software limits reached

[doncraig]

Hi Again,
I recently was given great help here to get my UCCNC/Stepcraft 420 setup operating correctly and I am very thankful for that. I even learned how to read the manual and follow instructions. lol. However there are other problems I found and would like to ask for some help.
When I start up my UCCNC and connect to Stepcraft 420 I can move all axes in all directions. However when I bring the gantry forward (Y axis) a screen pops up that says "A machine axis position software limit was reached. The axis has now stopped." I can jog the Y axis back ok but when I jog forward it stops with the same message again. What have I done wrong ?? Can anyone help with this problem ??.
I have another problem with this setup but will wait until I have sorted this out.
take care
Don W

[Robertspark]

If you go to SETTINGS >> AXIS and one of the options will be soft limits.

you can enable or disable them / set their dimension correctly.... it depends where you home your axis as to how large the soft limits zone will be..... because homing your axis normally sets Zero for that axis (or an offset if that is how you set it up).

[Robertspark]

Oh.... If you go to SETTINGS >> GENERAL SETUP

There is a checkbox to disable softlimits too

[doncraig]

Thanks Robert,
I have had a look in the manual and discovered the Softlimits + and Softlimits - Is it safe to enter figures here and try it out ?? Will I damage anything ??
I also found the references to Limit - and + port & pins and Home port & pin. Are these dependent on each other ??
I will try entering some figures in the Softlimits first

[ger21]

Softlimits are relative to the machine home position. Does your machine have home switches?

[laki]

From what I saw in the User Manual for Stepcraft 420, home/limit switches are connected to pin12.
The machine has a travel distance of 420 x 300 x 80 mm.

Try these values for softlimits:
X axis
Softlimit - (5)
Softlimit + (295)

Y axis
Softlimit - (5)
Softlimit + (415)

Z axis
Softlimit - (-75)
Softlimit + (-5)

Axes setup
Write offset on homing (0) for all axes
Back off after home
X (2)
Y (2)
Z (-2) Home positive
No brackets of course

[doncraig]

Thanks again laki for this information. I have applied these suggestions and find problems.
Write offset on homing (Units) will not go below 5. If I try 0 and try to save it changes to 5 this is for the X and Y the Z is -5.
Back off after home, is that in General Settings ? I can see a line there that says G73 back off (Units) 0.4, I can change that to 2 but that would be no good for Z? I have startedUCCNC and the screen gives this :- X=47.0100, Y=5.1000 and Z=-20.1900.
When I select 'HOME ALL' the Z raises to the switch and stops,the X moves across to the switch and stops then the Y moves back to the switch and stops. The screen now reads :-X=5.000, Y=5.000 and Z=-5.000. I can now move the X axis back and forth and the Z axis up and down but the Y will not move forward, it only jogs back and triggers the 'Softlimit reached' alarm. I then have to open the sides and manually unscrew the gantry back from the limit switch.
Thanks again for the help I think we may be getting somewhere with this, albeit slowly.
take care
Don W
PS The manual says something about the home position for the x and y axes is not at the front left where you would expect but at the back left which should be 0,417. I'm really not sure as this has almost turned my head and I am getting a bit frustrated.

[ger21]

Set the Y axis offset on homing to 417, or maybe 415?

[doncraig]

I have tried that Gerry but the X axis jammed against the frame when I homed all.
I am covered in grease/oil from opening up this machine and manually moving the axes. I will give up for the night and start again in the morning.
Thanks for the suggestions.
Don W

[Dale]

It sounds like your machine does not know where it actually is yet.

Home the machine with soft limits turned off, then after homing, turn them back on.
You should be goo after that.

I went through the same thing.

Cheers!
Dale