CNC Machining Plywood Parts - Marble Machine X #100

[shutters opening, light switch clicking]

Let's clean up this mess!
[clap clap clap clap]

Road to no compromise vibraphone!

[cheering sample][clap]
[♪ unreleased/Work ♪]

Check this out: These are the 22 Matrix Sentinel
marble gates for the new vibraphone drops.

In the last episode I built this vibraphone drop system
with all the metal rails.

[MMX playing a vibraphone scale]

And then I took the angle grinder and
just removed like ten days work.

In this video I will explain to you exactly
why I needed to make this redesign.

But before I explain that, I'm so excited
to actually start to build this,

so let's make some plywood pieces on the CNC.

Ever since I came up with matrix sentinels
for the drums of the Marble Machine X,

I have been toying with the idea to
use them for the vibraphone as well.

It took me a day to design this assembly in CAD,

and it consists of laser-cut metal parts
and CNC cut plywood parts.

I'm going to start making these marble shuttles,
that feeds a marble every time a note is played.

[♫]

[boom]

When I was at ThinkerCon in Alabama
I met my maker idol Frank Howarth.

He has the same CNC machine as I have, and I
asked him what end mills he's using for plywood,

and he was: "compression bits".

I had never heard of these kinds of end mills before,
they're also called "up and down", and the special thing

is that the flute direction is changing
in the middle of the end mill.

So in the top of the end mill, it's cutting down,
and in the bottom, it's cutting up.

So on the top of the plywood the end mill will cut down,
and on the bottom of the plywood it will cut up,

which results in much less tear out.

Normally, I had a great finish on the top of the plywood,
but a little bit of tear out on the underside,

which is expected when you're using
the down cutters that I normally use.

I was really excited to see
if this made a difference.

[♫]

[melody starts on vibraphone]

To cut into tight corners you need to use
a smaller diameter tool,

and I only have this up cutter for metal.

And you can actually see how it's leaving
a little bit of tear out on the top there.

Just because it's an up cutter.

[♫]

At this moment I realized I forgot tooolpaths for
some unique marble shutters that has a relief cut,

to clear these washers.

I also saw that I had some
interference on some relief cuts.

I needed to redesign them to make them longer.

And I checked the simulation for this extra cut,
very carefully, to not ruin my already cut pieces.

Today me and the CNC machine were kind of best friends
and it did exactly what I asked it to do.

[♫]

[part lands in box with a thud]

[music stops]

Okay, there's only one single operation left to do
for these marble shuttles before they're completed:

I need to pilot drill two holes for the L hooks.

And old Martin would just go to the
drill press and hope for the best,

but new Martin knows that when
you have a repetitive job like this;

To pilot drill 44 holes;
And I want them accurate

it's better to invest some time
in setting up the operation.

So I'm going to do this on the CNC machine,
do it properly.

I cut three locating slots with different tolerances
and found that the middle one had the perfect press fit.

And here I'm using a custom-made mallet that a
French maker and youtuber sent me: Olivier Verdier.

He has a fantastic channel, so check him out on YouTube!

It does feel very proper to locate these plywood pieces
with a custom plywood mallet.

Thank you, Olivier! I love the mallet,
and I love the "Puy lentils" as well.

Here I'm reaping the rewards from my upfront
time investment in making this into a CNC operation,

it's just to repeat the same tool path over and over
again, and the results are immaculate. Love it!

[laughing]
Close!

[noises from the activities]

[air blowing]

[Martin singing softly in Swedish:]
[♪ Allan Edvall: Du och jag ♪]

♪ Livet är en sand som i ett timglas rinner. ♪
("Life is the sand in an hourglass flowing.")

♪ Låt oss leva upp den lilla tid vi hinner. ♪
("Let us live the little time we are given.")

♪ Åh, du dyra liv som tynar och försvinner. ♪
("Oh, the precious life that fades and vanish.")

♪ Livet är en sand som i ett timglas rinner. ♪
("Life is the sand in an hourglass flowing.")

[bass beat start]
[♪ Spring Gang: You Left Behind (Instrumental) ♪]

[arcade game achievement samples]

[music goes airy]

[bass reintroduced]

[arcade game achievement samples]
[music stops]

Me and Wilson has leveled up enough
to take on the mini-boss of the assembly;

The bottom plywood part here.

You can see that it has a seven degree tilt,
and that is because the marble shuttles

are moving perpendicular to the Marble Machine X.

But the vibraphone is mounted at a seven degree angle.

I started by drilling holes for M5 bolts

and then I used a ball-end cutter
to cut these apple shaped marble grooves.

And then I used a two millimeter end mill
to cut the "internal walls" slot.

Those slots will separate the two marbles in each "apple".

Here I'm using a three millimeter bit
to cut a thin groove

for the vertical L hook that will go
straight through this plywood piece.

And I ran into a problem with this operation.

[CNC whirring]
[vacuum cleaner noise]

The wood chips had nowhere to go and they got
packed up and they broke off this little tool.

I tried redesigning the toolpaths and using another tool,
but I ended up breaking that as well,

so I redesigned the tool paths again.

In the end I solved this
by cutting only four millimeter deep,

and then pausing the machine and vacuum cleaning
out all the wood chips, out of the groove.

Then cutting four millimeter again,

vacuum cleaning and then four millimeter deeper
and so on until I was through the whole plywood.

Definitely learned a lesson here to actually plan for
proper chip evacuation on tight operations like these.

Here I'm using that same compression bit,
that I talked about in the beginning of the video, again.

I'm cutting the larger internal slots,
and then I'm cutting the contour.

And I have to say it works so much better
than a straight down cutter.

The result is actually perfect!

There's no fraying or no tear
out on the bottom of the plywood,

and that saves me a lot of sanding, and just
generally leaves a more professional-looking part.

[camera shutter click]

I don't remember when I made those burn marks,
I must have welded on top of this plywood or something.

But they will be hidden inside this assembly,
so no worries! [♫]

[whoosh]

[♪ unreleased/Helping Out ♪]

[music fades to background]

On the top of the assembly we have these PMMA pipes,

and the marbles come through them
into this 20 degree wedge transition piece.

And looking at the top of the piece we can see that
we have spaced the holes to fit the PMMA pipes,

but when the marbles go through this transition wedge,
they go closer to each other,

which means that I have to split this piece
to be able to machine this shape on a 3-axis CNC machine.

If we look from the front you can clearly see how the
transition from the PMMA pipes goes narrower,

in through the top metal piece.

Setting up the tool paths for this operation
was by far the most complicated,

because I had to indicate the pieces correctly,

and I had to be able to turn them 90 degrees
and machine them from different sides.

I started by cutting the two long plywood rectangles.
I plan to use the resulting pockets for indication.

I forgot to hog out the radius in the corners
so I'm just doing that manually here.

And now you can see that my plywood rectangles can
indicate perfectly into the corner of the pocket.

By doing it this way, the machine knows
exactly where my plywood rectangles are situated

and I can start the machining of the shapes.
[CNC whining]

[music continues]

I left rectangular blocks
on the side of the piece

so I can take them out when
I'm done machining from one side,

turn them exactly 90 degrees,

indicate them towards the same corner,
and run the next tool path;

Machining from a completely new direction.

This way I can achieve the quote unquote
"impossible shapes" on this three axis CNC.

[music continues in foreground]

So in this little plywood wedge there are 22 marble paths
that go at a compound angle,

and I really love the challenge to try to
make these kind of difficult 3D shapes

on a three-axis CNC machine from plywood.

I think it's really fun.

[♫]

[music stops]

When I first heard about CNC machines,
I thought they worked like this:

You put the machine in your workshop.
You put the power on and you press Start.

While the machine is making your perfect part,
you do this:

[birds singing]

That is not the case, in my case.
It actually feels more like this:

[panic alarm]

There's a lot of manual labor, the machine is actually
really really stupid in itself.

If you tell it to do something, it will do it
even if it's a bad idea! [chuckles]

And to figure out what is a good or bad idea
is entirely on your shoulders.

But this is a specific rabbit hole that I
really love in the Marble Machine X process.

I never get tired of cutting
Baltic birch plywood on the CNC.

[marbles dropping]

[laughing]

Great!
[marble rolls on the floor]

We're done with the plywood parts procurement
of this assembly.

I have to wait for the metal parts
from the laser cutting place

until we can put this together and put it on the machine.

In the beginning of time I made an assumption.

In engineering you should not assume anything.

My assumption was that a vibraphone bar wants to be hit
in the middle, so we designed these holders for that.

Then you guys helped out by posting brilliant comments
saying that there's better sound off center:

[vibraphone notes]

When this information reached me, we had
already made these vibraphone holders,

so I made a video showing
that I'm gonna do a compromise.

It was hitting closer to the sweet spot,
but not at the sweet spot.

But I thought that was going to be ok.

You guys again, were like
screaming in the comment field:

"Why don't you just shift the bars like this?"
and I was like:

"Ah, no, the resonator pipe has to be centered", I thought.

And then I made a test and the resonator pipe
was super happy to be off center.

So even moving a centimeter from:

[vibraphone notes, on an off center]

The vibraphone is the lead singer
of the Marble Machine X band.

It requires very very special conditions
to perform. Basically a needy bastard.

I don't know if that is a trait for lead singers,
but anyway... [chuckles]

I'm a needy bastard band leader myself,
I just don't sing.

Your suggestion proved to be absolutely,
probably the best.

And I hope you understand why I assumed
what I assumed at the time.

And now when I have the whole picture
I can see this much more clearly.

The vibraphone was just screaming
for the matrix sentinels solution.

Thank you for commenting and
thanks for helping out with this build!

I'm really touched by the amazing support
from the crowdfunding campaign,

all the new Wintergatan backers
who are supporting my dream.

I talk about it more and more, it's because it's growing
and becoming more and more important.

I can hire help around me:
It frees up my time

to actually think about

just where a marble should hit the vibraphone plate.

I could not live with this horrible harmonic!

When we could have
a clean transient with a good fundamental

of the singer of the Marble Machine X.

Thank you for watching. See you in the next video!

[blows air]

[thud]
What?

[fanfare playing]

[scratching sounds from lighting a match]

[ignition spark]

Yay.
[laughing]

The milestone I never wanted to reach, okay.

I just want to say seriously
thanks for following this journey.

Click like on this video if you believe
I can avoid episode thousand.

[blows air]

[vibraphone tone]
// Subtitled by Wintergatan Writers. Join our team on discord. //