Author Topic: 3D Printers  (Read 21818 times)

Spectere

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Re: 3D Printers
« Reply #30 on: April 30, 2018, 10:52:03 AM »
It definitely helps! I had both printers running for pretty much all weekend and the LulzBot was printing fairly nicely despite the Prusa shaking the crap out of the table.

The Prusa definitely has a bit of a speed advantage. It has a smaller and lighter toolhead compared to the LulzBot, as well as newer stepper motor drivers, so that thing can accelerate ridiculously fast. The LulzBot can move quickly, but it takes it a few moments to get up to full speed. The LulzBot also uses IGUS polymer bearings while the Prusa uses more traditional linear bearings (basically cylinders with tiny ball bearings along the edges). The IGUS bearings are known for introducing a bit of slop, so I suspect that the axis are slowed down intentionally to compensate. That said, after dealing with a seized linear bearing on the Prusa (which, in turn, gouged the crap out of one of the Y-axis rails) I think I prefer that!

It's kind of interesting when I feel the stepper motors while the printers are active. The Prusa XYZ-axis stepper motors barely get warm to the touch, while the E-axis (extruder) motor gets uncomfortably hot. Meanwhile, the LulzBot XY-axis steppers are hot to the touch while it's E/Z-axis motors stay cool. I suspect that's largely due to the extruder design. The Prusa uses two BondTech gears which grip the filament from both sides and push it in. This allows it to handle flexible filament a bit better, but it causes the motor a bit more stress. The LulzBot's standard toolhead uses a traditional setup, with a toothed gear and a pulley wheel pressing the filament against it.

The heated bed is a bit interesting. On both the Prusa and my old Wanhao printers, I could literally place my hand on a 60°C bed indefinitely without any major discomfort. On the LulzBot, 60°C actually feels like 60°C. I can keep my hand on the bed for maybe 2-3 seconds before it becomes painful, and that sucker can reach 120°C. O.O I'm not sure if that's due to how the hotbeds are calibrated, where the temperature is measured, or the type of material used, but it definitely makes a difference.

Also, I ended up ordering a 1.75mm toolhead for the LulzBot yesterday with a pre-installed hardened steel nozzle. The thermal properties of steel aren't quite as attractive as brass, but that'll allow me to print with abrasive filaments (glow in the dark stuff, carbon fiber blends, etc). Swapping nozzles is simple, though, so if I ever wanted to swap it with a brass nozzle it would be pretty trivial.

About the only nozzle that I wouldn't want to use on the LulzBot (though I could use it on the Prusa) would be the Olsson Ruby. Both printers do auto bed leveling, but they do it in different ways: the Prusa uses an inductive probe while the LulzBot uses conductive probing.

On the picture with both printers, take a look at the toolhead of the Prusa. You'll see a grey wire running along the right side of the extruder body. That's where the inductive probe is connected. It probes nine known points on the bed in order to build a mesh of the bed shape to account for minor warping.

Now take a look at the LulzBot. That one has four metal washers on the four corners of the bed. When it autolevels, it heats the nozzle up below the melting point of the filament, wipes the nozzle on the pad to the front-left of the bed, then gently lowers the nozzle down onto the four washers, checking for electrical conductivity. It uses that to work out what kind of angle the bed is sitting at. It's not as intricate as the Prusa's system, but since the LulzBot uses a glass build surface they can get away with that. You have to actually try to warp borosilicate glass.

So yeah, the reason it won't work with LulzBot's autoleveling system is because ruby isn't a conductive material. I've just made a short story long. You're welcome. <3
"This is a machine for making cows."

Spectere

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Re: 3D Printers
« Reply #31 on: May 10, 2018, 12:42:59 AM »
I printed with nylon (infuses with carbon fiber!) for my first time today. Really really awesome surface finish, but it's stringy as fuuuuuck. Definitely need to dial in retraction a bit more. Kinda nice that the 1.75mm toolhead that I ordered for the TAZ 6 came with a hardened nozzle--it saved me from having to change it myself. :P

I also want to design a toolhead for the TAZ 6 at some point, so I've been looking into ColorFabb HT as an ABS replacement. ABS has some of the best temperature tolerance (its glass transition temperature is around 105C), but it lets off smelly, likely toxic fumes and has a nasty tendency to warp unless you build an enclosure for your printer to keep the ambient temperature high. ColorFabb HT is a copolyester, so it lets off minimal fumes, doesn't tend to warp as much, if at all, and HT is a specific blend that has a glass transition temperature of 100C. Copolyesters tend to be a bit stringier, but I'd rather deal with that than ABS any day of the week.

The only real hangup that I have with ColorFabb HT is that I've been having difficulties finding any sort of real information on how it performs in the real world. ColorFabb makes awesome filament, but I'd rather see a third-party put it through its paces. Most of the videos I've seen were people comparing it to PLA (which makes absolutely zero fucking sense given that PLA softens at only 60C). I want to see it compared with ABS. Even r/3Dprinting doesn't seem to have a whole lot of posts about it.
« Last Edit: May 10, 2018, 12:45:59 AM by Spectere »
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Spectere

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Re: 3D Printers
« Reply #32 on: May 14, 2018, 08:44:20 AM »
I just installed an amazing mod on the TAZ 6:

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Spectere

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Re: 3D Printers
« Reply #33 on: March 30, 2019, 11:07:53 PM »
N-n-n-n-necro!

I ended up buying an X56 HOTAS (mostly for Elite: Dangerous) and decided to create and print a flight stick mount for my recliner.

"This is a machine for making cows."

Spectere

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Re: 3D Printers
« Reply #34 on: December 10, 2020, 01:38:03 AM »
Ended up snagging this for my TAZ 6, along with the universal toolhead adapter. Should be arriving tomorrow. Not only will it give me another 1.75mm-capable toolhead (the LulzBot printers typically use 2.85mm filament, which isn't as widely used these days), but it also pairs a BondTech BMG with a Mosquito hotend, giving a pretty kickass platform for printing flexibles, and allowing for fast and easy nozzle swaps. I modded my Prusa MK3S with the same extruder/hotend combo last year and it's kind of amazing how quickly that thing can chew through even soft TPE.

Gotta say, for as old as the TAZ 6's design is (2016!) it's still one hell of an awesome printer, and it's awesome that LulzBot is still supporting it (as well as the TAZ 5!) to some degree.
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Spectere

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Re: 3D Printers
« Reply #35 on: March 09, 2021, 02:41:22 AM »
Managed to score an Anycubic Photon S for $90 the other day. The original owner claimed that the LCD screen was bad, but I'm pretty sure the power cable wasn't plugged in securely as it works perfectly. From what I can tell the printer goes for about $270 new, so I was able to get the printer, a UV chamber (to cure the printed parts), and a bottle of resin for much less than the printer alone would cost.

It's pretty obvious why the printer is cheaper than upper end resin printers. While the electronics and mechanical bits seem a-okay, you can tell the places where they cut costs. The lid and plastic bits are kind of cheap and flimsy, but it does a good enough job sealing off the print chamber when in use. While the UI isn't great, it's very quick and responsive. The Z axis of the machine is whisper quiet. It didn't make a whole lot of noise in operation, and even my relatively quiet Prusa MK3S (which is hard to hear one room over) is cacophonous by comparison. The fan is the loudest part by far, so it'll probably be damn near silent if I upgrade that.

The Anycubic software is kinda balls by all accounts and doesn't run under Linux (which my trusty basement iMac now runs), so I wound up using ChiTuBox. It's not too bad, but it's a far cry from the level of polish of something like PrusaSlicer. Fortunately, it is possible to set up the print with supports using PrusaSlicer, export the results to an STL, and import that into ChiTuBox. Probably going to take that route moving forward.

It's my first resin printer, so I've been doing a lot of reading up on it. My first print wasn't exactly successful, but I found out that unlike FDM ("fused deposition modeling," or printers that take filament) printers, you don't want the build plate to be clean, otherwise the print will just sort of stick to the FEP film at the bottom of the resin tank. Whoops.

Resin is definitely stanky. It's not as bad as I heard it was (at least Inland standard resin isn't), and when you're dealing with small quantities it's not so bad. It's a bit more noticeable when you're funneling a tank of resin back into the bottle. Woof.

It's also worth noting that UV cured resin is toxic and certainly isn't something to take lightly. Someone on r/3DPrinting ended up getting resin all over themselves while moving a printer and ended up with some pretty nasty chemical burns as a result. The endgame is to put the printer in an filtered enclosure. The printer already has a couple of filters inside which do a surprisingly good job (you can't really smell it unless you're standing right in front of it), but the endgame is to install it in another enclosure to completely eliminate the odor.

If I remember I'll update this with a picture of my first successful print.

On an FDM-related note, FAME 3D pushed out another TAZ 6-compatible upgrade. The TAZ 6 came with a borosilicate glass build plate with PEI film on top. Good adhesion with the smooth properties of glass. The problem with that setup is that you need to take a scraper to the surface to get parts off. My Prusa MK3S, on the other hand, has a flex steel plate that I can remove and flex in order to detach the part, making it far easier to remove parts and eliminating the chance of scraper injuries (one slip == one hospital visit and very likely a bunch of physical therapy) at the expense of slightly less efficient heat transfer.

Well, they came out with an upgrade that adds a large flexible build plate to muh ol' boi, basically bring it up to snuff with the much newer Prusa MK3 platform in terms of QoL features. At this point I'm almost tempted to swap out the main board for one with quieter drivers to soothe the beast a bit.

The only real downside with the flex sheet upgrade in my case is that my TAZ 6 uses the classic heater design rather than the newer modular heater design. The old design features a silicone heater glued to the borosilicate glass, while the newer design is a modular heating system, with the build plate and heater being two distinct components. It's not difficult to swap any of this out, but it did make it a little more expensive. Definitely looking forward to getting that installed, since that basically removes the only minor annoyance that I have with that printer.
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Spectere

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Re: 3D Printers
« Reply #36 on: March 20, 2021, 05:05:01 PM »
Managed to score an Anycubic Photon S for $90 the other day. The original owner claimed that the LCD screen was bad, but I'm pretty sure the power cable wasn't plugged in securely as it works perfectly. From what I can tell the printer goes for about $270 new, so I was able to get the printer, a UV chamber (to cure the printed parts), and a bottle of resin for much less than the printer alone would cost.

Hoo boy. I'm not sure who had this printer before me, but they definitely didn't do their homework before trying to maintain this thing. Here's a quick rundown of why this thing wasn't printing, like, at all.

Instead of homing the printer, they just put spacers on the bottom of the resin tank to bring it up to the build plate. Easy enough to fix.

I dug in a bit deeper and found that they also tightened the FEP film (the film at the bottom of the tank) waaaaayyy too tightly. You're meant to tune it more or less like a drum, and it's supposed to be somewhere around 290-350hz when you rap it with your finger. It was hitting 490hz. Holy hell.

I cleaned it out thoroughly and replaced the film, dialing it in to a nice 333hz, and after starting a print I was able to hear it get pulled off of the FEP film between layers. Fingers crossed!
"This is a machine for making cows."