Knurled wheel sliding off of feeder. How to keep it on?

[rwig 2]

Several months ago, I purchased an Ultimaker 2 Go and it has been working just fine. The knurled wheel has stayed on/tight the whole time.

I just purchased a second Ultimaker 2 Go about a month ago. Two weeks in the knurled wheel slid off the feeder mid-print. So I had to unscrew the feeder, push the knurled wheel back on so that it was flush, screw the feeder back together and start printing again. It's been about a week and the knurled wheel has slid off again mid-print.

How can I make it so it stays on and doesn't slide off?

I found in the forum a couple similar posts like this one:

Knurled wheel - innie or outie??

In it, there are suggestions for tightening, or adding glue or loctite/threadlock to make it stay on.

Another commenter said: "Maybe just replace the grub screw. You could replace it with a black high tensile grub screw that you will be able to tighten it more without damaging the Allen key socket. I would recommend getting the upgrade kit to the new feeder which won't have this problem."

I guess the grub screw is the tiny screw that is in the knurled wheel. I have tried to clamp this with my pliers and tighten it but I can't get a grip on it. Should I get smaller pliers? I also tried using a mini hex screwdriver but it doesn't turn. Is this the solution to figure out a way to tighten this grub screw? Or should I use glue/lockite/threadlock to secure the knurled wheel to the feeder shaft. I'm not sure if this would cause it to not spin properly?

There's some differences with the serial number sticker and on/off button of my 2nd Ultimaker 2 Go leading me to believe it may be from an older batch where maybe the grub screws (or the whole knurled wheel) was not right or something. Or maybe there is a solution in just tightening or gluing it on? If anyone can suggest how and the right tools to fix this.

Thank you in advance.

Edited March 30, 2017 by Guest

[rwig 2]

Update:

I spoke with my reseller and North American Ultimaker support who said JB weld epoxy should work to hold it in place. I'm going to do that and think it will to, otherwise they said could mail a new piece out.

[Torgeir 247]

Hi rwig,

Why not use locktite blue, this will allow you to change the knurled wheel if needed and this is the "glue" that's meant to lock a "set screw".

Thanks.

Torgeir.

[rwig 2]

Thanks Torgeir,

(Please excuse my silly questions).

To remove the screw, should I get smaller pliers or vice grip pliers? It only sticks out a bit and my normal-size pliers can't grip it. And then I suppose just apply on the locktite blue and tighten back in?

It would be easier for me to just use the JB Weld epoxy as I already have it and both my reseller and North American Ultimaker support said that should work just fine to secure it. And they said if it doesn't, they can mail me the necessary replacement parts. But is that common someone would need to change their knurled wheel in the future? It feels like a solid part that will withstand years of retractions. Or is there a good chance I would need to change it in the future? If you think so, then maybe I should go buy the threadlock and special pliers or vice grip to remove the screw?

[amedee 349]

Maybe I am reading this wrong, but it looks to me you are missing an essential tool: a metric hex screwdriver.

Without that you have no chance to succeed: you won't be able to tighten enough the set screw.

[Torgeir 247]

Hi rwig,

As amedee says, you'll need a hex tool (set) metric and 1.5 mm for this set screw.

Thanks.

Torgeir.

Edited March 31, 2017 by Guest

[rowiac 53]

When you get a 1.5mm hex wrench, also get the Loctite threadlocker to apply on the screw threads before inserting it.

If you can find the purple threadlocker (Loctite 222), that would be preferable to the more common blue type (Loctite 242) since the screw is less than 6mm in size. If all you can find is the blue type, it should be OK, but the screw will be harder to remove if you ever need to do that. The JB Weld, on the other hand, may make it impossible to remove the knurled wheel at a later date.

[rwig 2]

Thank you! I will try this out.

[fergazz 60]

Thank you guys I will try Loctite 222!! The same thing is happening with my knurled wheel. I got Meduza's feeder gears, printed the cores and It's just missing this step. I'm trying with 1.5mm heaxdriver (two of those) including the hexkey that come with my UM2 and the screw is loose. My calipter shows that the size is exactly 1.5mm, it's working for all other screws. I already got a male screw removal kit but the smaller fits 2mm (M3) screws. Tryed vice-grips and it's not moving. Damn! 

 

@rwig Did you tryed those threadlockers: Loctite 222 or Loctite 242? 

Let me know if it solves you problem. Cheers!

[Torgeir 247]

Well, 242 is the blue one for screws that can be reopened. Some other Locktite product can really fasten to much..

 

Anyway, good luck.

 

Thanks.

 

Torgeir.

[rowiac 53]

Loctite 242 (blue) is for fasteners 1/4" (6mm) diameter and larger.

 

Loctite 222 (purple) is for up to 1/4" (6mm) diameter.

 

Using 242 on the typical Ultimaker M3 screws may cause them to be difficult to remove later.

[Torgeir 247]

Well, -where I been working (in the aviation) we used 242 on those screws -3 mm (and the equal inch standards sizes) all the time.. I'd never had any problem removing those screws..

But, -if you fill all the coil with this stuff, there might be a problem. - - -  So; we do not glue them with Locktite, we just lock them with a small droplet..

The black set screw is a high torque set screw, and the knurled wheel have just a few coils, -so here it is wise to use 242!

 

Just my two and half pence..

 

Take care and good luck.

 

Thanks

 

Torgeir.