one parallel rod top fixed on the base

One parallel rod top fixed on the base

With the sides of the cnc machine almost ready, I now concentrated on making the base and the movable bed. What I had available were parallel rods which came together with aluminium supports. One of the reasons, I chose to build a movable bed design was because of these parallel rods.

one side of the parallel slide rods fixed on the base

One side of the parallel slide rods fixed on the base

It would be shame if I could not put these to use, because with the supports, the rods would be expected to be able to stand much heavier weights without flexing in the center as in all simply supported rods. This would contribute to the accuracy of the machine which I needed badly because I did not have precision machining tools for this work.

Boring hole for linear bearing

Boring hole for linear bearing

The challenge for me was to use the open type linear ball bearings which I had available that did not come with bearing housings. I had made inquiries at the bearing suppliers, and was told that the housing were not sold separately, and that I had to buy a complete set of bearings which comes with the housing.

making the wooden linear bearing housing

Making the wooden linear bearing housing

Well, that defeated my purpose. It was not my aim to make a home-made cnc machine while those parts I had salvaged laid idle. I wanted to make use of whatever available and to fabricate if I could whatever I did not have as opposed to buying all the parts brand new.

try fit of linear bearing

Try fit of linear bearing

So my activities centered around making the movable bed, cutting, aligning and fixing in the parallel rods, making the bearing housings for the four open type linear bearings, aligning and fixing them in place.

linear bearing housing cut to size

Linear bearing housing cut to size

At the same time, I prepared some mdf blocks to be used as the spacers for the motor coupling area. In order to attach the lead screws to each motor, there would be a flexible coupling between the shaft of the motor and the lead screw.

Boring step hole to take motor housing

Boring step hole to take motor housing

A spacer was needed to facilitate the adjustment of the axial position of the motor. Because it was quite thick at 32 mm, I would need to glue 2 pieces of 16 mm thick mdf pieces together to make one piece of spacer.

After that it was just waiting for the glue to set.

gluing linear bearing housing to movable bed

Gluing linear bearing housing to movable bed

spacer for motor coupling area

Spacer for motor coupling area