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Fun with hobby CNC

Fun with hobby CNC

I’ve recently embarked into learning CNC machining, although just on a hobby level.  I’ve been wooodworking for most of my life, this seems like a logical next step.  I’ll be mostly trying different designs out for wood, but do have the end goal of using this machine to build the parts for a bigger machine.  I’d like to be able to cut an upright bass neck at some point!   Anyhow, with no further ado, here is what I’ve done so far:

So that was the build of the machine itself, now for some projects:

1.  The first actual cutting I did was a sign for my son’s room, fairly simple letters onto wood, but I did have some 3D shading on the letters to test out some capability.

 

2.  One of the main reasons I wanted a CNC was to cut out instrument parts.  If you saw my bass build  you know that I enjoy making unusual instruments.  Eventually I’d like to have a machine large enough to cut out bass necks and bodies.  This project was my attempt at cutting a ukulele out of standard Home Depot 2x material (2×4 and 2×8).  If you want the CAD for this let me know, the neck especially turned out very well.

 

 

 

3.  In addition to instruments, one of the goals is to cut shapes into wood that aren’t typically achievable with conventional woodworking tools.  This isn’t anything new, people have done CNC carving of this type of wave interference patterns before, but I felt that was a good test of capability:

 

Also, here is another one that I actually finished up.  It was cut out of a nice piece of flame maple that had a bunch of defects, which I think in this case are positive things.  It’s hard to see the 3D in a photo, but it’s there!

Cut on the CNC, finished all by hand with various dye colors and hand sanding.

Cut on the CNC, finished all by hand with various dye colors and hand sanding.

 

4.  Time to up the safety of this whole thing.  Not only is there a danger from the router bits and thrown material, but it’s also just LOUD.  This enclosure cuts down the noise significantly, and also makes it safe to watch the process.

 

5.  Any woodworker that’s made some furniture is probably interested in dovetails.  I wanted to try some funky shapes that wouldn’t be possible normally.  I wasn’t sure how good the tolerances on this CNC would be, would there be large gaps when the parts are assembled?  I was looking to buy a new rack enclosure for my band‘s PA gear, I decided to make one instead.  The connections ended up being perfect as far as I can tell.  You’d have to take a magnifying glass to see any issues.

 

 

That’s it for now, I’m sure I’ll be doing some more projects that I can post up soon.  If you want any CAD from any of these, just let me know.

 

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New Build: Upright steamer trunk bass

New Build: Upright steamer trunk bass

Over the last several weeks I made this upright bass out of an old steamer trunk I found at a thrift shop for $10 (no Macklemore jokes please).

Here is the finished product, but keep reading for more finished pictures and a description of my process.

The finished trunk bass.

The finished trunk bass.

Several years ago I tried building an upright bass for the first time, using a metal washtub that can be bought at any hardware store for a few dollars.  It was quite the learning experience, I ended up having quite a few things that just didn’t satisfy me about it.  Here are a couple of pictures from that build:

Obviously I made a lot of mistakes since it was my first attempt at something like this.  I was never quite satisfied with how it turned out, but it did see a lot of stage use!  Here are a couple of action shots:

 

Action shot of the washtub at the Flagstaff bluegrass festival

Action shot of the washtub at the Flagstaff bluegrass festival

Washtub bass on stage

Ryan got a lot of good use out of it!

 

Here is the trunk before I did anything to it.  The handles were already gone when I got it.

Here is the trunk before I did anything to it. The handles were already gone when I got it.

I finally decided it was time to make a new and improved version when I found this old steamer trunk at a thrift shop for $10, and I really liked the look of it for a bass.  You can see it here before anything was done to it, although I have some wood set out to make the first few cuts.  You can also see the old bass in the background, I had it there to take measurements as I worked (mainly to fix all the mistakes I made the first time).  I didn’t work off any plans, just used my previous work and some quick calculations to figure it all out.  One of my favorite things about this project, I already had most of the stuff needed to make this bass.  The tuners and pickup were the most expensive part of the last build, and this time I could just use the ones I had from before.  That made this bass much cheaper than the last, although better in the end.

 

It might be easier to show the rest of the process in captions:

 

Hole cut in the trunk to mount the main structural support.  It has a wedge glued to it to give the neck the proper angle in relation to the trunk.

Hole cut in the trunk to mount the main structural support. It has a wedge glued to it to give the neck the proper angle in relation to the trunk.

Grooves cut into the back neck layer to add carbon fiber stiffening supports.  This will solve some of the flex issues I saw with my previous build, as well as giving it an increased sustain and larger tone.

Grooves cut into the back neck layer to add carbon fiber stiffening supports. This will solve some of the flex issues I saw with my previous build, as well as giving it an increased sustain and larger tone.

 

A few images of test fitting everything together, prior to glueing.

A few images of test fitting everything together, prior to glueing.

Angle view of test fitting, you can see the neck angle from the wedge.  It's almost looking like an instrument.

Angle view of test fitting, you can see the neck angle from the wedge. It’s almost looking like an instrument.

Front angle of test fit

Front angle of test fit

Laying out the headstock was the biggest challenge.  On my previous attempt the headstock had to be rigged numerous times to get it to tune up properly.  I wanted this one to work the first time.   You can see the tuners held in by tape to check the fit.

Laying out the headstock was the biggest challenge. On my previous attempt the headstock had to be rigged numerous times to get it to tune up properly. I wanted this one to work the first time. You can see the tuners held in by tape to check the fit.

Another view, you can see the carbon fiber stringers in this view as well.

Another view, you can see the carbon fiber stringers in this view as well.

Time to glue it all up.  String was strung tight to allow me to clamp the neck straight to the body.  This glue joint took somewhere around 2 hours of prep, but only 1 minute of actual gluing before it was done.

Time to glue it all up. String was strung tight to allow me to clamp the neck straight to the body. This glue joint took somewhere around 2 hours of prep, but only 1 minute of actual gluing before it was done.

Clamp it down tight.  This  joint has to hold against over 400 lbs of string tension, which translates to a much higher stress at the joint.

Clamp it down tight. This joint has to hold against over 400 lbs of string tension, which translates to a much higher stress at the joint.

After the glue has set for a bit, it's time to get back to work.  Clamps get left on though.  You can see the headstock is getting closer to completion.

After the glue has set for a bit, it’s time to get back to work. Clamps get left on though. You can see the headstock is getting closer to completion.

Closeup of the headstock, with the contour cuts for hand comfort and appearance.  I added a small block to cover the stringer grooves.

Closeup of the headstock, with the contour cuts for hand comfort and appearance. I added a small block to cover the stringer grooves.

Another view of the headstock.

Another view of the headstock.

Here is a side view of the bass, nearing completion!

Here is a side view of the bass, nearing completion!

After giving it a few hours for the glue to set, it's time to start sanding.

After giving it a few hours for the glue to set, it’s time to start sanding.

Keep sanding!

Keep sanding!

Front view after sanding.  The goal was to get every corner rounded off, and no splinters to catch my hand!

Front view after sanding. The goal was to get every corner rounded off, and no splinters to catch my hand!

After 24 hours, it's safe to apply tension to the glue joints.  I put the exact same strings on as the previous bass.  The washtub is officially in retirement.

After 24 hours, it’s safe to apply tension to the glue joints. I put the exact same strings on as the previous bass. The washtub is officially in retirement.

 

So that’s the build.  Here are some more pictures of the finished beast.  Thanks for making it this far, hope you enjoyed it!

 

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Making manufacturing more simple

Making manufacturing more simple

Wired magazine has an interesting article today, about how a design student designed a bicycle powered lampshade maker.

While lampshades are hardly cutting edge technology, the article focuses on how the difference in today’s very fast and complex manufacturing automation, and the possibility of more energy friendly (although slower) processes.

When I look at an automation process, many times the needed machinery is much more complex than originally thought.  A human regards a task of picking up an object and placing it in another location as a simple and mind-numbing task.  When looking at the equipment necessary to replicate this, it is staggering how much design and control is needed to replicate the human motion.

To replicate the possible motions of a human arm (just one arm), a minimum of 6 motors are needed, all working perfectly in tandem, with incredibly accurate positioning.  There will need to be a dedicated CPU, and a drive for each motor.  To pick up an object weighing a mere 5 lbs, the equipment cost could easily be in the 10’s of thousands of dollars, and to integrate all the parts into a working system could cost just as much.

What is really going on with the bicycle?  Is it really an automated manufacturing process (as the article suggests)?  I would say no, it is just using a bicycle to spin a mold, a human must still load the mold with the liquid base, and remove the finished lampshade 40 minutes later.  If a person had a daily 40+ minute bicycle commute, I could see them starting a lampshade business on the side, they could make 2 per day (that’s a get rich quick scheme if I’ve ever seen one).

The direction automation technology needs to go is not the path of the ‘Peak Hipster’ in the article, but instead into the realm of approach-ability for the average person.  By this I mean using proven industrial automation, but utilizing advanced human-machine interfacing to allow the average user to design their own manufacturing cell, instead of relying on very expensive consulting.   When this happens, I think you’ll see former assembly line workers suddenly becoming manufacturing automation designers, using their experience in the human assembly process to design machinery to do the same thing.

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