Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly  

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

Oooops,  "I pretty sure I did put in the wrong size screw.."

Should be - I am pretty sure I did NOT put in the wrong size screw..

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

Posted by: @lonelymonkdeck

I was doing Chapter 7, Step 26. 

I started "by rotating the threaded rods (anticlockwise) at the same time, lower manually, the X-axis down etc etc...

The M3x18 screw inserted in 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly is scratching the metal behind it.  I pretty sure I did put in the wrong size screw..

Do I just loosen that screw so it doesn't touch, I very certain I didn't get the wrong screw.

 

 

 

Hello and welcome to the Prusaforum!

Prusa supplies a replacement bag of screws and other small items with every printer. You will surely find a suitable (shorter) screw.

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

There’s no way that’s a M3x18mm screw if it’s sticking out that much. It sticks out barely a mm normally. 

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

Like neophyl said, definitely not a M3x18 screw.

Also you might want to loosen the filament extruder tensioner screw, looks a bit tight. I would back it out till the tip of the screw is flush with the nut then tighten it up 5-6 full turns. This should get you close enough to get started and adjust from there as needed.

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

I'll second that isn't a 13 mm screw -- the plastic it runs through is 17 mm, with the nut pressed in 3 mm and the head recessed 1 mm. My guess is it's the 18 mm screw that should be in the tensioner side.

There's the more obvious question of why anyone would actually move past a step when there is that much extra screw thread dangling. There's a photo of the finished assembly that clearly shows the threads do not extend past the nut. What else has been assembled with this level of detail?

I'd strongly suggest you go back to square one and inspect everything and compare against the final step images.

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

Thanks

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

Posted by: @gkmakeit

Like neophyl said, definitely not a M3x18 screw.

Also you might want to loosen the filament extruder tensioner screw, looks a bit tight. I would back it out till the tip of the screw is flush with the nut then tighten it up 5-6 full turns. This should get you close enough to get started and adjust from there as needed.

I'm looking thru the book, can't find "filament extruder tension screw". Can you provide a reference?

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

Make sure you are using a M3x40mm screw here.

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

@gkmakeit

I doubt any other screw in the kit will even catch there.

But, not sure where the M3-13 reference came from - the X screws are both M3-18. So the screw that was used must be the M3-25 that's in the kit. Wonder if I tried reading this thread without my glasses. Sigh. Sorry.

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

@tim-m30

Just making sure the basics are covered.

RE: Assembly Original Prusa i3 MK3S kit, 3 X-Axis assembly, Step 5 X-end-idler - bearing assembly

filament extruder tension screw loosened.

Wrong size bolt replaced

Reassembly complete, Time for the next step

Thank you everyone