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Messages - veggie

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1
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: April 24, 2025, 02:47:47 PM »
Here is what I am currently planning.
Hardwood beams resting on a 1" rubber mat.
The system will not be anchored to the concrete but will be held in location by steel "bumpers" (red) which will be bolted to the concrete floor. The rubber mat seems have the correct natural frequency for this type of weight and vibration.
All experimental at this point so I accept that this may not work.

<click image to enlarge>

2
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: April 24, 2025, 02:41:20 PM »
R Forrester,

Very interesting, and useful info.
Thanks for posting that.

3
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 27, 2025, 04:06:02 PM »

Another item to muddy these discussions is that some engines have cast iron pistons and some have aluminum pistons. Throwing a cast iron piston up and down 10 times per second is a lot of reversing force to tame compared to an aluminum version at 1/2 the weight. This may be why some users have bigger issues than others.

4
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 27, 2025, 03:39:46 PM »
The only reason for a big slab of concrete is if you'd like to raise the engine for ease of service.  Or you have failed to understand 38ac's simple method.  It's brilliant.

I tried to find the 38ac method for balancing but all the text seems to have been erased  :(

5
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 27, 2025, 03:27:45 PM »

Thanks for that explanation BruceM.
I too prefer the high voltage systems but in this case I want the freedom of running the engine at any speed I choose. Also I no longer have access to steel and welders in order to build a new generator base for an AC alternator. So I thought I would try the integral Engine/DC-alternator design.
My GM90 type listeroid is different than yours. The GM90 engines have a counterbalanced crankshaft and the flywheels do not have counterweights cast into the periphery like yours. The Wheels are uniform casings and have been factory balanced with drill holes in the outer ring. How well were they balanced ??? I think I will have to remove them to find out.
If I find that they are unbalanced then there is a good chance that I can use a more simple rigid system after they get balanced.
If they are already balanced quite well, then I will continue to research methods of isolating the thumping.

This picture shows the 20" flywheels (not 23" used on 6/1 Listeroids)
Also you can see the elastomer vibration isolators that do a marginal job of reducing the thumping.


6
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 27, 2025, 02:23:16 PM »
Here is what I am thinking of doing if I rigid mount the engine (picture). Although I would prefer to soft mount it.
I could be over thinking this installation, but as I noted earlier, the engine has just been removed from the previous installation because of thumping forces making noises in the house. This new application is located off grid but it's still beside a cabin (5 feet from the building wall) so I wanted to make it as quiet as possible.
It is located close to the building due to the limited wire size and distance for a 24 volt system.
The engine alternator will drive a DC-DC charger to charger a Lifpo4 battery bank.

From the discussion in this thread I am concluding that there are two options:
1]Soft mount close to the building and eliminate most ground thumping
2]Rigid mount far away from the building where thumping would not be an issue
It's just the nature of these engines.

Oh, and option three ... rigid mount beside the building and tolerate any thumping  ;D


The issue with soft mounting the engine is that you have to get it right (type of isolator) or the engine jumps and bounces. This is why I was asking any who had luck "soft" mounting their Lister to pipe in an explain how it was done.
Simply using any rubber mount without knowing it's characteristics could create situations like this... which could be destructive to tubing and other components over time.
https://www.youtube.com/watch?v=SbqWkVC84bQ

7
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 27, 2025, 01:59:21 PM »
I concur. Using 38AC's balancing method is fast and effective. So much less work and expense than designing a base for a jackhammer.

Please expand on that BruceM. Even a balanced Listeroid has vertical forces from the power strokes.
What mounting method did you use for your balanced machine?

In my case I am mounting just the engine (not a generator frame). My alternator is mounted on the engine.
I could construct a small heavy wood beam frame or a metal frame if having a slightly bigger footprint would aid in the prevention of the "rocking" forces created with bare engine mountings.

8
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 26, 2025, 07:24:57 PM »
Bob,
The calculator and instructions were very helpful. Thanks
You did some great work with your system. A most impressive installation.
The issue am having is twofold.
1] I can't find data on my various insulators for in/lb load ratings in order to use the calculator so I had to estimate.
2] I plan to run the engine at 375 rpm constantly charging batteries. A speed of 375 rpm gives me an excitation frequency of 3.125 hz and the majority of the isolators I have access to all have a natural frequency of 7hz to 8hz.

All the guides I have studied recommend that isolators should have natural frequency of approx. 0.5 that of the excitation frequency in order to force them into the proper performance zone..

Natural Frequency vs. Excitation Frequency:
For effective vibration isolation, the natural frequency of the mounting system (where the engine is attached) should be significantly lower than the engine's excitation frequency.
Frequency Ratio:
Aim for a frequency ratio (excitation frequency / natural frequency) greater than 1.5 to 2, to ensure the vibration isolation system is working in the vibration reduction area.


So I have a mismatch problem for my low speed application.

Trial and error with soft mounts is a lot of work when mounting a 6/1, so I am still considering a solid mount with a 1600 lb base block as recommend by Lister.

I also invite other users to pipe in here and let us know what worked for you ( whether a solid mound or a resilient soft mount) What worked for you ?



9
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 21, 2025, 06:00:31 PM »

Bob, thanks for that explaination.
Just to be clear ... you did not anchor the system to the shop floor?
It's just resting on the rubber isolation pad, correct ?

Nicely done !   ;)

10
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 20, 2025, 09:33:47 PM »
Hey guys,

How's this for a generator base. Actual old Lister installation.
I looks like concrete mass (and lots of it) was the way of controlling vibration back in those days.

<click picture to enlarge>

11
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 20, 2025, 06:44:29 PM »
Thanks sailaway,

So, you poured a ~6 inch thick slab and then soft mounted the generator frame to the slab.
How does it perform? Did it control the thumping as you expected?
I would love to see a video of that unit running.  ;)

I'll take some time to study your methodology and calculator.

Cheers

12
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 20, 2025, 03:53:55 PM »
Here is an example of a "soft mounted" listeroid.
It seems that there is a trade-off between excessive shaking and ground thumping where one may have to accept a little of both in order to tame the lister.
https://www.youtube.com/watch?v=SbqWkVC84bQ

Also, each owner is probably different in that they could be running the engine at different speeds (pulse frequency), with generator bases and generator heads of different weights. So a generic solution likely does not exist.

In my case, I want to mount the Listeroid on its own. No Base frame. No AC generator head.
Just a heavy duty 24 volt DC alternator attached to the engine. I thought that a 1600 lb concrete block would kill all shaking and thumping but it seems I was mistaken. By the way, when my listeroid was thumping into the house it was only running at 500 rpm with a 1.5kw load. Not excessive. And it's a fairly well balanced engine.

13
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 20, 2025, 03:38:24 PM »
RandyBee1,

The isolators I currently use are made by Karman and were purchased through Acklands/Graiger.
Below is the drawing I made to incorporate the Karman isolator into my engine base design.

Also below is the softer "Navy" isolator I was intending to try on the listeroid.They are from Lord Isolators.

I should note that the Karman isolators were marginal in perforance. They did prevent my garage pad from cracking but they still allowed a thumping force to travel through the ground to my house.
In the case of Changfa type engines, the cylinder is horizontal so the combustion forces are sideways vs. vertical like the lister, so ground thumping is eliminated.


14
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 20, 2025, 02:07:58 PM »

PS: last month I removed the Listeroid and replaced it with a slow speed S195 Changfa which has internal counter-balance shafts.
Here you can see the soft mounts that isolated the listeroid base from the floor.
https://www.youtube.com/watch?v=j9jcvJQ2Gs8

The issue now is how to build base for the relocation of the Listeroid.

15
Listeroid Engines / Re: Lister(oid) Concrete Base
« on: March 20, 2025, 01:46:46 PM »
Powdermonkey,
So.., !   I am not the only one who has issues with the ground thumping.  :)
Here' my short story:
For several years I have used my listeroid which is SOFT mounted to the garage concrete floor located 25 feet from the house.
The generator base rests on 4 vibration isolators which are supposedly rated for the weight of the unit.
I suspect that while they are the correct weight rating, they are not rated for very low frequency power pulses and are better suited to higher rpm multi cylinder engines. I also worked very hard to make the exhaust almost silent so that the neighbors cannot hear the system running. All seemed good. Then last month I was running the engine to heat the greenhouse. When I went inside the house I heard a tapping and bumping sound. I went into the basement and could hear 2 distinct sounds. One was a plumbing pipe vibrating at the same frequency as the engine, and the other sound was a deep bass thump coming through the walls of the foundation. :-(
Remember, this is 25 feet away from the generator. I got concerned that my neighbors may also have this thumping in their foundation.
This is when I got the idea to move the generator to the country to charge batteries at a cabin. So I researched how Lister recommended to mount the engines back in the 60's. I was under the impression that a 1600 pound concrete block would eliminate the ground thump. The ground thumping while trying to sleep at a cabin is also not acceptable.
Your story is very useful and will potentially save a lot of time/effort.

Alternate method:
I did come across some Marine engine vibration isolators which are quite soft and would probably absorb most of the power pulse, however I suspect that the engine may also bounce around a lot. What is your experience?
There are a lot of previous threads relating to Lister mounting and I have read most of them but there doesn't seem to be any one solution that fits all applications.

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