Spring Drive Block Extruder for CTC Bizer (Replicator Clone) MK8 Remix for Makerbot Clone 3D Printers (FlashForge, Wanhao)

thingiverse

I've been working with this drive block for some time now, and have installed it on a few other CTC's without any issues. It was already a proven base model before I started making changes to it. However, I did experience some problems with the MK8 Spring Block and edge of the heatbreak shaving off filament from my CTC due to improper alignment. This resulted in prints being speckled with shavings and a clogged drive gear after a few hours. To solve this, I moved the block to perfectly line up with the aluminium block on the CTC and added an extra one for ease. The lever has a slot that allows you to quickly check if your extruder gear is packed full, and also enables you to clear it with compressed air during a print. This should not be necessary normally, but in case of any issues... On the bottom of the block I added a side gantry that may help to cool the filament and drive gear better, and provides an escape route for shavings when clearing the drive without removing the extruder. The lever has been reinforced and some material transferred from the cover (enabling prints without solid infill) as well as centered the v-groove bearing that was slightly out of alignment. Files are uploaded in both STL for direct printing and STP if you see a need to modify it. You can also download CTC_Drive_Block_Complete_LR.thing to start printing right away! Print Settings Printer: CTC Bizer (Replicator Clone) Rafts: No Supports: Yes Resolution: 0.2 mm Infill: 30 Notes: Print with 2 shells and at minimum use ABS | Roof and floor height - 1mm | Layer height - 0.2mm | 30% infill with a linear pattern (layer height for layer strength, and a linear infill pattern is both stronger than hex and also saves your printer from unnecessary jolting) --> See: http://my3dmatter.com/influence-infill-layer-height-pattern/ To aid cooling of the filament (very important when printing dual extrusion models), drill a few holes at the back of the heatsink as shown here: http://www.newmansworld.de/bilder/3D/CTC%20(13).JPG On a side note: This website is in German. For those who don't understand German, open the page in Chrome and scroll all the way down to select a language with Google Translate. It shows a good list of things to do for your CTC http://www.newmansworld.de/3d-druck/tuning.html Post-Printing Assembly You may need to take a 6mm drillbit and shave off some material in the recess on the lever where it pivots on the screw. You want the screw to just bottom out and leave the movement of the lever to be "snappy" when you let go without any lateral wiggle. Resistance in the lever movement prevents the tensioner from properly gripping the filament! You will also need to flip the drive gear so the filament doesn't run across the set screw. Parts list: M3 x 18mm Flat Head Cap Countersunk Hex Screw (the screws that mount the stock CTC drive blocks are 18mm) M3 x 8mm Flat Head Cap Countersunk Hex Screw M3 x 6mm Flat Head Cap Countersunk Hex Screw Compression Spring (7,5mm OD x 35,8 L) 32lbs/in spring rate https://www.hornbach.de/shop/Druckfeder-galv-verzinkt-7-5x35-8x0-7-mm-100-Stueck/7915842/artikel.html I cut the spring to about 26mm, but also tried it at full length - both worked fine, so your choice. Reuse the v-groove ball bearing that came with your static CTC drive block. If you need another v-groove bearing, it's a 3x12x4mm like this one: https://shop.stoutwind.de/Radialkugellager-mit-V-Nutprofil-V623-2Z-R3-x-R12-x-4-mm How I Designed This Source of original design I took the STL files from the Spring-Loaded Replicator 1 Drive Block (Thing:62510) and modified them using Fusion 360.