Yesterday I rode 75 miles, 1/3 of that in a pack of crazy wanna-be racers, and I'm STILL tired.
Today we had burgers. Mmmmmm. I haven't gone out for burgers in *years*.
That's about all.
I'm getting halfway good at layout in gEDA, but it's not what I'd call pleasant, alas.
Wednesday, June 16, 2010
Sunday, May 23, 2010
MORE about gEDA:
Put new parts in /usr/share/gEDA/sym/local. That way they're available globally without having to put an entry in a gafrc or the like. If you need parts just for one project, then a /symbols in the project directory, with parts in that, and a gafrc local to that project, makes sense.
Don't give a component a refdes of power, or pwr, or ground, or gnd. It messes with the netlister. The component will come through but it won't be included in the netlist so it'll show up with no rats.
The pcb netlist is straight ascii so if you need to fix something broken by the above -- if you really truly require a connector named power -- you can just stitch it in to the netlist by editing it.
The netlister includes a surprisingly comprehensive drc checker called drc2: it'll flag some surprisingly obscure problems.
Put new parts in /usr/share/gEDA/sym/local. That way they're available globally without having to put an entry in a gafrc or the like. If you need parts just for one project, then a /symbols in the project directory, with parts in that, and a gafrc local to that project, makes sense.
Don't give a component a refdes of power, or pwr, or ground, or gnd. It messes with the netlister. The component will come through but it won't be included in the netlist so it'll show up with no rats.
The pcb netlist is straight ascii so if you need to fix something broken by the above -- if you really truly require a connector named power -- you can just stitch it in to the netlist by editing it.
The netlister includes a surprisingly comprehensive drc checker called drc2: it'll flag some surprisingly obscure problems.
Saturday, May 15, 2010
dovetails, for next time
I cut the tails first and the pins second, unlike (apparently) everyone else, because I think it's a lot easier to mark the tails on the pin ends than the other way around.
1. Mark the thickness of each board on the other so I know how deep to cut the tails and pins.
a. The end of the board might not be square: don't trust the saw. They lie. Mark a perpendicular using a good square on the edge of the board, using the thickness of the other board as a gauge.
b. And add a little -- way less than a millimeter but more than the thickness of paper. Scribe. (This is so tails and pins stick out a little on the finished joint, because it's easier to remove wood than to add it.)
2. Mark the dovetails. They can be very skinny.
3. Cut the dovetails with a very low-kerf backsaw.
4. Slit several times into the dovetail waste so it comes out more easily.
5. Cut out the waste with a jeweler's saw because it's way faster and less irritating than using a chisel. Clean up the cross-grain wit a chisel, though. Rocking, slicing moves do better than straight hammer moves. Make sure the chisel has adequate side relief so you can get it down in the dovetail bottoms.
6. Put the dovetail board down on a flat surface, butt the pin board against it, butt them both against a true edge on what will be the bottom of the drawer. Mark the pins.
7. Cut the pins a sawblade-width wide of the mark.
8. True up the pins to fit the dovetails.
9. Remember when you dado for the bottom of the drawer, don't run it all the way through the siderails because then you'll have a tiny square hole in the front of the drawer, one on each side.
1. Mark the thickness of each board on the other so I know how deep to cut the tails and pins.
a. The end of the board might not be square: don't trust the saw. They lie. Mark a perpendicular using a good square on the edge of the board, using the thickness of the other board as a gauge.
b. And add a little -- way less than a millimeter but more than the thickness of paper. Scribe. (This is so tails and pins stick out a little on the finished joint, because it's easier to remove wood than to add it.)
2. Mark the dovetails. They can be very skinny.
3. Cut the dovetails with a very low-kerf backsaw.
4. Slit several times into the dovetail waste so it comes out more easily.
5. Cut out the waste with a jeweler's saw because it's way faster and less irritating than using a chisel. Clean up the cross-grain wit a chisel, though. Rocking, slicing moves do better than straight hammer moves. Make sure the chisel has adequate side relief so you can get it down in the dovetail bottoms.
6. Put the dovetail board down on a flat surface, butt the pin board against it, butt them both against a true edge on what will be the bottom of the drawer. Mark the pins.
7. Cut the pins a sawblade-width wide of the mark.
8. True up the pins to fit the dovetails.
9. Remember when you dado for the bottom of the drawer, don't run it all the way through the siderails because then you'll have a tiny square hole in the front of the drawer, one on each side.
Wednesday, May 12, 2010
gEDA, getting started
Work from this page:
http://geda.seul.org/wiki/geda:gsch2pcb_tutorial
Add a gnetlistrc and a gschemrc to /.gEDA
Change the gschemrc path from the tutorial to:
(load (build-path geda-rc-path "gschem-lightbg")) ;light background
To get pcb to run correctly in Mepis, it's necessary to apt-get install dbus-x11 (or in my case to use synaptic and mark dbus-x11 for installation) because the standard dbus doesn't handle windowing operations, apparently. If this isn't done, pcb will open without any parts being placed.
http://geda.seul.org/wiki/geda:gsch2pcb_tutorial
Add a gnetlistrc and a gschemrc to /.gEDA
Change the gschemrc path from the tutorial to:
(load (build-path geda-rc-path "gschem-lightbg")) ;light background
To get pcb to run correctly in Mepis, it's necessary to apt-get install dbus-x11 (or in my case to use synaptic and mark dbus-x11 for installation) because the standard dbus doesn't handle windowing operations, apparently. If this isn't done, pcb will open without any parts being placed.
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