Building the Avid Pro: Part 3 - Frame, Rails and Gantry.
The next step is pretty far from Home Built - just assembling someone else's design. Frankly, it was a joy to do. The Avid Pro is an incredibly well thought out design and the parts are really well machined. Everything fit like a glove. The attention to detail is amazing. The instructions were clear for the most part and the assembly went surprisingly easy over the course of three 4 hours sessions. Even when the instructions weren't 100% clear I was able to figure it out just by looking at the parts. There are a lot of videos on the web about assembling these machines so for this blog installment, instead of taking you through each step, I will give you a tour of the parts that I feel make this is an excellent CNC Router.
There were a couple of bumps along the way. The mounting holes of the stepper motors I bought were slightly too small for the provided bolts but I was able to drill them out pretty easily. There was one set of missing screws that Avid sent me right away when I asked for them. And, I had to reinstall the Y Axis cable track to make it easier to pop open the individual track sections.
As you can see from the photos, the frame is well thought out and quite sturdy.
The X and Y1/Y2 Axis stepper motor mount and pinion drive mechanism. The bolt on the left side secures it to the gantry (or Z Axis). Elegant in its simplicity.
Here the mount is attached to the Y2 side of the gantry. The bolt with the red spring pulls the pinion gear tightly against the rack. This allows you to control backlash.
This shows how the rack and pinion work together.
The gantry end plate and lower rail. No scrimping on connectors here.
The Z Axis and X motor Assembly. It shows both X rails and rack as well. Uses the same mechanism as the Y Axis. The Z Axis uses a ball screw that is well protected from dust and swarf.
Back side of the Z Axis assembly. Here you can see the pinion tensioning bolt/spring.
Right side Y Axis end plate with limit sensor target and bumper (lower left, not visible). You can also see the Y rail dust cover. Not sure how effective that will be.
Y Axis cable track. Generously wide. You can't see them very well, but each link has a top that snaps in place. Makes adding cables a, well, snap.
That's it for now. Next installment is electronics planning.