So last week I tried to use the 4th axis. Here was the setup. Loots pretty snazzy…… 😀

Here is the result. Unfortunately, the vibrations caused my favourite 8mm endmill to snap. :´(

When you look at it, it is fairly obvious. The total stickout including the chuck is something like 15cm or even more. And since I only used the first two bolts, you really could not expect much…..

So first attempt att making a real part today, and on top of that I wanted to try the new superglue+masking tape method. Many have spread the word about this method, but NYC CNC do it best, as usual:

The problem is that none of the products they mention can be bought in Sweden, and even their links to Amazon are getting stale. So I tried TESA Premium Classic masking tape and Loctite Power Flex Gel . I gave the glue a few minutes to harden properly below.

So it was quite clear last time that something had gone wrong with the Y-axis. It really was moving back and forth a full 0.1mm with a distinct click to it. So I opened up the machine again and pulled out the Y axis ball screw (Getting rather good at that by now :P).

The nice thing is that I realized I could do this without affecting any of the calibration of the machine. Just slide the X-axis over a bit to expose the Y-axis ball screw fastener bolts. Once done, reattach the Y-axis, slide back the X-axis and atach the X-motor to the bed. And done!

First up, I felt that the acceleration I set before was probably not the maximum possible. So now we have 6000mm/min and a full 1000mm/s2 in acceleration. That is pretty stiff.

About an hour of work later, and both the vice and the fourth axis are mounted and squared.

One thing is not great, though. It seems the the Y axis bearing has somehow set and now has a full 0.1mm backlash. I guess that I will have to take it apart and fix that. Fortunately I realize I can do that without affecting the rest of the machine. But I still need to remove and reattach the ball screw. So not very happy about that.

So done I am and the Terco is ready for work. Kudos to Scott who helped me on the home stretch with the X motor box and the Z bellows.

Here it is. 😀

To make sure we get the most out of the new motors, I trimmed them as well. Six times higher max speed and significantly higher acceleration will really cut down on the milling times.

But then, who does 3 axis CNC these days? When we have an A axis just lying around. Some alignment later and we have that squared up as well. 😀

I have to say that few tools are as satisfying as the angle grinder. Yeah, you know what I mean. 😀

So today the plan was to complete everything except the cover box for the X axis motor. And that is almost what happened. I give you the Terco with only the Z bellows and the x motor cover missing.

I had planned to use the Portal CNC to make fasteners for the bellows, but then I found an original piece in metal at the same time as the Portal CNC refused to start. So I made the pieces using sheet metal and the angle grinder. Quick, elegant and satisfying.

So the bearings were clearly too tight before and that was just not right. So today I pulled the entire machine apart and made sure to shim everything properly with aluminum foil to get those last 1/100s.

I also realized that my cheating with the bearing fasteners for the Y axis had come back to haunt me as the Y axis was both too tightly shimmed and still wiggled at the same time. not sure you can see it in the image below, but the pin does not go all the way through meaning the axel is not fastened symmetrically in the bearing holder.

So now all of the parts needed for actual operation came into place. Happy days!

First up was the X axis.

And a fee limit switches and some cable reattachment with Alvar and we have what could be a working (But ugly and fragile) CNC.

To quote an old colleague “stepper motors waking up are so cute”!

[wpvideo jc7KQ5Go ]

The next step was to check the rigidity of the entire construction….

So today was rather uneventful. Y axis got completed as planned and x axis is almost done too.

First step was to cut out a hole for the now a bit longer motor assembly. Normally, the angle grinder is the tool you go to when all else fails. Not today!

The angle grinder started on a good note but ground (No pun intended) to a halt a few millimeters in. This chassis is not made of regular aluminum I tell you. It has to be some sort of hardened version.

So I really love manual machining! If the mill and lathe had only had digital readouts I would probably have used those instead.

Either way. Today the Z-axis was completed. The drive belt is tight and the cables are all nice and tidy thanks to Magnus.

Next step is the Y axis. Since the new motors have longer axels, a 25mm thick spacer was needed.

Since the motor and bearing house both have circular centering edges, I decided to add matching edges to my spacer. Putting round concentric holes I a square piece turns out to be really easy if you start with a center hole big enough for the lathe chuck to grip it from the inside.