I have not been able to spend as much time on my machine lately, but have a few projects on the go in various planning stages.
This update shares planning and material sourcing work I have done so far on a new Z axis assembly for my X50 (w 3rd rail) Woodworker.
I wanted to try to add extra support and rigidity to my relatively long and heavy ATC spindle, as well as see if using linear rails and guides has a positive impact on my machining.
I spent a long time looking at ready made assemblies from a variety of sources (AvidCNC, RoverCNC, Ebay sources - USA made), and although I liked their design and functionality, the final cost to get them shipped to my door in Canada (and in Canadian dollars) had me looking at making my own. I have already started to gain experience and confidence machining aluminum, which my current setup does quite well, so this project does not seem unrealistic or attainable.
I have a good source for 5/8" cast aluminum plate, and making it myself means I have more money to spend on buying better quality components.
Given my spindle dimensions and mass, I knew I wanted to use double 80 mm mounts. I did a lot of research and liked the offering of Carbide 3D the best. They are well machined, are sized well, allow mounting from the front, and even have threaded holes for attaching accessories such as air/mister blocks.
This an upgrade I had wanted to do for a long time, so I have already been researching components and sources for a long time. I wanted to get higher quality/precision parts, in part to see if I noticed a difference, but also because I plane to build my own CNC in the (far) future, and this assembly will match the precision parts I plan to use for the other axes. My Woodworker will still have the original rather large linear bearings on the X/Y rails, which I believe contribute a fair bit to unwanted movement, but at least this way I am eliminating the relatively small spindle support the Z20 currently provides - I will redo my force/flex tests that I shared in another thread and see how the graphs compare.
My time on several other forums pointed me to an Ebay seller from overseas that sells a variety of machine components - new, used, NIB, NNB, etc… After weekly visits over the last several months I finally saw a linear linear rail/guide set (pre-owned) and ground ballscrew/nut (NNB) with the specifications I was looking for. I wanted high load guides on a 20 mm rail (15 mm rails mount with M4 screws which I do not like). The higher rail means I need to remove less from the spindle plate for clearance. The 1510 ballscrew pitch was a good compromise of speed and resolution. If any of you are ever sourcing machine components I highly recommend you visit dy-global. The items are accurately and thoroughly described, communication is excellent with quick responses to my many questions, shipping was (in my case free) with FedEx in only 2 days from Korea, and the packaging was excellent.
He did not have all the precision ballscrew/motor supports I wanted so I purchased them directly (new) from SYK in Taiwan. Again, in all respects it was an excellent experience., with the items arriving in under a week by FedEx. These particular components are precision machined and the fit and finish with the ballscew/nut was perfect. I opted for better angular contact bearings to compliment the C5 1510 ballscrew. I also chose the low profile options, again to reduce the amount of plate material to remove for clearance. The motor mount is specifically for the Nema 23 motors I have.
I had found a Canadian supplier for the SYK components but they stopped answering my email requests for information. It turns out it was much less expensive - and faster - buying direct from SYK. The linear guides and ballscrew I could never have afforded (nor spent the money on new) if not for this Ebay supplier.
I have a 12 mm sheet of clear acrylic coming this week that I will use to test the fit and design of the components and design of the overall assembly. Here are some F360 sketches I will use to locate the various holes for the back plate and spindle plate. The back plate will attach with the original 4 M5 screws, but I also plan to have it connected to a top plate that fastens to the top of the 3rd rail (I am sure those 4 bolts are fine, but something still bothers me about having the whole assembly hanging off just that much metal).
The following images show a mockup of the assembly components minus plates.
I will provide an update once I have machined the acrylic prototype plates.
