Need some large scale DC motor advice

Discussion in 'General Electronics Chat' started by Jack Puddin, May 4, 2011.

  1. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    I have received a DC motor that I am looking to work with. There are however a few things I am unsure about. The motor worked when it was given to me and I actually have a few of them. I emailed the company that made the motors and they sent me some data sheets about them.

    http://forum.allaboutcircuits.com/attachment.php?attachmentid=30214&stc=1&d=1304485999

    (the motor in question is the first set of sheets, I obtained a few of them and inquired about them all at once)

    The main things that puzzle me would be how the wiring is set up. And how the motor itself is controlled. I am used to using small DC motors that use PWM to control them but I've never really worked with a motor of this size yet. I have a few pictures of the motor itself.

    These are pictures of the top of the motor, The wires in question are shown. There is also a small gear at the top, is this for the tach?

    http://i832.photobucket.com/albums/zz248/half0/DSCF2281.jpg

    http://i832.photobucket.com/albums/zz248/half0/DSCF2283.jpg


    This is the side of the motor that has a couple wires disconnected inside of it. The are a couple screw holes that these wires are probably supposed to connect to but I am just wanting to be sure

    http://i832.photobucket.com/albums/zz248/half0/DSCF2282.jpg


    Any help you guys can give me would be very much appreciated. I don't really mind just hooking things up and seeing how they go but motor controllers can get expensive :p. Not to mention there is enough power here to cause all kinds of damage if not done correctly.
     
  2. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    Also another question, in the data sheets that were given to me it lists several motor windings. Is this something I need to take into account or are they just separate models? The plate on the motor shows the same values as the "A" column on the sheet. Can the windings be adjusted with the wires on the side?
     
  3. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    That is a GOLF CART motor. Notice that it doesn't have a normal 'output shaft' sticking out, but has a face plate of sorts.

    The fact that it was given to you implies that it is VERY used and may have a problem as well, perhaps it overheats.

    The little wires on the sides are from the black squares. Those are the 'brushes' and the large stripped surface they ride in contact with is the commutator.

    Google 'GOLF CART MOTOR CONTROL' and then read read read. They can be very useful to the tinker/hobbyist and I often wish I had one to play with.


    Good luck with it.
     
  4. BillB3857

    Senior Member

    Feb 28, 2009
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    Although the motor could be used on a golf cart, the more usual usage is on large machine tools. The machine in the video has 6 of these motors of various types. 5 of them are 5301 series and one is a 5302 series. The gear shown in you picture is for driving a feedback resolver. The tachometer is mounted to the motor shaft under the gear. These motors are usually driven by a 3 phase SCR system that takes a velocity command from the machine control. The velocity command is generated within the control by comparing the commanded position to the position reported back by the resolver. Take a look at the YouTube link for an idea of what you have.

    To answer your question about the A column of the data sheets. That denotes build parameters such as number of turns and size of the wire used in making the armature, so you really don't have the opportunity to change it. As you can see from the chart, these motors are quite power hungry. In service on the machine shown, they actually pump about 6 amps of A/C (crossfire) through the motor to provide zero speed holding torque.

    http://www.youtube.com/watch?v=Gbq-Hi9wcU4

    Out of curiosity, where did you get them?
     
    Last edited: May 4, 2011
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  5. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    These motors were used in a factory (sry kermit2 but you couldn't have been more wrong) The assembly lines that are normally used were packed up and sent to the new location while the back up lines (rarely used) were given away to speed the process.

    As for kermit2 you are close to right as to what I will be using them for. I have done lots of work with some small time robotics and want to move to larger scale. I am working on building a small work horse to help get some work done around here using an old craftsman riding mower as the chassis. I will want to hook a trailer up to it and maybe haul some rocks around and who knows in the future I may wanna put a deck on it :D.

    I have plenty of experience and schooling to be working with electronics (although I have yet to make this kind of current mobile) So I do understand fully the power requirements that are in this things future. I simply have worked with anything of this scale yet.

    As for now I gave the chassis to my brother to have him weld some serious support onto it to handle to torque made by this thing. Attached is a concept schematic I drew up real fast (no details included intentionally)

    The motor controller I was thinking of using is an older one I have laying around called a RoboPower Sidewinder. Here is a link for it:

    http://www.robotpower.com/products/sidewinder_info.html

    Do you think that will be enough? I know that it can cover the normal operating power but not quite sure if it will handle the start-up of the motor. I proly won't ever have thing thing pegged out to the max RPM but it will be moving loads of 250 pounds or more at various gear ratios.
     
  6. BillB3857

    Senior Member

    Feb 28, 2009
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    Since these motors are primarily used in a servo environment, there isn't a real concern about "Startup" current as there would be with a motor designed to run at a fixed speed. If you look at the specific chart for your particular motor, you can see the amount of torque per ampere supplied. That relationship will hold true pretty well throughout the speed range. Depending upon the voltage supply, your maximum speed will be limited. As an example, if you are using 24V, the maximum speed you could expect would be 203 RPM. (24/118=.203X1000)
     
  7. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    Can the voltage on a motor like this be switched up that much? The plate on the motor shows 15v DC so thats what I was going to run though it with varying amperage. Do you think that is the best way to run it?
     
  8. BillB3857

    Senior Member

    Feb 28, 2009
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    Are you sure you are looking at the motor voltage and not the tachometer volts/1000 RPM rating. As I recall, the nameplate doesn't show the motor voltage, only the model number which will send you to the charts you obtained.
     
  9. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    Lol pretty sure it was for the motor. I tried to take a pic of the plate itself but it doesn't really come out very well. I'll try again for you to see. Do you think that motor controller will be enough for a motor like this?


    Also I should be getting the frame back soon. I'll take some pics to show ya as well. Might start a blog to keep ya updated as I'm sure I'll have more questions.

    By the way thanks for the helpful info and thanks in advance for any more :D
     
  10. BillB3857

    Senior Member

    Feb 28, 2009
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    I took another look at the first listing in the data sheets you posted. TTR-5302A shows 118V/1000RPM V/k rpm for the motor and 19V/1000 rpm for the tachometer. Also, in the first picture of the motor you posted, if you look at the far side, you can see at about the 11 o'clock and 1 o'clock positions, tapped holes. These holes are for mounting a bar that would carry the resolver and its gear that would mesh with the remaining gear. You can see the discoloration where the bar once was. The small black and white wires that come out with the large green and orange wires are for the tachometer. The color of paint on the motor is one that was one of the colors used by Cincinnati Milicron for their machines like the one shown in the YouTube video I linked. Also, please fill out your profile so we know the area you are located.
     
  11. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    These are 'brushed DC servo motors' They are kind of like a stepper motor on steroids. They need a controller that gives them the "steps" and the "resolver" that tells them where(shaft position) they are.

    Don't just wire them to a DC source without using the positioner/controller. The motor will probably let out it's magic smoke, don't ask me how I know. While they will run continuous they are better used to position something.

    Like a stepper motor they will have a fairly low nameplate voltage but are normally used at ten or more times that voltage to get full torque from them.
     
  12. BillB3857

    Senior Member

    Feb 28, 2009
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    Wrong. Permanent magnet DC brush type motor! Spec sheet states DC SERVO MOTOR! Steppers don't have commutators. Part of the test procedure for these motors is to connect to a DC supply and run up to 1000 RPM. Measure the voltage. If within +/- 10% of spec, magnet field strength is OK. Can't do that with a stepper.
    Even though you say "Don't ask me how I know", I'm asking!


    To the OP: Check the color of this machine against your motor...
    https://www.apexauctions.co.uk/auction/itemDetails.htm?lotId=30641

     
    Last edited: May 4, 2011
  13. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    Yea sorry shortbus I'm afraid I have to go with billb3857 on this one. It is definitely not a stepper motor.

    As for the increase in voltage I did not see that coming.
    I can supply a steady 48v with my current controller with plenty of amperage in bridged mode but may not however be enough :(

    To bill: That does to be the same color. I wish I could say for sure the location in which it came from but I didn't work there. I can ask where though.
     
    Last edited: May 4, 2011
  14. BillB3857

    Senior Member

    Feb 28, 2009
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    Here is a link to the manual for one of the several drives that Inland married to these motors.

    ftp://ftp.kollmorgen.com/TechInfo/SPA_TPA/spa_spar_tpa_tparinstall.pdf Looks like cut and past is needed to reach it.

    It is complete with schematics, connection diagrams and adjustment procedures.

    Do you have any idea of just how much current you can push through the winding? Bear in mind that the resistance is only 1/4 ohm. Of course, current will drop off as motor speed comes up. Torque, according to the spec sheet is 0.825 lb/ft per amp. Typical no-load current for these is somewhere in the range of 3 to 5 amps.
     
    Last edited: May 4, 2011
  15. Jack Puddin

    Thread Starter New Member

    May 4, 2011
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    Wow thanks for that manual. I am really starting to love these forums :D

    As for the amount of current, yes I do realize how much current this thing can suck up. I am also beginning to think that this motor may be a bit much for what I want
    .

    I still wanna tinker around with it however I mean it would be a shame to let these motors go to waste.
     
  16. BillB3857

    Senior Member

    Feb 28, 2009
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    Agreed that it would be a waste. I wish I had grabbed a couple of them when I had a chance a few years ago.
     
  17. shortbus

    AAC Fanatic!

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    Was given one of those at one time. Without a servo motor driver I wired to a Standard DC motor controller(industrial).All it did was sit there did not turn the shaft, after a few minutes the rotor started to smoke. Thats how I know.

    Did not say it was a stepper motor! But they are used in the same type of applications. To move a 'machine' to a certain position. the position is determined by the resolver. The motor drives a ball screw usually in a CNC machine. But can also drive a gear train or timing belt, etc. a stepper motor does the same thing on a smaller scale without the closed loop of the resolver.

    The brushed type is not used as much as the brushless type servo motor. The brushless type is more like a stepper motor in that the rotor has the permanent magnet with many poles on it.

    Brushed dc servo motors aren't used as much because to get fine/small movements they need to be geared down to get the smaller movement. A brushless servo doesn't need that because of the way its made, with many more poles on the rotor.
     
  18. BillB3857

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    If you put DC on it and it didn't turn, it was a bad motor from the get-go, or the part number was a TTRB with the B denoting BRAKE! The brakes on these units are spring applied with electrical (90V DC) release.. I've been dealing with these exact motors for over 30 years, being involved in the overall maintenance of machines like those shown in the links I provided. The company I worked for bought 20 of those machines in the mid to late 1970's for machining titanium aircraft parts. More were added later. We received a lot of training on each sub-system, which included the motors and drive systems manufactured by Inland. Inland was later merged/bought by Kohlmorgan, which is now associated with Danaher.
     
  19. shortbus

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    @ BillB3857- I was just going by what the electrician at work that gave it to me said about power supply not being right for motor.
     
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