Re: [CAD_CAM_EDM_DRO] small cnc shop in northern colorado

Alfredo Sola wrote:

> I am now trying to decide whether to go for a completely home-made job,
> or get a kit from e.g. Usovo
> <http://www.usovo.de/shop/product_info.php?language=en&info=p274_Umbausatz-fuer-Proxxon-MF70-zur-MF70-CNC-2008.html>.
> It looks like the complete kit costs only a bit more than sourcing the
> parts, but success is more or less guaranteed. I think you can't go
> wrong with that reasoning, but still would like your input on that.
>

Every retrofit has compromises in it, as you are altering a machine made
specifically for manual
use to be CNC. You really need to know what these compromises are
before evaluating any
plan, either your own or a "kit". Having done a couple home-brew
retrofits, I am in a good position
to understand the compromises in it, as both of them required me to go
back and adjust the first
version a bit. So, I would suggest you look at whatever level of detail
you can get from these plans
before buying. You do have the manual machine there, so try to figure
out of there are any weaknesses
in the design before buying the kit. Yes, I know that could be tough,
depending on how much detail
the vendor gives.

For instance, on my portable mill, similar to the "X2", the X axis
leadscrew had a pair of ball bearings for the
thrust bearing, but the Y had a brass bushing. I had to modify the Y
bracket to accept bearings also. That
wasn't really a shortcoming in the CNC retrofit, it was a cheap
compromise in the original manual machine.
Your machine already has a screw drive on the Z axis, so that is one
thing you don't have to change.

Jon