# Building a bench top mill



## m_kilde (Aug 31, 2010)

Hi to you all

I have started to think about building a bench top mill of my own.

I got this crazy idea to make the machine base in reenforced concrite, and would like to hear some comments on this idea.
I have only been able to find very little on this subject on the internet, mainly about CNC gantry mills

TIA for any kind of comments


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## Hal (Aug 31, 2010)

Evan on the Home shop machinist forum built a CNC mill. Its worth checking out.
I thik its a 4 axis.

Hal


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## djc (Aug 31, 2010)

Concrete per se, made with Portland cement, is a bad idea as it creeps, shrinks and cracks.

However, POLYMER concrete, where an epoxy resin is used as the binding agent, along with a mineral (granite) aggregate filler is used very successfully.

Have a look over on CNCZone for 'epoxy granite' or 'polymer concrete'.


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## mu38&Bg# (Aug 31, 2010)

Here's what I did. I'd be happier with it if I was able to use a thicker piece for the base. The high RPM spindle works very well for the small parts I mostly work with and max 1/8" tools. For this, it's plenty rigid. For 1/4" tools in metal, it's barely acceptable. If I were building another, and I want to make a larger one at 24"x48", I'd go gantry with a double granite counter top for a base, unless I could find a cheap surface plate of the right size.

Think carefully about your Z travel and the distance to the table with various tools and fixtures. I made mine too tall to cut with short tools directly on the table. Only a 1/4" XL reaches, and I occasionally cut foam patterns with it.

Greg


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## Omnimill (Aug 31, 2010)

I've often thought "epoxycrete" inside a steel tube would form a good basis for a home made milling machine column - except it would end up awful heavy!

If you do try it use ball screws and linear slides even if it ends up as a manual machine, and don't forget - th_wwp  :big:

Vic.


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## m_kilde (Sep 1, 2010)

Hi Folks

Thanks for your input.

My plan (well right now it's only an idea) is to build a manual machine and not CNC.


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## Niels Abildgaard (Sep 2, 2010)

My Boxford lathe sits very firmly on a piece of granite.The holes is neither difficult or expensive if You remember to cool with water and the long cut was made in less than 5 minuttes on a professional diamond saw rig.Total price was less than 100 dollars.The stoner normally make grave monuments and my wife objected but my piece was leftover from a sculpture and i have not seen ghosts or broken tabs(yet).


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## m_kilde (Sep 2, 2010)

Hello Niels

I have seen your lathe bed on LDS.dk  :bow:

Thank you however for the comment


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