End stops auto homing stepers advice

New Home Forum LowRider Advice – LowRider End stops auto homing stepers advice

This topic contains 9 replies, has 4 voices, and was last updated by  Bill 1 month ago.

Viewing 10 posts - 1 through 10 (of 10 total)
  • Author
    Posts
  • #117876

    Kevin
    Participant

    Bought the kit with the mini Rambo what do I need to have end stops and auto homing what do the steppers do will the Rambo work with the end steps also is there a firmware to use for this or will I need to edit one to work

    #117879

    Jeffeb3
    Participant

    Auto squaring uses indepentent drivers for each motor. When they home, each end has an endstop and each end will.move indepentenly to reach it’s own endstop. After that, they will move in lock step.

    The mini rambo has only 4 drivers. So you could auto sqaure one axis, but not both, so that’s not a common configuration.

    With the mini rambo, you’re going to wire your duplicated axis with series motor wiring. After they start up, they will always move in lock step. All you need to do is make sure they start square and after that, they will stay square. You don’t need special firmware, just wire them between the (s) and (-) pins for the endstop. Not the (+)!!!

    Homing, or autohoming, is a very popular request, and it can be done with stock firmware. Since a lot of us are 3D printers by nature, it’s natural. But they are completely unessecary for milling. When you’re subtracting materials, the origin of the work isn’t based on the location in the machine, it’s based on the location in the material you’re carving.

    So you will set the 0,0,0 in CAM to be the lower left corner, at the top surface of the workpiece. Having it be at the min of the machine does you no good. Instead, you will move the machine to the 0,0,0 location and send a G92 X0 Y0 Z0 to set the origin. It’s also common to just add that to the starting gcode.

    I hope that helps.

    #117882

    Kevin
    Participant

    To  do the auto homing and centering what board and hardware would you recomend

    #117883

    Kevin
    Participant

    Oh also it is there instructions on how to center and square the system are there any other settings that need to be put in mini rambo

    #117884

    Kevin
    Participant

    i just got through with my build testing my lcd screen has ? for the x y z flashing what does this mean?

    Also when i try to auto home it errors out says to reset

    #117900

    Jeffeb3
    Participant

    To do the auto homing and centering what board and hardware would you recomend

    The full size Rambo.

    Oh also it is there instructions on how to center and square the system are there any other settings that need to be put in mini rambo

    I’m not sure what you mean by center. I have a mink rambo wired in series. The process I use is:

    – With the machine off, I move it to the lower left corner.
    – I knoe my table is square, so I have some little blocks I clamp on to the edge of my table
    – I pull the gantry against the blocks and now the gantry is square
    – I give each Z leadscrew a little twist up and let if fall back down. Now the Z is square.
    – I power on the machine.
    – I jog the machine away from the blocks and remove the blocks.
    – I jog to the origin of my work.
    – I send the G92
    – I start my milling.

    i just got through with my build testing my lcd screen has ? for the x y z flashing what does this mean?

    That’s fine. It’s just saying it’s not sure where it is. That will go away when you do a G92. I think there’s also a menu item in the lcd. Something like “set home position”.

    Also when i try to auto home it errors out says to reset

    Do you have endstops installed? You don’t need to auto home.

    1 user thanked author for this post.
    #117937

    Bill
    Participant

    I think @kevin might be planning on cutting from the center of his piece instead of from the corner. That makes it easier to make sure what you are cutting is centered on the piece without a lot of measuring. It does make things a little more complex, but it’s still easy enough to deal with without auto-homing. Just do as @jeffeb3 suggests but instead of physically moving the machine to the lower left corner, move it a pre-measured spot at the center of your work. You still do the G92 X0 Y0 Z0 thing which pretends to the software that you are already homed, then fire up the stepper motors by raising the Z a bit, turn on your router and start your project. Remember if you start in the center your model that the gcode was generated needs to also start in the center.
    Also note that it won’t work if you have the full Rambo with dual endstops. Then you are not allowed to move into a negative position so have to put 0,0,0 at the corner.

    #117952

    Kevin
    Participant

    I had been using a maslow and I always would zero in the z axis and i could move the home position to anywhere on the board where i wanted. I am not really understanding where to put everything. how do your tell the system what is them max of z axis. also how does it know what the size of your work area. I know these are questions i should know what the answers should be. Newbie

    #117959

    K Cummins
    Participant

    Since CNC milling is subtractive, if your stock fits on your workbed, it’s “in bounds”. Beyond that, the machine trusts you. I think that if you use workspace coordinates (G54-59.3) before setting your position with G92, and you’ve set the machine origin properly (and have the bounds set correctly in the firmware), it’ll keep you from being too terribly stupid. But overall, you gotta be smarter than your stock (and the g-code).

    For as finicky as 3D printing is, it really does hold your hand a lot compared to CNC (more importantly, it doesn’t try to bite your hand, soak itself in your blood as your sight fades to black, hurl spinning carbide at your face, or warm itself in a conflagration of your hopes and dreams)…

    #117961

    Bill
    Participant

    You decide the Z axis max depth by setting the cut depth in your CAM and setting Z0 to the top of your workpiece. Remember there is the max cut depth and the depth of cut (DOC), the latter is how deep the tool goes each pass, the former decides when to stop cutting.
    The only time you deal with work area size is also in the CAM, you just have to remember not to try and cut a piece where the cuts are larger than the physical limits of your build. There is a setting in the firmware for bed size, but that’s only used during homing and it just makes sure it doesn’t try to keep on homing forever if you don’t have working endstops.
    The standard procedure for getting a job started is to move the mechanism to the bottom left hand corner of the bed and jog to find the bottom left hand corner of your work piece, or just move to the bottom left hand corner of your work piece. Jog from there until the bit just touches the work. At that point everything is at where you want 0,0,0 to be, so you send the command G92 X0 Y0 Z0. Jog the Z back up a bit so it’s away from the work and fire up your router. From there you can just start the cut process and it’ll move to where the cut starts, drop down to Z0, then drop down by the DOC and start cutting. If you have dual endstops the first sentence is replaced by “move the mechanism by homing X and Y”. If you have a Z probe then you just the home Z command to set your Z0 instead of looking at the end of the bit and jogging down until it starts to touch.
    Once you start the first jog the stepper motors will be locked and moving by hand gets really hard, that’s why you typically get X and Y to where you want zero to be then jog Z down. It locks everything up at that point and the rest is all done by the software.

Viewing 10 posts - 1 through 10 (of 10 total)

You must be logged in to reply to this topic.