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Mix of wood and metal in the shop for the next week as I work to build a command gift for my boss. Turnover is this week into next with the Change of Command officially next Tuesday. I copied the ammodor concept since you cannot simply order one and have it delivered reliably and I guess because I can. So far it's coming out alright, more difficult to do what I want to than expected. Today's lesson - CNC's let you fuck stuff up with precision. Most mistakes have been recoverable, but time consuming. Only thing photo worthy so far is the custom panel for the inside of the top cover which houses the hygrometer and humidity packs. The box that goes in the box is glued up and curing. The tray that will nest into the box-in-the-box is also glued up as of 20 minutes ago. The bottom panel for each will get a laser-engraved logo, hopefully tomorrow night.

Pretty much done with Frisco’s Fancy as Fuck Dog Bowl Stand.

Been working on a box of sorts I guess. Unsure if my dad needs a box but he sure is gonna get one. Still need to do some sanding, cut the lid down to size and put finish on, this is just after the glue dried on the joints.

Here is an interesting figure The bottom axis is in kPa-cm. Atmospheric pressure is 100kPa. Let's say that we use a shoulder washer that goes into the ceramic insulator 0.5mm, so the overall arcing distance is 1mm, or 0.1cm. So we are interested in 100 x 0.1 = 10 on the horizontal axis. That says that the breakdown voltage is about 5kV - so we should be OK? Well no. Those curves (Townshend curves) are taken between two parallel plates, so an ideal measurement arrangement - the result of a very careful experiment. The case of a small diameter screw thread, which has voltage stresses from each thread peak reduces the breakdown voltage significantly. And it is uncontrolled - tiny bits of conducting swarf and other grot possible too. So an 0.5mm insertion into the ceramic is getting marginal for 500V. Increasing the insertion to 1.5mm gives an arc gap of 3mm (0.3cm), giving a (ideal, parallel plate) breakdown voltage of about 10kV. Even if this was degraded by a somewhat outrageous factor of 10 (1kV), we are still safe at 500V. Which is the basis for using shoulder washers that are as long as reasonably possible

Simple miter joints. Took a bit to set up on the table saw just right but glad I did. All the corners are 90 degrees. Going to cut splines in next weekend for strength. Trying to decide if I want 2 or 3 on each corner. Will be using more walnut to match the inlay.

Make sure the thermal compound paste you are using is non-conductive as well as not all of them are.

because the OD of the washer extension is larger in diameter than the hole in the bracket and PCB, assuming they are nominal clearance holes for the fixing screws.

Found the spec sheet in my T2 parts folder - looks like I used 7721-3PPSG . That has an extension of 3.81mm (1/8") and that clearly worked. Again Mouser - they have 11,500 of them in stock.

Regarding transistor mounting. I'm thinking back a looong time to when I built mine. I used steel screws, because I could not get enough torque on plastic screws (I use a torque screwdriver and read the data here https://www.onsemi.com/pub/Collateral/AN1040-D.PDF ). But the trick is to use the AAVID long penetration washers. You need enough length to go through the TO220 tab, and penetrate most of the way through the 4171G insulator. Now the problem is that the thickness of the tab is extremely widely specified - somewhere between 0.5mm and 1.39mm. I've done a straw poll of TO220 devices I have, and the vast majority are between 1.25mm and 1.3mm thick. My 4171G insulators are actually 2mm thick (at the top end of the tolerance; they are nominally 1.778mm (0.07") +/- 0.254mm (0.1"). So mine are towards the top end of the tolerance band. Anyhow, it looks like the AAVID 7721-13NG (Mouser has 8,000 of them) is the man for the job. I can't find the remainder of the ones I bought to check, but I think I used those. The extension is between 2.71mm and 3.26mm. You need to check your tab and insulator dimensions, but under most circumstances the shoulder washer will go through the TO220 tab and most of the way through the 4171G. If the tolerance stack goes against you, that shoulder washer might actually protrude from the bottom of the 4171G. If that is the case you absolutely must trim the end shorter. Otherwise you won't make thermal contact between the transistor and the heatsink. That will enable you to use steel screws and nuts (don't forget the lockwasher!). Oh - and you absolutely must use heatsink compound! Craig

My favorite Cowboy Junkies album is Caution Horses. Not as well recorded as The Trinity Sessions, but I like the music more. Sun Comes Up It's Tuesday Morning is just a beautiful stream of consciousness gritty song, and 'Cause Cheap Is How I Feel evokes a ton of feeling as well.... There was a newer release in the last few years, called Sharon, that has some of the first recordings from the album; it was a failed attempt to do similar single-mic recording as Trinity, but the space wasn't as good. Just some interesting stories around the making of the record.... Of course, I was in love with Margo Timmins too, so that helps the enjoyment 🙂

What do you mean, "if"?

Cleaning up my queue a little bit. I was listening to this when I read about Tina, so that occupied my queue for a while. Beethoven: Violin Sonatas Nos. 4, 9 & 10 Andrew Wan, Charles Richard-Hamelin 2021 https://album.link/i/1581150773 Example: Not great - but really good. I guess that is not really fair, I did like it enough to listen to it twice. I don't know the Label or the performers. It is well recorded with a very live feel. Phantasmagoria or a Different Kind of Journey Eivind Aarset 2021 https://album.link/i/1575767827 Example: Holy smokes that was cool. The info just talked about him being a guitarist, not an amazing composer and crafter of sounds. Added to my list of people. Now: The Trinity Session Cowboy Junkies 1988 https://album.link/i/299789347 Example: Famous in my world for all its audiophile goodness. I had been thinking about it ever since listening to Le Ren. It holds up for all the right reasons. An Incredible recording and just a super cool performance. Okay - caught up.

https://youtube.com/@BlacktailStudio Via reddit Apparently another helicopter pilot turned YouTube woodworker. Is it something about the fumes?

Actually two days ago. Went to see a play at Chichester, in the tiny Minerva theatre https://www.preevue.com/projects/minerva-theatre . The play was called 4000 miles, and we really went to see it because it has Eileen Atkins in it. A titan of theatre and movies. She was splendid, but looked a bit old (the character was of an old woman). It was only when we got home and checked: 88. Still treading the boards at 88! Hell she started as a professional leading actor in 1953 - three years before I was born. This is she - courtesy of Wikipedia https://en.wikipedia.org/wiki/Eileen_Atkins

Yesterday we took a day trip to Montreal so I could practice not speaking French. Visited the Archaeology Museum, had a nice lunch at an Asian bistro and walked around the city for a few hours.

RIP to my "Aunty Joyce." She was great friends with my mom from their early teens, and they lived in the same hometown for a bunch of years when they first raised a family; one of my best friends is her son. She was a kind and smart woman who still had a wonderful and sometimes biting sarcasm; I suppose that made her one of my favorites, too. She went downhill quickly, after an Alzheimer's diagnosis; though the signs were there longer. Larry lost his older brother to cancer more than a decade ago. Several years back his dad passed; and now his mom. My heart goes out to him as well. RIP Joyce, will certainly raise a glass tonight.

We expect our icons to go on forever, and are shocked when they grow old and shuffle off. RIP Tina. On another RIP, Professor Vicky Neale at Oxford and a specialist in number theory, a broadcaster with Radio 4's More or Less, has died aged 39 from a rare form of cancer (and fuck cancer royally) https://people.maths.ox.ac.uk/neale/