servo questions

[dbunyip]

Well this is what I aquired:

2 Westamp, Motor: M-133, Voltage: 92V O/P, Current: 9.6A, Tach Grad: 7V/1000 RPM.

2 SEM, MT30M4-59, Cont Stall Tq: 3Nm, Max RPM: 2400, Volts: 142, Pulse Amps: 30.

1 SEM, MT30F4-45, Cont Stall Tq: 1.5Nm, Max RPM 3100, Volts 140, Tach: 9.5, Amps: 21.

My first question: Is there a cheap way of finding out if these even work?

2nd: the 3 SEMs are what I'm more interested in using for a plasma table would these be a good start?

3rd: what controler would you recomend. before i found these drives i was thinking of geckos but the 140+ volts wouldnt work corrrect?

thats enough questions for now. thanks for any help.

[Al_The_Man]

If those are what I think they are DC brushed motors and can be simply run with an automotive battery to see if they run, it would pay to check the brushes (length) and inspect the commutator for wear, but they are fairly beefy motors, the size usually fitted to Knee mills etc.
If you use them at the max voltage you can up to the rated voltage you may not get full torque, but maybe enough for a gantry, especially with gearing.
You do not need the tach with modern drives so just remove the tach brushes when used.
Al.

[NC Cams]

Rutex has amps that will run these motors. Yes, the SEM's are "mill grade" servo motors.

Run them at 2:1 gearing or more and 130 to 140vdc for rull rpm and rated power.

You could darn near turn the earth with them when so geared and powered.

[dbunyip]

ok, I got them to run off a 12v batt and they spin, be it real slow, so I take it that means they work. Now my next step is to get on to spin via my computer, the rutex drive looks to fit the part but what else do i need? I need a power supply correct? What would you recomend? I would like to get something already assembled as there is less to go wrong (I hope). And the encoders, will I be able to do anything w/o them. If I understand what i've read it won't work at all but i'm hoping i'm wrong. just trying to spend as little money at a time. the equipment I got all this off has an encoder but I don't think it works (kinda dented up) is there a way to test them? Would it even work with the rutex?

Tag:
Industrial encoder
BEI Sensors & Systems
MOD NO: l256-625-ab-7406r-led-spt02
part no: 924-01008-1455
VDC IN 5V

I read something about rutex using 5V but it cant be that simple can it. Different encoders have different resolutions don't they?

[NC Cams]

First try to contact the encoder vendor to see if they have a wiring diagram or other info you can use such as encoder count.

I you Googled for "bei sensor", you'd find you really don't have to look too far into the search to find BEI's website.

No time or ambition to look: http://www.beiied.com/

Re; The 5VDC: Yes, it can be that simple. Reason: 5V is a/the common signal level for a majority of the encoders. If Rutex has a 5V + and -, you have the 5vdc and the return that you need for your encoders and it would be supplied by the very same system that ultimately will read them.

Encoders turn a generic DC motor into a servo. They provide the position feedback so critical to system performance. Yes, you can NOT do anything without them - unless you go to steppers.

Yes there is a way to test them. Apply 5v and ground to them and then turn the encoder. You can readily see what sort of signal is coming from the output channel by attaching an oscilloscope to the output channels.

Again, the type of signal infomation that shuld come out can be obtained from BEI. THis information will be inordinately helpful to you with regard to your retrofitting endeavors.

Re: encoder count. You have 3 choices. Either count the pulses in a rev, attach a frequency counter to the endcoder and spin them at an exact RPM (a bit of math later and you have your encoder count) or ask BEI for the information.

Yes, there are various counts per rev for encoders.

Re: will BEI' s work with Rutex = unless a member is familiar with that specific encoder type, it is a guess as to whether the encoders will work with Rutex.

Reason: encoders have different output signal types. The encoder has to have a signal output that is of a format that Rutex understands or can be made to understand. Again, info from BEI would come in real handy at this point.

In light of the way you are salvaging parts from other machines to make you system, the following thread might be inordinately helpful:

http://www.cnczone.com/forums/showth...9&page=1&pp=15

Specifically post #15

EDIT

Reason why the SEM motors spin so slow at 12vdc: they motors are running at only 8.6% of their rated terminal voltage. You're gonna need 130vdc to 140vdc to get the rated speed and power out of the motors. Better plan on some healthy amperage too to get the rated torque.

END EDIT

[Al_The_Man]

Originally Posted by dbunyip I got all this off has an encoder but I don't think it works (kinda dented up) is there a way to test them? Would it even work with the rutex? Tag: Industrial encoder BEI Sensors & Systems MOD NO: l256-625-ab-7406r-led-spt02 part no: 924-01008-1455 VDC IN 5V

I assume that is L56G ?
These show 625 pulses/turn, A/B pulses only so you don't appear to have a marker pulse, used for zeroing the axis.
Also these are not TTL as it show a 7406 open collector driver for an IC.
So you would need pull up resistors, connected from output to +5v to test them.
If you connect an ordinary meter up to the outputs reference to common, you can see individual 0 to 5+ transition if you turn as slowly as possible.
You may not have complementary outputs either, just single A & B, If yooou need complementary you can add a diferential IC if required
Al.