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Toolhead found to be built incorrectly
Open, Needs TriagePublic


@franklin brought me a printer that was exhibiting high x backlash to investigate.

I noticed the tool head seemed to struggle when actuating, and seemed like something was off as it looked kind of crooked.
I took apart the tool head and found that the bottom plate was installed upside down. this causes the rods to be shifted at an angle and will cause binding or high drag on the actuators.

Incorrect installation:

You can clearly see the edges are not flush

The filleted side should be facing the bottom of the tool head, this one is upside down

Correct installation:

The edges are flush when installed correctly

The filleted side is facing the bottom of the tool head when installed correctly

I imagine some machines might have been shipped like this, so we may want to put some checks in place.

Event Timeline

tutley created this task.Jun 3 2019, 8:24 AM
tutley added a comment.Jun 3 2019, 8:30 AM

Note: correcting this didnt affect x backlash measurements

@TyTh @Galadriel just something to watch out for.

robert added a comment.Jun 3 2019, 9:03 AM

We just caught and sent back 9 that had that issue.

DaniAO assigned this task to franklin.Jun 3 2019, 9:57 AM

@franklin would you be able to update Step 6 in the OHAI to make adding the bottom plate a bit more clear please?

Thank you!

DaniAO moved this task from Report Issues Here to OHAI Content on the Quiver board.Jun 3 2019, 9:58 AM
logan added a comment.Jun 3 2019, 10:16 AM

I have a clean fresh TAZ Pro Dual Extruder here at my desk, originally obtained for T7433 and T6675 that could be used for this as well. I recommend addressing those issues at the same time if re-photographing for this ticket.

per discussion in R&D chat i suggested we could modify the bottom plate such that the mounting hole for the blower shroud doesnt go all the way through. This would be a fairly easy change and would ensure that they get installed correctly

If everyone is on board with that change i can start an ECR/ECO

Upon further discussion we would like to modify the back plate such that there is an added fillet on the bottom that will match the fillet on the bottom plate.
I will get an ECO going for this change


@tutley so this won't be an OHAI change, correct? Since we are changing the part so it can only be installed one way.

@EricNugent we may need to update the photos with the new part.. and it does need to be a bit more clear on how this is installed.

logan added a comment.Jun 5 2019, 11:23 AM

@DaniAO @EricNugent
Here is the discussion between @tutley and I in MER chat:

(06/03/2019 10:31:46 AM) logan: another simple change that might make this more clear, what if the bottom edges of the back plate were filleted to match the fillet of the bottom plate? that way it may be more obvious also because you'd have a sharp edge meeting a filleted edge if it was wrong.
(06/03/2019 10:32:14 AM) tutley: that would be another easy change for sure!
(06/03/2019 10:33:44 AM) logan: that way we could specify in the OHAI, 'all mating edges should be flush/smooth with eachother'
(06/03/2019 10:34:47 AM) tutley: well to me that change is even easier than making the hole not go all the way through, so i would suggest that change, plus the phrasing you just stated

@logan sweet, thanks. I agree, the part change with phrasing/photo update for the ohai will be helpful.

franklin removed franklin as the assignee of this task.