Note: Page Under Re-Construction
Build and Assembly
Having MakeBot's CupCake around is nice, but it can do only so much. New bigger and better CNC machine would add to the manufacturing abilities. The Tesla CNC will be controlled by more common software for CNC machines that allows for milling, drilling etching and other abilities that are common in these machines. Unlike CupCake which has its own software of control that has limited gcode command acceptance.
The name Tesla CNC come from the hope that the experimental EDM (electrical discharge machine) tool head will be completed and would be able to process harder metals.
A bit longer movie promoting the design of the CNC Tesla Mark 3
RepRap Darwin whose frame was cube with reinforcing cross braces for frame stiffens. First Tesla CNC designs was very similar, but further modifications heavily changed the appearance and functionality. The main difference is that all xyz axises are joined together unlike Darwin's design where z axis is separated form XY axis. Another main difference between Tesla and Darwin design is that the moving parts are quite massive unlike Darwin parts, that are made of plastic and thin rods.
Further modifications of mark 1 were made for ease of manufacturing. These included simple wooden blocks as the connecting corners. This was to emulate purpose of aluminum plates in mark 1 design into the same shape. However this was proven to be difficult to manufacture with home tools.
There are no renders of Mrk II as the only thing that had been done was the prototype assembly that showed the behavior of the machine. This experience helped produce newer design, Mrk III, that has better and more stiffer frame.
Stepper Motor Drivers:
5 AXIS (TB6560) CNC STEP MOTOR DRIVER
KL23H2100-30-4BM BIPOLAR STEPPER MOTOR 495 oz-in
20mm CNC Router 13" Shaft w/Block & Bearing
20mm CNC Router Rails 30" Shaft w/Block & Bearing
Proxxon 38481 IB/E Professional Rotary Tool
There is a PDF version of the CNC Tesla Mrk III Complete Description (v0.75) available here.
An ACME upgrade had been added to the design. As the M10 and 3/8" have similar diameters (3/8" is 0.475mm thinner), it is possible to simply upgrade the existing design. The original M10 threaded rods were chosen due to cost efficiency, but for increased cost the mark III can be outfitted with the more reliable and durable motion system.
The below picture show all the water jetted parts for mark III design as well as the aluminum corners that have yet to be machined. Picture also include updated linear motion brackets which replaced the extruded ABS plastic brackets from version 0.75.
Finally, all the parts are complied at one place for complete assembly. Some minor adjusting and fitting of the parts was required, which included sanding and light girding. The water jet parts had satisfactory precision and fitting. Note that in the CAD drawing compensated for tight fit by 0.2mm space between all pats that had to fit together.
Need had arose for more aggressive drill bits than hose that come with the Proxxon Drill. After careful searching I found store [CARBIDE-PLUS] that sells PCB hole drilling bits, but also have miniature end mills bits.
Simple sample for manufacturing PCB's from EAGLE board layouts. The final results were unsatisfactory, however this was due to software not been calibrated for CNC tool size. New tests are under way with smaller tool bits.
Some of the sample test have shown that the Z-Axis has a minor glitch that can reduce the accuracy. The tool bit does not move in a perfect line up and down. This is due to the design flaw where the smooth rods are placed too far way from the centroid and motion transfer point. The flaw only shows up when the tool moves up and down freely or with little resistance, such as etching or vector drawing. It does not show up when drilling or milling a material that exert larger forces.
This issue has been addressed in new gantry system that replace the previous design. The new gantry was designed to be made on current version of CNC Tesla.
Unfortunately the code was not set correct speed and the end-mill tool broke off.