xiphmont

OPPP: OK, this is new unwork

....and, of course, immediately after mastering the water slide decal-fu, I discover the laser printer will, with no intermediate steps, print and fuse directly to the polyester diffuser sheet thankyouverymuch.

Ah well. Knowledge gained for next time. Hmmm.... I wonder upon what else this thing will print directly.

<img src="banana.jpg">

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xiphmont

OPPP: Water slide decals

First try went surprisingly well, but not perfectly, so of course I spent a day or two dialing everything in for future reference. The directions on the package leave out a few helpful tips.

Paper setting

Most importantly, the instructions stress over and over that a laser printer can melt the decal medium*, and so recommend settings that... did not work well in my particular printer.

I have a Color LaserJet MFP277dw, a popular choice for home printers right now (and I'm pretty happy with it). This printer has a low-temp fuser, and the recommended 'plain paper' setting for decals wasn't fusing the toner to the decal sheet reliably. The print tracked down the page (left side of the pic), and also tended to rub off after printing. The slower, higher-temperature 'transparency' setting works perfectly (right side of pic), and the print is durable to rubbing and scraping. Win.

Soaking and sliding

Secondly the instructions recommend soaking in hot water (good idea) for 20-30 seconds (in boiling hot water, maybe). I found a minute to be more like it, it depends on the actual temperature. Ideally, pull the decal out just before the edges start lifting from the backing.

The decal itself appears to be a vinyl of some sort. When it's hot, it's stretchy and pliable. When it cools back down, it becomes fairly stiff. In the usual 'building models' case, you probably want the label to conform to the target surface, so slide and apply while hot (being careful not to stretch the decal entirely out of shape).

For my use (meter scales) I want the decal to preserve its dimensions exactly. Letting the decal cool to room temperature before application works perfectly!

*The decal media is Papilio Laser Water-slide Decal Paper from texascraft.com. I've been using various specialty Papilio inkjet and laser media for more than ten years and have always been happy with them. These days it needs to be said: I've not been paid for any kind of endorsement, and have not been gifted any free or discounted product. I'm just a happy customer. There may be better stuff out there, but I've not bothered to look for it--- and that's coming from a perfectionist who's never satisfied with anything.

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xiphmont

OPPP: Laminating Plexiglas

I needed a few chunks of acrylic that were a little thicker than anything in my supply closet. Cyanoacrylate (superglue) bonds PMMA nicely, makes an optically clear joint, is easier to work with than acrylic-specific solvent glues, and doesn't add nasty internal stresses to the plastic.

On the downside, the bond isn't quite as fast (I suppose this is just as easily an upside) and the index of refraction of the glue won't be quite the same as the sheet. A perfect joint will still be noticeable right around the critical angle where seam's angle of total internal reflection will be a little different from the rest of the plastic.

IMHBCO that's small price to pay for getting perfect, strong, bubble-free joints every time without getting light-headed indoors.

Pic related: two in-progress parts curing and my go-to favorite CA glue. Once the glue is fully cured, I'll mill and polish them into rough lenses.


xiphmont

OPPP: These are a few of my favorite things

Since I love LEDs and I love meters, it is totally obvious to put LEDs into meters.


xiphmont

OPPP: Purpose-made Scales and Typeface Nostalgia

I hate to do this to a nice indicator made in the US, but it's the year 2000+17 and still no one has digitized any of the classic industrial control typefaces used by American manufacturers in the early- and mid-20th century.

A few used Futura or a close knockoff, but that sticks out a little too much. And no, Sublime is not a valid answer either. I used Leroy pen sets. Sublime is neither authentic nor true to purpose, it's just a more subtle kitch font.


xiphmont

OPPP: Unboxing Bread

This is my version of reclaiming childhood through eBay.

Some people collect old video games, others old equipment... I used to leaf though control indicator catalogues like they were porn rags, hence, this babby duck's lifelong fascination with analog meters and LEDs. It's the industrial design I grew up with. No color LCD screen can compare.

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xiphmont

OPPP: I'm way too proud of myself over this one

TD (@enginetankard) will concur--- I wouldn't shut up about it when he was here.

Chinese laser cutters often come with a little air pump; it's used to blow smoke away from the optics while cutting. You're supposed to set it up somewhere near the machine, and run an air tube in. It's a simple little AC coil/solenoid attached to a piston. It also vibrates enough that it will walk across a workbench under its own power unless you bolt it to something. I want my air pump internal to the cutter, and I want it automatically controlled to only be on when cutting. Vibration would be a major problem mounting it inside the case, so I took two of the little ones, machined a custom output valve housing/gasket and connected them in opposing orientation. Viola! No vibration.

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xiphmont

OPPP: the Laser Fist of Heaven

The radiator juuust sneaks in. And a big rad needs nice beefy fans, which double as smoke exhaust.

Also, it's nice of the vendor to use flimsy tack welds that snap right off with a little prying. I'm actually serious here. No reason to stupidly overbuild. This thing is made to be messed with.

Also also it's _really_ hard to nibble in a straight line.

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xiphmont

Old Project Progress Pictures: The Laser Fist of Heaven

I've built up quite a pile of project pics I took meaning to post, then never got around to it.

OK, so, laser cutter.

China sells a lot of cheap cheap cheap "It's so cheap I can't believe that price covers shipping let alone materials" maker tools. Some are better than others, and many barely work for their intended purpose out of the box. Overall, plan to get what you pay for, and I mean that in both the good and bad senses.

Most of these tools make decent starting kits though! Research a bit, then choose the kit with the most parts you want to keep (or the fewest you plan to toss).

I bought a K40 variant (SL320) on AliExpress, and I'm building it into a complete cutter now. It has a decent X/Y stage, came with a good tube (which I promptly broke while being an idiot), a larger than normal case, tubing, flow sensor, air assist head, and a better than average power supply. It also came with an exhaust fan and aquarium pump I don't plan to use, a useless Z-stage, and an air pump that makes half of the ideal.

Others are already doing a good, detailed job of documenting their K40 builds. I've been referring to Dons Things and Tims Machines extensively for tips in my own build. So, I'm going to stick to pictures, terse captions, and the few things I've uncovered that I haven't seen solved elsewhere.

I don't want my water cooling tubing dangling out back to an open bucket and a failure-prone aquarium pump, and I'm pretty sure an external chiller is overkill. I want a fully internal, closed water cooling loop. Water cooling may be useless (if still cool) for PCs these days (ha ha, see what I did there), but it does mean nice cooling parts are cheap and plentiful for other uses.

So, step 1: shoehorn in the biggest possible radiator core. And by biggest possible, I mean, "move everything else as far out of the way as I can to make more room". That starts with lifting the laser tube tray up by about 2cm. The original mounting flange is just tack-welded on. It's easy to pop it right off.

The limitation to how much higher I can go is actually the clearance of the mirrors along the left side, and the XY stage fitting under the door opening lip in the front. You can see I also nibbled off about half the depth of the left side of the door opening lip.

Aside: freehand nibbling is really hard to get straight.


xiphmont

George makes it his own

Last summer I bought a house in New Hampshire for living as well as greatly expanded workshop space. The kids are up here about half the time, and it's a holiday getaway for Camilla as well. I've been moving in slowly since July (Priusful by Priusful, with the occasional Minivan Marathon) and finishing the unfinished space inside one room at a time.

A few weeks ago, George apparently claimed one of the as-yet-unused rooms for his own workshop. (The other side says 'Do Not Disturb').

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