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LiquidCrimson

Knurled wheel - innie or outie??

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Hi all got my ultimaker 2 go in jan 2016 and couldn't print at first, searched the net and did everything twice then changed the filament again and hey presto it printed, perfectly.

Several of my own prints down the line all was going well until I did a longer (time wise) print and three quarters of the way through it all went wrong. Under-extrusion... but why? Well I did all the checks it wasn't blocked etc etc etc. Then I noticed that most of the images I had found showed the knurled wheel with the grub screw pointing outwards. I noted a post that said an improvement had been the small gap in the black plastic cover to enable easy grub screw tightening. Mine didn't have an accessible grub screw - see pic 5a331aa6870b1_004Howfarbackoriginalwheelsat.thumb.jpg.d7cabfee2075d15ae24588686a3d28e6.jpg was my wheel on back-to front?

I talked with the supplier who got ultimaker to send out a new wheel... this was longer than the original wheel. 5a331aa71200d_005Wheeldifferenceinlenth.thumb.jpg.928b83e0384507b04890b9c6e1a305ff.jpg

I replaced the wheel, tightened and attempted to print... the filament was chewed 5a331aa7a14a2_002Whathappenstothefilamentonceitisthreaded02.thumb.jpg.cba45f4cc43c94912cbf1acde4630fc9.jpg even though I've never changed the tension settings ever and both wheels are the same diam. This happened a few times.

Next I tried pushing the knurled wheel a little further in along the shaft 5a331aa841caa_007Wheelslidbackslightly.thumb.jpg.4f858ec12e06723253e42ddd2697968d.jpg and tightened it and result, it printed fully. I decided to do test print two, it looked like all was going well and then suddenly it stopped printing properly and the print became patchy like always. A quick look at the back showed the wheel has slid out of place again. 5a331aa895aee_011Post1stprint.thumb.jpg.cd793b60e521cb9054ca8bcc894d42e2.jpg

Repositioned wheel, re-tightened screw and tried again... same thing, started well then stopped as the wheel came out again.

A search around the web tells me that some machines have the wheels facing a different way and if this is so, how the heck do I tighten that with ease??

Not sure what to do now but I'm real sure the problems are down to the wheel and nothing else... it's as if a good print is based entirely on chance.

Any help, advice, suggestions, name of ultimaker person to give a piece of my mind to (lol) greatly accepted.

Thanks.

5a331aa6870b1_004Howfarbackoriginalwheelsat.thumb.jpg.d7cabfee2075d15ae24588686a3d28e6.jpg

5a331aa71200d_005Wheeldifferenceinlenth.thumb.jpg.928b83e0384507b04890b9c6e1a305ff.jpg

5a331aa7a14a2_002Whathappenstothefilamentonceitisthreaded02.thumb.jpg.cba45f4cc43c94912cbf1acde4630fc9.jpg

5a331aa841caa_007Wheelslidbackslightly.thumb.jpg.4f858ec12e06723253e42ddd2697968d.jpg

5a331aa895aee_011Post1stprint.thumb.jpg.cd793b60e521cb9054ca8bcc894d42e2.jpg

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It doesn't matter which way around the hobbled wheel sits but it is more convenient to be able to access the screw. You want the filament sitting in the middle of the knurling.

If it is grinding then the tension is to tight so try loosening it off a bit.

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The longer type replaced the shorter type a few months ago to give larger room for error. The longer one is mounted so that it's flush with the shaft, and the shorter usually sits about 1-2mm in on the shaft. The important bit is that it sits as close to the middle of the filament as possible like Labern mentioned.

If it's coming loose you're not tightening the set screw enough. It's very easy to destroy the head of these little screws with an allen key so I would recommend using a torx screwdriver instead if you have one.

It's also a very good idea to put some loctite/threadlock on the screw to make sure it stays in place. Another important thing is to make sure that the set screw hits in the middle of the flat of the shaft. Tighten the screw just a tiny little bit, then wiggle the sleeve so that it re-centers, tighten a bit again and wiggle and then finally torque it down hard.

The pressure is set to the minimum in your feeder which should be ok I think. You might want to try tightening it slightly, but probably not.

Is your nozzle blocked? have you tried cleaning it using the "Atomic method"?

http://support.3dverkstan.se/article/10-the

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no blockages, it prints perfect when in the correct place and the filament pours out with ease, did the tightening of the screw against the flat section of the bar. It only grinds if it is off centre, problem is it just won'y stay tight so when it is in the correct place it just comes loose. I think I'll go for the loctite and see if that helps. I have extra grub screws in case its that but my supplier had someone with the same problem with another machine so I thought I'd chuck it out here to see what ppl say.

When my ultimaker arrived the wheel was just placed on the bar with the grub screw in an inaccessible place inside so that kinda caused some confusion.

I'll have another go at tightening it and see how it goes.

Thanks :)

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Hi there did anyone sort this using loctite?

I've had the same problems happen again with my supplier saying other people were having the same problems.

When I got the larger wheel and tightened it, it worked fantastic for about a month then it slacked off again, I tightened and it was ok but this time it won't tighten.  Seems like the thread is damaged ass it won't stay tight so I'm awaiting a new wheel but I can’t seem to find one the correct size on open purchase so I have to wait while someone provides me with one.

At this rate I’m going to need a new wheel every 2-4 months.

Any advice would be great.

Thanks.

Edited by Guest

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You shouldn't need to keep replacing them. 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. If you can't afford the whole kit you could just contact your reseller and get just the new feeder or buy the bontech extruder. They are both a lot better then the original feeder.

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Aw you are amazing... I asked ultimaker was there any other kind of feeder but they didn't say there was and just suggested i glue the wheel on. I make really tiny, detailed stuff but soon as the wheel starts to come lose it really shows in my work. I'm gona take your advice, thanks :)

Edited by Guest

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@sandervg any ETA on selling the +feeder as a loose part... this guy has a pretty new machine so he probably doesn't want the full upgrade kit....

And getting all the loose parts is a pain... mostly for the resellers....

 

From what I've heard, Ultimaker has specifically prohibited selling or providing warranty Plus feeders separately to users who don't have a Plus machine or the upgrade kit. If you want the new feeder you'll have to get the whole upgrade kit. Can't see why it would make much difference if the feeder came separate though?

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@sandervg any ETA on selling the +feeder as a loose part... this guy has a pretty new machine so he probably doesn't want the full upgrade kit....

And getting all the loose parts is a pain... mostly for the resellers....

From what I've heard, Ultimaker has specifically prohibited selling or providing warranty Plus feeders separately to users who don't have a Plus machine or the upgrade kit. If you want the new feeder you'll have to get the whole upgrade kit. Can't see why it would make much difference if the feeder came separate though?

While the upgrade kit is very nice for user with an older UM2 (like myself) for user with an almost new UM2, the kit contains many parts that are not needed to replace, like axis and olsson block...

Besides that, @sandervg already stated earlier that the feeder would become an item for separate purchase, just unsure when....

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@ultiarjan It's good to hear they plan to make it available separately because the old feeder is a big point of contention for a lot of users. It would help avoid a lot of the grinding/jam issues that can require disassembly with the old mechanism. Fingers crossed this is soon, will make my life and a lot of Ultimaker users' lives a lot easier :)

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