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Minor issue with idler model  

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Paul Meyer
(@paul-meyer)
Honorable Member
Minor issue with idler model

The idler has many bearings and shafts. If you end up with a bearing that won't rotate, you may need to push the shaft out to clean up the hole or reposition the bearing. The idler is designed with through holes from the other end to allow the shafts to be pushed back out. According to "idler body assembly" step 3, you should be able to use the small holes to slide the shafts out. In the comments, PR has indicated that the long 2.5mm allen key is supposed to be used for this.

However, it didn't work for me. I had a bearing that wouldn't rotate (the recess needed some cleanup) and I couldn't get the shaft back out. The 2.5mm allen key would hang up on the previous bearing. I cleaned up the whole around the bearing and moved on.

Fortuitously, my idler cracked (separate thread), so I was able to do some destructive testing (since I now *have* to get those bearings out). As you can see here:

the 2.5mm allen bumps into the bearing and doesn't quite have the clearance to get by, even with the sidewall destroyed. I tried the same with a 2mm allen, no luck. I don't have anything smaller that I think will be stiff enough to push out the shaft.

Better angle here to show the amount of negative clearance:

Posted : 16/09/2018 9:03 pm
nuroo
(@nuroo)
Reputable Member
Re: Minor issue with idler model

I had a similar mishap. When screwing down the idler body to the shaft I over torqued the screws and ended up splitting the plastic. Was able to print another idler body on my other mk3 but like you I had to get all the rods and bearings out of old part.

What ended up working for me was using my drill bit set. I found a drill bit that was thin enough to easily fit into the exit slots. So drill bit combined with hex driver. Used hammer to tap both thru exit slot until they pushed the rod out.
If that does work for you, just destroy the plastic enough to free the rods and bearings. Just be careful not damage rods and bearings while attacking the plastic so you can re-use them in new idler.

But yea the exit slots should be a little bigger

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Posted : 17/09/2018 12:39 am
AbeFM
(@abefm)
Member
Re: Minor issue with idler model

I used a 1/16th inch allen key.

I maintain an informal list of San Diego, CA 3D printing enthusiasts. PM me for details. If you include a contact email and I can add you to the informal mailing list.

Posted : 26/09/2018 8:07 am
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