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John Bump
5,574 followers -
Mad scientist
Mad scientist

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I think I need one of these.
I'm driving. Who wants a ride? 
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Pic of a propane burner for the foundry. The brass tube with the control valve handles the high pressure propane, which exits at high velocity on a tiny hole in the middle of the tube. The peanut can is to shield the intake from gusts of wind, which will blow out the flame. Crockpot in back is a Sparex bath for etching firescale off jewelry.
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I know too many people who would enjoy this to tag them all.
We made a cell model cake today. 
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A couple of years ago several people here were discussing converting and analyzing gps waypoint lists. I spent some time today learning scripting with gpsbabel, which can solve just about any gps waypoint need you might have, based on examples from here: https://github.com/gpsbabel/gpsbabel/tree/master/style and using documentation here: https://www.gpsbabel.org/htmldoc-development/style_define.html which make it possible to compose a stylesheet for gpsbabel to read and define output formatting. If you know printf formatting, this will be easy. I can now take a garmin binary .fit file and in a single line convert it to a csv file containing just the data I want: timestamp, speed, heart rate, cadence. I recall +Richard Masoner was discussing this, but I can't remember anyone else.

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I had midday doctor appointments and the afternoon off, so I decided to try firing up the foundry for the first time in at least fifteen years. I'd forgotten how to get it started and that took about 20 minutes, but once it had a stable flame it only took another 30 minutes to melt about 5kg of aluminum and pour it. This was mostly just making sure everything worked, so I dumped the result into a muffin tin. The material was some cut-up fragments, some broken bike parts, a couple of pistons, and a ton of old hewlett packard cpu heatsinks that people were throwing away for cosmetic defects at a previous job. This is a project that demands 100% of my attention so I didn't take any pictures of the pour, but in the picture of the ingots in the mold, they're still molten. There's also a picture of a heatsink before melting, one that's partly melted because I didn't drop it in the crucible correctly so it was on the backside of the furnace, and one that's almost entirely melted because again it bounced out of the crucible. Also the steel crucible full of dross after I poured the mold material. Dirty aluminum results in a lot of dross. I used to put a bunch of charcoal and boric acid in on top of the melt to help prevent oxidation and when I get serious about making molds I'll start playing with that again.
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3/8/17
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As I'm having too much fun printing to mess about with troubleshooting, I still haven't gotten a usb connection to the printer running: I'm just running off sdcard. But I'd sure like to write in the different PID tuning parameters for the head. Can I edit the m-code into the first couple lines of a print file and expect it to stick? Presumably M301 P20 I0.02 D250
M500? This would work on my cnc mill but that's a very differently architected system. Thanks for any advice.

Just got one. Pleased so far. I have not yet managed to get repetier-host to talk to the printer, but I can run off sdcard. I'm curious if anyone else is running repetier-host on linux and has suggestions for getting them talking. I am new enough at this that I don't know if r-h or curaengine is where I'd need to make changes. r-h 1.6.2, not actually sure what version of curaengine, have slic3r 1.2.2 but haven't yet used it.

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Avery Brewery has a ceiling fan with a larger span than some small aircraft. Visited yesterday to acquire their brand new apricot beer.
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Monoprice mini: first print. It works ok. Really fast and smooth motion. Extruder heat control is worse than the worst reviews: so bad the filament solidified and jammed during one print. There are instructions for changing the pid parameters, which is vital. I have not yet because repetier-host on Linux is crashy for me so hey wow it is convenient that the mini prints off SD card. Hot end teardown to unjam was trivial. With just a small amount of design they could have made the hotend a truly nice screw-together design. Driver board needs more airflow. Still, for the price, it is seriously sweet.
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1/31/17
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Project suggestion: hack the login process on a linux or android system so if I enter username and password1 I get my normal filesystem, whereas if I enter the same username but password2, I boot into a nearly blank install with just enough personal data to appear to be used. (On a linux system I could just use an alternate user name, but on an android system the users appear as icons on the login screen.)
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