Simplify3D User Forum

The preview mode doesn't display accurately when you are using 2 or more print heads and when the tool-head offset is applied to the G-Code (not internal machine offset).

When using 2 print heads (for support, infill, etc) and you select "apply tool head offsets to G-Code coordinates" under the g-code tab, the preview window will show the material extruded by each print head, but they will not be in the proper locations (See photo attached). It appears the preview doesn't take into account the offset tool head location and this makes it difficult to:

1) tell the true location of the print relative to your bed if you are using just a single head (that is not the main tool) and
2) makes it difficult to see if you have adequate support structural because the alignment may be hard to visualize.


Fixing this issue might also tie into an enhancement request:

the preview mode only shows 1 "tool head". it would be great if the preview showed both of the heads even though only 1 is printing at a time. This is because when you have multiple bodies to print most people try to avoid the inactive nozzle dragging over a previously printed body (screws up on surface finish on the body you are printing). By showing both the heads it would be much easier to make sure you have adequate spacing between print bodies so you don't do the "dead nozzle drag".

That's because you shouldn't be setting the offsets in the software! It's always better to just set the offsets in the firmware instead of having to work around misconfigured firmware by offsetting all your gcode coordinates.

If you open the file, you can see that the gcode coordinates are actually shifted when you use the "apply toolhead offsets..." option, so of course that's how it's going to display it. If the coordinates are physically different, then the preview should absolutely show the movements as shifted in the preview. I wouldn't trust the preview otherwise.

Anyways, just configure your firmware correctly, either by editing the config file or saving your settings to the EEPROM and this will be solved

CompoundCarl wrote:That's because you shouldn't be setting the offsets in the software! It's always better to just set the offsets in the firmware instead of having to work around misconfigured firmware by offsetting all your gcode coordinates.

If you open the file, you can see that the gcode coordinates are actually shifted when you use the "apply toolhead offsets..." option, so of course that's how it's going to display it. If the coordinates are physically different, then the preview should absolutely show the movements as shifted in the preview. I wouldn't trust the preview otherwise.

Anyways, just configure your firmware correctly, either by editing the config file or saving your settings to the EEPROM and this will be solved

Thanks for your comments, I really do appreciate your knowledge in the area and your inputs. I understand that you can store toolhead offsets in the firmware for most printers however, please consider the following when we were talking about this request:

-The intention of the preview mode is to show what the final print will look like, as such this feature is operating in a degraded state when tooling offsets are applied to the G-Code. - whether there is a work-around or not; the feature is not working as intended.

-Yes, the g-code file will show a physical shift of the offset, as you mentioned, however the preview mode is well aware of which tool is printing (we know this because you can change the coloring to the active tool head!!!). As S3D knows the tool offset (because it shifted it in the g-code in the first place) it has all of the elements to fix the offset in the preview based on the tool (since it already checks for the tool head when its doing the preview).

- The default printer setting for the R3D is to apply the g-code offsets, not use on-board offsets. As this is a supported printer per S3D, it seems reasonable for a user to expect that full functionality of S3D will be available for a supported printer. It is *somewhat* unreasonable to expect a user to modify their firmware to support something which may not have been authored in their firmware to begin with (as a general practice) when the degraded feature exists within the programming software, not the printer itself.

- If you often remove/install nozzles it is easier to apply offsets in the g-code than it is to write them into a start script for each print (which also results in unnecessary EEPROM writes)

-The feature is in there for a reason and my guess it is to support printers which are unable to store on-board offsets. In those cases, there may not be a viable work around.

-Showing both tool heads and the true position of where objects are printed can also help eliminate crossing into objects or keep-out zones on the bed. Custom modifications to printers (clip locations, cooling fan ducting, filament routing, etc) may force keep-out zones to prevent a crash. It would be useful for some users to have a proper functioning visual representation of the print work space to help keep these in mind.

blaknite7 wrote:The intention of the preview mode is to show what the final print will look like, as such this feature is operating in a degraded state when tooling offsets are applied to the G-Code. - whether there is a work-around or not; the feature is not working as intended.

I definitely don't agree with this. The purpose of the preview is to show exactly what is in the file. It has no way of knowing how the printer will interpret it or how it will actually print. You can misconfigure all kinds of things in the firmware, and there's no way for the software to know. It's just to show you what's in the file.

You are welcome to your opinion, but I for one would not be happy if they changed the preview so that it isn't even moving to the actual coordinates in the file.

We actually want the same things... You are "right-on" that the preview should show you what is in the g-code file.

Currently the profile view makes the assumption that all extrusion occurs from the primary tool location. This is not correct. YES, the primary tool head will follow that path as listed in the G-code, but the extruded material does not always come from this position... which is your second point regarding interpretation.

I agree that it would be unfair to assume that S3D could know how every g-code command will be interpenetrated by so many printers. But if we all can't agree that a tool command (T0, T1, T2...etc) signifies another tool is being used, which by the laws of physics cannot occupy the same space, we are kidding our selves. This is no different for a G1 command, its accepted by the community as controlled movement... it just is... This doesn't even matter though because there is actually a menu "Firmware Configuration" where you tell S3D what the tool change command is, so even if its not T0, T1, T2, etc... IT KNOWS HOW TO INTERPRET THAT COMMAND!!!

The preview will actually tell you by color which tool was being used... this means that it is already making the correct interpretation for what tool is being used. Its lacking locational information which it would only have when the offset is applied to the g-code.

There must be some relative location for the supplemental tools. When the offset is stored in the machine, the offset (from the g-code perspective) is 0,0,0. The preview is assuming 0,0,0 offset so the preview image looks correct in this case. By selecting "offset in g-code" the user is telling S3D there is another tool at a specific location and its relative position is something other than 0,0,0. In this case the preview is still making the same assumption on the offset which is "not ideal for people who use this option".

If the "fix" was tied only to the "offset in g-code" command it would be completely transparent to everyone else who uses on-board offsets, but it would significantly help those who don't have another option. There are other out there who have questioned the same thing I have, so I'm not alone in this opinion. Simply, it would be nice if the preview mode worked for this group in future versions.

No, it still doesn't know how those commands will be executed. It has no idea what the true offsets are on the firmware. I could enter offsets of 10mm in the process settings, but the machine could be incorrectly setup with 50mm offsets, it has no idea. That's why it shows you the exact coordinates in the file and nothing else.

Anyways, as has been said many times, using the manual gcode coordinate offsets is a last resort. Any decent company with functioning firmware would always put these offsets directly into their firmware so that you don't have to hack around it in the software. So instead of trying to get S3D to change their preview, you should really email the manufacturer of your printer and ask them why they don't support something that already exists in every single firmware out there. That is the correct way to solve this.

In fact, I can see from some of your other posts that you're using a raise3D printer. They use the Marlin firmware, which already supports toolhead offsets in the firmware. So either they setup their own firmware incorrectly, or they did something silly like disabled this functionality all together.

CompoundCarl wrote:That's because you shouldn't be setting the offsets in the software! It's always better to just set the offsets in the firmware instead of having to work around misconfigured firmware by offsetting all your gcode coordinates.

While I agree that setting offsets in the firmware is probably the better place, the situation I came from (and, I assume, many others) is that Simplify3D is purchased after many weeks or months of using whatever slicing software came with the printer. In my case, My Geeetech G2S Pro with dual extruders came with Slic3r and Repetier Host. All of the installation, configuration, and calibration instructions direct you to set the offset in Slic3r/Repetier Host.

If, for whatever reason, the folks at Simplify3D don't want to make this change to their software regarding the Preview window, then I think this is yet another topic that should be covered in a "New User moving from Slic3r" guide. If they were clear and upfront about differences, I think it would reduce frustration for new users, and allow us to instead spend our time with all the powerful features that are new to us.

John

CompoundCarl wrote:In fact, I can see from some of your other posts that you're using a raise3D printer. They use the Marlin firmware, which already supports toolhead offsets in the firmware. So either they setup their own firmware incorrectly, or they did something silly like disabled this functionality all together.

I have a duplicator, which supports on-board offsets (sailfish) and a Raise3D. There are several things in the Raise3D firmware (from the supplier) that need to be changed. This is one of them. I have seen several iterations of user supplied changes based on the Merlin firmware but i have not been able to get the firmware code to compile correctly. Having limited firmware programing experience (like many other people) I am finding it difficult to make specific changes desired in the firmware and don't have the experience to conduct such a task. Instead of bricking the machine and turning it into a 3K spool holder I have to reluctantly wait for R3D to release new firmware where they hopefully change this.

With all that said, and having used on-board offsets for many years on the duplicator, I actually do prefer on-board offsets. However this hasn't been a viable option on the R3D.

I love reviving 2 year old topics

I've been using S3d for a couple of months now with my Anet A8 and it works great. Recently I built a 4 extruder printer and had Marlin installed. Setting the offsets in Marlin caused some serious issues with my z axis and I got little to no support for this. I switched to Repetier and was actually able to print from all 4 with little to no issues, except it took 20 seconds per toolchange that nobody at Repetier could figure out. 20 second can be a long time when it changes the extruder 2-4 times per layer. For a 600 layer print that can add hours onto the total time.

I removed all offsets in Repetier and set them in S3D and it takes less than 1 second per toolchange PLUS instead of extruder 2 going to where extruder 1 was using firmware offsets (the firmware does not look ahead to know where it needs to go before the toolchange is done), new next extruder goes directly to the place it needs to print saving even more time.

In my case, using firmware offsets is not an option and using S3D offsets is much faster printing. I would love to have an option to preview with or without offsets. There are plenty of check marks to view toolheads, travel moves, retraction and other options. Why can't there be an option that globally removes the offsets for previewing only when the "prepare to print" option is used. Or when hitting "prepare to print" have an option to view offsets before the preview comes up. Obviously you can't do it when just previewing gcode from a file as there are no offsets in the gcode.