Older blog entries for anttch360 (starting at number 7)

We took our robot arm and showed it off to the teachers and the director of the electronics program. They all liked it very much and there is a good chance we'll win the best project of the quarter. But I wont know before graduation on the 16th of September. Fred and I were both talking about adding a basic stamp to it instead of using a PLC. So we can take it down to the robotics meeting here in Southern California.

21 Aug 2004 (updated 21 Aug 2004 at 05:09 UTC) »

Good news we finally got our Robot arm working 100%! We have a new video posted on our site, and yes I know the downstream from the website sucks but its the best we can do.

Saw more fireworks today and lost another relay, but this time we have something to show for it. We decided to get rid of the idea to use switches and are now using timers in the PLC. We made our own IR detector and got that working. We even manage to put everything together and got the arm to close it's hand and then lift the object. Using the IR detector and the PLC it is now in a completely automated setup. But wait that is not all we even posted video of it working on our website so go check it out!

Not much to talk about today. We still need to find more relays everyone seems to be sold out, we need more leaf switches, and we need to buy an IR detector. But we did get the arm to work in the PLC and we started the programming portion. I missed the robotics meeting which sucks, registration at my school took longer then expected.

10 Aug 2004 (updated 10 Aug 2004 at 20:05 UTC) »

Yesterday It was fourth of July all over again, My partner in crime Gerald, accidently shorted 120V AC to Ground! After the blinding sparks were gone and a few smoldering wires. The PLC looks to be unharmed and my relays were still intact. Thank God!

Oh let me tell you about my little adventure to Radio Shack! Now I know there not the brightest technicians in the world. So before I left my house I printed up a picture for them of the relay I wanted. I told him when I got there what I wanted and gave him the print out. He look at it and walked over to where the relays where at and gave me the relay I wanted! Then he look at me and ask, "What are relays?" :rolleyes: So, I explain what they were used for and what not. He look at me with a blank face, turned around, then turned and faced me again. He asked, "Do you own a Cell Phone?" I almost busted out laughing.

As for my robot arm, our relay design to solve our problem is working 100%.

Fred just Corrected me . . . We need four 120V AC relays to control both directions for the two 12V DC motors. So I'm planning on running down to Radio Shack and picking up four $8.39 10-Amps 125V AC relays. Now we don't need the 10-Amps but it is all they have to offer in the store.

Oh, the next meeting for Robotics Society of Southern California will be on Aug 14. I plan on busting out my wallet and paying the $12 membership fee. I suspect Fred will be doing the same. They're supposed to have mini sumo competitions at the end of each meeting, but Fred told me last time they didn't have one. Guess I'll have to ask around to see what's up. Since, Fred and I want to build our own custom mini sumo.

For my first robot arm project, Fred and I just found out that the PLC that we are using only puts out 120V AC. Which is fine for our hand motor but our two other motors (base and arm) are 12V DC. Our teacher never bother telling us this... So now we are gonna use two 120V AC relays to switch on and off a power supply of 9V batteries, which would power the DC motors.

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