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Everything posted by GreekPIC

  1. Hmmm, I just saw my circuit doesn't have shortcircuit protection in case you press Up and Down at the same time. I'll work on it again later but it's a start
  2. Here's a simple elctromechanical solution. It would be better if Stop1 and Stop2 where two N.C. contacts on the same physical switch. The two microswitches can be connected in series with the two Stop swiches. Since (AFAIK) there aren't any three contact relays, you can use the extra contact to connect two LEDs for the Up and Down lights (arrows). As I said above, unless there's a quite big reduction ratio, the elevator's weight will make the motor rotate and return to the basement. You could use a brake device of some kind. Now for a more comlicated solution with a stepper etc I think someone else should contribute since I'm a newb in electronics too. P.S. What a game!!!
  3. I've made some changes in the board, you'll find them on page 12
  4. The stepper would also have holding torque but it is a bit more complicated to drive. Gear reduction would also help (it would multiply the effects of friction so that the motor wouldn't rotate with the power off). dandesign I'll draw a schematic later, I have to see the Champions League final now...
  5. Both leadnuts (X&Y) are bolted on the middle plate (you can see the X one and the bolts that hold the Y one. They are made from aluminum. -Lesson #1. Use Derlin for leadnuts. I thought the screw would wear the nut out to a point that binding will be minimized but its 7075T6 aluminum and I'll wear out before it does. You can see the motor support (laser cut & CNC bent) and the home/limit switches. -Lesson #2. Use timing belts to connect the motor to the screw. Otherwise the allignmen requirements will be very high. You can aslo see the ball bearing drawer slides. The middle plate slides along the Y axis over the base, the top plate (table) slides along X over the middle plate. Z uses the same slides and holds the chuck of a flexible drill shaft. The spindle motor is inside the body and this way the Z motor doesn't have to carry its weight. On top of the machine you can see the red emergency stop button and the start button. They operate a relay inside.
  6. Here you go, I think this makes it clear:
  7. You can use microswitches with rollers like this: If you don't want to have to hold the bottons you can use a couple of relays in a latching configuration. Have you figured the mechanical part out yet? Nikolas
  8. Well what I'm building now is just a test bed. I want to work all the details out so when I make the "real deal" there'll be no surprises. It's made out of everything I could find for free or really cheap. The body is melamine particle board (gift), the ways are ball bearing drawer slides, the motors from a scrapped printer, the spindle motor from a busted jig saw. The leadscrews are M8 threaded rod (gift). Ver2.0 machine will have aluminum frame, THK rails, ballscrews, 3ph spindle motor and VFD. If you need something small (e.g. fpr milling - drilling PCB's) I would suggest using rods & plain bronze bearings for the ways. There are nice rods where the steppers came from... ;D
  9. I also wanted to report my experiences from using this board: -First of all the ver2.0 board will plug-in connectors makes it a lot easier to use. While seting the machine up you will need to rewire often. Having to unscrew ~20 terminals isn't fun. -It runs really cool. With printer steppers at 15V and heatsinks on the UCN's I had it running for 3,5 hours, moving the table diagonaly back and forth. Temp at the heatsink was ~30
  10. Oh, now I see, not just a capacitor, thanks.
  11. Ok, thanks. So, if it's a cap, why doesn't my DVM agree with the nominal value?
  12. It depends. What is your hardware? What will the robot do? Execute a sequence of motions or react to something? Or even be manualy controlled? I've made this board: http://www.electronics-lab.com/projects/pc/008/index.html for a CNC mill and use TurboCNC (http://www.dakeng.com). I guess you could use it for repeated motion without input (or some limited input options).
  13. Could someone help me with this? There's one in every hand drill. I thought it was a capacitor (it says 0.33uF on the case) but I measured it with my DVM and it was not.
  14. You have to short pin 14 to pin 15 and it will turn on. (source:http://www.laserlab.com/atx_ps_connector.php) Nikolas
  15. Why don't you start here? http://www.electronics-lab.com/articles/index.html
  16. The camera CAN see it. For example if you are interested in wildlife photography you can take pictures of animals without them seeing a flash and running away. Junaid, I hope you have something like this in mind and not something illegal, like taking nudie pics from someones bedroom window...
  17. http://www.anatekcorp.com/driving.htm T.V. out is more complicated and would require messing with the horizontal and vertical frequency
  18. If you're still interested, a good place to find solenoid valves is a washing machine. I dismantled one that someone threw away (it was in perfect condition, just old). I took several usefull parts out of it.
  19. OMG, it's fantastic! I want to make something like this. Maybe an FM receiver in a transparent cover.
  20. You could use R/C servomotors. What are the arms specs? Range of motion, dimensions, what will it do, will it carry weight etc? If you come to a basic plan of what you want it will be easier to decide what kind of motor fits best.
  21. In most software packages you can change the pin assignment. I use TurboCNC and it does that, so does CNCPlayer which I've also tried. I haven't tried Mach2 but from what I've heard it does too. As a matter of fact it comes as a surprise to me that there are programs out there that don't give you this option.
  22. If it's just a matter of going off with the PC why don't you just drive a relay from the USB?
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