version 2.0 Igus-filament slider blocks/pads for D-Bot X/Y motion system by Rexipus

Last crawled date: 3 years ago

This is version 2.0 of the Igus-filament slider bearings and carriers that I posted in their original version as: https://www.thingiverse.com/thing:2373538
These carriers and pads replace the mini v-slot wheels that the original D-Bot plans specify to ride in the v-slot grooves as part of the D-Bot's X/Y motion system. The pads are designed to slide over both the outside surface of the v-slot rail, as well as fit closely into the v slot itself. The carrier blocks are designed to fit in the space between the plates that the D-Bot plans provide for holding the mini v-slot wheels in place over the rails, and hold the Igus-filament pads in place on the rails. This makes it easy to simply remove the wheels and the wheel spacers, put the carrier block/pad assembly in their place, retighten the M5 bolts, and drive on. This allows for an easy upgrade that preserves use of the original D-Bot printed parts.
This version includes a carrier block that more closely blends in its dimensions and shape with the original D-Bot X/Y motion parts. The D-Bot end plates, print carriage plates, etc. use a 6mm radius on their corners, and my 2.0 carrier blocks have slightly tweaked dimensions and this same 6mm radius, so that a completed assembly including the original D-Bot parts and my Igus pad carrier blocks will blend together better and look really nice.
The actual Igus-filament sliding pad that I include in this version 2.0 are "scooped" in the middle in order to reduce the amount of surface area that comes into contact with the rail. Given typical printing irregularities and microscopic surface imperfections, having two widely-separated contact areas with the slot also improves the likelihood that good alignment and stability will be achieved. I also "scooped" the portion of the pad that rides on the surface of the v-slot rail, further reducing physical contact area and improving stability.
The photo of a pair of these pads that I include in this thing shows two pads printed with the Igus I180 filament, which is easier to print with than the I170 filament. I printed these pads using Simplify3D with three separate processes. This allowed me to choose a 70% infill for the portion of the pads which comprise the two regions of contact on the flat side of the rail. I printed this process with no "top" layers, so that the 70% infill of that section is printed all the way to the surface. As you can see, doing it this way massively reduces the surface area of the pad that will be in contact with the rail, assuming a perfectly good fit between the pad and the rail.
If you use something other than Simplify3D to print these pads you probably won't be able to print the "skeletonized" version that I show in this photo, and your surface contact area will be 100% in these regions. This should still be fine, though I think the "skeletonized" version is better. My original Igus pads with 100% contact along the whole length of the pad have been printing just fine on my D-bot for 7-8 weeks now.
I have upgraded my own D-Bot with these version 2.0 Igus-filament carriers and pads on the Y axis. I haven't printed out new carriers to replace the version 1.0 ones on my print carriage yet, but that'll happen this week. I just wanted to test out these version 2.0 carriers and pads before posting them. So far so good, and I have no reason to think they aren't at least every bit as good as, and likely a nice improvement upon, my version 1.0 blocks.
I've printed these Igus-filament pads with both Igus I170 and I180 filament. Igus' marketing materials claim that the I170 material has better wear and friction capabilities than I180, but is more difficult to print. I can second this, at least in terms of ease of printing. The I170 is definitely more challenging to get a clean, successful print with. I've got I170 printed pads on my printer right now, but would not hesitate to use the I180, and will probably do most of the development of further ideas I have using I180 just because it's easier to work with.
Read my original comments on the version 1.0 version of this thing if you want my explanations for what advantages I believe using these Igus-filament sliding pads offers over the original D-bot mini v-slot wheel system.
I have included both the STL files for the carrier blocks and the Igus-filament pads, but also the SolidWorks parts files that these STL files are generated from.