XY Table location

[renatoh]

Hello Folks

I am pretty excited
I've just came back from NC with my Butty 48 Alpha and installed it.
After a little bit work to take it out off the truck, put it on the garage floor, figure out where all that wires go, now is all working good.
Yesterday I started to run some files and every thing seems to be fine, but when I try to zero the XY axis.
When I run the (TS) routine the machine give me a zero position on a place more like 8" X and 4" Y
Does some one has an idea what is going wrong?
Even though I know that I can place the zero XY wherever I want I would like to have a routine that I could run and the zero would come to my bottom left of the bed.
Any suggestion would be appreciate

[dana_swift]

Run the C3 command and have the machine go locate the prox switches.

When I start my bot, the first thing I do after a reset is find the XY home (C3) then C2 to find z-zero.

With the Buddy's, SB thinks that the XY zero should be the lower RIGHT of the bed, which is illogical to me, I changed my definitions to make it lower left.

I want my X axis to increase from left to right, and my Y axis to increase as the router cuts away from me. Changing the axis definitions will get you most of the way there. I changed my "find home" command so it would know to check for the other prox switchs.

D

[ghostcreek]

Dana, could you explain the "axis definition"? I was thinking about doing this. It truly does make more sense for XY zero to be lower left. It also makes drawing files easier (no Rotating drawings). Thank You in advance.

[mikeacg]

Dana,

Thanks for the info on C3 and C2. I will try that tomorrow.
One thing about the 0,0 controversy is that I guess it depends on your use of the machine. I have my Shopbot computer on a counter across from the box (closest place for the wire to reach) so to me, the current 0,0 setting IS at lower left. When operating the machine I am usually standing in the walkway between the computer and the Buddy. I design everything (unless I am using the powerstick) on a 24" wide x 48" tall template and the machine set-up seems perfectly natural to me. I almost never stand facing the machine the way a number of you do (except to load materials) since I can't reach the controls. I also have an outfeed conveyor for the powerstick mounted there so it becomes a pinch point with the machine operating.

Mike

[renatoh]

Ok Dana,
Thanks for the thought, it did work just fine.
What i need to do next is put the xy axis on the bed.
Now they are more like 2" off the bed, but I may leave this for tomorrow.
Hey,
bye the way have you already experienced different hightes on shopbot's bed?
Today while I was cutting a piece I noticed that the midlle portion the bed was lower than the center, where the power stick is located
thx

[dana_swift]

Reversing X and Y axes.. this works for PRS machines, I don't know about PRT's.

Moving XY zero to the lower left corner instead of lower right corner.

Step 1: (Tell the shopbot which stepper is x&y)
With the VI command-
set Channel 1 Driver -> Y
set Channel 2 Driver -> X

Step 2: (Invert the axes motion)
With the VU command
set X Unit Value, same value make it negative
set Y Unit Value, same value make it negative

Step 3: (Tell the C3 command to use other prox switchs)
Edit the file "C3" to use the attached file for XY Zero. The attached file should be saved in the "C:\sbparts" folder.

The file "C:\sbparts\custom\custom3.sbc" should resemble:
'Home X & Y Axes using Prox Switches for the PC router
'--------------------------------------------------------------------------
FP, c:\SbParts\XYzeroFIXED.sbp

' the following step is to locate the table corner
' your values will need to be different
J2,-0.070+0.08,0.400-0.08

' now zero the bot at "home"
Z2
'---------------------------------------------------------------------------
' ... executing Custom Cut File



Upgraded XY zero routine

3637 (6.5 k)

I don't believe I have left any steps out. To return to the original configuration it should only be necessary to undo steps 1 and 2, the file I provided should work with either configuration. The location of "home" will need to be adjusted of course in Custom3.

No warranty, offered "as-is" as usual..

D

[dana_swift]

Renato- a critical step to getting Z accuracy from the shopbot is to follow the instructions on surfacing your spoilboard. This removes the variations across the surface, and any sag that may exist from location-to-location.

Put a sacrificial spoilboard on top of the provided table material, feel free to add C rails, etc to this board. Then surface it according to the instructions.

The Z accuracy depends on this step..

D

[ghostcreek]

Dana, Thank You very much. I plan to do that this week. It will be really cool to have the XY where i need them. Thanks to all who contributed. I learn so much here.

[renatoh]

Dana

You have just saved my weekend.
I was thinking to take out the power stick and re adjust all rolls. I guess I would never get to align them

Thx!

[dana_swift]

Glad to have been of help!

Entirely welcome. The trick of putting the move to the home location then zeroing X&Y is really handy. If you do maintainence on your bot, just update that value so everything ends up back at the same location.

D

[tomahack]

I change the reference point as described but I lost "x" axis accuracy. I'm off by 0.5" at the end of the travel. Any hint?

[dana_swift]

Jean.. when you say your are "off" by 0.5 at the other end, do you mean that if you commanded the bot to move 24" that it moved some other distance? If so the "unit values" are off for that axis.

On the other hand if the bot reaches the limit sooner the 0.5 is not "missing" it is on the other side of zero.

Changing the X and Y axis definitions does not re-scale the amount of motion of the router for a given distance command.

Hope that helps-

If in doubt, you can always change it back.

D