Remove the servos and stick them on eBay is where I'd start, and then buy some modern 1.5-2.0KW servos.And where do I start on these electrics? Brushed servos.
@awemawis your starting pointHow will I make room for this
And where do I start on these electrics? Brushed servos.
Send one of your bigger lathes down to meHow will I make room for this
@awemawis your starting point
Getting one ready soon.Send me your bridgeport on a pallet. I could do with an upgrade.
These motors also either have an encoder or a resolver, it's just that the details for them will be on a separate plate/label on the encoder/resolver section.@fizzy funnily enough I finished designing a board last night for a 180Vdc brushed motor... Reviewing tonight and then etch the board and test.
Same controller will work quite happily down to 140V. Uses an encoder for position feedback though but could be converted for tacho use.
Based on that data plate I'd have said that its a tacho that produces an analogue voltage proportional to the RPM. The way I read it is that it's 9.5V per thousand RPM. Gives you motor speed but you'd need something else as you say to determine position - at least some limit switches but then they're not particularly accurate for positioning.These motors also either have an encoder or a resolver, it's just that the details for them will be on a separate plate/label on the encoder/resolver section.
The Tacho is part of the motor section, and was used by old servo drives to create a speed control loop, as older controllers couldn't respond fast enough to handle torque control.Based on that data plate I'd have said that its a tacho that produces an analogue voltage proportional to the RPM. The way I read it is that it's 9.5V per thousand RPM. Gives you motor speed but you'd need something else as you say to determine position - at least some limit switches but then they're not particularly accurate for positioning.
The Tacho is part of the motor section, and was used by old servo drives to create a speed control loop, as older controllers couldn't respond fast enough to handle torque control.
Positional control was then handled via a resolver (early analogue tech) or encoder (later digital tech).
Any SEM motors I've seen of that era have always had the motor and resolver/encoder sections labelled separately.
More modern DC servo drives are available that will use the encoder signal to create speed control, neglecting the need for a tacho.
(stuff in brackets isn't aimed at you, as I'm sure you know what they are, it's more for those who don't understand what they are)
Well you don't live far awayElectrical, electronics, mechanics and computers steep learning curve all together - that should keep you busy for a while @fizzy
Any suggestions would be most welcome!Shame you are so far away, I would love to help you convert that monster! It will be an interesting project sourcing a controller, drives and servos etc
Thanks.I would scrap the existing control and put in new if it was mine.
Good luck with it.
Axis runaway isn't unheard of on CNC machines with DC servos either.The early ASEA (later ABB) robots had no error checking on the servo drives so if you got a broken wire on the resolver it would apply maximum drive to that axis, known as an axis runaway which could be quite frightening/dangerous if it was one of the major axes. Later models compared the resolver and tacho feedback so if it lost one of them it would shut down.