of a company that has 'plug and play' components that can accomplish this?  Or, has anyone built a system using readily available components that would be kind enough to share with the board?  The system I have outlined seems very complicated to me, if someone knows how to accomplish the same goal with less complexity, please advise.

Best regards,
Copybell
Omega brand 6/1
Fuking brand 6/1
Satyajeet brand 20/1
Mini Petter

Jim Mc

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Re: SPEED CONTROL
« Reply #1 on: April 08, 2006, 04:32:00 AM »
Oh, come on now.  Computer controlled linear actuators??? That ain't right on a Listeroid.

First, how is the regulation now?  Why do anything at all?  May be that you're fixing a problem that doesn't exist.  Say the speed droops from 62 Hz at no load to 58 at full load.  Who cares?  I can't think of a typical domestic load that would have trouble with that.

More droop than that?  I'm guessing you may need a longer, weaker governer spring.  Not sure what the rated speed on that engine is, but I suspect it was considerably higher than 510 rpm.  If you've not fiddled around with different springs, that's the first place to start.





hotater

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Re: SPEED CONTROL
« Reply #2 on: April 08, 2006, 04:45:57 PM »
Copybell---

It sounds like you have the wick turned so far down the governor weights are the wrong weight to control it.  The governors are designed to be optimum at a given speed, usually a couple hundred higher than you're running.  As it is now the weights are trying to balance against the return spring at a place in their rotation that's unstable and hard to hold.

  You would need to add weight to the governor to stabalize at the lower rpm.  One way to do that is drill each weight and epoxy tight fitting plug(s) of tungsten carbide in the hole.  Carbide is about 17 times heavier than cast iron.

I thought about casting lead in the holes as a cure, too.   Pre-heat, flux and pour.  It should make a weight that won't loosen up or come apart, but I'd put the hole(s) where centrifical force doesn't have an effect.

I don't know how to calculate what's needed for what rpm and trial and error would be hard work.
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

Jim Mc

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Re: SPEED CONTROL
« Reply #3 on: April 08, 2006, 07:00:47 PM »
Carbide is about 17 times heavier than cast iron.


Huh?  Carbide may be dense, but no way is it 17 times that of cast iron. 

It'll be a heck of a lot less effort to work on the spring first.  Lower speed needs a weaker spring.  Worked on my Listeroid just fine...

hotater

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Re: SPEED CONTROL
« Reply #4 on: April 08, 2006, 11:23:14 PM »
You're right!  Slightly more than twice.  Iron = 7850 kg per cubic meter.  (water = 1000).  Tungsten is 7850 and lead is 11340.  :-\

The leverage and mechanical advantages change with the position of the weights.  The greatest force with least movement is at the 'sweet spot' where balance is achieved.  Changing to a lighter spring will govern the engine but at the expense of stability, especially the important transition between lots of load and suddenly no load.  Weak  or mismatched springs  can cause a run a way under those conditions.

I've found that one run a way triples the mechanic's caution level.   :o :o
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

kyradawg

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Re: SPEED CONTROL
« Reply #5 on: April 10, 2006, 03:41:04 AM »

Peace&Love :D, Darren
« Last Edit: August 03, 2006, 05:24:42 AM by kyradawg »

Doug

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Re: SPEED CONTROL
« Reply #6 on: April 11, 2006, 03:14:26 AM »
Ouch thats going to be some mind bendingly expensive stuff.

I used to buy and sell surplus automation equipment as well as parts sensors and related geewizzery.
You could for a song buy a Modicon 984 compact, assorted parts down load the free software from Schiender electric and hobble together something crude to work with the factory govenor...
This also holds the promiss of monitoring other functions as overtemp, low fuel ect.
Programing is bear unless your a fast self learner or take a night course at a community college.

Ar this time I am not selling anything here. In the past too many people have bought stuff from me at sweet heart deals and not used it as promissed in their non Listeroid projects.


Here's a good example of a 1500 + controller when new going for less than dirt (I have some of these nice little units)

http://cgi.ebay.com/LIKE-NEW-MODICON-SCHNEIDER-AUTOMATION-I-O-UNITS_W0QQitemZ7608099821QQcategoryZ97184QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/Modicon-984-145-with-I-O_W0QQitemZ7607675397QQcategoryZ97184QQssPageNameZWDVWQQrdZ1QQcmdZViewItem




Last time I saw one of thee for sale it was stolen property from my employer. The guy never got caught.

http://cgi.ebay.com/AEG-MODICON-BRIDGE-PLUS-NW-BP85-002-MODBUS-PLUS_W0QQitemZ7607000895QQcategoryZ97184QQrdZ1QQcmdZViewItem

Worth about 2000 CDN new




Doug

listeroidsusa

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Re: SPEED CONTROL
« Reply #7 on: April 11, 2006, 03:40:12 AM »
All these bring back old memories! I remember the old modicons, mako 4's and mako 5's from the late 70's and early 80's. My company sent me to school on these when I was working as an electronics tech about the time these were first used in plastic injection molding machines. Back then all machines ran on relays, and would have 4 to 6 panels full. Solid state logic cards reduced it to 2 panels. After the first "plc's" were installed they still had all of the panels, but all but one was empty! It was amazing that all of the logic instructions were contained in that one "brick"! They were huge compared to what we have today but back then these were a marvel of engineering! Today, a pico or nano plc contains more instruction sets than all of those old panels together and fits in the palm of your hand. With plc's, if you can imagine it, there is a way to do it!

Mike Montieth
Listeroids/USA

kyradawg

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Re: SPEED CONTROL
« Reply #8 on: April 11, 2006, 06:43:53 PM »


Peace&Love :D, Darren
« Last Edit: August 03, 2006, 05:24:12 AM by kyradawg »

snail

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Re: SPEED CONTROL
« Reply #9 on: April 12, 2006, 01:19:54 AM »
G'Day all,
          At 3am this morning I was lying awake thinking about lister governors.How sad is that? No wonder my wife just shakes her head and walks away... ;)
          Allow me to pontificate. This may not be correct and I'm certainly open to correction but there must be something in this.
         Imagine a lister with big holes around the governer weights.With the spring removed, reach into the (Stationary ;D) motor and move the governor weights outward to simulate increasing speed . What happens (Obviously ::) is that the injector rack moves "in" to reduce the fuel. As there appears to be a sweet spot in the movement of the weights, this must correspond to a given rack position.We are fortunate(?) on our engines that we have miles of external linkage to play with. Would it be possible to vary the length of the linkage so that the weights are in their optimum position for the usual load.The spring would then be modified/adjusted to give the correct RPM.
        My thoughts(guesses ;) on this were sparked by the fact that the Lister L(petrol) version was rated at anywhere between 450 and 650 RPM without changing the governor weights.I don't know if any of this is of any practical use but it's just my 2c worth(and of course we all know that 2c Australian is worth less than 2c US! ;)

Cheers,

Brian

listeroidsusa

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Re: SPEED CONTROL
« Reply #10 on: April 12, 2006, 03:18:52 AM »
YES!!! the linkage length is critical. There are two items that come into play, centrifugal force increases with the rpm, AND the effective travel of the governor changes with the rpm. Imagine a pendulum. The length of the pendulum has a lot to do with the travel, but we can't adjust this in a Lister. What happens is at low speeds the governor pendulum is at rest near the centerline of the pendulum. As speed increases it does not take much to effect a large movement of the linkage as the weights fly outward. As speed increases the pendulum weight flies outward in proportion to the speed, however, the movement is much less as the speed increases. (the weights rise a lesser amount in height than they do at slower speeds) All of this is compounded by the fact that increased speed results in more centrifugal force, along with the resulting change in height of the pendulum weights. These 2 factors, working together, is what determines the sweet spot, which will be different even on similar engines. Shortening the linkage rod too much will result in hunting, (the weights are biased toward the lower portion of the height-arc) while longer linkage will result in a lazy governor regulation. Turn your clevis in or out 1/2 turn at a time to find your "sweet spot". My GM-90 holds within 1/10 of one cycle within its load range with this method. Heavy starting loads do change the rpm slightly, about 2 hz., but it quickly recovers without overshoot or hunting.

Mike Montieth
Listeroids/USA

Doug

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Re: SPEED CONTROL
« Reply #11 on: April 12, 2006, 04:24:56 AM »
This happens in the Onan CK and CCK engines too, and many others I suspect.

Doug

Tom

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Re: SPEED CONTROL
« Reply #12 on: April 12, 2006, 04:24:04 PM »
Hello Mike,

I've read the same info that you've posed before and done some experimenting with the linkage on my engine and never found the spot where it hunted. What I did find is that if the clevis is set to far out I won't get full rack and with it too short I can't lift the shut off lever. However at either extreme no hunting. Since I am certain that you probably know what you are doing  ;) do you think there might be a problem in my governor system and if so where should I look. Mine currently is a bit lazy and I have a bigger fluctuation in voltage then I would like between full and no load.

Also thanks for sharing info here and good luck with the EPA stuff.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 3k hours.

listeroidsusa

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Re: SPEED CONTROL
« Reply #13 on: April 12, 2006, 05:57:40 PM »
I personally have not worked on an ashmawaugh (spelling?) but if you are not getting the results then I'd think the most likely scenario is the lack of governor weight or that models geometry. I've been studying up on steam engine governors lately. They were developed to a high state before their eventual demise. I'm considering building an external flyball governor based on the steam engine principles to see just how far I can take it. I'll drive it off of the end of the camshaft and rework the governor linkage to suit it. I won't have time to fool with it until school is out next month.

Mike Montieth

sid

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Re: SPEED CONTROL
« Reply #14 on: April 13, 2006, 01:21:23 AM »
mike// your idea sounds interesting with the fly ball governor//I meet a man in portland indiana that takes an b/s engine and modifies it and put a brass flyball governor on itand turns it in to a hit and miss engine/ he takes a $100.00 junker engine and when he finishes with it sells it for $1400/ he has a waiting list for them/ when he finishes with them you could not tell they are a briggs and stratton/ I will see if i can find a picture of one of them// by the way /// how are you able to ship so cheap thru the mail// I know that 40 lb pully that you sent me was less than 10.00// let me in on your secret//sid
15 hp fairbanks morris1932/1923 meadows mill
8 hp stover 1923
8 hp lg lister
1932 c.s bell hammer mill
4 hp witte 1917
5 hp des jardin 1926
3 hp mini petters
2hp hercules 1924
1 1/2 briggs.etc