3D Printer Challenge - Solution for 800 top case brittle screw posts?

[800_Rocks]

Does anyone have a solution for replacing a broken/shattered screw post on the 800 top case?  In particular, take a look at this example of the four posts that the 800 keyboard is attached to.  The attached images show an example of a good/intact set of the four posts labelled "1" thru "4".  When these shatter (due to over-tightening, age, brittleness, etc.) and you are unable to superglue them back together... what are your options?  Here is my thought and I wonder if anyone has tried this.

 

Challenge to all the 3D printer folks out there !!!

 

My Ideas:

 

1) Post 1 may be tricky because it is so close to the RESET key however, posts 2, 3 and 4, if there were completely cutoff and sanded flat... could a 3D replacement post be made that has a large 1cm X 1cm square base?  The base may be big enough to superglue into place.  I think if the base/post angle were correct it may be worth a try.

 

2) If there is enough of a remaining post... something that could superglue over the remaining post and could then be cut to size.  Call it a glued-on post replacement sleeve.

 

Other ideas?

Picture1 - Showing all 4 keyboard attachment posts (in good condition)

 

Picture2 - Close-up showing posts 1 and 2 (in good condition)

 

Picture3 - Close-up showing posts 3 and 4 (in good condition)

 

[leech]

If the post is still there, but just cracked so it no longer holds a screw, or it's stripped, the solution I've used on an ST was this stuff.  https://www.amazon.com/Moldable-Plastic-Thermoplastic-Beads-8OZ/

Basically heat it up, pour into the hole, then put in the screw to create the threads before it cools and hardens.  Worked quite well (you need very few of the beads). 

 

Edit: It's been my experience that most 3D printed stuff doesn't really have the sort of strength to handle screws without being extra thick. 

Edited November 11, 2022 by leech

[+DjayBee]

The shows only a dog for me

 

and the message that the page was not found.;)

[xrbrevin]

its tricky due to the torsion forces when the screws are installed or removed. the bond has to be strong enough to resist.

many people have had success using acetone. you add it at the breakpoint between the 2 broken halves and it melts the surface layers that then fuse together.

ive never tried it, maybe if i win another 810 on ebay i'll get chance to..! 🙄

[TGB1718]

1 hour ago, DjayBee said:

The shows only a dog for me

Me too, nice little doggy

@leech any chance of a working link, my ST has the same issues and I've done a few "bodges" but really

need a decent solution..

 

I think what's really annoying with this type of problem, for the sake of a few pence/cents they could have

put those metal collars on the tips of the posts to prevent splitting.

[+kheller2]

These?

https://www.amazon.com/Moldable-Plastic-Thermoplastic-Beads-8OZ/dp/B077874HM8

 

[+DjayBee]

Wow, amazing.

[ivop]

26 minutes ago, DjayBee said:

Wow, amazing.

Yes, it's very nice stuff, but be aware that if you heat it again, it becomes soft again. Another option might be Fimo clay. Create a new screw post, screw in the screw, bake it at 120 degrees Celcius (normal oven), unscrew the screw, glue post inside case. Might work

[leech]

10 hours ago, kheller2 said:

These?

https://www.amazon.com/Moldable-Plastic-Thermoplastic-Beads-8OZ/dp/B077874HM8

 

Yes!  Not sure what happened to my link...

[leech]

7 hours ago, ivop said:

Yes, it's very nice stuff, but be aware that if you heat it again, it becomes soft again. Another option might be Fimo clay. Create a new screw post, screw in the screw, bake it at 120 degrees Celcius (normal oven), unscrew the screw, glue post inside case. Might work

Hopefully you aren't going to be sticking your ST case into hot ass water after you patch the screw post.  But it definitely seemed to help with mine.

[mdivancic]

I think #2 would be a better option. I would design it such that it uses threaded heat set inserts and the appropriate screws. One would need a complete 800 in hand to do this work. I found that it take multiple try’s to get a part to fit exactly right. 

[BillC]

On 11/9/2022 at 7:37 AM, 800_Rocks said:

2) If there is enough of a remaining post... something that could superglue over the remaining post and could then be cut to size.  Call it a glued-on post replacement sleeve.

Perhaps something like the threaded metal caps crimped onto the posts on the 810 lower case.

Edited November 17, 2022 by BillC

[leech]

One trick I learned somewhere, make sure every time you unscrew something plastic, that they are likely self-tapping screws, so you want to rotate the screw to the left until you feel it 'click' into place, as that will be where the original threads are, and that will also make it easier to screw it back together.

[+DjayBee]

7 hours ago, leech said:

One trick I learned somewhere, make sure every time you unscrew something plastic, that they are likely self-tapping screws, so you want to rotate the screw to the left until you feel it 'click' into place, as that will be where the original threads are, and that will also make it easier to screw it back together.

I do it like this for many years now without breaking posts.