I'm building a steel tube cabinet who's main function will be to support a manual bench mill.
I'm trying to decide which material I will use for the top plate on the top of the cabinet, on which I will bolt the mill base.
My choices of material have narrowed down to:
1. epoxy granite
2. "specialized" grout or concrete (a kind that is available at driving distance)
3. "hardware store" / cheap concrete
The slab will be 18"x24", and the thickness will depend on the material chosen, to obtain sufficient stiffness, massm, and vibration dampening.
Inside the slab/plate will be a rectangular steel frame of 2" x 4" steel C-beams ( more exactly 4mm x 10mm, with 5 mm thickness), and also a rebar matrix.
I believe all of the above candidate materials can easily satisfy the "mass contribution" strength and stiffness criteria, but in terms of vibration dampening, I suspect that epoxy granite is a far superior option.
I have read enough about EG on this site to know that it's quite a challenge for a DiY to fine tune the mix and to get results anywhere close to "professional" EG.
But I suspect that my application is forgiving: stiffness and strength is already provided by the steel frame, the mill only weights 250kg, I can exagerate on the rebar for cheap.
And I can also take "shortcuts" to make things easier, like putting a bit more epoxy than the optimal, to ease the mixing, and air purging, vibraiting, etc.
From what I understand, the downside of a higher than optimal epoxy %, is loss of compression strength, and lower stiffness, but is better at vibration dampening.
For my application, perhaps an off the shelf "specialized grout", might be close enough, cheaper and easier.
I have found this grout, specialy designef for machine bases: https://can.sika.com/en/construction...routpakle.html
But it costs an arm and a leg ($648 for 28.32 Liters)
There is this other grout, also easily available, with a much more reasonable price:
https://can.sika.com/en/construction...grout-212.html
But the technical sheet says nothing of the vibration dampening, I suspect it's very close to "normal" concrete, and the only added benefit is that it doesn't shrink while curing.
Another reason I'm tempted to go through the trouble of Epoxy granite, is to gain experience with the material, and eventually use it for other projects: filling the mill column, making a CNC mill with it, etc.
So, even if EG is a bit overkill for a mill base, I will gain valuable knowledge and experience.
I'm trying to decide which material I will use for the top plate on the top of the cabinet, on which I will bolt the mill base.
My choices of material have narrowed down to:
1. epoxy granite
2. "specialized" grout or concrete (a kind that is available at driving distance)
3. "hardware store" / cheap concrete
The slab will be 18"x24", and the thickness will depend on the material chosen, to obtain sufficient stiffness, massm, and vibration dampening.
Inside the slab/plate will be a rectangular steel frame of 2" x 4" steel C-beams ( more exactly 4mm x 10mm, with 5 mm thickness), and also a rebar matrix.
I believe all of the above candidate materials can easily satisfy the "mass contribution" strength and stiffness criteria, but in terms of vibration dampening, I suspect that epoxy granite is a far superior option.
I have read enough about EG on this site to know that it's quite a challenge for a DiY to fine tune the mix and to get results anywhere close to "professional" EG.
But I suspect that my application is forgiving: stiffness and strength is already provided by the steel frame, the mill only weights 250kg, I can exagerate on the rebar for cheap.
And I can also take "shortcuts" to make things easier, like putting a bit more epoxy than the optimal, to ease the mixing, and air purging, vibraiting, etc.
From what I understand, the downside of a higher than optimal epoxy %, is loss of compression strength, and lower stiffness, but is better at vibration dampening.
For my application, perhaps an off the shelf "specialized grout", might be close enough, cheaper and easier.
I have found this grout, specialy designef for machine bases: https://can.sika.com/en/construction...routpakle.html
But it costs an arm and a leg ($648 for 28.32 Liters)
There is this other grout, also easily available, with a much more reasonable price:
https://can.sika.com/en/construction...grout-212.html
But the technical sheet says nothing of the vibration dampening, I suspect it's very close to "normal" concrete, and the only added benefit is that it doesn't shrink while curing.
Another reason I'm tempted to go through the trouble of Epoxy granite, is to gain experience with the material, and eventually use it for other projects: filling the mill column, making a CNC mill with it, etc.
So, even if EG is a bit overkill for a mill base, I will gain valuable knowledge and experience.
This is a companion discussion topic for the original entry at https://www.cnczone.com/forums/epoxy-granite/468982-machine-base-manual-bench-mill-epoxy-granite-new-post.html