Phase nine: Casting the Z-axis carriage


To save space, I put the TK-421 on top of the IG-88. I also fabbed up this cool rack to hold all of my cnc junk. This works quite well because I can roll the whole assembly outside and let the saw-dust or metal shavings fly all over the place. The Arcsin controller is mounted inside the box there on the top. I haven't finished the front panel yet, but the joystick sure works well. The TK-421 is shown with the twin hot-wire towers mounted.


It has been almost 9 months since I cast any parts, so I was a little unsure if I could remember the process. However, after getting back into Turbocad and TurboCNC, it all came back to me! Here is the TK-421 in action cutting the Z-axis carriage. This part will hold 8 roller blade bearings on the 45 degree cuts, and the deep V shape will hold the spindle motor. The Delrin nut will fit in the cutout area at the bottom.


I sure forgot how perfect hot wire cnc cut parts turn out.


Ahhhhh Yeahhhh! What a beauty. The carriage is sitting on top of the Z-axis frame. I still have to cut the 3/4" round SS rails and install them in the frame.


The old R2 furnace coughed and sputtered as it burned all the spiders out, but after a few minutes, the old tin can was cranking out the BTU's.


Foamy sprues all prepped and ready for the pour.


R2 glowing nicely as the Aluminum comes up to pouring temperature.


The head-pressure tool creates a perfect reservoir for the aluminum supply as it enters the cavity.


A few minutes later after I popped the button off and put it back in the crucible.


The carriage block right out of the sand, barely 10 minutes old.


Then a quick cooling off with the garden hose and the plaster falls away to reveal another perfect part! Now on to the finish machining and assembly!


After an hour and a half of drilling and tapping, here is the result.


Elegant, yet simple, and extremely rigid.


This design glides super smooth on the 3/4" stainless shaft.


Here you can see the adjusting bolts that push one shaft towards the other. This allows you to take all the play out of the system and make some adjustments as things wear.