Wednesday, May 11, 2011

Oh Noooooo!!!!!


I would hold off on that Rennbotics servo shield for now. I think I burned $1000 worth of servos connected to it! All servos were digital Hitec HS-5990tg and HS-7954sh with 6V pack as the supply and groung plugs confirmed. Prior to connecting them all, I verified operation via a Turnigy servo tester using the same 6V pack. While connected to the Freeduino via USB to my PC, they responded somewhat to commands from the keyboard but twitched and never realized full speed or range of motion. After disconnecting, I retested using the servo tester and saw mass failure! Some moved sluggishly and some not at all. I ordered a Hitech HPP-20 servo programmer in the faintest hope that maybe a board reset may be possible.

TWO WEEKS LATER.....


Some good news: 
Using a Hitec HP-20 servo programmer, I managed to revive all the digital servos and even the analog 645MG's! While I was at it, I turned on protection, which will halve the motors output in the event of a stalled situation and enabled 180 deg rotation instead of the as-shipped 60 degrees. Best $26 I ever spent!

Going through the old threads regarding PLM designs. I have settled on one easy enough for me to hack together in the garage using the basic hand tools at my disposal. So here's what I'm shooting for. The 45 deg brackets are Lynxmotion SES offset brackets I plan to drill holes into to allow attachment of the parallel link. I have not yet decided if the twin knee servos will be necessary as I am using HS-5990TG's for the upper and lower links.