Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
This is a really annoying problem. I have a multi-hour (6-10, depending on the variation) print that shows no obvious sign of problem. Slices nicely, first layer well adhered, etc. But whenever it gets to ~60% complete, the nozzle hits the part. I've had it hit from the side, and the latest attempt, the nozzle plunged into the workpiece. At that point, I just get the air extruded bird nest.
I find this puzzling, because all other layers are being laid down quite nicely. Does anyone have any clue why this is happening? Printer is calibrated, belts are tight.
This is turning into a very expensive problem! I am also finding it somewhat odd that even after a physical collision, there is no shutdown of the print. Maybe there is a clue in that.
RE: Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
Any chance the part is coming loose from the bed, thus creating the spaghetti? Any changes in what's being printed at 60% (e.g. transition to lots of infill) that might result in different speeds? A quick and simple test is to simply dial speed back 50% using the front knob mid-print and see if the print completes. If so, you know it's likely slicer settings.
For more specific help, save your part & settings in a 3MF project file, zip it and attach it to a reply here. That way we can see the details of the part and your settings and give more specific suggestions.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
@bobstro
Thanks for your reply. Unfortunately, this part is proprietary. But I can answer your questions, and abstract the description of the part...
Firstly, no, there is no chance that the part is coming off, prior to being struck. I thought the same, but the last print, I actually heard it being popped off the bed from another room. It sounded like someone had pulled a rivet out of sheet metal. Secondly, in the first 2 attempts, there was a melt mark in the side of the part. Not really much to draw a conclusion from. But the last run, the nozzle actually came straight down into the part, and left a dimple. All other layers looked perfect. Thirdly, no change, as this part is a thin section part, with 100% infill for the entire piece. It's a cylindrical section, ~35mm dia X ~170mm standing on the bed. I'm using it as a functional prototype, and have determined this to be the best print orientation.
I have not found that the part needs brim or support. It has definitely adhered well to the table.
I will try to dial back the speed. Although, that does make this a 12 hour print. But I suppose that it is better to know.
Thanks so far...
RE: Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
[...] I will try to dial back the speed. Although, that does make this a 12 hour print. But I suppose that it is better to know.
You could just wait on a regular print until it starts, then dial back. Even better, if you can cut the part so only the troublesome area is printed, that might save a lot of time. Scaling might work as well.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
Hi,
100% infill sometimes gives issues.
can you increase the top and bottom layers so there is no room for infill and hopefully this will overcome some of the potential problems.
tall thin parts often cause issues due to deflection.
One approach I have heard of, is to use Hot Melt glue to attach temporary braces to the model during printing
I think this was relating to a large scale model of the joel telling 3d printing nerd figurine... which has tall spindly legs.
Aparrently the Hot melt glue peels off afterward without leaving a mark...
you could test the accuracy of these words with the waste models before you try hot melt glue on the real model
Use a number of skewers at an angle to triangulate the model.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
Brim cost nothing (time or plastic) in terms of overall, it's easy to remove and it lets temp and pressure in block and nozzle a chance to settle before first layer.
I accept this may not solve your problem but it certainly wont make it worse.
RE: Tall, narrow part with 100% infill - print head keeps hitting part when past 60% complete
So i did get this to run successfully. What I did:
First, I changed it to 50% infill, and used gyroid pattern. (not solid part on this run, will try next) Then, I dialed the speed back to 75%. Lastly, I bumped the temp up 3 degrees.
At 67%, there was a layer that didn't stick, and it did extrude a small bird nest into the part. However, the rest of the part recovered successfully, and overall, the print was not affected. I can see, however, that this may have been a problem with a faster speed.