General 3D Printing Thread


 

Andy Snider

TVWBB Fan
3d printing is more voodoo than science. Try sacrificing a goat. Even better, grill it afterward. mmmm, cabrito.

My ABS warping is usually cured by temp/speed or some combination of the 2. It's a goldilocks thing - too slow is as bad as too fast. Too hot, same as too cold....
It's probably mostly a difference in measurement accuracy, but I print ABS (Hatchbox, Makergeeks) at 223-224*, 230-240 doesn't do a damn thing for the warping, makes it worse if anything. I'm using the stock DaVinci thermistor w/e3d hotend
A gunked up nozzle also seems to cause issues. And/or cleaning the bed really well with acetone and re-brushing abs juice on. I use abs pellets (no color) & mix it very thin. Apply with a paint brush to a warm bed until the glass is cloudy
Then after the 'usually', you have variations in the filamentl diameter. I was getting down to the last 10-15% of a spool & started having bed adhesion issues, prints coming loose after 10-15mm Z. After trying all of the above, I measured it - it got slighly smaller in dia & wasn't squishing to the bed any more - bumped extrusion multiplier from 0.96 -> 0.97 & was going great again.
I also ALWAYS print with a 3-line skirt 0.4mm from the part - like a brim but not as much of a pain in the *** to remove. short/wide parts get 1 layer (for prime), tall/skinny parts get 2-3 layers to keep the heat trapped down low & reduce corner lifting.

I've only printed ~60% of 1 spool of PETG, but I'm ordering more to see if all of Makergeeks PETG works as well as that 1 spool. No warp, much stronger parts than ABS & I could use less infill & still have nice looking upper surfaces.
 

John Bostwick

TVWBB Wizard
I narrowed down the feed problems to my spool of filament and feeding to the feed gear.

I built a plexiglass case for the printer for ABS and I moved the spool from the side of the M2 to above it on the outside of the case. I then printed a filament infeed that held the ptfe tube. Well I think the filament was getting hung up in that area. After I put it back to the side of the printer all is well.


The print had less warping. The bottom looked pretty good, but the top still letting in the corners evenly on all four corners. This has been the only printer that has really been a pain.

I am going to try a Mic6 and pei plate again. The first plate I recieved was not flat and I couldn't get a good print. I can get one made for about $70.
 

Bryan Mayland

TVWBB Hall of Fame
For what its worth I sat down today and worked out how to make the top and bottom edge bevels a rounded bead that runs along the whole edge instead of the intersection of 3 triangle shapes that it is now. Once I got it working I realized that a rounded bevel makes no difference, because the part that contacts the build plate is still a point. A corner radius that goes up at a 45 degree angle for that radius leads to a point. Using a larger radius than the height means that the edge is round, but you need to increase wall thickness because the larger radius cuts into the walls more. I tried reducing the height and that gave me rounded edges which touched the build plate, but their radius was small at that point (around 1mm) and that made no difference in my print. I am testing by turning down my build plate 5C and observing the lift, where the corners now just start to come up. The cases are still usable but the edges are clearly not perfect.

I then tried turning the corners into 3-sided bits, so instead of having 1x 90 degree corner I'd have 2x 45 degree corners. That ended up looking slightly better, but it still lifted and the difference between the two was so minor I'd say the improvement was enough to call it within the margin of error. No go there either.

Now I'm printing a 4mm radius (up from ~3mm) with a 1.5mm height (down from 2-3mm) which is the same values it appears are used on Tom's 4.2 case. That makes the contact corner radius 2.5mm. However, this makes it so that the corners aren't completely as thick as WALL thickness. At the very least I'm going to have plenty of 4.3 misprint cases in the HeaterMeter store now!

EDIT: And just to make sure you saw it, if you go to Thingiverse you can use the customizer to select which half you want (or both). Or you can use Slic3r's split button, or S3D's "Mesh" menu (although it looks like the latest STL one of the alignment bars isn't attached! will fix)
 
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Andy Snider

TVWBB Fan
I narrowed down the feed problems to my spool of filament and feeding to the feed gear.

I built a plexiglass case for the printer for ABS and I moved the spool from the side of the M2 to above it on the outside of the case. I then printed a filament infeed that held the ptfe tube. Well I think the filament was getting hung up in that area. After I put it back to the side of the printer all is well.


The print had less warping. The bottom looked pretty good, but the top still letting in the corners evenly on all four corners. This has been the only printer that has really been a pain.

I am going to try a Mic6 and pei plate again. The first plate I recieved was not flat and I couldn't get a good print. I can get one made for about $70.

If you're having feed issues, you might be under-extruding on long runs & corners, such as the outer perimeters of a HM case. my spool holder is just a 1/2" PCV axle sitting on uprights on top of the printer. there are times, especially when making a long run or a long travel move, that the filament gets tight & I'm sure the extruder gear is fighting it. If I don't have it positioned correctly, the filament will also bend & flex at the entry point. This has caused some warping & lifting for me as the bead that gets laid down is "under tension", even though it contracts normally, it has nowhere to go but upwards.
 

John Bostwick

TVWBB Wizard
Since, moving it back inside my case, its been running great.

I'm going to redesign the entrance to the Ptfe filament hose. I think thats what was causing the issues and the filament was hitting the edge of the plexiglass.

Today, I'm going to be printing some translucent yellow PETG. Going to make a 4.2 case for a customer. Hopefully, I can get the settings good enough to get a nice print.
 

Guy Barton

TVWBB Member
We have completely different printers but, I had great success with eSun PETG by using my PLA profile and modifying it with ABS temps(245C / 100C). It just worked.

PETG is a great plastic. When I build my new HM, the case and damper will be PETG. I think I will gradually move completely away from ABS as I use it up.
 

John Bostwick

TVWBB Wizard
We have completely different printers but, I had great success with eSun PETG by using my PLA profile and modifying it with ABS temps(245C / 100C). It just worked.

PETG is a great plastic. When I build my new HM, the case and damper will be PETG. I think I will gradually move completely away from ABS as I use it up.

Yeah, thats my goal too. ABS is Nice, but that warping is terrible. Im thinking of making an Extruder and making my own PET. I can get the virgin material from work, as I work with mainly PP and PET, sometimes HIPs
 

John Bostwick

TVWBB Wizard
Definatly, going to stay with PETG. It sticks really good to hairspray and kapton. Virtually no warping and the parts looks pretty good.

I will post a picture of the case, later. Printed in MakerGeeks.com transparent yellow, nice and shiny.

Petg is kinda of a pain to get set up and running. I was able to only get one calibration cube printed, as I was printing at 250°c and I could not get it to extrude constantly. So I went up 2° c at a time and settled at 265° and a bed temp of 90°c. My calibration cube looked great, once it did print. PETG also hates being pressed down, so you have to print a little higher, then you would with PLA or ABS, as the nozzle will grab the petg and you will have hairs of plastic all over the place.
 

Bryan Mayland

TVWBB Hall of Fame
Yeah I thought PETG was great for a while too, but like you said it is so sticky. The nozzle collects every minute scrap of errant plastic until it builds up enough to deposit on the print and it is so hard once cooled that the print head can be stopped dead in its tracks. I stopped printing with it because I had to slow down to like half speed from my 70mm/s (18mm3/s) prints to have ~0% chance of wrecking the print or just making it ugly. It just wasn't worth it to me especially considering most of the PET colors were semi-translucent and those don't really sell that well on the HeaterMeter store.

John, have you tried the latest 4.3 case design (with the thicker angled base, USB reinforcements, and rounder edges) in ABS to see if it made any difference in your curling?
 

John Bostwick

TVWBB Wizard
I will be trying tonight, I have to print a damper, in the yellow petg, then will be going back to ABS for a 4.3 case

One thing about PETG, you need to almost air print with it, so that is doesn't hit the previous extruded material. If Petg gets squished, it will collected on the nozzle and drop a bugger on your print. Also, the retraction, is a must, I'm at 1.2mm. And slow and steady. I'm at 32mm/so, I believe. It took 5 hours to do the case, of course I have a .35 nozzle and a print height of .20mm
 

John Bostwick

TVWBB Wizard
First Petg print, turned out fairly good. I will do some tweeking next time.

7BV7tgAng.jpg
 
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SteveCK

TVWBB Pro
That PETG is sposed to be pretty good stuff once you get it working on your printer. I remember SethRC posting about it (a while ago), looks like all the PETG is super high gloss though. Anyone see some that isn't?
 

John Bostwick

TVWBB Wizard
Oh wow, that was the software (Octoprint) I wanted but didn't know about. Deployed it on a PI on the weekend, works great!

I used Octoprint, but I had problems when it was printing curved areas and circles. The printer would stop and go all the way around. It was to much information to be going over wifi and to the Raspberry pi. I use it from every once in a while, though.

I do use the video connection for it, all the time, and that works great.

I have my printer connected to a laptop, that I only use when I travel, so it's always there.
 

Dan Francis

TVWBB Fan
I used Octoprint, but I had problems when it was printing curved areas and circles. The printer would stop and go all the way around. It was to much information to be going over wifi and to the Raspberry pi. I use it from every once in a while, though.

I have used Octoprint now for almost 2 years over home Wifi to a rPi B+ to RAMPS without a single hiccup. Wonder if it has to do with your dongles or rPi model. I don't think you should be having an issue like that. Doesn't really matter tho, sounds like you have the situation covered!
 

Bryan Mayland

TVWBB Hall of Fame
I used to run my i3 with OctoPrint on a Pi A with the camera at 640x480 2 FPS and it never had a problem. I now have both my printers with OctoPrint on Pi 2 with 640x480 at 5 FPS with no stuttering.

Those PETG prints look great though John, just perfect!
 

 

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