Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations JAE on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by sensij1

  1. sensij1

    Is NI LabView suitable for use as control system

    If you are looking for something you can grow into, you might want to consider Opto22's programmable automation controllers (PAC). They may cost less than even the NI system you are considering, run on dedicated hardware, and avoid the costly software licensing renewals that NI and others will...
  2. sensij1

    PLC Training Tutorials and Videos for Self Training.

    Opto22 tries hard to make their systems accessible to new users as well: http://www.opto22.com/lp/self_training_guide.aspx
  3. sensij1

    Constant Torque Motor

    Referring back to the OP, if the jack screw catalog is specifying 2.75 kW at 1500 RPM, and you are planning to operate more slowly, then the power requirement will scale down with speed, with maybe a little non-linearity due to speed based friction/lubrication changes in the jack. So yes, as...
  4. sensij1

    VFD encoder PPR

    With my hardware, the quickest average cycle time I've been able to get for capturing the speed and torque is around 3.8 ms. I logged at least 30 sec of running under the conditions I described above, and got the following: Estimated speed feedback Avg Speed = 411.81 RPM Std Dev Speed = 1.67...
  5. sensij1

    VFD encoder PPR

    This particular drive won't do much more than collect data on min, max, and average. It can also create a histogram showing the distribution of current readings in 10% buckets, but that isn't what I'd need either. I've checked the manual, and setting the communication speed to "fast" will...
  6. sensij1

    VFD encoder PPR

    Ok, thanks for the suggestion. I had seen a few of your posts about sensor bearings in the archives when I searched this topic before posting. I had not been aware of them, but I can think of a few places where they would be a much better fit than traditional encoders. I'm definitely filing...
  7. sensij1

    VFD encoder PPR

    Ah, I think maybe I was defining speed regulation incorrectly to compare it to that chart. The same white paper defines it this way: The speed regulating capability of any constant speed motor or adjustable speed drive is defined as the maximum speed change as a percentage of base speed that...
  8. sensij1

    VFD encoder PPR

    Great, that's just the response I was hoping for. In terms of load inertia, the motor is 1.5 HP and the roll it is turning (through the speed reducer) is 18" in diameter and weighs about 100 lbs. The inertia is probably still high enough to wash out any improvement from the encoder, but maybe...
  9. sensij1

    VFD encoder PPR

    The question in general is: When using a PPR to provide feedback to a VFD, is there a maximum value above which higher PPR can actually hurt? I understand that a higher frequency signal may be more prone to error than a lower frequency signal, so that is one aspect to consider. In this...
  10. sensij1

    AB Powerflex 70 [VFD]

    Has the VFD been configured to run with this particular motor? Does it work alright if you disconnect the load and just run the motor on its on?
  11. sensij1

    I am looking for a rotating joint

    I'm not sure the straight spherical ball joint does what the poster is looking for. If his machine is anything like the youtube video, I think a bearing assembly of some kind is called for. Are the driven rod and driving rods collinear? If so, I would be looking at some kind of coupling...
  12. sensij1

    NEMA frame adapter

    I've got an older speed reducer with a mounting flange sized for a 184C DC motor. I'm looking to convert this machine to AC control with a VFD + encoder, but it doesn't appear this is a common motor size. I've identified a 145TC motor that would work well for the application... is there a...
  13. sensij1

    Tapered roller bearing vs Drawn cup needle + needle thrust bearing

    Sorry about this mispost, I misunderstood how attachments work. Anyway, the outboard side of the same bearing pictured about is shown here. Outboard = away from the work roll = round side of the drawn cup. Inboard = facing the work roll = stamped side of the drawn cup. You can see a...
  14. sensij1

    Tapered roller bearing vs Drawn cup needle + needle thrust bearing

    Attached are a couple more pictures. I went through the last set that was pulled out and found one so worn that thehttps://www.dropbox.com/s/ee05or07nmbdh7w/Bearing%20-%20outboard.jpg
  15. sensij1

    Tapered roller bearing vs Drawn cup needle + needle thrust bearing

    The load estimates come from load cells that I've placed at the end of the jack screw and monitored while the mill is running. Yes, the mill is capable of delivering more force than the estimates I've provided, but we are working with strip that is only 0.002" - 0.010" thick, it doesn't take...
See more

Part and Inventory Search

Back
Top