I’m new to the forum, just planning my first machine. I know there is a lot of stuff out there about table size, but there is a twist I promise! Can I use tubes that are say 100-250mm (4"-10") longer than needed for the machine I am building while I am getting started?
Here is my problem: I have the parts pre-printed for a 25mm machine. A friend made them for me a while back. I can’t get to screwfix (until June?) to pick up 25mm conduit and they don’t deliver it. So I’m looking at ordering some pre-cut tubing from a metal supplies place. Most places seem to charge for a full 6m of tube, so regardless of the size of machine, I’m looking at spending £70 ($90) (£27 delivery) for mild steel (i.e. not galvanised) or £95 ($120) for stainless. I want to start out with the recommended machine size, but I also don’t want to spend another ~£95 if I want a slightly bigger machine in the future.
Do I get stainless tubes that are too big and use cable chains to manage the wiring? Or am I just making things really difficult for myself and I should just jump in with the right sized tube and see what happens later? I’m mostly thinking of routing softwood, MDF and plasterboard (drywall).
I wanted stainless steel but wasn’t sure what size I needed and as this was my first build, I didn’t want to go with stainless steel if I got it wrong.
I am building my CNC based on a 900mm x 600m piece of 18mm ply. If (and only if) this works, I’ll move to a larger one. Hopefully the longer X tubes will then become the Y tubes and I only need to buy three more tubes. That’s the theory anyway.
Rob
Here’s a picture of my CNC, it’s still being built so I can easily move things around.
I’ve deliberately made the feet mounts smaller to demonstrate over sized tubes. The outer ones will still be OK as they simply stick out the ends.
The middle two are where the Z-axis is mounted. I think they will interfere with the belts if they stick out. They certainly interfere with the orange belt roller plates and stop them being vertical. You can see it best on the right hand edge of the photo.
I think you might as well just go straight for your full size build - another 10" might halve your accuracy (or slow you down because you have to take lighter cuts) but you won’t know if that’s a problem until you try it. If you’re just carving wooden signs, you will probably be absolutely fine.
So the place that advertised 25mm tube actually sent me 25.4mm tube in the end. After about 2 months I managed to get a refund, what I really wanted was 25mm tube, but they were out of stock and not able to get any more in at the time. The whole thing took so long that I lost heart a bit. Now I’ve been looking a bit closer at the parts that were printed for me and some of them have warping issues or slight missing step offsets. So I’ve decided to stick with the tubes I’ve ended up with and print some better 25.4mm Primo parts as I will probably end up with a better build at the end and the filament will cost less than ordering more tube. How did you get on with your build?