Build an Excavator from Scratch

[Tgrzes]

I think it

[pufferfish]

Todays work was a repair of the stick cylinder. Before the final assembling i've made the mistake to pull the rod complete to the end. During normal operations this never will happen due to the geometry of the stick.

At the end of the cylinder the piston collides with the oil input flange


thereby the piston seals get damaged



To open the cylinder i have to loosen the head. Sealed with loctite 542 thread sealant it just needed some hot air



After replacing the piston o-rings and refilling the oil then thread sealant is applied


Now I have to wait 24 Hours before the glue is cured.

[pufferfish]

24 hours later: The repair was successful.


The stick holds his position.

After this I've made a last stress test.

Mounting all the 20kg ballast as counterweight


And a little mandrel press was the lifting object


her weight


and finally the test. lift and hold. passed.


I'm very satisfied with this result. After a holiday the final work on the hull begins...

[pufferfish]

Detailwork.

A rough sawed


and fine filed patch for the cutout of the ladder lever


A door handle


and handrails complete the second of four parts of the hull.

[pufferfish]

Hi. Nothing new due to a vacation, but today i have a first training session for my eye hand coordination.

Works a bit better but still much to learn

A short clip

https://vimeo.com/727432466

[pufferfish]

At least, the Beast is done

The official pictures of my first scratch build of an excavator in 1/10 scale.










Thanks for watching

[Blender]

Looks great.

Will it be painted in a specific brand's colors or left in bare metal?

[frizzen]

Great job, that's an amazing machine!!!

[pufferfish]

Hi there,
during some test digs i've noticed that the beast have an issue when the body stands not exactly horizontally. due to gravity and the small rotary drive motor/gearbox the loaded arm turns every time toward the lower end. just active steering against is avoid uncontrolled movement of the arm. thereby it was difficult to dig and put the load into the dumper.

Somebody told me, that cascaded planetary gears are tends to self-locking. I buy some of them and a couple of tests later i decided to change the rotary drive.

old motor vs new motor


after some adjustments of the sledge it fits well.
the gear ratio is 130:1



mounted in his small place



and then the first test. i'm happy when i've realized that it works pretty well

it runs smooth and hold the arm with load even if the body is tilted


additionally i've changed the esc to a hobbywing 1080 with active hillbreak for the last bit of holding power.

[jerry56]

I never thought about that ... but yeah I can see where you would need either a planetary gear or a worm gear to hold the boom in place once you stop swing...
I used a 90 degree worm drive motor in mine so I never had the problem...

[pufferfish]

Thanks. This is my first excavator and i don‘t have any experiences or knowledge of these monsters before the build. Thereby i‘ve underestimate massively the working forces.

Learning by doing

[frizzen]

That's really cool!
I didn't know that stacking planitary gears like that could give a locking geartrain.

[kerst]

Impressive!

Kerst

[pufferfish]

thank you guys.

The next step was the improvement of the hydraulic cylinders. The old version works well, but is a little bit leaky.



I've used O-Rings as seals and simple Stainless Rods. The upgrade is replacing the o- through x/quad-rings and using hard chrome plated rods.
It was not easy to find them in only 10mm diameter. But here they are



First item was the bucket cylinder.

A challenge for me was the new material C45/1.0503/AISI 1045 but it was easier than expected, including turning a m10 thread (a tap wrench doesn't work proper)




Additionally I've made better fitting pistons





To change the cylinder head from o ring to x ring grooves i need a 3mm wide internal grooving tool.
I've grind a rough thing from a blank





close but works



Aaaand after a 20 min testdig with really heavy clayey ground (directly from the excavators trailer to avoid too much dirt in the shop)




the cylinderhead is still sealed



Next step: upgrade the other cylinders.

[egronvold]

Always a great feeling when the hours in the shop finally pays off

[pufferfish]

Indeed

After upgrading all other Cylinders i've discovered the new opportunity to move more than one Cylinder at a time

https://player.vimeo.com/video/779644929

Upgrading is done. Next step will be a quick change system.

[pufferfish]

Actual work: A little Rock Ripper and a first Setup of the Quick changers locking mechanism.

[pufferfish]

After 16 month of work on this Project, it finally comes to an end

The ripper is ripping, the changer changes and all other things are now oil-proofed and working.

A last clip from this little Monster while ripping and digging compacted embankment in my garden.

https://vimeo.com/787182149



Thanks for watching.

[Krewmember]

Awesome build, and to your own design as well that makes it even better!
It looks like it has good digging power.


-Shawn-