I'm going to un-zombify this thread at least a little. There has not been much action on this front. Among other things I was trying to figure out a way be able to solder like a normal human being. I NEVER was able to design something to do that.
HOWEVER, last night I was working on my 750W sewing machine motor conversion on my drill press. I got the motor installed and successfully worked through some of the tweaks required to keep the stupid thing from slamming on the brakes when it stops. The one thing about the servo control that I REALLY don't like is the speed control. It's designed for an industrial sewing machine, so it's set-up as a treadle connection. They used a Hall effect sensor so the speed control is over a very small range of movement. Using on-line information from others, I decided on converting this to a speed pot with a run/stop switch.
OK, last night I was able to try putting together my perf-board speed control conglomeration... It didn't work. The board that is, I wasn't getting ANY voltage from the wiper of the pot. That, I think is due to a couple of problems. First I think I screwed up the switch while trying to solder the leads onto it. My shaking hand couldn't apply the solder, I kept missing. I had the soldering iron on the switch WAY too long. Second, I think I probably screwed up the perf-board connections too. I was working from a sketch, yeah - my drawing, barely legible. This perf-board is individual solder pads on both sides of the board and I think I confused which edge of the board I should have been counting pads from.
My neurologist and I disagree as to what's doing OK regarding my tremor. He's of the opinion that if I can still feed myself I'm doing OK. I set the bar a little higher, I'd like to be able to at least read my own writing - that can be a real challenge at times.
I did have an epiphany though last night while working on this control board, or maybe I was just channeling a Gibbs/DiNozzo moment? You know, where Tony gets smacked up-side the head? (With me being the smackee, not the smacker.) A tutorial on TIG welding from the Fabrication Series flashed through my head, and I remembered him harping on arm/wrist placement. That you need to get comfortable with your arms resting on something solid. I got to wondering if TIG techniques would apply to soldering... THEY DO, THEY DO!!!! I was able to make good looking joints on a perf-board with a 0.1" pitch, that's 2.54mm for you Imperially challenged folk. I WON"T be doing any surface mount PC building, but I CAN build a through-hole board. Even it it is only one joint per set-up, one joint at a time is better than none ever.
I started out the night trying to use one of the 3rd hand rigs, you know - the alligator clips on swivel joints. That didn't work for me in it's normal position - too high. And my hands kept shaking because my arms weren't steady enough. When I WAS able to make a joint it was crappy looking and had the heat on the joint WAY too long. I wound up working with the board at about a 45° angle, slightly above the workbench top, with my arms resting on the workbench. I've got to figure out a better way to hold the board. I was still using the 3rd hand to hold it and it was a ROYAL PITA to set up. (Plus, you know, alligator clips?)
By the time I got done and got the board installed on the drill press it was about 10:00 PM. So when it didn't work I didn't do much trouble-shooting, just took a few voltage readings. I've got 5V coming into the board, and 5V on one side of the switch - Nada on the other side, in either switch position. I've got 0V on the signal lead, that could be me screwing up the board connections when going from solder side of the board to component side. I don't remember checking to see if I had any voltage on the wiper of the pot, I'll have to check that tonight.
For any of you other guys out there with tremors in your hands, try watching some tutorials on TIG welding and see what they recommend about hand/arm placement. Might not work for you, but then again it might - in this application it did for me.
Don
