584,841 active members*
4,467 visitors online*
Register for free
Login

Search:

Type: Posts; User: sswitaj

Page 1 of 2 1 2

Search: Search took 0.00 seconds.

  1. Re: Trying to understand stepper behavior on forced stall

    This is pretty typical behavior for a small stepper. Imagine you're slowly advancing into your stop, one microstep at a time. As you load up against the stop the motor finds it harder and harder to...
  2. Replies
    3
    Views
    1,250

    OK, here's the formula... First, figure out...

    OK, here's the formula...

    First, figure out how many step pulses you need to turn your motor one full turn. The base number here is the number of steps per revolution (in your case, 48) but unless...
  3. Replies
    284
    Views
    94,072

    It's kind of a shame. The Toshiba chips are...

    It's kind of a shame. The Toshiba chips are really pretty good for what they are, but they get built into these poorly designed products and they almost inevitably fail.

    My little company produces...
  4. Replies
    14
    Views
    23,581

    I would suggest the likely culprit is the...

    I would suggest the likely culprit is the direction line going to the driver. Put a voltmeter on it and see if it toggles as you command the axis forward and reverse.
  5. Can anyone identify this mystery breakout board

    Hi Guys;

    I need a little help identifying a mystery breakout board.

    148347

    Probably circa 1998 - 2002, judging by the machine it arrived in ( from what I
    can tell, a straight-up parallel...
  6. Actually, it's kind of trickier than just their...

    Actually, it's kind of trickier than just their parallel resistance.

    Rotating machines like permanent magnet motors (and step motors) also act like generators when they turn. In fact, they even...
  7. Here's the basic issue - motors and generators...

    Here's the basic issue - motors and generators are very mechanically similar.

    Step motors, like many permanent magnet motors, will generate electricity if back-driven. Imagine a motor generating...
  8. Replies
    7
    Views
    1,210

    One drive dying is a fluke. But two dead drives...

    One drive dying is a fluke. But two dead drives on the same axis probably means something.

    I would suggest you very carefully check all the cabling out to the motor, paying special attention to...
  9. Thread: PIC based DRO

    by sswitaj
    Replies
    112
    Views
    33,862

    Has anybody mentioned the encoder interface chips...

    Has anybody mentioned the encoder interface chips from USDigital yet?

    ( US Digital | Products » Interfaces » ICs )

    I often have to do low-volume encoding based systems in microcontrollers, and...
  10. >> Go to McMaster Carr, they have about every...

    >> Go to McMaster Carr, they have about every type tubing/fitting setups ever made.

    My first thought.

    Sadly, I seem to have found the one industrial part on the face of the Earth that McMaster...
  11. need help identifying mystery oiler fitting on Asian mill

    Hi guys;

    Simple question - I'm rebuilding an old specialty mill that has a one-shot oiler, an Asian copy of the standard 80's bijur type, by a company called "flyhorse"

    It works OK, but all the...
  12. Replies
    5
    Views
    1,347

    I'm assuming that you're using the internal PWM...

    I'm assuming that you're using the internal PWM registers. Check carefully that you're not accidentally writing garbage to those registers. If you have an ICD, stop the chip and check that the actual...
  13. Replies
    4
    Views
    996

    If you're using a dropping resistor for the LED...

    If you're using a dropping resistor for the LED don't forget that the resistor has about 46 volts across it.

    At 20 ma, it's going to dissipate an appreciable amount of power ( 46V X .02A = .9W )....
  14. Replies
    6
    Views
    1,355

    The difference between a schematic and an...

    The difference between a schematic and an assembly diagram is that the assembly diagram is (roughly) that an assembly drawing tells you how to build the thing, but provides little conceptual...
  15. Replies
    8
    Views
    734

    RFQ, Small job, mounting brackets

    Hi guys;

    Sadly, this is only a small job, but maybe someone has a couple of hours open that they'd like to fill.

    This is a mounting bracket for circuit cards, .25 x .25 x 1.65, with 4 threaded...
  16. Need to refill a linear bearing (lost my balls)

    Hi Guys;

    Got a weird one.

    One of my clients is a company that does some specialized 3D photography. about a year ago, they purchased some small “camera sliders” from an outside vendor. These...
  17. > In your lens clamp.pdf, the groove or notch...

    > In your lens clamp.pdf, the groove or notch shows .250 - .630 gap.
    > Is this a typo? should it be .125 - .163?? It just seems wide for an 8-32 pinch bolt.

    JoBwan;

    You are, of course,...
  18. RFQ 6 copies, milled part, 9 copies turned part

    Hi Everyone;

    Today's posting is an RFQ for a small quantity of parts for specialty lens mountings for industrial CCD cameras

    There are two parts, both are aluminum, load is not an issue so...
  19. Just quickly glancing at the L297's data sheet,...

    Just quickly glancing at the L297's data sheet, it looks like you'd want current-limiting resistors in each line between the L297's output and the transistor bases.

    Right now, to the L297, the...
  20. Replies
    7
    Views
    1,532

    That's a heckuva range for conventional chemical...

    That's a heckuva range for conventional chemical batteries. Are you dealing with something unusually exotic, like supercaps?
  21. Replies
    16
    Views
    2,148

    First, Gar's absolutely right, if you're...

    First, Gar's absolutely right, if you're expecting to pull more than a few milliamps out of your regulator, you're going to dealing with power dissipation issues.

    Linear regulators do what they do...
  22. Thread: PWM controller

    by sswitaj
    Replies
    2
    Views
    878

    DMX, also called DMX512 = Digital MultipleX, a...

    DMX, also called DMX512 = Digital MultipleX, a serial command format developed by the stage lighting industry used to control large arrays of lighting equipment in concerts and similar venues.

    My...
  23. Replies
    7
    Views
    1,036

    You have a TTL device driving your parallel port....

    You have a TTL device driving your parallel port.

    There are two basic "families" of 5v logic devices, TTL (also called bipolar) and CMOS.

    Because of the way TTL parts are built, it's common for...
  24. Thread: PWM controller

    by sswitaj
    Replies
    2
    Views
    878

    PWM controller

    Anybody know of a good (digital) PWM chip?

    I have an app (motion control with a DMX lighting interface) where I have to control a lot of channels via PWM chopping. (far more than are available on...
  25. Replies
    17
    Views
    6,407

    Poll: I had an ElDorado for a couple of years. I was...

    I had an ElDorado for a couple of years.

    I was using it as a "home" machine in a secondary shop so I didn't have to lug work around just to put a couple of holes in projects.

    Like most...
  26. How many do you need? I'm on a project at the...

    How many do you need?

    I'm on a project at the moment in Portland Oregon, right across the river from US Digital in Vancouver, Washington. I use their product all the time, and if we're talking...
  27. Thread: Hot Steppers!

    by sswitaj
    Replies
    9
    Views
    2,087

    In stepper motors, there are two basic sources of...

    In stepper motors, there are two basic sources of heat. The first is the the straightforward power lost by driving current through the resistive conductors, basic I-squared-R losses, and , for the...
  28. Replies
    33
    Views
    4,323

    I noticed that the subject of using an old HP...

    I noticed that the subject of using an old HP penplotter for PC boards has come up.

    I have one of these (a 7475A, I believe) sitting new, and apparently unused, in a box in my shop.

    It came...
  29. That green coating on commercial circuit boards...

    That green coating on commercial circuit boards is called soldermask, and, although it's an insulator, it's not really intended for electrical isolation.

    It's actual function is to control the...
  30. Thread: DIY H-bridge

    by sswitaj
    Replies
    14
    Views
    3,986

    Have you looked at the LMD18200 H-bridge from...

    Have you looked at the LMD18200 H-bridge from National Smiconductor?

    I designed a couple of them into a small motor contol project this summer, they were much easier for the manufacturing guys...
Results 1 to 30 of 41
Page 1 of 2 1 2