CNC Machining Plywood Parts - Marble Machine X #100

["Road to no compromise vibraphone"]

Let's clean up this mess!
Road to no compromise vibraphone!

[cheering sample]
[♪ 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 Martin 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 assemby 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.

[music continues]

[boom]

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

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.

[music continues]

[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.

[music continues]

At this momentI realized I forgot to pass for some unique marbled 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.

[music continues]

[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 two paths over and over again, and the results are immaculate. Love it!

[laughing]
Close!

[audible noise from the activities]

[Martin singing softly in Swedish:]

♪ 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 ♪]

[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 use 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 problem with this operation.

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

I tried redesigning the tool paths 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 sound]

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!

[vibraphone music beat]
[♪ unreleased/Helping Out ♪]

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 the 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 two 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.

[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]

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 continues]

[music stops]

When I first heard about CNC machines, I thought they'd work 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:

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!

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]

[lauging]

Great!

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:

[confirming that off center has a clearer tone]

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 I was going to be ok.

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

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

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

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

So even moving a centimeter from:

[playing examples, 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...

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!

What?

[fanfare playing]

[noise from trying to light the match]

[ignition!]

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.

["I Believe"]
[vibraphone tone]