Why is there so little going on in Epoxy Granite?

If you look at how much has been discussed about the topic, it seems that there is very few builds going on in EG, compared to more traditional materials.

Why is this?

Is the material itself so hard to work with, compared to the more traditional construction materials? Or not so much hard to work with but outside most peoples technical scope?
Is it that is seems only to be suitable for heavy machining equipment, like for milling steel, so it is not a suitable choice for routers?

There is lot going on in Germany. Most of the builds are in CNCECKE.de. It is called mineralguß in german.

Mark

It seems so easy at first but in reality there is a lot more to it than just mixing pebbles, sand and epoxy to make an instant mill. E/G is not a solution to cut cost and get a cheaper mill. By the time you have worked out all the finer details of aggregate mix, how to mold and cast and how to compact the structure while avoiding thermal stress induced by the epoxy setting, you are in the thousands for material alone. You still need a good mill design and money for all other components.

As RotarySMP saids, its really going on in Germany. decoding cncecke.de forum is not that easy tho.
But yeah epoxy, gravel and pebbles isnt cheap in the end.

On the other hand, its harder to cast iron than casting epoxy. Thats why im running with the E/G in the end.

Regarding the mill design, well i've spent better part of 3 months designing. It takes time to iterate. =)

I just realised another reason why people may tend to stay away from EG.

With the other materials you can easyly add a hole or a screw later, if you have forgotten something in the design stage.
That allows for a lot less design work to start with, if that is how you prefer to work.

With EG, every nut and bolt needs to be planned in advance so it is incorporated in the mold.
If you forget something, it is harder to add it once the epoxy has cured.

On the plus side, once the design is done and the mold is made, actually making the thing takes less time.

I don't really agree with either the cost or the differculty of adding a hole.

At least the test peices I have made, I am looking at about €1,70/kg for the ingredients. This could easily be halfed by buying the Epoxy in larger amounts, and finding a cheaper source of the fine aggregate (I am using alumina from a pottery supplier). The other 80% of the aggregates cost les than 10c/ kg. I cant see finding a cast iron foundary who will do a one off, walk in job for anything like that money. Using a Cheap chinese mill is not really a basis for comparison, as the have nothing like the damping or rigidity, so you would have to consider the cost of an industrial machine as the basis for retrofit.

Adding a hole is not differcult. Diamond core drills which are cheap and widely available will drill it fine. Then epoxy in either a threaded insert, or a slug which can be precision drilled and tapped.

EG is suitable for small machines. Light Machines Corporation, later owned by Intelitek, made mills from the early-mid 1990s through 2012, with the same EG frame throughout production. I have an early PLM2000, very nice, quiet and smooth running mill with servos.

Asking price for used ones in working condition usually starts at $4K. I got mine in non-working condition for $2K. Only needed one wire fixed.

My remarks were more about percieved difficulty rather than actual dificulty.

With EG you can not call on the more traditional engineering skills. O rshould I say, you should mix several fields of skills, It is a good point that diamond drills can be used. And you can also bond stuff everywhere if you forgot to put something in at the design or mold stage.

I would disagree that EG is inherently more suitable for smaller machines. The benefits and challenges do scale with size for all materials (eg it isn't 'easy' to cast a 5t Mehanite frame either).

I have a LightMachines bench top mill. Last night I had the control box off. I thought you might be interested in these photos.
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Originally Posted by CaptainVee

I just realised another reason why people may tend to stay away from EG.

With the other materials you can easyly add a hole or a screw later, if you have forgotten something in the design stage.
That allows for a lot less design work to start with, if that is how you prefer to work.

With EG, every nut and bolt needs to be planned in advance so it is incorporated in the mold.
If you forget something, it is harder to add it once the epoxy has cured.

On the plus side, once the design is done and the mold is made, actually making the thing takes less time.

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Epoxy castings are easy to modify, once you know how.

ITW Philadelphia Resins appears to be still in business. I wonder if they still have the molds for the ProLight frames?