Author Topic: Governor weights out... need more weight ?  (Read 5745 times)

38ac

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Re: Governor weights out... need more weight ?
« Reply #15 on: January 29, 2018, 01:36:16 PM »
Edee, I used to think that also  (thus it must be sound reasoning  ;D),, but I have since found that my sample of engines was too small and my standards of  "reasonable" governing were a bit lax.  Lister chose to change the weights at some point and one would have to assume there was sound reasoning behind it. I have two parts books, one shows same part number for 500, 650 and 800 RPM weights and another shows 500, 650 being same weight and 800 being different. I did not have a set of 800 RPM weights handy to weigh but those 1000 RPM weights look lighter yet??   

Been playing around with my 8/1 KOEL and the 16/2 DES, a box of springs and two sets of weights  and gathering information to maybe do another FAQ type thread (rant?) What  I have found with the weights is the heavier set gives decent governing down to 400 RPM or so but below that the governor gets lazy no matter the spring, above 750 it takes a LOT of spring. The 800 RPM weights will give decent governing at 600 but anything less than that the governor gets pretty lazy.If those 1000 RPM weights are lighter yet than Lister 800 RPM weights I can see his problem arising.   Another factor is due to all the extra linkage and resulting friction and slop  the twin governor does not respond as well as a single.  It seems that the further you get out of the sweet pot for the weights the more particular the governor is about the spring used.  As I have said many times, and you just said also,  the lightest and longest spring that gives the required RPM without causing the governor to hunt will give the best response, period. That doesn't mean you will have good response in all RPMs with any set of weights, what it means is it willbe as good as it can be with that particular set of weights.
  I saw a 6/1 running in an Amish powerhouse that did not have a spring, but a lever with some weight hung on it.  The owner saw me looking it over and said, a spring changes as you stretch it, the weight stays the same through the movement. It was working is all I can say, LOL

I guess the bottom line for this post is once a person has adjusted the linkage properly, eliminated slop and bind and tried a few springs  the next step is changing the weights.
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EdDee

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Re: Governor weights out... need more weight ?
« Reply #16 on: January 29, 2018, 03:47:22 PM »
Hi 38,

By and large, agreed... but one thing that is generally overlooked is the length (number of coils) of the spring.... To give a rather oversimplified example, a little imagination is required, so here goes....

Imagine a spring of infinite length, ie the little bit of stretch that the governor linkage gives it, causes little to no increase in tension over the governor arm travel.... The motor starts and speeds up, the rack being held open by the spring... as the weights give enough force to overcome the spring, they fly outwards, but the spring tension doesn't increase noticeably as there is little increase in its length ratio....ie it is still resisting the pull of the governor with pretty much the same force as it started with.... now we need to look inside the governor at the weights for a moment... they started held close to the camshaft, but are now some distance from it as they have overcome the spring tension... As their displacement from center increases, so does their "pull" on the spring...but the spring has the same amount of force on it as when it started, so the governor weights fly out a little more, and continue doing so, until they max out their travel and as such, have closed the rack (hopefully) fully.... The engine starts to wind down but the governor weights will continue to overcome the spring, until it is well below the revs you are aiming at... The cycle then starts again, ad infinitum....

But, if the spring is unreasonably short (few to no coils), the increasing tension in the spring overcomes the governor weights before they can fly out and throttle back on the rack, causing overspeed.... To alleviate this, one would think that by simply giving the system a bit of slack on the spring would solve it....Not so. if there is no "residual" or "start" tension to pull the rack to a reasonable semblance of fully open to get maximum power...

I found, for best performance on the few units I have played with over the last few decades, stick with the longest springs possible to get the beast to your required level of governing needed...

800 RPM weights were probably made a bit lighter to allow for the same governor springs to be used. Would you be so kind as to check your books to see if the governor springs were of similar nature across the range, just for interests' sake....

With a bit of playing about to verify the above info, I have, in the past, been able to successfully govern the beasts way lower than their intended rpm, granted, due to low rpm they are a tad "lazy" to take up load, but this I ascribe more to the fact that when turning slowly at around 250 to 350 rpm, load can be applied a damn side quicker than the inertia of the flywheels can sustain, hence a rapid sag and a slow recovery...but hey, lets not get too deep in here!!

About the Amish unit... that could work, but its a crap shoot, constant force on the governor arm, relying on forces changing due to a "geometry change" as the weights on the governor fly outwards around their hinge pin...Whichever way you look at it, the weights would have to only work above the centerline of their hinge pins to give a reasonable semblance of regulation ...

Still though, the the biggest problems that I have noted so far, are binding and secondarily wear or slop on the linkage.... with too much slop, the pump wont respond snappily, and likewise with binding...

To overcome the crappy fit and finish of the Indian CS's I have put very weak springs on the racks of the IP's, effectively getting round the sloppy fit that is sometimes "required" to prevent the binding... One of my units has it on the "Pull to open" side, the other has it on the "Pull to close" side, they work the same performance wise, but one will survive a little better should a linkage fail... Incidentally, both were 1000rpm units that I have governed down to 750 and 650rpm respectively.... They both hold frequency to within about  1 to 1.5hz (If I remember correctly)....

Enough of my bs...

Cheers
Ed
« Last Edit: January 29, 2018, 03:50:17 PM by EdDee »
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32 coupe

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Re: Governor weights out... need more weight ?
« Reply #17 on: January 29, 2018, 04:50:34 PM »

I feel confident in my setup. No slop, no binding.
I did not try a longer spring but did thinlk about it.
If the new weights don't do the trick I will go that direction.

I went to the trouble of taking it apart so I will not put it back
together without changing the weights.

I tried a handful of springs and spent 2 days playing with it.

I will post results.

Gary




After that I am convinced it is the weights.

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38ac

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Re: Governor weights out... need more weight ?
« Reply #18 on: February 02, 2018, 12:10:15 PM »
Hi 38,

By and large, agreed... but one thing that is generally overlooked is the length (number of coils) of the spring.... To give a rather oversimplified example, a little imagination is required, so here goes....
Cheers
Ed

" As I have said many times, and you just said also,  the lightest and longest spring that gives the required RPM without causing the governor to hunt will give the best response, period. "

I think we agreed on that also,  ;D

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dieselgman

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Re: Governor weights out... need more weight ?
« Reply #19 on: February 02, 2018, 04:10:38 PM »
003-00167 governor weight - .5lb

From stock 6/1 cam assembly - .5lb

I think I need to find a much better scale. The above readings are from our 400# capacity shipping scale... apparently not sensitive or accurate at the low end of scale.

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Re: Governor weights out... need more weight ?
« Reply #20 on: February 02, 2018, 04:12:27 PM »
Gary,
Get your foot off the scale ! :laugh:
Gary
Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"

dieselgman

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Re: Governor weights out... need more weight ?
« Reply #21 on: February 02, 2018, 04:16:40 PM »
Yep... I have a 400# shipping scale and a 100g gold scale, nothing in between handy here.

dieselgman
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Re: Governor weights out... need more weight ?
« Reply #22 on: February 11, 2018, 05:37:53 PM »
Received the new weights thanks to Gary.

They only weigh about 1 ounce more than the stock weights. Stock comes in
at 9.7 and the replacements are 10.5 ounces.

The new ones will need some attention as the surfaces that ride on the  governor
sleeve are quite rough with one side being not finished at all as compared to the
stock set.

I would like to get started on it but my back has been giving me some problems the last
week or so.

I will report on progress as soon as I am able.

New on the left, original on the right.


Gary


« Last Edit: February 11, 2018, 05:40:26 PM by 32 coupe »
Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"