change tool z move

[JV]

Hello Guys
I need your help again, i have two extruders on my 3d printer, this is a cartesian type and the heated bed move up and down.
when the printer make the change of tool the heated bed goes down (until yesterday it moves just 50mm)
This machine can print till 400mm height.
The problem is that each time that i print a part higher than 50mm the tool will crash with the part. so i have to change the script to make move the bed 10mm more than the total height of the part that i am printing in that moment.
but if i have to do a part with a height 400mm each time even in my first layers, the bed will go down 400mm to make the tool change and it will take too much time.

Is possible to give an incremental height to the Z in the tool change script?
I mean is possible make that the bed goes down 10mm more than the layer that is printing in that moment?
I think that i should put a G91 in some part of the script but i really don't know where.
Thanks guys

[dc42]

Please clarify: do you mean that the new tool crashes into the part when you change tool in one direction?

What do you have in your tool change files at present?

[JV]

Hi David,

Sorry, I forgot to said how the tool change works.

when the tool change start, the heated bed goes down (the Z value that i would change in an incremental value) and the old tool goes in a station to clean it after this the new tool goes in an other station where start to heat up.
when the the new tool reach the temperature, it extrude 30mm ,then is cleaned with a mettalic brush, after that the heated bed turn up to the height of the new layer to start to print and then the tool moves to start to print the part.

So the problem is that the old tool crash with the part if the heated bed Z position in the script of the tool change start is lower than the height part (OBVIOUSLY)

one solution is make than the heated bed go down 400 mm and i am sure that the tool will never crash with the part because is the maximun height that i can print wiht the machine, but the problem is that each time that the machine should change the tool even in the first layer, the Heated bed should go down 400mm when it just be necessary go down 10mm.
In this way the print will take too much time to be complete.

So i think that the best solution is: when the tool change start the heated bed moves down just 10mm more than the height of the layer that is actually printing.

This is my tool change file, in this case if the part is taller than 120mm the old tool will crash with my part in the tool change operation when the print reach over the 120mm height

{IF NEWTOOL=0}T0 ;Tool 0 select
{IF NEWTOOL=0}M42 P6 S1 ;tool 1 down
{IF NEWTOOL=0}G1 Z120 F30000 ;Heated bed goes down to not crash with the part
{IF NEWTOOL=0}G1 X788 Y250 F20000 ;go to the tool cleaning station
{IF NEWTOOL=0}G1 Y90 F15000 ;Start Cleaning tool1 process
{IF NEWTOOL=0}G1 X780 F15000 ;Cleaning tool1 process
{IF NEWTOOL=0}G1 Y200 F15000 ;Cleaning tool1 process
{IF NEWTOOL=0}G1 X772 F15000 ;Cleaning tool1 process
{IF NEWTOOL=0}G1 Y90 F15000 ;Finish Cleaning tool1 process

{IF NEWTOOL=0}M42 P6 S0 ; tool 0 down
{IF NEWTOOL=0}G1 X-75 Y250 F30000 ;go to the tool0 cleaning station
{IF NEWTOOL=0}G1 X-85 Y140 F30000 ;go to the tool0 cleaning station
{IF NEWTOOL=0}M109 S230 T0 ; Set T0 new active extruder to 230 and wait for it to reach temperature before proceeding.
{IF NEWTOOL=0}G1 E30 F250 ;Extrude
{IF NEWTOOL=0}G92 E0 ;set extruder position
{IF NEWTOOL=0}G1 X-68 Y200 F15000 ;Start Cleaning tool0 process
{IF NEWTOOL=0}G1 Y90 F15000 ;Cleaning tool0 process
{IF NEWTOOL=0}G1 X-60 F15000 ;Cleaning tool0 process
{IF NEWTOOL=0}G1 Y200 F15000 ;Cleaning tool0 process
{IF NEWTOOL=0}G1 X-52 F15000 ;Cleaning tool0 process
{IF NEWTOOL=0}G1 Y90 F15000 ;Finish Cleaning tool0 process

{IF NEWTOOL=1}T1 ;tool 1 select
{IF NEWTOOL=1}M42 P6 S0 ; tool 0 down
{IF NEWTOOL=1}G1 Z120 F30000 ;Heated bed goes down to not crash with the part
{IF NEWTOOL=1}G1 X22 Y230 F20000 ;go to the tool cleaning station
{IF NEWTOOL=1}G1 X22 Y200 F20000 ;Start Cleaning tool0 process
{IF NEWTOOL=1}G1 Y90 F15000 ;Cleaning tool0 process
{IF NEWTOOL=1}G1 X30 F15000 ;Cleaning tool0 process
{IF NEWTOOL=1}G1 Y200 F15000 ;Cleaning tool0 process
{IF NEWTOOL=1}G1 X39 F15000 ;Cleaning tool0 process
{IF NEWTOOL=1}G1 Y90 F15000 ;Finish Cleaning tool0 process

{IF NEWTOOL=1}M42 P6 S1 ;tool 1 down
{IF NEWTOOL=1}G1 X878 Y250 F20000 ;go to the tool1 cleaning station
{IF NEWTOOL=1}G1 X890 Y140 F20000 ;go to the tool1 cleaning station
{IF NEWTOOL=1}M109 S230 T1 ;Set T1 new active extruder to 230 and wait for it to reach temperature before proceeding.
{IF NEWTOOL=1}G1 E30 F250 ;Extrude
{IF NEWTOOL=1}G92 E1 ;set extruder position
{IF NEWTOOL=1}G1 X878 Y200 F15000 ;Start Cleaning tool1 process
{IF NEWTOOL=1}G1 Y90 F15000 ;Cleaning tool1 process
{IF NEWTOOL=1}G1 X873 F15000 ;Cleaning tool1 process
{IF NEWTOOL=1}G1 Y200 F15000 ;Cleaning tool1 process
{IF NEWTOOL=1}G1 X866 F15000 ;Cleaning tool1 process
{IF NEWTOOL=1}G1 Y90 F15000 ;Finish Cleaning tool1 process

thanks

[dc42]

You are getting the crash because you are handling the tool change in the slicer, which doesn't know about the tool Z offsets or isn't handling them properly. Why don't you handle the tool change in the RRF tool change files instead? It will also save you having to re-slice files when you want to try out a change.

[JV]

@dc42
ok, i will try to do that and i will let you know
Thank's again

[CHANGE3D GmbH]

Hi there,

To move the tool just 10mm down from the actual printing position, you have to set the Z-axis with G91 to relativ movement instead of absolut. Then you can send a G1 Z10. After that you have to go back to absolut movement with G90. These three commands should be in the tfree#.g file of the RRF tool change files I guess.

Best,
Markus

[JV]

@change3d-gmbh thak you Markus i'll try
bye