alden

Forum Replies Created

Viewing 15 posts - 676 through 690 (of 702 total)
  • Author
    Posts
  • in reply to: Funky tool chain questions #1593
    alden
    Member

    Perhaps buying another grblshield? (hint hint) 🙂

    Alden

    in reply to: Probably a bug in enable pin management #1632
    alden
    Member

    Thanks for he heads up. Sounds like you have a solution to your problem, however. Since you are in there at the grbl source code level I’d just enable the enable pin all the time. I can’t really answer the timing question you ask about the innards of the grbl code, but you might post this as an issue to the grbl github.

    Also, since you are not using grblshield you may just want to get the “official” grbl release from the grbl github (simen/grbl). The changes in the grblshield patched version are there to support the pin signal polarities in grblshield and since you don’t need that I don’t think there’s any advantage to using the patched version.

    By the way, the grbl edge branch (grbl version 0.7) is now compatible with grblshield, so we won’t be needing the patched version once the grbl project moves version 0.7 to the master branch (and publishes the master .hex file).

    Thanks for letting us know about this anomaly.

    in reply to: Funky tool chain questions #1591
    alden
    Member

    Can’t answer your question about the toolchain, but no, you can always re-load the Arduino code from the Arduino menu (somewhere in the upper right part of the screen, IIRC).

    Alden

    in reply to: Inches vs MM in Grbl settings #1630
    alden
    Member

    I believe the number you want is 157.480315 steps / mm. 1 revolution is 200 steps, and a revolution is 0.05″, or 1.27mm. So steps / mm is 200 / 1.27, or 157.48 mm

    Alden

    in reply to: Need installation instructions #1627
    alden
    Member

    There are no user changes required on the v1 board
    (which, by the way, is the only version in production – there is no second thing…)

    There was a note on the wiki about needing to remove a resistor if you didn’t want to configure the motor Enable line to be active LO, but this is unnecessary if you use the patched .HEX file, or (more recently) use the grbl 0.7 release from the grbl github edge branch. That wiki text has since been removed because it caused more confusion than it cured. You can ignore it in the hard copy instructions, too.

    Alden

    in reply to: Need installation instructions #1625
    alden
    Member

    OK. Now I see your confusion. We never put installation instructions on the grblshield wiki because that’s a grbl project thing. Sorry for the blank page. I have edited the getting grbl page to reflect some status updates, and to point you to the official grbl site for installation, configuration, etc.
    http://www.synthetos.com/wiki/index.php?title=Getting_grbl#Getting_grbl

    Alden

    in reply to: What type of matching connector is that for the stepper #1794
    alden
    Member

    Here are some links I found by searching around that explain stepper basics and how to figure out what wire is what.

    http://www.reuk.co.uk/Examining-a-Stepper-Motor.htm
    http://digital.ni.com/public.nsf/allkb/0AEE7B9AD4B3E04186256ACE005D833B
    http://techref.massmind.org/techref/io/stepper/wires.asp#step2 (for 5 wire motors)

    Alden

    in reply to: Need installation instructions #1622
    alden
    Member

    Here’s the grblshield wiki. It should point you in the right direction.
    http://www.synthetos.com/wiki/index.php?title=Projects:grblShield

    Thx

    Alden

    in reply to: What type of matching connector is that for the stepper #1792
    alden
    Member

    Unraveling a motor without specs can be a challenge. I first always look for a data sheet by searching on the motor part#. It’s often on the motor, but not always. If I can’t find the data sheet it’s time for the ohmmeter.

    Wire colors can be clues. Green and black are often the outer leads to a winding, and red and blue also often go together. Sometimes there will be a solid colored lead and a striped lead of the same color. These also usually go together. In a 4 wire motor (bipolar winding) if you test these pairs and they come back with the same low impedance (e.g. 4.2 ohms for a big motor, 92 ohms for a small one) you are done. These are the two windings.

    In a 6 wire motor (unipolar winding) there will be an additional center-tap lead in between the outer leads. A white lead is often the center tap for the red / blue pair (red, white and blue), and a yellow lead is a center tap for the green / black pair. The ohmmeter will read 1/2 the resistance from the center to the outer leads. So if the resistance between the outer leads read 4.2 ohms, the resistance to the middle should be 2.1 ohms. I usually wire across the outer leads and leave the center alone (but insulated). I’m told you can also get higher torque (and consume more power) by running a unipolar just from the center to an outer, but I’ve never tried this (probably should).

    Sometimes you are lucky enough to find a 6 pin header on your motor (the wrong size for your application, of course). Test these for outer1-center1-outer1, outer2-center2-outer2.

    But don’t trust the colors and plug alone. I’m looking at a NEMA17 motor right now that’s 6 pin plug is wired green-black-yellow, red-blue-white. The colors are right, but the yellow and white center taps are not wired to the plug pinout the way I just described. Can’t be non-standard if there IS no standard.

    So always test with an ohmmeter.

    Mark, did you post your method somewhere?

    Alden

    in reply to: What type of matching connector is that for the stepper #1790
    alden
    Member

    The motor connectors are the same as those used on the Reprap/ Makerbot electronics. They are 0.156″ Molex headers, Molex part #09-50-3041. These are just the shells. You also need the pins (“terminals”), which are Molex part #08-50-0134

    These can be found at Mouser Electronics:
    http://www.mouser.com:80/Search/ProductDetail.aspx?R=09-50-3041virtualkey53810000virtualkey538-09-50-3041
    http://www.mouser.com:80/Search/ProductDetail.aspx?R=08-50-0134virtualkey53810000virtualkey538-08-50-0134

    There are many other manufacturers that make and sell similar parts. They also sell (very expensive) crimping tools for these terminals, but I just use needle nose pliers to crimp the low volumes I need.

    Alden

    in reply to: 2 steppers hooked on 1 driver? #1786
    alden
    Member

    Thanks. I’ve never done this and am curious about your results. One possibility is that since a stepper driver is just a kind of power amp, and you can parallel speakers to an audio amp, you should be able to do the same. OTOH, a lot of what the stepper driver does is damp back-EMF through various clever decay schemes, and if doubling up on the motors complicates the back-EMF waveform these schemes may not work. I’m curious as to your results. How good are you at soldering fine-pitch surface mount 🙂

    in reply to: 2 steppers hooked on 1 driver? #1784
    alden
    Member

    I think you are better off driving them with separate drivers. You could try wiring the motors in parallel, but I’d be concerned about what that does to the driver. They are not designed to work this way.

    in reply to: alternative for stepper motor connectors #1776
    alden
    Member

    We realize the problem and apologize for your inconvenience. We will begin selling the connectors in kits on the site so they can be packed with the order.

    We also have located some really nice copper heatsinks that we also want to make available in kits. We’ve found that the TI drivers actually do quite well without any external heatsinking as the boards have as much copper as we could get – given the limited footprint of a shield. But the heatsinks extend that range a bit further.

    If there are any other parts you think would be helpful, please let us know.

    in reply to: Suggestion for grblShield #1559
    alden
    Member

    Since you posted your message the source for the grblshield patched code has been put up on the grblshield github at https://github.com/synthetos/grblShield
    The lines added/changed from the grbl edge branch have been labeled as /@grblshield@/ so you can find them easily.
    The pinouts used by grblshield are the 0.6 pinouts in config.h
    As for limit switches, I have not used these, so I’m afraid you are on your own to see how grbl uses them.
    Please let me know if this gets you where you need to. — Alden

    in reply to: limit switch/spindle control support ? #1772
    alden
    Member

    test post

Viewing 15 posts - 676 through 690 (of 702 total)