Yeti – Component Purchase

Since the last article all the way back in September the build hasn’t move very far forward but I thought it was time for an update as a few interesting things happened in the last couple of days. My main focus has been on getting the power supply designed and getting all the parts ordered – a good few wallet moths escaped in the process.

The ballscrews and nuts, bearings, mounts, collet set, spindle and VFD were all ordered from Chai and arrived within a few days. I got a reasonable price on the package and it was well shipped (everything from China seems to come cocooned in parcel tape), a couple of the mounts appear to have a very light surface rust on the corners but all the important bits (e.g. bits that move or are machined) are in good shape. I had the ballscrews end machined to my specification to add some extra length on the end to make mounting a pulley easier. I think the machining for the bearings is perhaps a little on the tight side though, might need a touch with some emery paper to bring it to size.

The rails (15mm THK) came from an eBay supplier in South Korea. They are used parts but in good working order, the X and Y rails appear to have had an easy life, the Z rails have clearly been worked harder. Unfortunately I didn’t fully understand what I was buying when I placed the order and while the X and Y rails are perfect the Z rails are actually better suited to horizontal use due the arrangement of the bearings.

I’ve bought the stepper drivers from a supplier on Ali Express, again with excellent and prompt deliver. I decided to splash out on the break out board and went for a PMDX-126. I figured that as I was importing things from the US I might was well got for a PMDX-107 spindle controller as well. Ball nut housings again came from a supplier on Ali Express (they’re expensive for what they are) but get the job done. Energy chain came from an eBay supplier in China and finally 25m of 1mm^2 5 core CY cable came from a friend on the forum.

So far the spend has been about £1,300 and my costing spreadsheet indicates there’s about the same still to go assuming I stick to the plan, I’ve had a couple of ideas for ways to improve the machine.