Alright, I got this MPCNC built, it moves, it cuts, you were able to follow the entire
build process live here on YouTube.
Last week, I was out filming a few project and when I got back, I wanted to actually
tune this thing in and get it to cut well.
Because what we were seeing on the last livestream was that there was an enormous amount of chatter
and just bouncyness in the toolhead, especially in the aluminum cut, but also already in MDF,
I know even from flimsier machines, that shouldn’t be that way, but somehow, this machine was
just not rigid enough to mill into the material.
And yeah, I did build this one slightly larger than they normally are, but what I was noticing
was that the belt and the way the belt was mounted introduced a lot of flex into the
drive system.
Like, I could easily stretch the entire belt assembly by a millimeter or two, even with
the zip tie as tight tight as possible.
Now, in the comments, you guys have already suggest a bunch of different areas where my
machine could also have issues, like these long M8 bolts that are used in the carriage
having a smooth shaft instead of being threaded all the way through, which could have the
carriage flex more than usual, but I wanted to go step by step, fix the obvious issues
with my machine first and try and understand the MPCNC a bit more during all that.
And I thought it would a good start and an easy fix for the belt with a new printed part
that would directly clamp the belt with no zip ties.
But it wasn’t that easy.
While I was already drawing a new part, I wanted to go ahead and work on a few other
challenges that I ran into during the build, like the fact that there are only a handful
size options available for tubing, none of which are really as cheaply available here
as metal conduit is in the US, the fact that almost none of the nut traps were grabbing
the lock nuts properly and I’d had to jam a screwdriver in there to hold them, and a
few of the parts only seem to be made for imperial-sized hardware from the start, not
metric.
So I started in Fusion 360, created a new parametric design and drew up the first part,
one of these corner pieces with adjustable wall thickness, screw size, rod diameter,
and, of course, it has the belt just pushed in sideways with no zip ties or anything.
Worked great, so I tweeted about it, was like, hey I created this part, if anyone wants to
use it, here’s the Fusion360 design, I’m sharing this as Creative Commons 0 aka public
domain, print it, modify it, include it in your project, you don’t even have to give
credit for it, basically, do whatever you want with it.
And here’s where it got complicated.
Because Ryan of V1 Engineering, he designed the the original MPCNC parts, came in and
was like, “Hey Tom, you can’t actually release these parts as public domain, they’re
a derivative work of my original parts, so you need to release them as Creative Commons
Attribution Non-commercial.”
Now, just to be clear, I didn’t just import the original stls into Fusion, chop off the
zip tie brace and add the belt slot, this part is designed from the ground up.
I spent a couple hours on the design to work out kinks with being able to adjust the dimensions
as parameters without the whole design falling apart, and yeah, it does look like the original
because it fits the other original parts and, honestly, there just aren’t a whole lot
of other options to design a part that does the job of holding a belt right there and
clamping down onto a section of tubing at the same time.
We’ll actually come back to that later.
So what followed on Twitter was two days of discussion between Ryan and me of what is
a derivative design and what is not, who holds copyright to what and what the morally right
thing to do was - and you can still read the entire conversation, I’ve linked that below.
Now, obviously, I don’t think this part counts as a derivative design from the original
MPCNC, but what Ryan kept pointing out is that he basically considers any part a derivative
of the original as long as it fits onto the other parts because the dimensions and positions
of features are the same as the original.
So I was like, ok, if you’re saying that any part that does the same job is a derivative,
and that would require me to only release my design as Creative Commons Attribution
Non-commercial, too, then so be it.
But then please do respect that license and don’t use my original work commercially,
either, including in derivatives.
Now if we follow that line of thought, Ryan owns the copyright to this area, I own the
copyright to that, and in the end, nobody gets to use it.
I thought holding up a mirror would show how ridiculous this entire thing would be, but
instead Ryan accused me of wanting to destroy his MPCNC project.
Like, what?
So, just to be clear, I started out by wanted to release my design with no restrictions
for everyone to use, for the MPCNC community and for whoever wants to make the part, there’s
also an awesome community supporting this channel, so whenever I spend my time and design
something, I want it to be available for as many people as possible.
And for me, that means releasing as open-source.
A non-commercial license isn’t considered open-source because it comes with so many
restrictions in how you can use a design, for example for educational use, in a makerspace
that, yes, usually has member fees, or in any other context where someone is making
money with it.
For example, me even building the MPCNC on this channel is a pretty grey area because
I am “using” the parts in videos and livestreams that, at the end of the day, put food on my
table.
Thankfully, I do have implicit permission in that case.
I have no intention of harming any project that enables people to do awesome things,
in fact, I want the MPCNC to be as awesome as possible, which is why I started making
modified parts in first place.
But it looks like, for the time being, the MPCNC is going to be Ryan’s project alone,
with him wanting control over the entire thing.
And he obviously made it pretty clear that he didn’t want me “interfering” with
that by making open-source, compatible parts.
Now, there is still that little detail in copyright where if a part only has a certain
shape, because it has to do a certain job, copyright just doesn’t apply to it.
That’s why, for example, your car’s brake discs aren’t protected by copyright from
Ford or someone, because the shape they have is not “design” in the artsy way, it’s
purely function, and copyright only applies to “art” and creative work in the widest
sense.
I’m pretty sure that, aside from the MPCNC logo on here, these parts are very much only
functional, too, so copyright really wouldn’t hold up.
I’m certain that all things considered, I did nothing wrong, but I’m going to respect
the fact that Ryan doesn’t want this.
So that’s what I’m going to do, unfortunately, this means I won’t be spending any more
time on this MPCNC, the only thing left to do is to take this machine apart.
I’m sure I’ll find a new home for the spindle, electronics and all that.
Again, my intent was to make the machine better, more flexible, more accessible and of course
I don’t care if this belt clip thing makes it into the official design or even ends up
being sold as the MPCNC.
I mean, after all, this design was CC-0 to start.
And that even includes use in projects with a restrictive license, too.
So while I’m un-building this machine, I want to say thank you to my supporters over
on Patreon.
This month, a shoutout goes out to alephobjects
Adam Green Ken Graham
Kurt Wubbels Sean Berry
Robert Baum nm creator
James Koch Filip Goc
neil youngberg Brian Raker
Andrey Jimmy Lee
Matthew Oswald Dorian Gray
Olivares Mike McGee
James C. Foley Jonathan Malin
Markus Harms Andy Fair
Robert Hornburg Jeffrey Nikoletich
Filastruder Christopher Day
Rudolff Vang Paul Arden
William Devine Francisco Peebles
and everyone else who’s directly supporting the channel on Patreon, through YouTube memberships
or even just watches and shares my videos.
So thank you all for watching, I’ll see you in the next one.