Re: [CAD_CAM_EDM_DRO] Re: Mini Mill Conversion or CNC Kit

I agree with Johann, and shudder when I look at those 'machines'. I think
the irony is that if one doesn't realise the limitations of such a
contraption, then you may as well buy it. It will become your learning
expense.

Also, gluing, epoxy, and granite are coming into their own these days. The
benefits are numerous. (broad topic, google....)

For example, if you are building a small machine, have a stiff rail, and
want to get it perfectly orthogonal; then set it up using squares, but leave
a mm or two gap at the fixing points. You then epoxy the mating faces
together, with zero force. When it has cured, you THEN bolt it all up. The
epoxy, sandwiched between the faces, is virtually incompressible, and is
acting as a spacer, and not as a securing mechanism. Use the bolts for that.

Using this method, you can assemble an accurate machine. This can then
machine parts to 'upgrade' itself, or make a new machine.

Regards
Roland

On 26 October 2010 13:45, johann_ohnesorg <bigdukeone@...> wrote:

>
>
> http://lumenlab.com/d/micro
> >
> > Pricing would be in the same bullpark.
>
> Stay away from that kind of machine. This is apiece of junk that will flex
> and bend under loads to whereever it wants. If it wont bend, it will chatter
> like hell and ruin both part and tool.
> Even if the gide rails have 5/8", they will flex a lot.
> There are plans out there for gantrys made from aluminum extruded profiles
> with linear ballbearing guides and a lot of trinagulation for stiffness.
> Lasercut and glued ones (don�t laugh, it�s pretty stiff if you glue areas,
> not line contacts)) are somewhere i between.
>
> The mini mill will beat them hands down any day of the week.
>
> Do you need work envelope? Go the cnc router way.
> Do you need stiffness and the ability to cut metal? Buy a dovetail mill and
> CNC it yourself.
>
> Where are you located, amybe a user nearby can let you take a look at his
> machine.
>
> Cheers,
> Johann
>
>
>


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