Step 23: 4th Axis (Metalworks)

posted in: Construction CNC DIY | 0

I have continued to develop the design, especially considering the available resources to adapt to my tools, materials and possibilities. Basically keep the same structure, but I have adapted many measures and concepts to what I hope is the final design. I’ve also used for machining metal parts, which require some resources that I do not have in my workshop (lathe, drill, milling, TIG welder, bandsaw …).
I’ll start then describe the design details:
Block holder shaft support parts:

Cuarto eje CNC Casero (3)

Cuarto eje CNC Casero (1)

Here I have modified a little the shaft I modified the lengths of the ends to make it more versatile. On the one hand I extended the shaft and I left Ø10mm to install the ring gear I’ve bought. A crown of 60 teeth, bought on Ebay. On the other end, still has a Ø12 (for bearings 6001) but I have pursued a M12x1 thread. My idea is to screw a small jaw chuck of lathe Emco Unimat also I have:

Cuarto eje CNC Casero (20)

This way, I can take small pieces very easily.

The shaft is finished and looks like this:

Cuarto eje CNC Casero (23)

I’ve got mechanize with H7 tolerance in bearing supports, which I have zero clearance, which I think is essential.

I have also prepared the support plate parts, to prepare a prisoner ring I welded:

Cuarto eje CNC Casero (18) Cuarto eje CNC Casero (19)

Motor support block:

Cuarto eje CNC Casero (9)

This would be the section of the assembly, so I need a steel plate where screw it all, here it is:

Cuarto eje CNC Casero (17)

These components have not changed much from the original design.

Belt tensioner:

Here I modified a little something, needing something with sufficient structural strength to keep the belt tight, but I had the possibility of vertical adjustment:

Cuarto eje CNC Casero (2)

With a vertically oblong plate, I have prepared a small piece that support distributed and to be screwed with a long screw that take two bearings, which will be coming into contact with the belt. I’ve calculated the perimeter length of the belt, the range of adjustment I need, and the length of the oblong therefore by.


Basically it has not changed the design remains an M12 threaded rod that is secured with two nuts, I welded two plates with two holes for screwing the MDF:

Cuarto eje CNC Casero (4) Cuarto eje CNC Casero (5)

These plates have already cut and welded, this is the set:

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I also took the opportunity to weld a plate on the end, which I will use later hand cranked.

What I have changed, as seen in the design is that all the counterpoint is a block that is screwed up, so you do not have to remove the entire plate to move. I have also practiced calibrated centering holes to put him, so I hope to always keep the correct position on each anchor point. Obviously I will have to adjust to both the axis of the workpiece and tailstock are perfectly aligned. But that and will be a matter of machining MDF.

Therefore, I consider the design completed, except for some small change on the fly. Now I only cut and machined MDF plates, which of course will bring my own router.

Continue with Step 24: 4th Axis (MDF Structure)