GregValiant

It can be done in post-process. Niche things like this are often easier to get done with a post processing script. The script can be quick and dirty (delete the top layer) or involved (adjust all the Z's and E's). Quick and dirty would mean that the model would be short by a layer height. It might not matter, or you could make an adjustment.

Bowden tubes are "consumable" items. As a print progresses the tube can spin in the hot end retainer and the little knives that hold the tube in will damage the tube. Heat is another issue and the "Capricorn" tubing has a higher tolerance for heat. (they are blue so you may already have one). Trimming the tube back by 5 or 6mm on a regular basis can keep the problem from becoming severe enough to affect prints. Eventually it will get too short. That's why it's considered a consumable.

Some background. The feature was added in (about) Cura 5.5 in response to problems that occurred with the first layer of spiralize. Spiralize would start at "full flow" even though the layer height was only a fraction of a full layer height. That caused a ridge as the first spiral layer would be over-extruded. @burtoogle came up with a fix in his Cura Master build and it appears to be what is used in UM Cura. So now the first spiral layer, and the overall top layer, have variable flow rate based on the actual height above the previous layer at any particular point.

@tigercjn I don't think that will work. "material_bed_temperature_layer_0" is not "Settable per extruder". The "T0" and "T1" lines are superfluous in the Extruder StartUps. The code will run at every tool change so you are setting the "initial layer" bed and hot end temps whenever you switch tools. The entire print will be run at Initial Layer values. G92 sets the extruder location and you are setting it to "1" instead of "0". You have a "G1 E30" purge line in there. That will occur over the print at every tool change. Have you tried enabling the "Purge Tower"? That will move the print head out of the way. It is generally best to allow Cura to handle the tool changes and temperatures. A problem can occur with the StartUp gcode when there is an ABL involved. Most people don't want the hot end(s) at printing temperature during leveling because they will ooze across the build surface. It's a fancy dance ordering the temperatures so that enabled extruders are at the correct temperature during leveling, and then when starting the actual print. Once you have brought both hot ends up to temperature there is no way to shut off an unused extruder. There is no way to do something like "if T1 is not used then M104 S0 T1". Therein lies the problem.

"If I use both, it creates another problem. Any tuning disappears when you change the extruder." Yes, that will happen. The upside to putting the M207 into the regular "StartUp Gcode" is that it would not happen. BUT doing that insures that each extruder would have the same Z-hop height. That may not be important. Once you get your tuning dialed in then you could put the lines back into the Extruder StartUp gcodes. Because what you really want to do is missing a setting in Cura, you would need to jump through some hoops to make this work exactly right. Ex: Enable z-hops, change the hop height, disable z-hops If you use Extruder StartUp then tuning would still be an issue because of the M207 lines at each tool change. I would probably go with this in the regular StartUp Gcode because this allows any tuning to continue through the print: M207 F{retraction_retract_speed*60,initial_extruder_nr} S{retraction_amount,initial_extruder_nr} Z{retraction_hop,initial_extruder_nr} M208 F{retraction_prime_speed*60,0} Essentially what that does is turn the "Z-Hop Height" setting into the on-off switch. When Z-hop height is "0" then the Z parameter is "0" and there would be no hops. "Z-hop on Retraction" and "Z-hop after extruder switch" would ALWAYS need to be disabled in Cura so all that extra code doesn't show up.

This is the gcode I get from the above. G10 G92 E0 T0 G92 E0 M207 F600 S3 Z0.6 M208 F600 M105 M109 S220 M104 T1 S210 M205 X10 Y10 G0 F9000 X227.315 Y214.697 Z8.4 G0 X230.419 Y216.924 G0 X229.228 Y216.425 M104 S230 G11 I set this up with different values for each extruder. At the next change the numbers are different. G10 G92 E0 T1 G92 E0 M207 F1500 S6.5 Z1.0 M208 F1500 .... G11

Welcome in here. It's always good to start out by mentioning the printer and any customizing that was done to it. Load the model (if you can share it) set Cura up and use the "File | Save Project" command. Post the resultant 3mf file here. It will contain the model, your printer, and all your settings. PETG can be difficult. It gets gooey and stringy, and wants to stick to the outside of the nozzle. When enough material is stuck on the nozzle it will drop off on the print. I print about 75% PETG as most of my stuff is functional or will be outside. Temperature is important. Long retractions are necessary. I print PETG a lot slower than I do PLA. At 35mm/sec for the outside walls and with no fan - they look nice and glossy. Sometimes things don't scale up well. Other times a small scale will help hide issues and scaling up just scales up the size of defects that existed in the test model.

Alright. I think I have it. Maybe. If "Firmware Retraction" is enabled, and "Z-hop on Retraction" is enabled you want an option to handle the Z-hops with G10 or with the regular Cura Z-hop code. So the setting you want doesn't exist and would require a feature request. I think the best way to do that (for now) would be to put a feature request in for the Klipper Plugin and maybe the author can add the function. It already does the retractions and appears to take multiple extruders into account. It is probably faster than waiting for the Cura team to add it. The Klipper plugin uses this line to set up the G10 parameters: SET_RETRACTION RETRACT_LENGTH=6.5 RETRACT_SPEED=35 UNRETRACT_SPEED=25 ;KlipperSettingsPlugin It would need at least one additional setting box (Enable Z-Hop for G10) and one more parameter in that SET_RETRACTION line. Right now you have to do it manually. Enable "Z-hop on retraction" Set the Z-hop heights for each extruder. Disable "Z-Hop on retraction. If your Z-hop height, Retraction Speed, Retraction Amount are the same for each extruder you can put this into your Startup Gcode: M207 F{retraction_retract_speed*60} S{retraction_amount} Z0.6 M208 F{retraction_prime_speed} If you want to disable Z-hops for a print you would need to go into the StartUp and change the Z parameter to "0". If you want to change the Z-hop height then enter the new number. If your Z-hop height, Retraction Speed, or Retract Amount is different for each extruder (Ex: E1 has 0.6 Z-hop height and E2 has 1.0 Z-hop height) then you need to put the M207 and M208 lines into the Extruder 1 and 2 StartUp: M207 F{retraction_retract_speed*60,0} S{retraction_amount,0} Z0.6 M208 F{retraction_prime_speed*60,0} This goes into Extruder 2 StartUp: M207 F{retraction_retract_speed*60,1} S{retraction_amount,1} Z0.6 M208 F{retraction_prime_speed*60,1} If you want to disable Z-hops for a print or change the hop heights you would need to go into the StartUp for both extruders and change the Z parameter. The " ,0" or " ,1" are required so Cura can add the right number for the extruder. The Klipper plugin enters the retraction settings using what looks like a Klipper macro line "SET_RETRACTION" so having the speeds in mm/sec is fine . You are unable to do the same thing with the Z-hop and M207 is a regular Gcode command. I think you will find that you need the "*60" in there. All the other F parameters in the file are in mm/min.

Cura marks invalid surfaces with a polka dot pattern. Your model has several areas with flipped normals. When I try to repair the model the entire thing disappears. So one reason you can't get rid of the support is because the "top" surfaces down low in the model are calling for support on their upper sides. Both models are in need of serious repair. Here is what I get when I tried to bring a support blocker in. I've never seen this before. The entire world turned inside out.

Let's start from the beginning... What printer are we talking about? That would seem to be a basic thing to know. I had to figure the Klipper thing out from an image because it was never stated. I understand that you are trying to alter the z-hops to get better seams, Exactly how are you attempting to accomplish that? Are you trying to not Z-hop at one particular place on each layer? Not Z-hop for a range of layers? What is it that you really want?

Retraction Hop is a separate setting. Retraction can be turned on without Z-hops being enabled. The Hop Height can still be used by your M207 line. I don't understand why you think that it isn't tuneable. In the case of M207, the Z height is still controlled by the firmware. If you were to move the M207 lines from the Extruder StartUp gcode into the regular StartUp Gcode then if it was M207 F35 Z0.5 and you were to add "M207 Z0" at layer 25 then you would have 0.5 z-hops until the end of layer 24 and from there up to the end of the print there would be no z-hops because the height has been set to 0. I just don't see a problem here. If you want to use firmware retraction, and you want Z-hops, then set the Z parameter of M207 to the hop height you want and turn Z-hops off in Cura. You have customized your printer from whatever it started out as. There will necessarily be workarounds. I have read that UM may consider adding Klipper as a gcode flavor. I have no idea where they are on that.

You still haven't mentioned what printer you are talking about. I see "Klipper" on one of your images so I "guess" it isn't an Ultimaker which would likely configure the M207/M208 internally dependent on the material. UltiMaker does the heavy lifting on writing Cura so (I'm guessing again) there is no M207/M208 required from their point of view. How are you "tuning on the fly"? Are you using a print server? Some sort of Klipper Console? To start - You have to multiply the speeds by 60 to convert to the gcode "mm/minute". M207 F{retraction_retract_speed * 60} That might be one of the problems you are having as "G1 F35 Exxx" is a lot different than "G1 F2100 Exxxx" You have a dual extruder printer. The Z-hops can be different for each extruder. You would need to explain that in your M207 lines. M207 S{retraction_amount,0} for extruder 1 and M207 S{retraction_amount,1} for extruder 2. If you turn on Z-hops in Cura then (as you have noted) the "G1 Fsss Zxx.xx" will be hard coded in the gcode. You can't "tune" that on the fly because every time there is a retraction there will be a Z-hop line and the height is fixed. What you can do is enable Z-hops in Cura, set the hop height for each extruder, and then turn off "Z-hops" in Cura. The numbers would be available in the Extruder Start gcodes. Every time there is a tool change the Hop Height will return to what that line says. Your "tuning" would then revert to the value in the M207 line. If there are multiple tool changes in a file, every time there is a tool change the Z-hop amount will be set back to whatever {retraction_hop} for the current tool. If you want to tune the retraction hop height during a print you need to turn off "Z-Hop" in Cura. The G10 and G11 lines will still be in the Gcode and they will be configured the way you told it with the M207 lines.

I apologize because I have to guess here. If you could post a project file ("File | Save Project") it would be helpful. If your "firmware retraction" of your printer is handling the Z-hops then you should probably turn off "Z-hops" in Cura. You don't want to double-dip on the Z-hops. Cura does not typically insert M207 or M208 in gcodes. Whatever retraction distance (and z-hop height) is in the printer as defaults are what is used whenever the printer sees a G10 or G11. An option would be to add M207 (and M208) lines to your StartUp Gcode so you could tune them to the print. Cura can now do some math and logic in the StartUp and Ending Gcodes. I'm not giving any guarantees here, but something like this in your StartUp MIGHT allow you to use Cura inserted Z-Hops. M207 S{retraction_amount} F{retraction_retract_speed * 60} Z0 M208 F{retraction_prime_speed * 60} You can allow the Firmware Retraction to handle the Z-hops, or let Cura handle the Z-hops, but enabling both is not a good idea.

The printer is as Ender 3 S1 Pro so not the same as was stated and it appears to be a direct drive so not a bowden printer. I read the gcode into MS Excel to do the analysis of the extrusions. There is no problem within the gcode. I altered the temperatures and changed the retraction distance from 0.8 to 6.5 and it printed fine on my machine. @muscato57 you are always welcome to post a bug report on GitHub. I do much of the triage over there and I would perform the same investigation there that I did here. I just don't see any problem within the gcode you posted.

There isn't anything wrong with the gcode. Your printer is under-extruding by a lot. I happen to also have an Ender 3 Pro and it's a problem that showed up a couple of times. Starting at the beginning: The filament spool needs to move freely. No loops or snags on the spool. If you have a plastic pressure arm on the extruder they have an amazing failure rate of 100% and when it cracks at the pivot point the arm doesn't put enough pressure on the filament to move it to the hot end. The hot end itself can develop a gap between the bowden tube and the back end of the nozzle. If it does then molten plastic can get pulled into the gap by retractions. The plastic hardens and forms an o-ring sort of partial blockage and after printing for a little while under-extrusion starts. I can almost talk myself into seeing that with the brim of your print. Not very popular but not completely unknown (it happened to me) is a bad stepper driver on the main board. If it isn't a broken pressure arm then it time for maintenance on the hot end. Warm it up to get the nozzle out. Take it apart and clean it out. Trim the bowden tube back by about 6mm (with a nice square cut) and put it back together. Warm it up again to get the nozzle back in. It should be snug. My printer came with a 1.1.4 "loud" board. I had the machine a month or so and it was driving me nuts so I ordered the 1.1.5 "silent" board. The first one had the E stepper driver fail after 1 week. Another time the under-extrusion started the problem was the not end. After fooling with it a bunch of times I went with an "all-metal" hot end.

Change your "Top Thickness" to 0.8 and the "Top Layers" to 4. Change the "Skin Removal Width" back to 0.4. The ribs are just thick enough to require some top layers and right now you are only getting bottom layers. That is affecting the very top and all the mid-ribs. The Skin Removal Width at 3.0 is causing the little support gussets to disappear. If you change to "X-ray" mode you can see the internals and they should all print. Airplane parts are tough. This one seems to be designed pretty decent. This is a mid rib with your settings. It starts with the designed in infill and doesn't have a bottom surface. This is with the suggested changes. This is the same layer but now there are 4 layers of skin below and the little side gussets are in place.

When I find it to be an advantage to split parts for printing, I put 2.1mm holes (for 1.75 filament) into each part by subtracting small cylinders from the STL or adding the holes in CAD. That way the holes in each piece line up perfectly. After printing, I put short pieces of filament into the holes in one part and they become locating pins. The parts line up exactly. This is a visor for a Kindle tablet. If the legs were in place for printing then the entire bottom would need support. You can see the holes I added to line the legs up so they will assemble in the exactly correct position. (The legs get printed upside down.) Super glue holds everything together.

Cura cannot give you a spiral pattern for the Top/Bottom Skins or infill. It would be nice if you could: Spiral a layer outward Move up Spiral back to the center Move up etc, etc, etc. That's a fair sized nozzle - are you running a pellet feeder? In addition to Slashee's suggestions, you could set Cura up so the print is all walls (Wall Count = 1000) and a Random Z seam. The travel moves would change on each layer so they wouldn't "stack". Another thing to try would be ZigZag pattern for the Top and Bottom Skins and for the Infill with the Infill at 100%. The nozzle keeps extruding for the little connector line that connects each long extrusion. With ZigZag the setting "Randomize Infill Start" is available so the nozzle wouldn't be returning to the same spot all the time.

@braddach you have to give us something to work with here. What version of Cura? Early versions of 5.x had issues with the Machine Settings dialog box not saving changes. A workaround was to make your change and then click somewhere else (like in the Ending Gcode box) to set the change before closing the dialog. Load a simple model, set up to slice, and use the "File | Save Project" command and then post the 3mf file here.

It doesn't look like anything Cura did to insert it. It's an odd color as well. If it was Cura it should be gray indicating the brim/skirt/raft area. If it came in with the model it should be the same color as the model. Use the "File | Save Project" command and post the 3mf file here. Somebody will take a look.

In Cura, switch to the "Custom" settings. In the Search Box type in "Printing Temperature Initial Layer". What does the setting say? (I'm guessing that it's 195.)

Sorry about that. That is the "Lite" app "Greg's SD Print Tool" and it is basic. The Cooling tool is no longer in that version, just the full "Greg's Toolbox". (I was maintaining two versions and since that post processor was to be included in Cura, I removed it from the app.) Here is the actual Cura post processor: AddCoolingProfile.zip In Cura 5.6.0 use the "Help | Show Configuration Folder" command. On my Windows system it is: C:\Users\...my name...\AppData\Roaming\cura\5.6\scripts Unzip the file and put "AddCoolingProfile.py" into that "scripts" folder. It will be available with the other post processors right inside Cura. The script is not version specific so it will work fine. Let me know if you would prefer to have it in "Greg's SD Print Tool". I never removed the code, just hid the button. I would need to take a look again to make sure it is up to date.

I always blame Python. It certainly can't be MY fault when something goes wonky.

It's PETG so the strings are hard to get rid of. Hotter print temp gives you better layer adhesion but a greater chance of stringing. For this model... Set the "Combing" to "All". Set the Z-Seam location to wherever you want and then look at the "Z seam X" and "Z Seam Y" and make a note of them. Go to the Travel Settings and make the "Layer Start X" and "Layer Start Y" the same as the Z seam locations. You won't get as much travel through the center of the print. If I have a screw connection I know that it will loosen over time from "cold flow deformation". That plastic wants to flow away from the pressure exerted by the screws. Those three cheesy walls around the screw hole are going to crush. In the MarketPlace is a plugin for Cylindrical Support Shapes. Here I've added one to a bolt hole in the flange. It's 12mm dia by 3.2 tall. The bottom is at 0.8 (resting on the bottom skins) and it ends at the first top skin. It is set as an Infill Mesh with 8 walls. It's an example of something you can do to make a model stronger in one area rather than filling something with infill. I just eyeball them into the XY position. It isn't like anyone will know they are there. X-ray view helps.

Yeah baby!!! That's what I'm talkin' about. Smooth, and it slices very nice.