3Dman GT2 20 Toothless Bore 5mm Aluminum Timing Belt Idler Pulley for 6mm Width 3D Printers (10pcs)

Fits perfect on my ender 3 pro

Worked well in replacing toothed pulleys on smooth side of belt.

They all have 5mm Bore and bearing is almost flush with the body -- so you need speacial shim/washer -- 6mm OD max .. where do you get that! These vendors keep selling these but there is attempt to make them easy to use -- I use them as idlers and you can't really tighten the core too much .. no matter what washer you use - they work but are very uselessly designed.

The construction is good in general and the bearings are relatively smooth. I gave it a low rating because of the axel depth with relation to the wheel. With an M5 screw and two small washers on each side (very hard to source), I would expect the washers to hold fast to the axel while allowing the pulley to freely spin. This isn’t the case as the axel depth is the same as the wheel depth, meaning there is no clearance for the washers.

Only needed two but glad I purchased ten as these don't last very long. Cleaned and lubed each before installation but bearings never felt like they should - more like metal on metal than having aballs to ride on, almost like the balls are dragging against metal instead of rolling... Bearing on side of one idler came apart while sliding fastener through center. One of the ten felt okay after cleaning and lubrication but it failed faster than the others.

A couple of the bearing are a bit notchy, but that's not going to cause a problem for this application

Upgraded my Ender 3 with these pulleys. The belt tensioners came with toothed pulleys which were a constant problem (layer shifts). The prints with these are absolutely smooth and works great. A highly recommended upgrade that's even cheap.

Tutto ok

Die Teile halten was sie versprechen. Top. Alles Bestens. Laufen an einem CNC-Plotter.

I use these on 3d printersz and they're great for Gates GT2 6mm belts. A few of these came with dry, or rough bearings which was a pity. Otherwise they were decent quality, and the belt surface and aluminium outers were good.