TAZ 3 Upgrade Path

I recently acquired a TAZ 3 for free and wondering what would be the best path to upgrading this dinosaur. I’m not new to 3d printers. I have others (non lulzbot) and was considering building a new printer from scratch before I got this. I’d like to reuse most of the frame if possible but I’m perfectly ok with replacing all the electronics, motors, etc. Could I upgrade it to a workhorse or pro? Or should I go with something completely custom? What would you do?

I can print parts with my other printers. I also built a mostly printed cnc so if I need to cnc anything, i could do that as well. I also have a background in software engineering so I’m not afraid to build firmware from source if I need to modify parameters to fit the new printer but I’d like to avoid any heavy coding because I’ve been doing that for a living for 20 years and really don’t enjoy doing it as a hobby much anymore.

Keep the frame, motors and wiring. Build a lightweight tool head from a biqu h2 revo with a bltouch mount. Replace the board with an SKR 1.4. do a custom marlin build, of course. Not even light coding required.


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I was reviewing the docs for this printer and it appears to be a taz 4, not a taz 3. The person who gave it to me was mistaken. It’s also insanely loud and the z-axis doesn’t even move, just makes a loud grinding noise. I’ll probably be replacing a lot of parts.

Grinding z axis is usually a total lack of (or gummed up) lubrication. Give it a good cleaning and lube them up. At worst they need to be hit with a solvent and re-greased. Even if the steppers are toast, they’re cheap to replace.

Yeah I planned to tear it down, clean it, lube it, and make some upgrades while I had it apart, but maybe I should just get it working first then upgrade what’s needed. I really don’t mind dumping money into it as I planned to build a new one anyways but I’m sure that money will be better spent if I take my time and do a good, thorough inspection and cleaning first. But since this is my largest printer, the end goal is to make it the fastest as well. I’d like to build large parts as quickly and quietly as possible. I’d also like the ability to easily swap tool heads and maybe even dual extruders at some point. My next largest printer is a mk3 and while it prints really good, it’s not exactly fast and swapping nozzles is often more trouble than it’s worth.

I rebuilt a couple of Taz 4/5’s. I would recommend the Duet 3D boards. Very easy to get the printer set up and working. I used BLTouch’s for mesh leveling but if I did it again I would use a non contact probe. I converted the hot end of the extruder to a an E3D (volcano with a .6 nozzle on one and supper volcano with a 1mm nozzle on the other). Big prints need big nozzles! Big nozzles need to move a lot of plastic. I’m going to try replacing the Supper Volcano with a Std. Volcano and a Bondtech CHT nozzle. The supper volcano is just too long. Also installed Wham Bam build plates and took out the leveling springs (shimmed the bed level to start),


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Why? Isn’t one of the main advantages of a bltouch or non contact probe that you don’t have to do that?

Yes. But it is best to start with the corners of the bed as level as possible when you build the printer. Then the mesh leveling is compensating for a bed surface that is not perfectly flat.


When compensating for the bed, it will adjust the Z to adjust for the bed for the first layer, but fades that difference in Z height over a few millimeters (amount adjustable in firmware). Therefore, if you are printing a rectangle, the top will up at right angles to the sides, but the bottom would be at a (very) slight angle off from square with the sides. The more parallel you can get your bed relative to the X axis gantry, the less compensation is required.

If this fading the difference didn’t happen, you’d have vertical towers that should be parallel to each other pointing in different directions as they exaggerate the bed irregularities as they get longer.

Once you have a good level, and have a removable sheet so you don’t have to knock the bed around to get things off, those springs just serve to make the surface less stable.

I thought the auto leveling would negate this. But I suppose it’s not a problem if I only have to do it once, or once in a while, and not for every print.

I would like to upgrade to a removable textured steel sheet. The octograb magnetic flex bed v2 looks nice but it looks like I’d have to first upgrade to the modular print bed heater for $140 plus the magnetic flex bed for $160. That’s a $300+ upgrade for just the print bed, plus whatever modifications I would need to make it work since it doesn’t seem to support the taz 4. Are there other good options out there or is this pretty much it?

I just stuck the Wham Bam magnetic sheet down to the glass (removed the PEI sheet first). Probably not the best way but perhaps the least expensive. Seems to work fine, even at ABS temps.

Ah, when you said wham bam I was thinking mutant as that’s the only product of theirs I’ve seen before. That makes more sense now.

I was also thinking that since I have a cnc, I could just cnc my own aluminum sheet with magnets for less than $10. Then I could throw any spring steel sheet on there that I want. I’d still have to upgrade to the modular bed heater for $140 but that would still bring the price down quite a bit and I imagine it would be quite a bit more efficient than trying to heat the aluminum through a layer of glass.

If you have the capability of machining out your own aluminum plate, get a good cast (edit: originally misidentified as forged) aluminum plate, flatten it, use the CAD drawings for the factory plate from the devel.lulzbot.com site to get mounting points right, put magnet holes in it, and slap a mains-powered bed heater/relay on there. No need to have the lulzbot modular bed system at all.

I was going to use 6061 aluminum because it’s cheap and easy to work with. 12"x12"x1/8" is only like $10. What grade aluminum should i use? 5052? I’m not sure I have the tools to machine anything stronger than 6061. I’ll have to look into it.

I was looking for the CAD drawings yesterday for the octograb magnetized plate but couldn’t find them. Or do you mean use the drawings for the bed plate and mount the new plate directly to that with metal standoffs instead of the plastic/spring setup? Either way, should be an easy cut.

I like the idea of a ac powered heat bed. However, since this printer comes with a giant external dc converter, there’s no ac power at the control box. So I’d have to run another line from the wall or replace the dc power supply with a meanwell or something so i can bring the ac into the control box. It’s quite a bit more work for roughly the same cost. It’s probably worth it in the end though so i’m definitely considering it.

Here’s the article I was remembering from earlier, pretty much exactly what you need - you’ll want 1/4" or thereabouts, not 1/8". Ensure it’s CAST tooling plate - not rolled.

Replacing the Glass Print Bed on the Taz 3 Printer | Milwaukee Makerspace

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So something like this… McMaster-Carr ?

I should be able to cut that fine but it seems excessive. Not sure I want to spend that much on a print bed. Maybe I’ll come back to it after I get the printer going with the new motherboard and tool head.

It’s significantly less than the modular bed from LulzBot. You do need to factor in the cost of adding a heater and your time though. But it’s far superior to the glass when done right.

I agree it’s far superior, even to a dc powered modular lulzbot print bed. Significantly cheaper though? Maybe I’m looking in the wrong place…

Modular bed heater - $140, textured flex bed v2 - $160 = $300 for the modular bed or I can cnc the aluminum sheet and add magnets for $10-$20, get the spare sheet for $65 and bring that cost down to about $220 plus tax/shipping and it’s very little work.

For the more custom ac bed heater, a 300x300 (keenovo) is around $80 if i can find it in stock. $70 for the aluminum, a good, properly rated solid state relay is about $40, the same textured spare sheet from lulzbot is $65, and figure at least $20 in misc hardware, wiring, magnets, etc, and I’m already up to $275 plus tax/shipping. And if I want to replace the psu so I don’t have to use a second ac outlet, the meanwell rsp-500-24 is $115 more or the cheaper lrs-350-24 is $40. Which 350 watts is probably more than enough since we aren’t heating the bed with it but i’m still over $300.

And once you’re at nearly half the cost of a P1P, it’s harder to justify.

If it’s going to be a project you enjoy, go for it. Just don’t get bit by the sunk cost fallacy by ignoring the cost of something free is the end goal is just to have something functional.

Journey vs destination and all that.

Agreed. This is mostly just for fun anyways as I really don’t need another printer. I just like building stuff. I will probably end up going with the ac heater upgrade at some point but I think the first goal is to get good quality prints, then work on getting quiet prints, then go for the luxury upgrades. Too many things at once and I might get overwhelmed trying to get the printer dialed in and lose interest. This is my first custom printer build so I’m sure I’ll hit quite a few bumps along the way. I’d also like to avoid spending $3k to end up with a $2k free printer in the end.