Well they maybe the cheapo servos, I just dont know, I paid $450 US for them. They are Amatec brand. I have since found out that they were excess stock for reel to reel computer tape drive machines.
Someone said to me that they may have cost the seller $10 bucks a piece originally. I could feel ripped off, but the seller has been very supportive to me in advice. No need for me to get caught up in regret, they will do what I want, and I will have to learn to shop a bit harder in the future. I shouldnt complain about entreprenurialship. I was happy with the purchase before I knew the facts.
The encoders are Renco encoders. They are open ended encoders. I didnt realize that open ended encoders wont allow long runs of cable. I am told about 2 M run maximum. Rutex has a conversion card that can make the encoders run on longer cables. The convertion cards cost $19 each.
The encoders came already fitted on the servos. The encoders are 2000 pulse per revolution. I put a mark on the shaft of the servo, and on the servo itself. I ran the servos for 9 million pulses and when they stopped, both the marks lined up perfectly. Seeing this is probably normal to most CNCers but for me it was amazing that it could do this. Just seeing this has made me feel very excited about my project.
The other amazing thing about the setup is that the servos can run at full speed and then come to an immediate stop with no overrun. This can be achievd by tuning the driver board with the servos. The overrun results are then displayed on the computer.
You asked about cables. I am running sheilded power cable to the encoder, and a seperate shielded counter cable to the same encoder. I am told this is a good method of practice, to avoid signal interferance. The servo supply cable are plain old extension cable cut to suit. I guess they should be shielded too to stop leaking interfereance.  |