Archive for November, 2019

CNC 3018-Pro: Collet Pen Holder

Along the same lines as the MPCNC pen holder, I now have one for the 3018:

CNC3018 - Collet pen holder - assembled
CNC3018 – Collet pen holder – assembled

The body happened to be slightly longer than two LM12UU linear bearings stacked end-to-end, which I didn’t realize must be a constraint until I was pressing them into place:

CNC 3018-Pro Collet Holder - LM12UU - solid model
CNC 3018-Pro Collet Holder – LM12UU – solid model

In the unlikely event I need another one, the code will sprout a max() function in the appropriate spot.

Drilling the aluminum rod for the knurled ring produced a really nice chip:

CNC3018 - Collet pen holder - drilling knurled ring
CNC3018 – Collet pen holder – drilling knurled ring

Yeah, a good drill will produce two chips, but I’ll take what I can get.

There’s not much left of the original holder after turning it down to 8 mm so it fits inside the 12 mm rod:

CNC3018 - Collet pen holder - turning collet OD
CNC3018 – Collet pen holder – turning collet OD

Confronted by so much shiny aluminum, I realized I didn’t need an 8 mm hole through the rod, so I cut off the collet shaft and drilled out the back end to clear the flanges on the ink tubes:

CNC3018 - Collet pen holder - drilling out collet
CNC3018 – Collet pen holder – drilling out collet

I figured things would eventually go badly if I trimmed enough ink-filled crimps:

Collet holder - pen cartridge locating flanges
Collet holder – pen cartridge locating flanges

The OpenSCAD source code as a GitHub Gist:

, ,

Leave a comment

Crock Pot Base Screw

While washing our ancient electric crock pot (“slow cooker”), I wondered how corroded the inside of the steel shell had become. A simple nut secured the base plate and unscrewed easily enough, whereupon what I thought was a stud vanished inside the shell.

The shell wasn’t rusty enough to worry about, but the stud turned out to be a crudely chopped-off thumbscrew on a springy rod pulling the base toward the ceramic pot:

Crock Pot Base - OEM thumbscrew
Crock Pot Base – OEM thumbscrew

Evidently, they pulled the thumbscrew through the base, tightened the nut, then cut off the thumbscrew flush with the nut.

I desperately wanted to drill a hole in a new thumbscrew and repeat the process, but I no longer have a small drawer full of assorted thumbscrews. So I must either lengthen the existing thread just enough to complete the mission or build a screw from scratch.

The thumbscrew is threaded 10-24, I have a bunch of 10-32 threaded inserts, so pretend they have the same thread diameter and tap one end to 10-24:

Crock Pot Base - tapping insert
Crock Pot Base – tapping insert

Jam the new threads on the thumbscrew and jam a 10-32 setscrew into the un-wrecked end:

Crock Pot Base - thumbscrew extender
Crock Pot Base – thumbscrew extender

You can see the surface rust in there, right?

Make a Delrin bushing to fit around the insert poking through the base:

Crock Pot Base - drilling Delrin button
Crock Pot Base – drilling Delrin button

Reassemble the internal bits with permanent Loctite, top with a nyloc nut, and it’s only a little taller than the original nut:

Crock Pot Base - assembled
Crock Pot Base – assembled

The setscrew let me hold the new “stud” in place while torquing the nut, plus it looks spiffy.

Memo to Self: If it ain’t broke, don’t look inside. Hah!

Surprisingly, both Amazon and eBay lack useful thumbscrew assortments …

,

6 Comments

Obfuscated Signage

Spotted in an arboretum:

Not for Public Admittence into the Area
Not for Public Admittence into the Area

How about good old “Keep Out”?

I’m not sure what the “do not touch” icon is supposed to mean, other than a lack of “no entry” icons.

4 Comments

Monthly Image: Deposit Slot

The Dutchess County Board of Elections occupies the building at 47 Cannon St which, if I recall correctly, was a Central Hudson Gas & Electric Company office back in the day.

CHG&E accepted bill payments at all hours through a little slot high on the wall:

Pay Bills Here - overview
Pay Bills Here – overview

A closer look:

Pay Bills Here - envelope slot
Pay Bills Here – envelope slot

It’s solid cast brass, neatly milled, and built to last a thousand years. They don’t make ’em like they used to, probably for good reason.

I’m told somebody once stuffed burning trash through the Arlington branch library’s book return slot. Nowadays, the fire code apparently requires the room behind the slot to be fireproof and isolated from the main structure, which may account for the popularity of outdoor book / media return boxes.

Leave a comment

DOT-01 NP-BX1 Battery Status

Back in February, a quartet of DOT-01 NP-BX1 lithium batteries for my Sony HDR-AS30V helmet camera had mediocre performance compared to an older Wasabi battery:

Dot01 NP-BX1 - new 2019-02
Dot01 NP-BX1 – new 2019-02

After eight months of regular use, they’re even further into mediocre:

Sony DOT-01 NP-BX1 - 2019-10-29
Sony DOT-01 NP-BX1 – 2019-10-29

In round numbers, they’re down from 2.8 W·h to 2.5 W·h and now run the camera for about 70 minutes, rather than 90+ when new. Our typical rides go for about an hour, which means I must swap batteries somewhere along the way.

I still dislike the notion of sticking a 16850 cell next to the camera and powering it from the USB charger running the M20 rear camera requires another helmet cable, but it’s obvious NP-BX1 batteries lack enough active ingredient for the long haul.

Leave a comment

Kenmore Gas Stove Oven Temperature Control Encoder

For the last year or so, the oven temperature control on our Kenmore gas stove has been decreasingly stable, sometimes varying by 100 °F from the setpoint before settling down somewhere close to what it should be. Spotting a replacement control board for a bit over $100, I decided the board used an absolute rotary encoder of the open-frame variety, so I took the thing apart:

Kenmore oven control - PCB overview
Kenmore oven control – PCB overview

The encoder was, indeed, an open frame:

Kenmore oven control - rotary encoder
Kenmore oven control – rotary encoder

The red droplet is DeoxIT, the rest of which went inside, just ahead of the contact fingers, and got vigorously massaged across the switch contacts on the wafer by spinning the shaft.

Some time ago, the membrane over the TIMER ON/OFF switch cracked and I applied a small square of Kapton tape. Having the entire controller in hand, I replaced the square with a strip of 2 inch Kapton, carefully aligned with the bezel marks embossed on the membrane, and now it’s smooth all over:

Kenmore oven control - Kapton tape cover
Kenmore oven control – Kapton tape cover

The MIN(ute) ^ switch required a much firmer than usual push, so I tucked a shim cut from a polypropylene clamshell between the membrane and the pin actuating the switch.

Reassembled, it works perfectly once more.

Gotta love a zero-dollar appliance repair!

2 Comments

Tire FOD

We rented a van to haul our bikes on a vacation trip, but the tire pressure warning alarm sounded when I turned into the driveway. Measuring the tire pressures showed the left rear tire was at 51 psi, far below the 72 psi shown on the doorframe sticker, and a quick check showed a possible problem:

Tire FOD - in place
Tire FOD – in place

The small circle in the tread to the left of that mark turned out to be a metal tube:

Tire FOD object
Tire FOD object

Their tire contractor determined the tire wasn’t leaking, the metal tube hadn’t punctured the carcass, and all was right with the world. After, of course, two hours when we expected to be loading the van.

The rental company was good about it, perhaps because I reported they sent the van out with the other rear tire grossly overinflated to 86 psi (!); obviously, their prep didn’t include checking the tires. Somewhat to my surprise, the space under the passenger seat for a jack was empty.

During the trip, the van laid an egg:

Transit Van with Egg
Transit Van with Egg

A good time was had by all, but our next bicycling vacation will definitely have much more bicycling and much less driving!

Leave a comment