Epoxy granite or mineral casting

**audioandy** · 30-09-2012

Originally Posted by JAZZCNC

Me too.!! . . . Yes please Sir.!! . . . (Would also mean Andy and I could play in the slap dab together. . lol)

Mike looking forward to the info,looks like myself and Jazz could be playing in the slap dap after all

**Peter.** · 29-09-2012

I love it when practical experience makes a mockery of the theorists

**Jonathan** · 30-09-2012

Originally Posted by Peter.

I love it when practical experience makes a mockery of the theorists

It's a case of different objectives - I think what the 'theorists' are mainly discussing is a more demanding application than what mike has found out about.
I think the difference is that in the long thread on CNCzone they are (or were) trying to find a resin/aggregate mixture that would when set leave a surface smooth, accurate and stable enough to mount the linear rails directly to it, hence the suggestion of using a flame to remove bubbles. However if you're just making a base or frame with it and embed steel strips, or other means, to mount the rails, that can subsequently be machined or adjusted to obtain the required accuracy then you can get away with all sorts of things. There are quite a few examples of where people have not used fancy resin etc on their machine and got good results, such as this one.

**JAZZCNC** · 30-09-2012

Originally Posted by Jonathan

It's a case of different objectives - I think what the 'theorists' are mainly discussing is a more demanding application than what mike has found out about.

C'mon Don't get much more demanding or accurate than CMM's thou does it.?. . . . Most of that thread is over complicated Bullshit.

**Ger21** · 14-10-2012

Originally Posted by JAZZCNC

. . . Most of that thread is over complicated Bullshit.

I agree with that 100%. My gut feeling says a bag of sand and a bag of gravel is all you need to make an incredibly strong machine base.

**audioandy** · 14-10-2012

Originally Posted by Ger21

I agree with that 100%. My gut feeling says a bag of sand and a bag of gravel is all you need to make an incredibly strong machine base.

Someone agreeing with Jazz! That's a first!

**martin54** · 29-09-2012

Being new to all this I went & had a read of a couple of articles when I saw this thread so I would have a better understanding of what it was all about.
I could be wrong (often am) but from what I picked up what they are trying to achieve is not the same as filling a machine to increase it's weight or help with vibration dampening. Haven't read the long thread on their forum but I think that is why they are still theorizing & testing different mixes.

**Peter.** · 30-09-2012

I could have brought home half a dozen bags of fast-setting concrete from site last night that would do a pretty good job. I don't know what it's proper name is but the track workers call it 'Boff' - it comes in small bags of about 15kg, mixes directly with water, pours, doesn't shrink and crack and you can run trains on it within an hour of pouring. Very fine aggregate in it but by God is it tough, I dread having to break it - even with the demo robot it's hard going.

**boldford** · 30-09-2012

Originally Posted by Peter.

I could have brought home half a dozen bags of fast-setting concrete from site last night that would do a pretty good job. . . . .

Does that mean NR will need to keep that firmly under lock and key henceforth?

**Peter.** · 30-09-2012

Dunno what you mean...

Actually, the stuff does shrink somewhathaving thought about it as I have seen cracks in large pours - no getting away from it when it's mixed so as to be pourable I guessbut I bet if you mixed it dry enough it would be reduced to a minimum. If you cast it into a steel form why would it not be good enough to fix rails to it directly?