John Deere 744k Wheel loader

[Ramon]

Nice work mate, keep the photos coming.

[mkerkovius]

When building the hydraulic cylinders, what do you guys use to solder/braze them together with? soft solder, or a good silver braze? They will be running at about 20-25 bar of pressure.

[mkerkovius]

So it's been a while since I've last checked in. I have been lurking maybe once a week on here for the last 3 years as I have been super busy with University during this time but recently I have been able to get a lot of work done on this thing! There have been some significant changes made to some of the early pieces such as the boom now being made from steel rather than aluminum, and all new hydraulic cylinders.
Boom made in steel

top cap, it gets fitted with an o-ring for a seal and a dust wiper

the top cap fits into a sleeve which is soldered to the brass cylinder tube. It gets bolted down with 8 m1.6 hex cap screws


Bottom cap/plug of cylinder, it gets soldered in

This cylinder served as the tester for proof of concept. The rod used is 8mm hard chrome plated

All cylinders completed and ready to be painted

Next up the axles were machined. I chose to machine them from free machining aluminum purely due to the small amount of time to machine as compared to steel. I have used the "flexaxle" differential gears kit from AFVmodell for these along with their wheels and tires.



I decided to put the pieces together to see how its going to look when assembled



parts cleaned, bead blasted and ready for paint

paint and plumbing done!!




plenty of articulation on the rear axle




I have since managed to wire everything up and have tested tested it, unfortunately no video yet . I have discovered a few issues, such as the steering cylinders being hooked up so that they both push/pull the same direction at the same time, haha oops!!. The drive also has only enough power to drive it on flat concrete and not much else. I have extracted a motor from an old drill that will be much more powerful and have yet to fit it in.
Thanks for looking!

Mike