Craftbot Z-Axis Offset Adapter

thingiverse

This adapter lowers the z-axis origin of your Craftbot printer before you e.g. - add a magnetic mat or glass plate on top of your heat bed or - modify your Craftbot hotend for standard Volcano heatblock and nozzle (I am working on it). ==================================================================== Update 20 December 2021: Craftbot 3 hotend V2 modification for standard Volcano nozzle Problem: The genuine Craftbot 3 V2 nozzles are available in only a few material variants, essentially brass and steel, and are somewhat expensive. They differ from genuine Volcano nozzles in that they have an M6 fine thread. The V2 heat block and heat break have an M6 fine thread as well. Standard Volcano nozzles have (normal, not fine) M6 threads. Therefore standard Volcano nozzles cannot be used in the genuine V2 hotend. My general idea: Replace nozzle, heat block and heat break; keep everything else. The resulting hotend assembly will be some 8 mm longer than the genuine V2. Therefore the z-axis origin has to be lowered by this amount. Instead of modyfying the genuine z-axis end stop sheet steel angle (elaborate) I designed the enclosed 3D printed part to be mounted on to of the untampered with end stop sheet steel angle (easy). Initially I also wanted to replace the genuine extruder with a Bondtech extruder. However I learned that the genuine Craftbot extruder is quite good - provided that you select the appropriate nozzle temperature. If you run into trouble with the feeding of the filament (e.g. filament sensor alarm): Increasing the temperature will almost certainly solve the problem. But back to the hotend modification. You will need: - The 3D printed part to be put on the end stop sheet steel angle. Print it while still using the genuine V2 hotend ;-). Do not bend the end stop sheet steel angle! The 3D printed part should fit easily on the end stop sheet steel angle but not wobble. - A Volcano heat block (20x20x11.5 mm) - A Volcano nozzle - A 6mm diameter x 30 mm long heat break with M6 thread (available e.g. on aliexpress.com, see picture). You will have to reduce the diameter of the cylindrical part from 6 mm to 5 mm on a lathe. Make it a snug fit into the genuine V2 heat sink in order to maintain a good heat transfer. - The 5 mm borehole in the V2 heat sink is deeper than the length of the cylindrical part of the new 30 mm long heat break. You will therefore have to bridge the gap with a short tube of 5 mm outer and 2 mm inner diameter. Adjust its length such that the new assembly (V2 heat sink + new heat break + Volcano heat block + Volcano nozzle) is 8 mm longer than the genuine assembly. This is still work in progress. I purchased heat break, Volcano heat block and Volcano nozzle, turned the heat break down to 5 mm diameter on my lathe, took some comparative length measurements on the genuine V2 and the new assembly, and designed and printed the 3D part. That is how far I am at the moment. May be you will overtake me ... ==================================================================== Tested on Craftbot 3 only. May work on other Craftbot printers. Inspired by https://www.thingiverse.com/thing:3126680 but different solution: With my design you can build several adapters and change them quickly and easily. Install the adapter on top of your Craftbot's z-shaped steel sheet angle, below the z-axis limit switch. CAUTION: Whenever you mount or unmount the adapter on the Craftbot's steel sheet angle you may alter the bed leveling by inadvertently bending the steel sheet angle. If you bend it downwards - even to an invisible amount - you will run the nozzle into your hetatbed upon the next zeroing. Therefore carefully check the bed level after each unmounting of the adapter. The adapter should mount over the steel sheet angle with only very little friction. To correct excessive friction see the note below. The enclosed .stl sample lowers the z-axis origin some 8 mm, which may be sufficient for a Volcano heatblock and nozzle. If you require a different offset: 1. Download and install OpenSCAD from openscad.org. 2. Open the enclosed .scad source file in OpenSCAD (File/Open). 3. Edit the "z_offset" parameter value at the beginning of the file. 4. Render the adapter (Desing/Render). 5. Export the result as a .stl file (File/Export/Export .stl). 6. Print a prototype adapter. Test it with your Craftbot printer, adapt "z_offset" if necessary and print another adapter until it matches your needs. NOTE: The adapter should mount over the steel sheet angle with only very little friction. If the friction needs to be reduced, increase the "d_slot" parameter in the enclosed .scad file and print another sample.