Specifications

Practical tips
62 ProtoMat 95s/II
8.0 Practical tips
• Set the milling depth such that
engraving is too deep
rather
than too shallow. Insufficient depth when engraving increases
wear on the milling tool.
• There are a number of reasons why the
milling width (depth)
might be uneven
.
It is important that the
machine bed is truly clean
.
Adhesive tape residue and such like can have a significant
adverse affect on the milling depth. Millings between the machine
bed, drilling base and board reduce precision.
Greatly
distorted materials
bend such that the sag shows
underneath; in this case, secure the edges well with adhesive
tape. Another important point for precise milling depth is that
millings and drilling chips are
removed by suction
.
• Hooks can occur between the milling tracks if the incorrect milling
quence is followed, in particular with circles.
If a circle is to be milled anti-clockwise with a tool which rotates
clockwise,
fine hooks
can occur between the copper areas if the
milling tracks overlap.
The reason for this is that the cutting speed on the outer edges is
reduced. The solution is to select the correct direction of milling.
In addition, you can select the
Remove spikes
option on the
Strategy
tab in
CircuitCAM
when you set up the isolation job.
•
Milling burrs
can be caused by blunt tools or incorrect traverse
speeds. Deeper settings can be used to make corrections if the
structure being milled permits. Otherwise, change the tool.
•
Burrs
arising during contour milling or
cut edges which are not
clean
are caused either by a blunt tool or an incorrect feed rate.
• With some materials, the
colour of the milling pass
gives some
indication of the condition of the tool.
Dark isolation tracks on epoxy materials indicate that the tool is
sharp, while lighter tracks indicate a blunt tool.
•
Drilling burrs
are caused either because the tool is blunt or the
head is being lowered too quickly.
In the first case, change the tool. In the second case, the tool
height over the material must be reduced.
•
Drill deflection
occurs where thin tools which are no longer
absolutely sharp are used.
However, surface structure of the material may also be a factor.
Drill deflection cannot be avoided even with a sharp tool if, for
example, the glass fibre structure of FR4 materials penetrates
the copper.
Drill deflection is very slight for materials with additional,
removable copper film (FR4 material with 18 µm or 9 µm copper
coating).