In a previous video I explored using different tools and parameters to start
to build a catalog of best practices for this machine (Precision Matthews PM25 mill) when programming (Autodesk) Fusion 360.
Using what's been learned so far, in this video I'll mill a bracket for a (Misumi) magnetic
door catch sensor. The sensor ultimately attaches to this PLC and is used to lock
out motors when the door is open to protect the operator. I previously made
one of these brackets and then it took about an hour to mill and you can find
that video in my library. Now it takes nine and a half minutes and I think
eight minutes is reasonable. Ultimately, we're limited by the power available
through the spindle of the mill. For comparison I also 3d printed the part
and it took about an hour on a Taz 5 3d printer, but there are no tool changes
necessary. The rest of the video is the milling of the bracket with a small
amount of commentary. If you have any comments or suggestions please let me
know. It's small parts like this that we learn a lot from to the prepare us for those more
complex parts.
Did you see how the tool retract to do a chip break above the part. That's going
to come back to haunt us a little later.
This shell mill has been fantastic to use. I have a few other modular insert tools
from Tormach and I hope that they're just as effective.
One of the easiest improvements that one can make in (Autodesk) Fusion 360 to improve
milling time is careful selection of your heights. Careful to not crash but
also careful to not cut air.
Just to be certain, let's make a little bit of clearance.
This chip breaking height is a little excessive.
What I'm trying to achieve at the toolpath on the
right is to not lift the tool off the part while it's cutting. Unfortunately,
with 2D Face, there doesn't seem to be an option for only lead-out extension.
Using the Kronos high-speed camera we can check to see that each tooth of the shell mill is cutting.
It looks like the shell mill is doing a good job, but let me know what you think.
I've been swapping out my roughing-finishing endmills for standard endmills
because the roughing-finishing endmills leave ridges.
Earlier we saw that this drill didn't start at the right height so it didn't go
deep enough. The correct tool was called for the height was set right. I'm not
sure why this happened. In Linux CNC I might have forgot to reload the tool library after entering the tool height.
Using the glass bead blaster, I blend the machining marks.
This works really well, but be sure to plug any threaded holes with screws.
I also made this part in 2016 and you can find a video of that in
my video library. There I also explain the theory of operation of the sensor.
In 2016 I was obviously more conservative about cutting this part.
I really like this quote I saw on YouTube and it makes a lot of sense when comparing 2016 to
2017, seeing a difference of 50 minutes when making this part.
I'm probably still working at less than minimum wage but things are getting better.
I also printed the part with a Taz 5 3d printer which took about an hour. I printed the part in this
orientation so that when the door struck the part it had strength and didn't break between the layers.
Thank you for watching and sorry I didn't have time to
do an installation of the part. Come back soon for a demonstration of it and the PLC.