Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The Y-axis leadscrew on a Sherline milling machine sits exposed to all the crap blowing off the cutter; maybe it doesn’t matter, but it seems nasty.
Throw them out when they're this dirty!
So I made a set of way covers from the template available here or here, except I used plain old printer paper, stuck in place with double-sided tape. The picture shows what one looks like after surviving the rigors of a trip to Cabin Fever Expo.
The key feature is that, when they get too schmutzig, you just throw them away and fold up a new set. It’s easier than dismounting and cleaning something more substantial that you can’t just discard because you’ve developed a serious, deep, long-term emotional attachment.
Everybody at Cabin Fever Expo liked them and wanted the template. If those links have rotted out, I have a copy of the file in the Useful Stuff section: here.
Bellows Folding
Update: Here’s a closeup of a new set. Start with the printed lines up, then fold the end tabs up: the printed side will be down (as in the bellows on the right) and nobody will know how poorly you followed the lines. Click to get a big pic with decent resolution if you need more detail.
So I hauled my Sherline CNC milling machine gadgetry, an assortment of trivial projects, a stack of handouts with pix & G-code, and a pile o’ EMC2 doc to Cabin Fever Expo for two days of Performance Art…
Ed Nisley Demo-ing CNC at Cabin Fever. Picture courtesy of Brian Glackin.
The key is to have the knobs turning: an inactive machine is just background clutter that everyone walks right past. It’s not nearly as interesting as miniature tools or a chuffing steam engine.
There’s something to be said for being on the crowd side of the table, as that lets both of you see the monitor. A bigger display might be more helpful; I duct-taped a 14-inch 1024×768 LCD panel to the top of the desktop PC box.
Although I brought some blank stock along, it quickly became obvious that live-fire milling under show conditions is a Bad Idea: far too many distractions and far too many things can go wrong. So I contented myself with cutting air; nobody really minded and I could switch programs in mid-stride to show folks the G-code program they really wanted to see.
Plenty of folks stopped by, many of whom either have CNC running or are in the throes of getting started. A surprising number of conversations started with “I have this old Bridgeport …” and went on from there.
There’s a crying need for a comprehensive machine design tutorial that explains how all the pieces fit together, with sort of a flowchart outlining the choices (I know it’s more complex than that, but a diagram would be a starting point for discussion). I don’t know enough of the servo end of the biz, but someone should show how the machine’s size determines the motor size and, thus, the motor driver size, with plenty of examples. There’s a misconception that you can run a big machine on little steppers or puny servos, with the controller making up the difference.
Many people do not understand the difference between CAD, CAM, and what EMC2 provides. I described the process as three layers: CAD makes the pretty pictures, CAM digests those pictures and emits G-code, EMC2 converts G-code into motion. That seemed to help.
The single most attention-getting part of the exhibit was, to my astonishment, my Orc Engineering counterweight (described here and here) supporting the Sherline’s milling head. I had to explain just exactly why you need a counterweight in the first place (heavy offset motor, short Z-axis ways) and how much it weighs (13 pounds, a bit too much). Some folks commented that they put similar counterweights on their much larger machines and after a while I stopped feeling inadequate.
EMC Penguin Mascot
At least a dozen people picked up my EMC doc and asked if I was selling it; took me a while to realize they wanted to buy the booklets. I don’t know if you could make any money at it, but there’s a definite market for ink-on-paper books with no plot and weak character development. Now, if Chips were was way more shapely, we could have a real bodice-ripper cover. Somebody get on that, OK?
I make booklets using Adobe Reader’s print-as-booklet feature, a printer with continuous-flow inking, and an Ibico comb binding machine, but there’s enough fiddling that doing much of it for anybody else just doesn’t make sense. Something like Lulu might work, but there’s a stiff (to me, anyway) up-front charge and the EMC doc changes often enough that you’d have to run plenty fast to stay in the same place.
Other people picked up the books and asked if I was selling the software. They seemed puzzled when I said it was free for the download and that not only was the software free, but the GPL meant that they were, too. I need to work on that part of the schtick… should’a had a few CDs to pass out, too.
I remembered to bring a bag of cough drops, ate ’em like candy, talked almost continuously, and wound up hoarse anyway. Probably convinced a few folks to try EMC, didn’t terrify many children, and a good time was had by all.
Although live-fire milling is scary, it’d be fun to make something like a finger ring (as in Dan Statman’s gorgeous designs, but plastic) as a hand-out freebie. The whole process should take no more than five minutes, tops, which might be tough. Running a rotary table and the mill would be a real crowd-pleaser; my 4th axis attracted some questions. Perhaps an EMC tag-team would suffice: one to mind the mill while the other works the crowd?
As always, Cabin Fever is stuffed with gorgeous examples of machine-shop work. Those guys actually know what they’re doing; I can write G-code, but it’ll take many more years of experience before that code actually makes passably pretty parts.
I just finished re-typing my (admittedly limited) list of contacts, merging the lists from my ancient Virgin Mobile Nokia Shorty and my new-but-defunct Kyocera Marbl into the replacement Marbl.
These things should be able to bag up their internal representation of my Contacts into some standard interchange format, place that file somewhere, download such a file, and poof be up and running.
If Virgin wants me to keep buying phones, why do they make it such a pain to start up a new one? Come to think of it, I know why: they don’t make any money on the phones, so they must maximize the phone’s lifetime, while simultaneously touting new features to entice new customers.
I’m still grumpy from driving too much, even after a mid-morning nap.
Oh, that Kyocera Marbl from Virgin Mobile I mentioned here? One of its bullet item features is “web browsing“.
The screen is roughly the size of a large postage stamp and displays text amounting to, in round numbers, five lines of three words each. Graphics are not an appropriate use of screen real estate.
I have not signed up for a “data pack” to enable cheaper browsing.
There’s nothing I can say about this that doesn’t sound snarky.
Wireless mice have fairly good power-saving routines; if they’re not moving, they shut down. Alas, if you’re packing a mouse to bring along with your PC, it may stay awake for the whole trip… at least until its battery goes flat.
Isolating tab for storing a mouse
You can remove the cells, but then you’re stuck with a bunch of moving parts: mouse, receiver, a couple of AA cells. Now you need a ziplock baggie. Fooey.
Better to take a strip of thin plastic, like a small plastic Post-It flag, and isolate one cell. Make it long enough to stick out through the slot in the case and you’ll have a reminder that the mouse won’t start up automagically.
Mouse with battery disconnected and tabbed
Some mice actually have a mechanical switch, but if it’s a pushbutton then you may as well insert the plastic strip.
This works for cell phones, too, at least if you’re the sort who can afford to turn the phone off because you’re not expecting any calls.
Basically, we don’t need a cellphone except for the occasional biz trip and to tote along while cycling Just In Case. Paying a buck or two a day for something we don’t need doesn’t sit well with us.
So here’s the cheapest alternative we’ve found…
Go to virginmobileusa.com and buy a $10 phone. Some are free, but as of right now the Kyocera Marbl has the longest battery life and the fewest features. It’ll be obsolete by the time you see this; struggle through their “compare phones” and specs to find the really valuable number: standby battery life.
They strongly encourage a monthly plan. If you actually use the phone, a monthly plan might make sense. If you never do any talking and don’t expect any calls, skip all that.
The key step: sign up for Auto Top-up with either a credit card or PayPal. That reduces the mandatory payment to $15 every three months. Well, it’s really $16.22 after title, taxes, tags, and tip, but you get the idea: five-and-change a month for a phone.
The cost per minute is staggering: 20 cents/minute or some such. That’s 75-ish minutes of air time per month, far more than we ever talk. We must occasionally talk to somebody and burn down the account just to keep it under control.
Text messaging is worse: 10 or 15 cents each. A major ripoff. ‘Nuff said.
Coverage is by Sprint, so you take your chances. It’s marginal in the house, OK outdoors, better elsewhere.
Their Website is choked with gratuitous Flash, difficult to navigate, has no search function, and suffers from terrible layout. Oh, yeah and their customer service is stunningly bad.
I did get an actual competent human when I had to swap out the first Marbl: the hinge spring broke, holding it slightly open. As they say on the website: For everything else, give us a call at 1-888-322-1122.
It’s not obvious that paying more gets you better service, though.
The Smell of Molten Projects in the Morning 