El Beast - Initial design phase, comments and critique welcomed!

[Zeeflyboy]

Hope everyone had a good break over Christmas!

I've been using my time not working on this project to continue mulling over my design for the X-axis, and I think I've decided to go a slightly different route on the protection belts.

One problem with my current design was that it prevented me from securing the 25mm rail plate to the extrusion as positively as I would like, given that the belt is running behind the Rail and covering an extrusion slot. It also means that to remove/clean/replace the belt would require disassembly of the X-Axis which isn't ideal.

So this is a result of a bit of playing around with ideas... The belt now runs through the extrusion itself, with access from the outside of the gantry arms. There will be cover plates to hide it all away and help keep out the dust, although I though some clear or perhaps tinted perspex would be quite cool too as you could see the belt mechanism at work.

Also got the Gantry tramming adjustment in there now which should allow to nicely fine-tune the alignment to the bed.

Sadly means I wasted my time with those last parts, but won't be the first or last time I'm sure!









I also took delivery of a big load of alu plate, including the bigger 25mm plates for the gantry arms so I've got all the plate I need to finish it now (assuming I don't mess up of course!).


I have a couple of things I want to do before continuing properly with this though. Firstly, I'm in the process of making a proper CNC enclosure at long last and I want to get that done before I do any large amount of milling. Secondly, I've been thinking how I can accurately make the parts that are too big to fit on my CNC and decided I can kill two birds with one stone.

I have wanted to build a router table for a while now to go with the table saw, and some recent furniture I've made has reinforced how much I could do with one... So I have designed a nice little router table lift unit using a 2.2kw spindle mostly around spare parts (rails, extrusion etc) I have lying around anyway so I can do it cheaply, and will use that to cut the larger pieces to size. The Tramming plate and spindle mount are identical to the Z-axis, so I can just borrow that one for now meaning not much machining is required to get up and running with it. The table itself will just be fairly simple - some melamine MDF with fence and rails etc.



The router table will allow me to accurately make most of the gantry parts that are too long to fit on my machine. As for the rail plate, that will require me to make the external dimensions on the router table and then my CNC can work the interior.

Good news is that the enclosure and router table shouldn't take me too long to make, and then work can properly resume on the X-axis.

[Davek0974]

The belt idlers will be running on the toothed side of the belt? I guess they will be toothed idlers?

[Tom J]

The belt idlers will be running on the toothed side of the belt? I guess they will be toothed idlers?

They not drive belt, they serve as protection to rails against chips/mist etc. Many of us use concertina folded covers.
Zeeflyboy has brought design to different level - read higher:)

[Davek0974]

Nice, thanks for clarification ;)

[Zeeflyboy]

As Tom says, these are just flat belts (polypropylene webbed belts to be precise) which are acting as shields... due to the compact nature required in my case, bellows etc would just have wasted work area which is why I'm trying to be a bit more creative with shielding/sealing.

[Wal]

Heh. This thread continues to impress... Excellent.

[Zeeflyboy]

Cheers!

So got a chance to make the new belt guides today.or simplicity I just 3D printed the bodies in my XT-CF20 - in this new design they don't take any real force as they are supported by the gantry arms so no need for anything stronger. Had some Acetal rod which I used this time for the rollers.

Making the rollers on the lathe






3mm axle rod, printed body, turned roller:




Wash, rinse, repeat: