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Bed chain mount screw alignment/crossthreading
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Description

We have had some reports that the screw to mount the bed chain is difficult to thread into the insert. Sometimes this can lead to cross-threading.

This might be caused by mis-alignment of the Y cable cover hole with the hole in the bed plate as can be seen in step 3 here https://ohai.lulzbot.com/project/y-axis-assembly/quiver/. There does not look to be any means of adjustment, so maybe opening the tapered hole diameter a little would help solve the issue.

Event Timeline

kent created this task.Apr 8 2019, 9:07 AM
kent created this object with edit policy "LulzBot Hardware Products (Project)".
west added a subscriber: west.Apr 8 2019, 9:42 AM

There is adjustment in the y cable cover. I recommend sticking a driver in the tapered hole then tightening the m3 screws so the m5 screw is aligned with the hole

kent claimed this task.Apr 8 2019, 2:43 PM
kent added a comment.Apr 9 2019, 8:56 AM

I looked at some of the beta machines and they definitely have this issue. I was able to fix it by loosening the three screws that hold the y cable cover and aligning it with a 4mm driver. I can definitely see why people are crossthreading this since it's not super visible while you are threading it in (its under the bed). Maybe some kind of guide that would keep the cable bracket aligned would help prevent this, or better yet, a clip-in cable bracket.

Step 3 here https://ohai.lulzbot.com/project/y-axis-assembly/quiver/ needs a picture of a driver in the hole to align the printed cable cover with the bed plate. It only mentions one HD-BT0148 but there are three so we will need to add those to the ohai and verify they are on the bom for the y station. I think the reason why it is the way it is is because the cable cover makes it harder to put the heatbed on but it's doable to get the wires in there once you know how to do it, so I think we can add the bolts back in the y station.

logan claimed this task.Apr 16 2019, 10:49 AM
logan added a subscriber: logan.

I have taken photos of this to add to Y-axis OHAI and requested BOM correction on T6423

Orias added a subscriber: Orias.Apr 22 2019, 10:47 AM

On Beta unit 0030, the Y-axis M5 screw was easily cross-threaded into the cable chain mount. The screw without having anything attached was hard to turn, making it hard to determine how strongly things are being tightened. Would freeing the screw along the Z-axis help keep things aligned and self-centered?

kent reopened this task as Open.Apr 22 2019, 11:17 AM

@Orias can you loosen the three screws that hold the cable cover on and follow the alignment procedure that logan created and report if that makes a difference?

Orias added a comment.Apr 22 2019, 3:33 PM

Loosening the top two screws prior to tightening the M 5 screw (followed by re-tightening the cover) releases the pressure on the screw, allowing for easier cable chain installation. My earlier comment occurred with a new user.

kent reassigned this task from logan to EricNugent.May 1 2019, 10:10 AM

Ok I think the added instructions in the y-axis assembly will help prevent this issue in the future. @EricNugent can you review the y-axis assembly OHAI to confirm the instructions are clear and if so resolve this ticket?

EricNugent closed this task as Resolved.May 1 2019, 12:09 PM

Instructions are pretty clear cut and pictures are informative.