On Thu, Sep 30, 2010 at 2:10 PM, Stephen Wille Padnos <spad...@sover.net>wrote:
> Stuart Stevenson wrote: > > Gentlemen, > > I am working on a project on the Enshu. I am not sure how valuable it > will > > be but I sure want to try it. I want to tap threads using the MPG. > > > How do you envision this working? Does the handwheel make the machine a > virtual hand tapper? (ie, spin 1/2 turn forward, 1/4 turn back, but all > with power assist) Does the handwheel control the spindle > orientation/position or the Z depth? Does the spindle/Z need to go > forward and backward? > My first thought was to control the spindle with the MPG and have the Z (or other linear axis) scaled to the correct feedrate. With the MPG controlling the spindle the reversal should not need to be as abrupt. > > The spindle drive is a full servo. The spindle motor has a resolver > for > > feedback to the spindle drive. The EMC2 DAC signal to the spindle drive > is > > +-10V. I have found a quadrature signal out of the spindle drive. This > > spindle drive uses the resolver feedback to generate this quadrature > signal > > (A and B). The spindle has a prox and amplifier that feeds a signal into > a > > daughterboard on the spindle drive for spindle orientation during tool > > change. The daughter board has a pin that outputs a pulse once per > > revolution corresponding to the radial position of the spindle. I intend > to > > use the A and B as encoder feedback into EMC and the orientation pulse as > an > > index pulse into EMC. This will allow full servo control of the spindle > as a > > C axis. > > > It sounds like the hardware is enough to do the job, if the spindle > drive handles low speed and reversal well. > > I would like ideas on the best way to implement this. I would like to > have > > the spindle set up as a C axis but without a C axis display on the screen > > (unless I am using the C axis as an actual C axis but that is another > > project). I don't think I NEED any display for the spindle for this > project. > > I think I would like to be able to command a G code to engage the spindle > > and an F code for feedrate to move the C and Z in a coordinated fashion. > > Maybe I am thinking backwards. Maybe driving the Z axis with the MPG and > the > > C (spindle) coordinated with the Z is the best way. > > > You can drive more than one axis with a single wheel. Connect the > encoder counts output to both Z and C, but change the scales on both so > they match. Maybe use a scale block in HAL to do that (with an enable > also, so you can "disconnect" the two axes), so you can change the > increment on Z and have the spindle still follow along (or the other way > around). > > Other than that method, I'm not sure how you could get hand tapping and > EMC auto control in the same config. I suppose you could have some M > codes that twiddle HAL signal connections, but that seems a little > dangerous. > The only reason I mention the interface and hand tapping is 'How do you restrict the interface to only the hand tapping mode while the mode is engaged?' If it is not integrated will it be possible to confuse the control during the hand tapping if other buttons are touched? > > I don't think it's possible to make the C axis appear and disappear on > the DRO through G-code or other dynamic means. You could add HAL input > pins to AXIS to remove axes from the DRO though (I would think). > > Since I am thinking 'manual' then maybe a button is better than a G > code. > > If I had a button how would I tell the machine the pitch of the thread? > > > Pyvcp input? > Touchy is the interface screen. I have seen some discussion of auxiliary displays along with touchy. Or maybe have the touchy FO display the chosen feedrate when in hand tapping mode. > > Maybe a screen display like the FO/SO/MV displays. This would adjust in > > proper increments per the chosen units and allow the MPG to set the pitch > > prior to engaging the coordination button. > > thoughts - comments - ideas > > thanks > > Stuart > > > > > > > ------------------------------------------------------------------------------ > Start uncovering the many advantages of virtual appliances > and start using them to simplify application deployment and > accelerate your shift to cloud computing. > http://p.sf.net/sfu/novell-sfdev2dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- dos centavos ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
