Cat 340D Excavator build

[crueby]

Been some 'boring' days lately, boring out and turning the spindle and hub for the cab rotation bearing assembly. The spindle/hub are steel, the washer and nut are brass (just since I had some offcuts the right size, otherwise would have been steel too). The gear was bored out as well to fit the hub, there will be a gear motor inside the cab by the boom base driving a spur gear against the big gear. The big gear and hub stay stationary with respect to the track frame, and the spindle/cab spin around on that. All fits well, and the hub spins freely without play - no grease in the roller bearings yet, just since it will be handled so much for a while. Here are some pics of the top/bottom of the assembly.


Bottom view, the end with the nut will face downwards in the final assembly.




Top view - the inner spindle will bolt to the cab floor.



With these parts done, now I can lay out and start drilling the patterns of holes in the cab floor for the spindle as well as the boom base and its drive motor....

[crueby]

Getting the floor plate drilled for the mounting screws, and test fitting the parts....


Bottom view:





Top:





Need to open up one hole for the base frame, missed that one by a little bit. Then get the spacer block under the motor drilled/installed, and add the angle-aluminum around the rim to hold the cab shell on. The cab is most likely going to be a wood frame clad in thin plywood, set down over the top.

[crueby]

Got some more done on the floor plate, riveted on the angle pieces around the edge to hold the cab in place, and bolted down the motor and boom base parts.





closer look:





The vertical motor at the lower right of the boom base frame is to turn the cab around on the track base. It will drive this spur gear (once I make the shaft to connect it) against the large gear on the hub. The hub and the large gear will be bolted to the track base.

[crueby]

Started in on the framework for the undercariage - this will hold the spindle/hub for the cab on the top, and the tracks out at the lower arms.





lots of drilling/tapping later...





Still more holes to go to get the lower arms on...