New to me Taz5 Two?

General LulzBot TAZ
1

Hey all! I’ve got a little story before I get started.

Today I picked up a little Taz 5 from my local library. They had reached out to anyone who wanted to help them get a new 3d printer and I walked over. So they had this Taz 5 sitting in a closest “not working for a year or so” and they were looking for donations to help them get a Bambu Labs printer.

So I said I’ll donate $200 to their new printer if I could have the old one. And they said yes! So I brought it home and plugged it in, they told me it didnt work, so I expect a bit of work ahead of me, but all in all, it looks like its in pretty good shape.

After turning it on, the first problem that comes up is

“Err: MINTEMP E0

PRINTER HALTED

Please reset”

I have a little bit of 3d printer experience, but not too much, but I know that MINTEMP usually means that the hotend is at 0degC.

So I think my first step is to replace the thermister. Taking a look i do see a broken wire, but also a very complicated looking hot end.

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However, I have no idea where to start.

With my googling, I’ve found that the Lulzbots printers are open sourced and very modifiable. Thats awesome, but thag usually also means that finding the right information is tough. So I have a few questions for your guys.

  1. They kindly labeled the printer it says “Taz5Two” What the heck is a Taz5Two?

  2. on the extruder portion there are what looks to be 2 arms that move back and forth? What the heck are those things? Tensioners?

And 3)

How far off am I with the thermister diagnosis? And what part do I need?

If you have any helpful videos, or other threads I could read too, send them my way. Any information is greatly appreciated.

2

Bottom line up front:

You’re about $40 away from a printer that can do ABS well (and slow). It will print PLA poorly until you upgrade the poor part cooling (which you can fix with printing new parts, of course). Your donation to the library is great, and you should learn a lot along the way of fixing up the old Taz 5, but if printing was your actual goal, you’d have been better served buying a modern printer for under $300.

Back to the answers:

#1 - I’m guessing there was a second printer - “Taz5One” - that sat beside it at one point.

#2 - For reference, everything about that hotend can be found in the OHAI site - https://ohai.lulzbot.com/project/2b36d92e-a984-4e61-af92-245ea7fcaeaf/a16b1f2d-5c1f-47fe-a83d-9d68cca5d62c/ . That site isn’t the most easily found, so direct links can be handy.

The rest of the Taz 5 assembly is also on OHAI.

The tension is adjusted with the bolts on the tensioner arm (T), which overlaps to put tension on the idler arm (I).

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From your photo, it’s also clear that the factory toolhead has been modified. It may have been modified to run 1.75mm filament, or just modified to get around the lack of replacement Hexagon hot ends. To begin: The aluminum plate that the Hexagon hot end was attached to has been replaced by a printed plastic plate to adapt to the e3d V6-style hotend. It shouldn’t get that hot up there, so ABS would hold for a while, but if that’s PLA, it will fail.

The e3d-style hotend looks completely clean and unused, so whoever built it apparently gave up when it didn’t work. A v6 hotend uses cartridge thermistors, while the hexagon used a glass bead thermistor. Where the cartridge thermistor would be in that hotend, I believe I see a the one good wire and the stub of the second wire that was ripped off.

I’m guessing they tried to re-use the glass bead thermistor instead of using the proper thermistor for that hot end. A glass bead style is not going to be contacting properly to give consistently accurate readings. Remove the screw from the thermistor hole, remove what’s left of the old thermistor from there, and replace it with a standard 100k cartridge thermistor. They’re cheap. The thermistor should be held in place by a set screw in the bottom of the hot end.

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Also, obviously, the little blower-style hotend cooling fan is also broken and wires ripped out. With a plastic adapter plate, this will absolutely lead to failure of that plastic plate. Even if it’s wired up and working right, it’s not a good fan for that purpose. You’d be better off getting a e3d fan duct and 3010 5v fan to go with it to replace the blower.

Once you get the toolhead working, you will need to adjust the Z homing switch to account for the different toolhead position.

3

This is wonderful thank you so much for this response. For sure if I wanted a cost efficient printer to just pump out parts, i should have went with something else. But i figured $200, and i get to help the kids in my community, PLUS i get a cool little project to tinker with, i take that as a win.

I knew it was a 100k thermistor, but the glass bead vs cartilage stumped me a bit on my own. Cheap and easy with your answer.

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Heres another angle. I can take more pictures tonight too, buti definitely want to add more part cooling. From my previous printers, I have a lot of PLA kicking around thag I woikd like to use. Otherwise, ABS isnt expensive.

4

Check to see if it’s running 2.85 or 1.75mm on that hot end. The Wade extruder can push both sizes, but is definitely better at 2.85.

See if you can inspect the closet for the old parts - the aluminum plate for the toolhead would be good to have. The throat of the v6 is a little bigger, so it would be loose initially, but you can print a thin spacer to put on there in addition to the aluminum, so you get the heat dissipation and strength of the aluminum with just a little plastic to fill in the gap.

5

Okay you might have to explain that in a bit.morr detail for me.

I have a Bernier, so I might be able to measure the size, but im not sure where to.

And the build plate, im not visualizing what you’re saying. The very end of the hotend is loose, so what I think you’re telling me is that they tried to upgrade the hotend to a v6 version, but they forgot a piece? I think i remember seeing some other forum explaining the same thing, so I’ll have to find it again

6

The 2.85 and 1.75mm refer to the size of filament. There are 2.85mm e3d V6 hot ends, but 1.75mm was much more common… but if you’re replacing a 2.85mm Hexagon hot end, you’d probably stick with 2.85mm. You’d be measuring the size of the opening for filament at the top of the heatbreak.

The throat of the V6 is 6mm:

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The throat of the hexagon hot end is 4.5mm:

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So you would need to make a 1.5mm spacer the same shape as the aluminum plate so the 6mm throat is tight.

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7

That makes much more sense. Thank you. Ill have to tackle that and come back with my results.

However, the base of the hotend (probably using wrong terminology) is "loose”, not the portion you’re pointing out. Is that normal?

EDIT: forgot to add a question

8

I assume you’re talking about the heater block. The heater block is secured between the nozzle and heatbreak.

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When you put together a V6 hotend, you thread the heatbreak into the heatsink until it’s good and snug. Then you thread the nozzle into the heatbreak, so the flared portion of the nozzle touches the surface of the heatblock, then back it out about a quarter turn. Then you thread the heater block onto the heatbreak. Once the heater block is snug, back out the nozzle slightly so you can rotate the heater block into the best position for wiring/clearance. With the heater block held in position, tighten the nozzle. Now, you can use the heater block to help tighten the heatbreak into the heatsink a little bit more. It shouldn’t be moving much, just a couple degrees. if it moves more than that, and your heater block is in the wrong position now, just loosen the nozzle, rotate the block, and re-tighten the nozzle.

The threads of the nozzle and heatbreak pushing against each other are what keeps the nozzle and heater block from loosening from the heatbreak, and the heatbreak threaded into the heatsink keeps the heatbreak, heater block, and nozzle from rotating as a unit.

So… if the block is spinning on the heatbreak, tighten the nozzle… unless the nozzle is already flush against the heater block (there should always be a small gap between the two). If the heatbreak is spinning in the heatsink, tighten the entire the heater block. If after everything’s tight, but the heater block is in an odd position, loosen the nozzle while holding the block, twist the block into the preferred position and tighten the nozzle.

Once everything is in the right position, and tight, you move onto heat tightening.

Secure the heater and thermistor into the heater block and the clip the heatbreak fan on.

Turn the machine on, bring it up to 150c and turn the machine off. Grab the heater block with a wrench and tighten the nozzle. With the nozzle tight, use light force to tighten the heatbreak into position. You have to be careful, as a hot heatbreak tube can be twisted and snapped VERY easily. You are just making sure that it can’t freely rotate and start un-threading itself.

Now, repeat the heat tightening at 180c. (On, heat, off, tighten). Again at 210c, again at 240c and again at 270c.

There should be very little if any movement you can feel, but if you don’t heat tighten properly, there will be a gap between the nozzle and heatbreak inside the heater block when it does heat up. That leads to jams, leaking plastic from the top of the heatbreak (a common reason for ruining a hot end), or other print failures.

I’m pretty sure this video covers it as well: https://www.youtube.com/watch?v=JKyJl2_x6k8

9

Ahhh that all makes sense. I ordered the new thermistor (got a 5 pack just in case), and a couple of fans to replace the squirrel cage one that’s on there.

The other question i had is about the bed. Im. Used to my old printer which was an Ender 3, and I had to physically take the bed off every time to remove the part, and relevel every time.

This bed looks much different, and im.not sure im supposed to be removing it every print. Others have suggested a “Wham Bam” bed system, but I havent had much time to look into that yet. Any advise?

10

Definitely go with a magnetic bed system.

The lulzbot (octograb) system is amazing, but the price is high. I have it on my employer’s machines. On my personal lulzbots, I have the Fysetc 300mm one that’s just over $30. I only use the textured PEI side, as the “carbon fiber” one can stick and break off chunks. Whambam’s is also good, but pricier than the fysetc one.

11

I wanted to add - to make the system 100% more useful, add BLTouch clone or similar and the custom Marlin build to support it. Proper bed leveling will make that thing actually reliable on 1st layer. Clones are like $10.

12

For sure, that’s in my plan for the future. But messing around with the firmware intimidates me to no end. So thatll be a whole new process to figure that out.

13

Doing custom marlin is nowhere near as intimidating as you’d think.

install Visual Studio Code. Point it at the lulzbot marlin github repository. It’ll ask to install some add-ons to make things easier, then you just go through about three configuration files that are basically self-documenting and hit build. I think the least straightforward part is just telling the Lulzbot configurator what machine you’re building on.

Or, you could join drunken octopus’s patreon and download the pre-built firmware binary from them.

You might need to change a few things, but the Taz6-BLTouch firmware I use might just work for a Taz 5 as well. Toolhead settings (e-steps, PID tuning) and nozzle/probe offsets would be put in for sure, but I think that can be all done without changing the firmware.

14

Little update.

I finally got the parts in and installed the new thermistor and the error went away!

I did have the issue with the spacer being the wrong size, so for right now I have a thin piece of heat resistant plastic in there acting as a spacer. One of my first prints will have to be a proper one.

It’s currently -8degC in my garage where the printer is set uo right now and I dont really have a way to enclose it and keep it temperature controlled yet, so im going to way until things warm up a bit before I start cranking the heat.

15

Another update:

After bringing it in to work inside, and out of the cold I let it warm up. After letting it get acclimated, I did some movement tests.

The X, Y and Z all move, are smooth and responsive and appear to move their whole range.

However, the extruder doesnt move when I try to move it with the LCD controls. Im hoping its not broken, because that seems like a more expensive fix than the thermistor. Is there any ways I can test it?

16

Hot end needs to be up to temp before the extruder will move.

Warm up to 200c and give it a shot.