So Vegemite is basically yeast poop left over from making beer. It is spread over toast in Australia. I went 3 years living in australia before a girlfriend insisted I had to try it. I hated it, but she had it on her toast in the morning and after the 3rd or 4th time trying it I got used to it and grew to like it. Now when I miss Australia I get a hankering for Vegemite.
So Ian came over again Sunday – he brought the bottle of Johnny walking black and the second half of his Christmas gift project. A man who knows how to get invited back.
So this plaque was for his dad, and was the word DAD with the A replaced with a stylized sail boat.
We cut the part from some 1/8in 6061 Aluminum stock I had in the scrap pile. After the part was fixtured we tried something new. Normally I do an air cut of a pencil outline of the part to be cut, checking the clearance and placement of the part relative to the stock. This time I held a sharpie against the endmill. The result provides a pretty useful way to visualize where the pattern to be cut will sit on the stock. I am definitely going to use this trick more often.
After that we just cut out the part. My spindle was going 1280rpm, and we used a 12.8ipm federate with an 1/8in diameter end mill. Seemed to like cuts just shy of 1/16th of an inch. Once we had the part cut out Ian filed the edges and polished it with 150/320/400 grid sand paper on my surface block. Wetting fluid with Isopropanol and not water, but other than that pretty straight forward. I unfortunately forgot to tell him I had a scotch wheel – so he de-burred the edges with small files.
So a while back I tried and online dating site. As part of the process they ask you a bunch of questions. One of which was – “on a typical Saturday night you are…” with a bunch of options. None of which seemed a good fit. So last Saturday night I was looking at the bench next to my mill where I was working and it struck me – yeah this is a pretty good pictographic representation of my typical Saturday night.
So Ian came over Sunday with a project and a bottle of Johnny Walker black. An excellent combination.
The project was milling two plaques – one for his mother and the other for his father. His mom is a pilot – so her plaque were the letters MOM with an airplane at as the hole in the O. For his father’s plaque the A in DAD was replaced by a boat.
We spent a while messing with software and screwing around getting things set up – so we only cut the MOM plaque. Cut it from a 1/8 inch thick strip of wild cherry I had in the shop.
For fixturing we clamped a board to the mill – then screwed the cherry into that board. This way we could machine through the cherry into the wood below with a sacrificial cut. Doing this helps get a clean edge on the cut.
So the series was pretty obvious in retrospect – the summation of integer values from 1 to N has a known series that is so close I should have seen I could start there and work backwards. Ugh.
Yeah, I know I could Google this stuff – but where’s the fun in that?
