Messages

31

General Mach Discussion / Re: Help w/ cnc plasma issue

« on: May 03, 2011, 02:13:57 PM »

Grounding. I used to install commercial machines and we had a couple locations where we had problems because of gounding problems. You need to make sure everything on your carriage is grounded to a common point on the carraige, then run a ground wire to a common point with the rails and table. then run a ground from that point to a good earth ground. Depending on your location you may need to water the the ground rod as excessive drought can affect teh quality of your ground. You might also look for a copper shield to run your torch leads in.  A woven copper sleeve around your torch lead and the it tied top the common ground at one end.

Every location will not have this problem. I have installed machines with no groundimng and had ZERO problems. One of the machines with a grounding problem would move erratically and unpredictably. The other machine would blow encoders. Get a bad ground and an encoder would fail.

32

General Mach Discussion / Re: Possible to keep limits enabled during home?

« on: April 06, 2011, 10:20:33 PM »

You should not be able to drive past your home switch. (shouldn't be able to drive past your limit switches either...)

Are you saying separate home and limit switches is a bad design? Because if they are separate, you'll have to go past one of them, unless you set them to the exact same spot. 

NO - Homing switches should have some sort of mechanusm that keeps them tripped after you pass teh leading edge of the home switch, UNLESS you trust the operator to ALWAYS make sure they position the machine properly BEFORE starting the homing sequence.

You could have a home position that is mid travel, you would just need a very long cam to keep the switch tripped as long as you are on the "wrong" side of the switch. A proper homing switch should stay tripped as long as the machine is physically past the home switch in the homing direction. Either that, or you must create a homing sequence that will ALWAYS place the machine physically on the proper side of the switch BEFORE doing the actual homing sequence.

The only other homing sequence I have seen hits the switch 2 times in the homing direction - it goes toward the homing switch at high speed, when it hits the homing switch the axis reverses travel and moves off the homing switch and then  moves toward the homing switch at low speed.(machine had 100 foot travel) It then sets home when it trips the switch. In this case a home switch that you could go past has the potential to be a real problem.

Sorry - I think you should design your homing switches/cams so they function in a more standard way, not require a software change for a sub-optimal design.

33

General Mach Discussion / Re: What happens whe power supply is gone?

« on: April 06, 2011, 05:32:01 PM »

Modify your wiring so that teh power supply holds in a relay in the E-Stop circuit. If the power supply drops teh machine goes into E-Stop and Mach will stop executiong the program because of the E-Stop. That is a rather common way to wire industrial machines. One of the conditions for the E-Stop to be cleared is that the machine has electrical power. Otherwise you could possibly have an E-Stop cleared when power comes on and things could be moving and who knows what could happen...

34

General Mach Discussion / Re: Possible to keep limits enabled during home?

« on: April 06, 2011, 05:27:22 PM »

It sounds like you are trying for a work-around for poor home switch design.

You should not be able to drive past your home switch. (shouldn't be able to drive past your limit switches either...) What you then need is a workaround in your limits so that if you hit a limit then you know you went past your home switch, you then have to reverse and make sure you go past your home switch and then start the homing sequence all over again. The homing sequence is then needlessly complicated.

Homing sequence begins - Move in the homing direction and check for the homing switch. When the switch is found reverse direction and then stop once the homing switch changes state.  Clean simple and reliable. If you start out on the switch the machine will sense that teh first condition is true and then back off the switch and call that home.

35

General Mach Discussion / Re: Home liimits problem

« on: March 21, 2011, 10:24:39 AM »

What switches are you trying to use for homing? if you are using the limits, then set eh home switches up the same as the limit for that axis. Should work that way. Just make sure you have correct input or homing won't work. (On my machine the factory had the inputs for X & Z swapped. the limits behaved just fine, the homing didn't, swapped the pins in the configurtationand homing works.)

36

General Mach Discussion / Re: project has Text text ok in LC but cuts mirror in mach3

« on: March 21, 2011, 10:19:13 AM »

Mirroring. Does it Mirror in X or in Y? You need to alter the configuration for which ever axis is mirrored. In other words yoiu have positive and negative swapped for one axis.

37

Sieg Machines / Re: Setting up Homing and Soft Limits

« on: March 17, 2011, 09:32:37 AM »

Once you have homing setup you can then jog to the opposite end of travel and figure out where the limits will trip and set your softlimits to some value slightly less that the trip point.

38

Sieg Machines / Setting up Homing

« on: March 17, 2011, 09:30:24 AM »

As delivered my KX3 did not have homing configured. I started out manually homing, but decided it would be nice to have the homing process automated. The process should be the same for the KX1 and it appears that some of them have teh same error in the config that I found.

The initial step to configurring homing is to make sure the limits are set up properly. Go to the Config Menu, select Ports & Pins and then select the Input Signals tab. As shipped the the table looked something like this - (only the necesay collumns shown)

Signal     Enabled   Port #    Pin Number   Active Low   
X++       Green     1            11              Green
X--         Green     1            11              Green
XHome   Red        1            0                Red
Y++       Green     1            12              Green
Y--         Green     1            12              Green
YHome   Red        1            0                Red
Z++       Green     1            13              Green
Z--         Green     1            13              Green
ZHome   Red        1            0                Red

I Changed the XHome, YHome &ZHome to match the other entries for those axis so now the table looks like this -

Signal     Enabled   Port #    Pin Number   Active Low   
X++       Green     1            11              Green
X--         Green     1            11              Green
XHome   Green     1            11               Green
Y++       Green     1            12              Green
Y--         Green     1            12              Green
YHome   Green    1             12              Green
Z++       Green     1            13              Green
Z--         Green     1            13              Green
ZHome   Green    1             13              Green

It may seem strange to use the same input for all fuctions on an axis but Mach is able to figure it all out.
I clicked on Apply and closed that window.
I then Cliked oon Config and Homing/Limits.
Z axis wants to home full up. X & Y really don't matter, I home Y full forward and X full to the right.Puts the table at a nice place to change parts.

The necesary changes to this tabel were -
X Axis - Home Negative - Green
If you want the X Axis to home to the left leave the Home Negative Check red.

Now at this point I attempted Homing and the Z Axis would go to the top and hit the limit and the Z Dro would just keep counting. It turns out that the X & Z Input Pins were swapped.
I had to make the Input Signals look like this -

Signal     Enabled   Port #    Pin Number   Active Low   
X++       Green     1            13              Green
X--         Green     1            13              Green
XHome   Green     1            13               Green
Y++       Green     1            12              Green
Y--         Green     1            12              Green
YHome   Green    1             12              Green
Z++       Green     1            11              Green
Z--         Green     1            11              Green
ZHome   Green    1             11              Green

and then Homing worked perfectly.

There is a way to check how you machine is hooked up - at the bottom of the Input Signals there is a button labeled Automated Setup of Inputs. Click this button and a new window opens and in the pick box it will say X-Limit Switch ++ and next to it is a button the says Autoset - click this button and then trip one of the X Axis limits and the little message box will say Signal set to Port#1 Pin ??. Select next Signal. if the 2 question marks say 11 then the machine should home using the factory settings, it the ?? is 13 then all the XAxis pins need to be 13 and the Z Axis pins need to be 11.

39

General Mach Discussion / Re: Machining Damascus Steel Questions

« on: March 17, 2011, 09:01:05 AM »

Never machined it, but due to the nature of the way it is made (heating and forge welding, some carburizing of the layers) I would expect that you would encounter problems with hard & soft spots. All the damascus steel I have seen was manufactured by the blacksmith making the product. Good luck on finding blocks of the stuff...

40

General Mach Discussion / Re: Is this possible????

« on: March 15, 2011, 12:17:48 PM »

You might look at Formulas under the setup. If you can come up with a formula for both axis that describes what the changes are you might be able to use that.