LCD bracket installation sometimes destroys printed mount
Open, Needs TriagePublic

Description

In step 15 here it says:

Using two M3x25 FHCS [HD-BT0206], secure the LCD assembly to the front top right corner of the machine.
The screws go in the open holes on that corner of the frame.
Torque to 5in*lbs

We are seeing some parts coming back that have holes in them from not being seated fully on installation before threading the screws into them. This is happening probably more because the frame is threaded in addition to the mount, so the fastener has something to push against while its being threaded in. @tomc what do you think?

kent created this task.Jun 22 2018, 8:18 AM
kent updated the task description. (Show Details)Jun 22 2018, 8:23 AM

The issue I am seeing with the design of this part is the threads on the insert will never perfectly align with the threads of the frame, or at least a very small possibility it will happen.

On average I get about 9 a week through NCMR rejects, all with this same issue.

If we used a nylock which we held in place during assembly, the threads would be better aligned by hand and aid in reducing waste for assembly problems.

west added a comment.EditedJul 2 2018, 8:19 AM

@EricNugent I agree that the inserts isnt ideal but it was decided against in gyrfalcon that there wouldnt be a nut due to difficult assembly
@kent it seems to me like the production is forcing it. If there is resistance dont keep tightening., loosen and readjust also they arent even reaching the insert so it being double threaded shouldnt have anything to do with it. Its misalignment

This comment was removed by EricNugent.
kent added a subscriber: draubach.Oct 17 2018, 9:43 AM

@draubach here is the ticket that I mentioned a minute ago FYI.

DaniAO added a subscriber: DaniAO.Mon, Dec 3, 10:47 AM

@draubach @kent are we still seeing this a problem when building these?

@DaniAO We saw 2 just last week.

DaniAO added a comment.Mon, Dec 3, 3:24 PM

@paulette how many of these are you seeing and how often?

oliver added a comment.Mon, Dec 3, 3:31 PM

I can verify part of what @EricNugent said earlier in this thread. I will typically get around 5 to 10 LCD assemblies and about 50% of them will be red tagged due to the inserts on the mount being pushed or pulled out.

bowman reassigned this task from tomc to wolffchadd.Tue, Dec 4, 1:34 PM
bowman added a subscriber: wolffchadd.

Worked on this issue with @kent and it was determined that we could fix with a re-design, however, since the product is released, we can look into it more for a later rev if needed.
In the mean time, we can correct most of the problems by making sure that the parts are aligned properly during installation at final assembly. We have had several new people learning mini final assembly recently.
Re-assigning this ticket to @wolffchadd to work with Kent/MER and provide training to all final assembly personnel. As well as make sure that the Ohai instruction set documents this.

DaniAO added a comment.Tue, Dec 4, 2:06 PM

Please post any production feed back, and once the OHAI has been updated. Will close the ticket down after that has been done.

@kent can we get the OHAI update assigned to some one in MER please? not a huge priority until Quiver Alphas are done.

Thank you!