Re: Smithy CNC

--- In CAD_CAM_EDM_DRO@egroups.com, "Walt & Craig Smith" <fom@m...>
wrote:

> IF you are seeing this more then once--I'm sorry-- But I'm new and
> will lear my way around
>
> I currently have both a Sherline 5400 mill and Sherline 4400

lathe.

> These have been converted to CNC by Backtrack CNC. I an trying to

do

> milling on Alum paintball gun bodies. this is basicly "engraving"
> using a ball mill. I have tried different feed rates (slow to

ultra

> slow) faster speeds, light cuts, different mills, drowning it in
> lube--in short everything I can think of and still get mill marks

in

> the cuts (whick will later be anodized and look like shit)
>
> I've decided that the Sherline is just not ridgid enought to get

good

> results on this type of work (I can SEE the head delflecting at the
> start of a cut)
>
> At any rate- I'm thinking real hard of getting a Smithy. I've seen
> the machies in person and they loog good to me--of course they

weigh

> about 10X as much as the Sherline too. I'm thinking of the Midus
> with
> the CNC conversion. Does anyone have any expericence or coments on
> this? Thanks in advance
>
> Craig

machining aluminum parts on sherline cnc requires a finish pass of
about 0.010" deep.You will get mill marks no matter what kind of tool
you use.I'm working with a KIA industrial machine center(the size of
a compact car)we machine small 6061 aluminum parts 8 at the time,and
when they get out of the machine it looks like shit,burrs,and mill
marks,(but not steps) after this they send it to the deburring and
tumbler and still you can see the mill marks.
if you are doing 3d engreving than the z axis on sherline mill is
not very good for it(backlash).
backlash is a pain!
One possible solution is to have the parts being soaked in a acid
solution prior to be anodized,this way the acid would eat some of the
aluminum.