Oct
27

Week 43, 2013 – Links and Things

Well, I ordered some more stuff from Harbor Freight…  I took another shot at getting the air compressor, I bought the powder coating system, and picked up some little bins.  The air compressor was on sale for only $99, less than last time, even!  But guess what? They didn’t ship it this time either! Well, this warranted a phonecall.  It turns out that despite being on the frontpage of every flier, and being part of every damned sale every week, it has in fact been DISCONTINUED for several months!  So now I’ve even got a powder coating system I can’t use without an air compressor I don’t have…  (And then my family made the remaining money disappear…they’re really good at that.) It’s always some god damn thing, isn’t it?

Anyway, some of my projects are on hold, but other than that, the lack of visible progress is mostly me being lazy.  Not that I’m completely idle, I’m just not documenting anything I’m doing, which is part of the reason I came up with these status reports.  Though at the moment most of what I’m doing involves putting my ducks in a row…which isn’t terribly interesting anyway.

Let’s see here… My current expenditure priorities for the next couple months are…

  1. Paying for my webhosting… Which I’m not even sure I can do entirely come the first, and it’s already past due.  Gotta email them.
  2. Getting lithographic film, chemicals, and darkroom supplies.
  3. Getting an air compressor.
  4. Getting the extended bed for the lathe. (It sure would be nice.)

My father and I are also both rather interested in joining the ARRL, in case there were any doubt that we are both enormous nerds.  Maybe do that for Christmas, or early in the new year.  I’d really like to get the 100th anniversary version of the 2014 ARRL Handbook.  We’ve got to get out to Burlington to take our license exams though.  I took a practice exam and got everything except questions about specific frequencies.  (So, with no prep at all, I almost got a passing grade.  I shouldn’t have a problem after I actually learn what I need to.)

Some nifty links!

The YouTube channel of John Grimsmo, knifemaker and just fairly awesome guy. Him and his brother make some totally amazing knives using some crazy materials like Titanium for the handles and hardware, and do it all using CNC.

A photo-heavy Home Model Engine Machinist forum thread about a project 1/4 scale V8…  Usually when you see something like that they don’t mean EXACT SCALE REPLICA… But this thing’s a real internal-combustion engine with electronic fuel injection, using an ECU and everything.  He even made his own scale spark plugs.

A very cool robot thing, with an especially impressive neck joint.  Lots of gears.  The video details a bit of the machining process.

A series of videos detailing the design, fabrication, assembly, and test flight, of a very nice carbon fiber quadcopter frame.  The second video (coincidentally enough posted on my birthday) proves an idea I’ve long held; the only truly smart and safe way for the hobbyist to mill or route carbon fiber sheets is if they’re submerged in a shallow water bath to catch the particles.

And last but not least, I learned a new word.

Oct
20

Week 42, 2013 – PCB Process Revisited

So, as some of you know, I’ve had no end to trouble producing printed circuit boards (PCBs); there’s always some damn thing that isn’t quite right…  Toner transfer is always a crapshoot, quality-wise.  And photo-resist is iffy because my laser printer can print good high-density positives, but not negatives, and my CraftRobo can’t cut rubylith fine enough for the kind of PCBs I’m making…

I’m left with two options;  Screen-printing resist to the board. (Since burning screens is a positive image process)  Or! Using lithographic film in an emulsion-to-emulsion contact exposure with my laser printer transparencies to yield perfect high-contrast negative films to expose the dry film laminated photo-resist on the PCBs with.  (I can also use lithographic ‘duplicating film’ to turn so-so positive transparencies into film positives with perfect contrast.)

Right now I’m just waiting on money for supplies.  Like a hundred bucks in chemicals, film, and darkroom stuff.

In the meantime, here’s some YouTube links!

Oct
13

Week 41, 2013 – Digital Readout

A couple years ago I bought a bunch of cheap Chinese digital calipers with the notion of using them to build my own DRO (Digital Readout) for a mill or lathe, or getting one from ShumaTech which now seems quite defunct.  A couple weeks ago I stumbled upon a newer project using an Android device as a DRO, with a simple Arduino hardware interface to some magnetic scales.  The developer has since added support for the Texas Instruments MSP430 Launchpad board, and is in the process of adding support for the cheap Chinese scales and calipers.  I’ll do a full write-up when I build the system.  (I’ll be installing it on the lathe, since the mill will be converted to CNC in the near future.)

He was supposed to release an updated version of the firmware that supports the Chinese calipers the weekend this was originally posted, but it’s been two weeks now, and nothing.  So I think I’m going to have to get back to writing my firmware now that I have my sample voltage shifter chips from TI.

Oct
06

Week 40, 2013 – Shars Tools

I fell a bit behind; I had these posts partially prepared but never posted.  I’m going to try and add at least a couple links and pictures later.

So I made an order from Shars Tools.  Shars is where I’ve gotten the majority of the tooling and instruments for my machine shop.  It’s basically the Made-in-China-dot-com of the machine tool world, and judging from the AOL and gmail mail addresses, I swear it’s run out of somebody’s house, and they don’t actually have any inventory, it just comes direct from China and they send it off to customers…it really wouldn’t surprise me in the least. But their prices are hard to beat, they’ve got one of the best selections, and their customer service is good and very responsive, especially considering it really does seem to be run by like ONE PERSON.

This time I picked up some handy bits and bobs, for instance, a set of telescoping gages, and a direct-reading ‘mechanical digital’ micrometer accurate to 0.0001″.  Very good tools for inspection.

I picked up some new inserts for the indexable tools for my lathe; since I can’t run it fast enough to reach the optimal cutting speeds for carbide inserts on aluminium I’d been meaning to get some aluminium-specific inserts…which are sort of hard to find for some reason.  I also picked up a matching indexable boring bar.  I wanted to get a pair of internal and external indexable threading tools with special thread-forming inserts, but they were like $30 each.  Need to do that though if I’m going to really do any serious fabrication on the lathe.  I also had my eye on this great grooving and profiling tool.  Profiling will be a big deal if I ever convert the lathe for CNC.

Also picked up an indexable dovetail mill for the milling machine.  I figured it didn’t cost that much more than the non-indexable version, so screw it. This way, any time it gets dull, I can just replace the cutting edges instead of buying a new cutter. Inserts are relatively cheap.

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