This week, I have been mostly working on... » CNC

…Fritz Lang’s Theremin Stand

Stephen Hobley — Sun, 06 Nov 2011 20:13:27 +0000

(Sounds like something you’d find in Warehouse 13)

For many weeks I’ve been trying to come up with a cabinet design for the vacuüm tube Theremin I built a while ago.

I decided that the electronics were far too marvelous to hide away in the classic RCA “drinks cabinet” – and that something more radical was required. (Electronic design by Mark Keppinger – more information is available here)

…and it had to have *lots* of elliptical curves. (‘Cos nothing says CNC like ellipses)

What I wanted was something that would be open enough on the front, back and sides so that the coils and tubes would be visible. It was routed from 3/4″ MDF and then the beveled edge was created using a small table router and “tracing” bit.

I still need to figure out a way to attach the antenna – and replace the 1/2″ copper tubing with some stainless steel, or brass. The front panel will eventually house the pitch tracker and midi interface I designed.

(Yeah… it’s dusty)

The speaker is not in the ‘ideal’ place for performance – it should really be behind the player’s head. This position does allow the speaker to be placed facing forwards or backwards, and it can be removed completely and placed on another stand if required.

I’ve been experimenting with different paint finishes – and I think that black satin is probably the best. High gloss would be nice, but requires more maintenance. Unfortunately the seasonal window on spray painting is starting to close, so it might be spring next year before I can finish the project.

…and even though the Fritz Lang thing was a joke – it does remind me of this scene from Metropolis.

Update:

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DIY CO2 Laser Cutter – more test cuts…

Stephen Hobley — Wed, 12 Oct 2011 03:13:07 +0000

I re-aligned the bounce mirrors, added an air-assist, and did some test cuts on acrylic, plywood and hardwood. Slowing the feedrate seems more effective than increasing the power.

Need to spend some time with different materials, figuring out the cut parameters for each one.

Oooh shiny!
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…making some initial cuts with the CO2 Laser

Stephen Hobley — Tue, 04 Oct 2011 20:13:26 +0000

Yes! Finally, after several iterations we have the installed, aligned and focused CO2 laser wreaking some serious havoc on a piece of MDO.

There are still many tests to run and various safety mechanisms to install, but the system works, and is aligned over a 24″ x 24″ area (at least).

I can think of at least half a dozen improvements to make right now, but they’ll have to wait – for a day or two anyway.

Again – safety glasses are *mandatory* for this kind of work.

The first part of the movie covers some tips for beam alignment, the cutting is right at the end.

…almost forgot about the air-assist nozzle…

…for making nice clean cuts in acrylic.

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…installing the laser tube

Stephen Hobley — Wed, 28 Sep 2011 21:59:36 +0000

After much wailing and gnashing of teeth I finally got the tube installed in its new home. However I’ve now realized that it’s 4″ too short and I need to build a new base and position it correctly .

Still, I hooked up the cooling system, and thankfully there are no leaks – I gave it a quick test and it’s bouncing the energy straight up in the air.

The high energy physics laser emitter aperture – or 3″ plumbing flange:

The next challenge is to get it to bounce across and hit this mirror:

Like this :

Click here for further adventures…Similar Posts:

…building my Destructor(tm) beam

Stephen Hobley — Sun, 25 Sep 2011 13:54:59 +0000

More progress in the laser/CNC saga.

I built a cage from steel and MDO for the laser tube – fits really nicely. Next step is to add the first bounce mirror which will turn the beam straight up – into a PVC tube attached with plumbing flanges (The sales assistant at Menard’s asked me what I wanted it for – I’m pretty sure he wasn’t expecting the answer he got).

www.stephenhobley.com I moved the CO2 laser tube out of its box and into a steel and MDO cage. Now I'm ready to install it in the BlackToe CNC gantry." longdesc="" />

All the parts are in – I was able to repurpose some Laser Harp spares for the mirror mounts, and found a 25mm Silicon/Gold mirror on eBay for under $30 – a bargain.

www.stephenhobley.com Ready to be installed in the BlackToe CNC gantry. (This is the business end)." longdesc="" />

I finished the last of the designs today – now all I need to do is cut it out and assemble it.

Pete came over on Thursday night and we tested the ‘volatility’ of the unfocused beam on a variety of building materials…

“Impressive. Most impressive…”

New update here.Similar Posts:

Laser Cutter 2.0 : That is one big *ss tube…

Stephen Hobley — Sat, 10 Sep 2011 19:57:44 +0000

Good news! The laser tube, power supply and cooling system arrived yesterday.

The 80W tube is *MASSIVE* – even though I knew the dimensions before I ordered it, I guess my subconscious had chosen to ignore the fact of exactly how long this thing was going to be.

Hmmmm… I might have to move my router bed somewhere else.

First thing to do was hook up the active cooling system and take it for a spin. I put just under 2 gallons of distilled water in the tank and hooked the inlet/outlet ports together. Everything seemed good, water was flowing and the readout displayed 22 degrees centigrade.

It looked like the port connectors and tube connectors were different sizes, so the supplied pipe wasn’t going to do it. A quick trip to the local hardware store got me the following:

Watts SVHF10 (Clear vinyl tube) 10′ x 7/16″ OD x 5/16″ ID [x 2]
Watts A-277SH; SH-77 Hose barb adapter 5/16″ x 3/8″ [x 2]
Watts A-298 3/8″ Barb x 3/8 FIP [x2]
Teflon tape.

I was then able to hookup the laser tube to the chiller. Be very careful when connecting vinyl tube to the glass of the laser – it would be very easy to break it at this point. (Latex hose might be better).

So that’s got the cooling up and running.

The next challenge is hooking up the PSU and actually operating the tube.

Update :

That’s got the tube running successfully. Now I need to build an enclosure for it.

I’ve ordered another bounce mirror, due to space requirements I have to ‘fold’ the laser beam one more time before I can direct it towards the gantry.

It goes without saying – I’m wearing safety glasses throughout all the testing procedures.

So should you.

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…an update to the laser cutter / mill saga

Stephen Hobley — Tue, 30 Aug 2011 15:47:57 +0000

It turns out that the laser tube I have will not work with the generic PSU units on E-bay. Not entirely sure why this is, but I did notice that the insulation on the tube is starting to *melt* so maybe it’s time to move on.

So… it looks like my only option right now is to bite the bullet and go for a full 80W system. This requires a chiller to run the water coolant. The significant increase in the heat generated will soon warm up the water reservoir, and so active cooling is required. Which in turn is going to push the costs up to around $1400.

So I’m going to have to do some creative accounting to get that one through the books

In the meantime I’m going to look into adding a rotational axis to the mill.

More to come…

Update : So I just ordered the new tube, power supply and chiller unit. Should ship today from China and get here in a week or two…

Update² : Also the motor and controller for the fourth axis is on its way. I’ve got most of the parts cut too, so it’s only a matter of time now…

Yay! The tube is in…Similar Posts:

Adding a laser cutter to the BlackToe CNC Mill

Stephen Hobley — Sat, 06 Aug 2011 22:11:13 +0000

It’s time I took the CO2 laser from the Chinese cutter and attached it to the gantry of my BlackToe CNC mill. Effectively increasing the size of the cutting bay from the tiny 5×8″ to a whopping 2′x 4′ – the small size of the cutting area was starting to become annoying – and it seemed ridiculous to have the larger gantry available and not be able to use it.

So…

…the first task was to strip the laser tube, power and control systems from the original cutter.

The next step is to construct a heavy-duty housing to mount the tube alongside the milling gantry.

UPDATE : After a weekend of futzing around with lots of different combinations – this is the final configuration of flying mirrors I’m going with.

I split up the focus head and will attach the lens to the base of the milling head – so I can adjust focus with the Z axis control. I can also switch between spindle and laser without adding/removing anything…

UPDATE UPDATE : So… having very carefully removed the laser and power supply from the original casing I’m sorry to report that the PSU is dead. The flyback driver is no longer flying the way it should and the laser isn’t lasing.

I’ve put in a bid on a replacement PSU and we’ll see how that works out. Kind of annoyed about that, as I really didn’t want to buy another 40W PSU – I was hoping to upgrade to a full 80W system.

UPDATE³ : OK so the new PSU is on its way – should take a couple of weeks, in the meantime I’ll make some refinements to the optics.

Click here for an update.Similar Posts:

At the Maker Faire in Detroit

Stephen Hobley — Sun, 31 Jul 2011 11:34:53 +0000

Spending the weekend up at the Maker Faire in Detroit.

Check out the Maker Faire Daily stream for more info.

UPDATE : Just got back from the Faire – always a pleasure to go to these, and nice that they’re more local than San Francisco now…

Wow lot’s of stuff to see and do. The Henry Ford Museum was a great venue. Many ideas for toys and games for Sarah Jane – I also managed to pick up a copy of the “Eccentric Cubicle” – a makers guide to weird and wonderful devices.

Here are some of my pictures from the event:

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The Clock Of The Long Weekend…

Stephen Hobley — Mon, 25 Jul 2011 15:40:17 +0000

I’ve spent a lot of time on the “The Long Now” website lately – I would urge you to check it out if you’ve not seen it – one of the things that caught my attention was the 10,000 year clock they are trying to build in Texas.

Inspired by the design, I thought I would have a go at redesigning my EM clock to use a governed rotary regulator.

The design is similar to a Torsion Pendulum, but it does not oscillate. It turns continually, driven by an impulse drive and feedback/monitoring electronics. It’s not as consistent as a pendulum, but it does have advantages in terms of size and stability (since the EM pendulum is driving the clock – it tends to swing more violently than a regular escapement driven one).

It was also an excuse to learn how to design Geneva wheels…

Here’s a time-lapse of the Geneva mechanism…

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