Pnncof Tandem Y axis problem

Rod wrote:The Z axis will home (it is homed at the top right?) to clear any stuff on the gantry, then The X axis will home, then the Y axis will home in unison.

with this:

add this to your ini for each joint
Joint 0 - HOME_SEQUENCE = 1
Joint 1 - HOME_SEQUENCE = -1
Joint 2 - HOME_SEQUENCE = -1
Joint 3 - HOME_SEQUENCE = 0

I would think the Z would be first then then X and Y would all move together, so Joint 1 and 2 should be HOME_SEQUENCE = -2

Clive wrote:

Rod wrote:The Z axis will home (it is homed at the top right?) to clear any stuff on the gantry, then The X axis will home, then the Y axis will home in unison.

with this:

add this to your ini for each joint
Joint 0 - HOME_SEQUENCE = 1
Joint 1 - HOME_SEQUENCE = -1
Joint 2 - HOME_SEQUENCE = -1
Joint 3 - HOME_SEQUENCE = 0

I would think the Z would be first then then X and Y would all move together, so Joint 1 and 2 should be HOME_SEQUENCE = -2

The order is up to you but joint axes home last.. Negative numbers denote joint axes and when they are the same negative number means they are the same axis.

You could change joint 0 to be = 0 and then this will home the X and Z at the same time which saves time but then I learnt the hard way when the torch hit something, this was not a good idea .

andypugh wrote:

It looks like pncconf will create HOME_SEQUENCE entries if every joint has a home switch input defined.
Unless something is wrong. Did you define home switch inputs?

No I did not define any home switched,

When I built my machine I was so excited to get it cutting I did not install any home switches and never got around to it.

In CommandCNC they are not necessary to have the machine running as you can just home the machine in any position.

I cannot say I noticed any unsquare cuts from my machine. I have done alot of cutting with it and have not noticed any out of square parts from the gantry being out.

See below for my biggest part ive cut, It is completely square. Although my gantry is very tight due to its design and does not rack when moved by hand with the gear boxes disconnected,

rodw wrote:

But when I think about it, unless I'm off the mark, you can't have a gantry without working homing switches.

In theory it seems like it is not possible but in reality I have done it for over a year successfully.

Maybe my parts are not as perfect as they could of been if I had home switches, I will look at installing them soon if I cannot get Plasmac branch to work without them.

It is really handy tho for a plasma to work without them. I understand the point of getting the Y axis gantry square but when I have multiple sheets on my table it is great to be able to jog to the position I want to start the program from, Home the DRO and let it run.

I do understand that is not how it works in the Mill and Lathe world but in the Plasma world, providing you are cutting multiple sheets at once it is much simpler to home in position rather than using offsets.

I have enough drama teaching my guys who have never seen let alone used a CNC machine before how to use the machine. It might not be the "proper" way to use it but in the real world it does work.

You can certainly configure your hal file as a non-gantry machine and be able to jog without homing if you wish (this is independent of plasmac)

One important thing you do lose without homing is soft limits...

PCW wrote:

You can certainly configure your hal file as a non-gantry machine and be able to jog without homing if you wish (this is independent of plasmac)

One important thing you do lose without homing is soft limits...

I still need the DRO to home (as in go to 0.00) so the program will function correctly,

I just dont always need to go to a hard home switch and only work from that point.

Is it possible to have both, Immediate homing and homing with a hard home switch.

I can see the benefit in have the gantry perfectly square by using home switches.

I will be getting a new GUI designed specfically for plasma, Could it be possible to have hard homing buttons that activate a hard homing sequence and soft homing buttons that allow you to home at any position on the table?

For a job that you cant afford to be stuffed up I can see the benefit in having a hard home to return to if something were to happen- power outage etc. But for small jobs that can be reset easily soft homing is acceptable.

Just realized after I posted that CommandCNC has this ability so it is possible.

But you only need to home once a day or whenever you power up your machine. Its 4 keypresses in Gmocappy which are near automatic for me by now. YOu don't need to home for every job.

Personally, I think the "I'm too lazy to home my machine" argument just does not cut it. If need be, park your machine near the home position at the end of the day and it will take a few seconds in the morning. You can even add a Gmocappy macro button to park at the end of day. Besides because of the 2 speed homing, your machine does not have to crawl along on the first leg. Just you need to allow room to coast to a stop between the home sensor and the end stop.

rodw wrote:

But you only need to home once a day or whenever you power up your machine. Its 4 keypresses in Gmocappy which are near automatic for me by now. YOu don't need to home for every job.

Personally, I think the "I'm too lazy to home my machine" argument just does not cut it. If need be, park your machine near the home position at the end of the day and it will take a few seconds in the morning. You can even add a Gmocappy macro button to park at the end of day. Besides because of the 2 speed homing, your machine does not have to crawl along on the first leg. Just you need to allow room to coast to a stop between the home sensor and the end stop.

Homing the machine is not the problem,

When you home the machine the DRO goes to 0.00, That is what your G code program starts from,

If the 0.00 is in the corner of your machine you need to apply offsets to the dro value to have the program start at the point you want it to start.

What I have been doing is setting the corner of the sheet as 0.00 then running the program. When I have multiple sheets I just jog to the corner and home the x and y axis then run the program.

Is there a easier way that I am not seeing?

Yes there is an easier way and I just found it recently myself. SO don't feel bad. Just jog to the position you want to start from and use the blue buttons in Gmocappy to touch off X & Y to 0,0 to the G54 offsets. THat will reset your DRO to 0,0.

Recently, I saw Todd shared a snipit of gcode that did this for X & Y at one time. Eventually, I would like to get his in a macro button.