Taz 6 toolhead wobble

So I got my Taz 6 assembled and ran it through a few test prints. When I was mounting the toolhead I tried my best to ensure that the bottom of the toolhead was seated firmly in the X axis carriage while tightening down the 2.5mm hex screw at the top, since I had seen in the review by 3dPrintingNerd on youtube that there could be issues with the bottom of the toolhead being or becoming slightly loose.

I ran through the rocktopus test print and a 17g print of my own design, and then went back to check the toolhead only to find a disturbing amount of free play. I could lift the bottom of the toolhead away from the carriage in the Y direction by about ~1mm with a moderate amount of force, and could wobble it back and forth in the X direction with a fairly light touch.

I loosened and retightened the 2.5mm hex screw, again taking care to apply downward pressure to the toolhead to ensure it seated firmly in the carriage. The toolhead now feels secure again, with only a slight amount of free play in the X direction, but I’m worried that this problem might come back as there’s no positive retention of the tool head in the Z direction to keep it from jacking upwards out of the carriage due to X axis forces (like from the nozzle cleaning cycle).

Is there a torque specification for the 2.5mm toolhead retainer bolt? The head is pretty small so I feel like if I try to crank it down it’s just going to sink into the plastic and chew things up.

Has anyone devised workarounds for this issue? It seems like a piece of electrical tape placed on the bottom corner(s) of the toolhead might help prevent the toolhead from shifting in the X axis during cleaning, and prevent the head from jacking upwards?

It should be an M3 bolt with a washer on it, and you should crank it down enough that there is no risk of the toolhead shifting, but not enough that it splits layers.

So crank it down until it cracks, then back it off a quarter turn? :wink:

You want a little play otherwise you will tend to rip the brass heat insert loose in the carriage.

I’ve contacted support about this. My first V2.1 toolhead didn’t wobble much. The flexystruder was solid. Then I received an RMA V2.1 and it wobbled much more than the original. Support said this was normal. I received a full Taz 6 RMA and there is some wobble, but not as much as the first replacement. So it goes…

I’ve never had an issue with it becoming loose once secured… When you slide the bottom of the tool head into the slot (V shaped thing) on the carriage can you slide it back and forth in the X axis direction (before you bolt it down)?

I recently printed my own upgrades (carriage, back plate, ect) and the actual V shaped portion that goes into the slot on the upgrade printed was about 2mm short of the width needed. Sure you bolt it down but it ends up not being secure and ends up acting more like a pendulum.

I figured I had 3 options.

  1. Reprint the entire carriage and rebuild the tool head (which I had just done for the upgrade). Nope I was feeling lazy.

  2. Reprint the actual part that the tool head slots into, its just a small piece that bolts on with 4 screws to the back plate… my only concern was future toolheads then not fitting after I modified the part.

  3. Ghetto rig it and build up the width with some other material. You mentioned electrical tape… I went with something more rigid. I mixed together spare filament and some acetone into a type of putty and then slathered it on. The beautiful part about it… is that once it dried a little bit I could push it down into the slot that it mounts to and it would create a perfectly formed fit. Just be sure to pulled it out to let it finish drying so it would adhere to the carriage.

  4. Sure you could contact customer support… wait a week for them to ship it and then another week for it to actually be delivered.

Welcome to the world of Taz, great printers that become even better once you start to tinkering.

So I was about to reply saying “so far, so good” after re-securing the toolhead, but I just walked over and checked and somehow it’s worked itself loose again? Not even sure how. I’m almost wondering if the toolhead is expanding when warm, then shrinking when it cools off, working itself up out of the carriage that way. Puzzling.

I haven’t tried adding electrical tape yet, or some other filler material. Will experiment more…

The toolhead wobble is a lot worse with the dual extruder. With the weight of the two half-height steppers, it bows the mount… so there’s play vertically also. Its actually kinda frustrating… T1 can only be used under 50mm/s.

I’m to the point of modifying the mount so that longer bearing holder screws (on the X-carriage) can further secure the toolhead.

An easier way to remedy this may be to print the V-shaped part of the X-carriage at a finer layer height (the gcode file on devel.lulzbot.com is generate at .35mm). This could allow the toolhead to “slip-in” without catching…

I’ve been thinking about ordering a Taz 6, but after seeing the disturbing comments about the toolhead wobble I’ve decided to wait until this is resolved. Does anyone know what the current status is?

Its the same basic toolhead socket the taz 5 had, with a few tweaks and stronger rods. This guy got a bad one, but the hundreds of other ones out there have been pretty solid for most people.

Yep… I have to agree. You’ll more than likely be okay. My single extruder was rock solid… or the wobble didn’t affect the prints.

My flexydually has some play too, but I have not noticed any impact on print quality.