With the power supply down waiting for parts the oppertunity to do some problem solving was now at hand. The TOS FN20 protects the ways with a fabric bellows. When I obtained my machine all of them were ripped except the Y axis as it was at the back of the machine away from the oil and chips presented in machining.
I have always liked the look of the stainless steel way covers so I set out measuring and forming a set of covers for the Z axis made from 18 guage Stainless Steel. Metal Supermarkets in Canada is a great soarce as they often have cut off sheets of stainless steel and also have shear to cut strips to size. For trimming I used my Plazma cutter and the cut was clean and quick to do.
Since I do not have a break that will form 18 gauge Stainless Steel I used a hard maple former. The former was made the size of the first section of the chip guard size to be made, clamped, then hammered to size. I then cut the former 3 x the thickness of the sheet smaller and formed the next section. This progressed untill all 4 sections were made. The same was done for the top but with 5 sections. The back is shown with the fingers that keep the sections from falling apart. Welding the fingers was done with my TIG welder at 35 amps DC. I used the TOS FN20 mounting strips for the Bellows to mount the top and bottom sections. Method of attachement , MIG Weld. I also formed a drive belt guard fo the X and Z axis to keep the chips from clogging the belt and possibly jumping a tooth.
A bit of electrical theory.
Supply to my house is single phase 120/240 volts 60 Hz. The single phase primary on the street (16.6KV) steps down the Utility line voltage with a transformer. The transformer secondary coil has a centre tap that is grounded and called the neutral tap. From the neutral tap in either direction 120 volts is presented. Across both windings 240 volts is present. I wired the Antek power supply up the same way, although connecting the neutral to the centre tap is not required this connection does not allow the primary of transformer to see more than 120 volts to ground. The inital set up used 2 electronic relays to switch the 8 amps of load on each primary coil to the power supply. I will also note that if only 1 coil is energized the power supply will still work, but will only work at half of it's current rating. Both windings are required to obtain the full out put of the power supply secondary voltage. The relays are picked up by the EPO circuit in Mach3. When the reset is pressed and is sustained the Sound Logic Break Out Board energizes relay #4, the normally open contacts now close and pick up 2 electronic relays the energize the Power Supply. This was my first encounter with electronic relays and I have now changed them out for an Allen Bradly 30 amp contactor. More about that in the next post.