Gen set mounting ideas and feedback needed

[pigseye]

Hi All,
As many of you know I purchased Rockets 12/2 Ashwamegh with a 7.5kW gen head.  Thanks Rocket!

I'm a long way from having a generator shed for a lot of reasons.  Bottom line, I need to "temporarily mount the genset in the garage.

Of course I have a slab and if you're familiar with Rocket's gen set he built his on 4x6 white ash.  It seemed to run fine on the dirt floor of his barn which gave me an idea.

What if I build a border box out of 4x4s that is just a little bit larger than the wooden frame of the genset.  Screw this box to the slab.  Then place a couple of inches of sand in the box and place the genset in the box.  It couldn't walk away since it would be inside the sand box and maybe the sand would provide a little cushion and minimize the energy transfer to the slab.

Have I really over thought this and should just bolt or chain the frame to the slab? 

Other thoughts?  Your insight is greatly appreciated.

Thanks,
Pigseye

[Procrustes]

If you haven't done so you should read this thread http://listerengine.com/smf/index.php?topic=733.0 carefully.  Various of the denizens here asserted that you can crack your walls by vibrating the foundation, and that it's actually better for the engine to be bolted to a block.

If you read that thread, and what you are asking is how much will a couple of inches of sand guard against these effects, then I don't know.  I guess it depends largely on what you mean by "temporary".  That's a grave word around here.

[cujet]

My friend Bruce (here in Florida) has mounted his twin lister setup (steel frame) on an H pattern of 8 x 8 timbers.

I built a steel frame for his engine out of 4 inch 3/8 I beam. It is very sturdy. Bruce then mounted my frame on 4 large timbers. That gets the engine higher for easier cranking. It also gives a larger footprint so he can drag the setup out of his garage with his Jeep. Bruce made sure to bevel the ends of the timbers so they will not dig into the dirt. It is a very sturdy setup. His engine runs just fine without shaking around or moving.

I took a different approach with my twin . I put pipe (as axles) on the bottom of my steel frame. I then used Lister pulleys as wheels. I am able to wheel the unit with ease. My setup will need to be in the dirt to avoid wheel problems.

Chris

[slowspeed1953]

http://www.enidine.com/Airmounts.html These look promising! Heres a blurb

Enidine Incorporated offers an excellent vibration isolator with high lateral stability for those applications where vibration isolation is required for machinery or equipment with high centers-of-gravity. The Enidine Air Mount provides the solution for these types of applications, extending your industrial machinery’s life.

  With its heavy-walled construction and air-cushioned isolation, the Enidine Air Mount system will provide resiliency and prevent static deflection and permanent set/drift with your machinery.  It also has neoprene padded top and bottom surfaces for soft interface with all connecting and supporting surfaces.

  Typical applications for the Enidine Air Mount are as follows: air compressors, CMM machinery, most rotating industrial equipment, tools, fans, laundry and general machinery.

The Enidine Air Mount can be sized for a wide range of loads operating in a 15  – 140° F (-10 – 60° C) environment.

Check out the PDF tear sheet it's mid page on the left hand side.

They use these mounts for forge presses they should be more than enough for a listeroid.

Best wishes

[Rtqii]

I would not use the Enidine type mount on a heavy flywheel Lister type engine, that may be a fine mount for a commerical washing machine or air compressor. Flexible type isolation mounts will transmit the vibrational force to your crankshaft and the main bearings. Also, I am not so sure about the strength of the Indian cast iron, if the main bearings don't fail... The bearing housing may. Work hardening of the crankshaft is another problem, the metal starts to crystalize and eventally snaps. Avoid these type mounts at the cost of a new engine or a major rebuild.

As for a temporary mount... I intend to use one until I have a block mount cast, I will need my genny running to mix the concrete and cut the rebar. Checking around it works like this:

You either dig a shallow trench or construct a raised frame of timber.  You bed the bottom with a couple of inches of coarse gravel, then a couple of inches of 3/8" inch minus grade crushed stone, then top with sand.  Set the genny skid in the sand and use chains to strap it down. As the engine runs it will compact the gravel and sand so the strapping chains need to be tightened periodically. This is OK for a temporary bed, say on a construction site.

 

[GIII]

From my experience, either mount the engine solidly to the center of the earth via a LARGE concrete base, or make a frame that weighs AT LEAST as much as the engine, then maybe that can be mounted on something soft and springy.  For instance, Chevy motor mounts should work without a large, heavy base, right?  I can tell you that the engine will hop very high and do the crazy dance until it can be shut down.  But those same mount under a very heavy base can work well.

[pigseye]

OK, what about this idea?

I'll cut out a section of the slab, dig a hole, build a form, and then pour a large concrete base to mount the engine. 

My question is do I have to mount the generator on a concrete base or can I build a solid wood base to support the generator?

Thanks

[hotater]

pigseye---

I'd suggest a solid to concrete mount for the genhead but wood can be used as the 'cart'.  It WILL loosen and eventually wobble.  My next is heavy steel bolted to the center of the earth.
  If it can wiggle it WILL escape, sooner or later.

[pigseye]

Hi HT,
I'm trying to minimize the permanent foot print in my garage by building an engine only base.  If I build a base big enough for the engine and generator head, I'll have a concrete block that sticks above the garage floor by 8 to 12".

What if I pour a base up to garage floor height that is large enough for an engine and generator and then raise the engine and gen with I beams?  Would that be solid enough?

Sure seems like a lot of work for a "temporary" set up.

tHANKS

[Andre Blanchard]

How about I beams that are say 10 or 12 inches tall cut and weld into a four sided box say 3 feet wide by 6 feet long.  Drill holes thru the web along the top and bottom of the sides and weld in some rebar X bracing.  Weld in some more rebar in a logical 3D grid.

Set on a piece of plywood (for a smooth bottom) with the plywood on top of a rubber mat like for cows.
Fill with concrete and mount the engine and gen head on top.

Then when you want to move it get two or three 1 1/2 " pipe 4 feet long and make like an Egyptian.  When you get it to the permanent location you can bolt the whole thing down solid.

[pigseye]

Andre,
what a great idea.  I'll look into this.   This might not be as heavy or as solid as pouring a form in the ground but it would be very heavy.

Thanks
pigseye

[pigseye]

If concrete is 145 lbs per cubic foot, and you built a 3' x 6' x1'  box out of 12" ibeam there would be 18 cubic feet of concrete.

18 x 145 = 2610 lbs 

I probably wouldn't use plywood or mats for the engine mounting.  I want to make the system as rigid as possible.

One additional idea would be to pour 4' cylinders of concrete, like for deck posts, in each corner and then mount this on top.

hmmm, more thinking required.

Thanks