On 7/26/2011 3:41 AM, Viesturs Lācis wrote: > 2011/7/26 Andrew<[email protected]>: > >> 2011/7/26 Dave<[email protected]>: >> >>> My question is: What would be the best way to implement this two "X" >>> axis control scheme with EMC2? >>> >> I'd suggest a custom kinematics file, probably based on gantrykins. >> With HAL pin connected to hardware switch choosing between tables. >> >> > I see 3 theoretical solutions: > 1) You have a g-code filter, which substitutes X with U for the parts > to be produced on second table > > 2) You can write custom HAL component with 4 inputs and 4 outputs and > 1 selector pin, so that You can take these pins: > axis.m-pos-cmd > axis.m-pos-fb > > axis.n-pos-cmd > axis.n-pos-fb > > and link them to these pins: > > motor.m-pos-cmd > motor.m-pos-fb > > motor.n-pos-cmd > motor.n-pos-fb > > in a following way: > If selector is "false", then > > axis.m-pos-cmd<-> motor.m-pos-cmd > axis.m-pos-fb<-> motor.m-pos-fb > > axis.n-pos-cmd<-> motor.n-pos-cmd > axis.n-pos-fb<-> motor.n-pos-fb > > If selector is "true", then > > axis.m-pos-cmd<-> motor.n-pos-cmd > axis.m-pos-fb<-> motor.n-pos-fb > > axis.n-pos-cmd<-> motor.m-pos-cmd > axis.n-pos-fb<-> motor.m-pos-fb > > Obviously, You can switch them _only_, when corresponding pins of m > and n are equal. That is, X and U positions have to be the same. > > 3) My favorite option would be the one already suggested by Andrew - > custom kinematics module. > I was thinking that also this solution would require putting both > tables in equal positions, but then I realised that this is the place, > where it can be hacked. I just did not yet come up with a solution. > I just would like to oppose Andrew's opinion about using gantrykins as > the place to start - I do not think so, because gantrykins is > generalised for any kind of "2 joints on a single axis" combinations > and thus it actually is pretty complicated. > I think that You should start simply with trivkins and do 2 things: > a) add a HAL pin > b) in forward and inverse kins add the "if the HAL pin is true or > false" conditions and how tran->pos.x and pos->u are related to > joint[m] and joint[n] > > > I think that both last options are of equal level of difficulty, IMHO > not very hard. > In any of the cases You can drive the selector pin with M64 command > from g-code so that operator just needs to change the parts, but > machine does all the production in non-stop. > > Viesturs > > > I was thinking that moving both tables to the same position might be a problem, but now I am thinking that might be the simplest solution.
If I did that change in the kinematics module, would both axes have to be in the same position to make an axis swap? Dave ------------------------------------------------------------------------------ Magic Quadrant for Content-Aware Data Loss Prevention Research study explores the data loss prevention market. Includes in-depth analysis on the changes within the DLP market, and the criteria used to evaluate the strengths and weaknesses of these DLP solutions. http://www.accelacomm.com/jaw/sfnl/114/51385063/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
