Fused Deposition Modeling (FDM) Technology users sometimes find material buildup on tips or embedded material in the part. This never causes frustration (cough, sarcasm). When we are asked for solutions, the first thing we look at is the brush and flicker height. Believe it or not, these little pieces of equipment are vital during the build cycle.
If the flicker is off by a just little, this can cause buildup over time. When adjusting, we always make sure the brush and the flickers are offset from one another. (The brush should be higher than flicker -- please reference your user guide.) Wipe assemblies that come with the machine or are ordered later will come pre-set, so all you have to do is install and make an adjustment afterwards.
When adjusting the tip-wipe assembly, we always make sure the metal tip (model) hits the flicker. (The white tip shroud does not have to touch.) If the tip does not hit and is higher than the flicker, you'll probably get buildup. Since the the flicker can't remove excess material from the tip, the material can get mashed into the wire brush. If the wire brush doesn’t catch it, unfortunately it has nowhere to land except for the location it extrudes, in this case the part. As you can see, the trend starts to build an array of problems no one likes to encounter. We always recommend and remind users to check the tip wipe height before starting any build. A three-second check before starting your build can save you time and hundreds of dollars.