On Tue, 8/13/13, TJoseph Powderly <tjt...@gmail.com> wrote: Subject: Re: [Emc-users] How to test brush type DC servo motors? To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Date: Tuesday, August 13, 2013, 11:35 PM On 08/14/2013 12:26 AM, Gregg Eshelman wrote: > I want to see if my motors will run. How do I identify the motor wires VS the tachometer wires so I can hook up to a DC power supply just to see if they'll run?
a picture would help but often the motor wires are heavier gauge also the 4 wires ( assumption ) are often not gathered together because the tacho easily gets noise from the motor and the tacho is usually at the end of the motor opposite the shaft and the motor wires are nearer the brushes (often, not a rule ) hth TomP tjtr33 The motors have flex conduit attached with the bulkhead connectors that have screw collars. I'd rather not have to take that apart. Is there a way to identify the motor wires with a continuity tester or ohmmeter? Is there any wiring standard for those connectors? I'm considering getting a set of steppers with encoders - 6 NM peak torque, drops to around 3 NM at 1,000 RPM according to datasheet. 3 NM is peak on the DC motors I have - so the steppers will have more torque around the speeds they'll likely be running much of the time. Matching drivers from the motor manufacturer are also in the package, so are motor and encoder cables. Cost for all that (used pulls from a functioning machine) is about the same as a single old Servo Dynamics SD1525-12 driver board. Better yet, they're much shorter length and weigh less than the DC motors and the system only needs 115 volt AC so I can take the big power supply out of the box, and I get the benefit of having the encoders and the linear scales. I'll have room in the big box for a phase converter for the spindle motor and everything else. I'm thinking a mini-fridge is a possibility so I can keep a supply of Mountain Dew Throwback handy... it's a really huge box. Or I could move the spindle control relay components into it and get rid of that slightly less big box. I'm a cheap scrounger and there's just no way I'm spending multi-thousands getting my mill into working condition. :-) With patience I will find the components at prices I'm willing to pay. If a good SD1525-12 board dropped in my lap at a price I figure is decent for a piece of quarter century old electronics, I'd grab it and stay with the DC motors and the old drivers. That's why I snagged that one motor for $299, because it matched the other table motor and was at a sane price instead of being priced as if it was a rare antique vase. Then there's the 'little' issue where I have no idea if *any* of the motors and electronics on the mill are good. There could be reasons beyond the broken CRT and fried monitor power supply why this mill was sidelined and cannibalized for parts. Buying less expensive, newer, used motors and drives looks like a safer play to me. ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
