Re: Build an Excavator from Scratch
 

I think it

Re: Build an Excavator from Scratch
 

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
https://blog.rb-fotos.de/wp-content/...r/img_7708.jpg

thereby the piston seals get damaged

https://blog.rb-fotos.de/wp-content/...r/img_7711.jpg

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

https://blog.rb-fotos.de/wp-content/...r/img_7710.jpg

After replacing the piston o-rings and refilling the oil then thread sealant is applied
https://blog.rb-fotos.de/wp-content/...r/img_7712.jpg

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

Re: Build an Excavator from Scratch
 

24 hours later: The repair was successful.

https://blog.rb-fotos.de/wp-content/...r/img_7717.jpg
The stick holds his position.

After this I've made a last stress test.

Mounting all the 20kg ballast as counterweight
https://blog.rb-fotos.de/wp-content/...r/img_7720.jpg

And a little mandrel press was the lifting object
https://blog.rb-fotos.de/wp-content/...r/img_7718.jpg

her weight
https://blog.rb-fotos.de/wp-content/...heavylift2.jpg

and finally the test. lift and hold. passed.
https://blog.rb-fotos.de/wp-content/...heavylift1.jpg

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

Re: Build an Excavator from Scratch
 

Detailwork.

A rough sawed
https://blog.rb-fotos.de/wp-content/...r/img_7752.jpg

and fine filed patch for the cutout of the ladder lever
https://blog.rb-fotos.de/wp-content/...950314e8c3.jpg

A door handle
https://blog.rb-fotos.de/wp-content/...r/img_7751.jpg

and handrails complete the second of four parts of the hull.
https://blog.rb-fotos.de/wp-content/...d78fb5cb9a.jpg

Re: Build an Excavator from Scratch
 

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

Re: Build an Excavator from Scratch
 

At least, the Beast is done :D

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

https://blog.rb-fotos.de/wp-content/...img_7986_0.jpg

https://blog.rb-fotos.de/wp-content/...img_7982_0.jpg

https://blog.rb-fotos.de/wp-content/...img_7983_0.jpg

https://blog.rb-fotos.de/wp-content/...img_7984_0.jpg


Thanks for watching

Re: Build an Excavator from Scratch
 

Looks great.

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

Re: Build an Excavator from Scratch
 

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

Re: Build an Excavator from Scratch
 

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
https://blog.rb-fotos.de/wp-content/...r/img_9153.jpg

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

https://blog.rb-fotos.de/wp-content/...r/img_9180.jpg

mounted in his small place

https://blog.rb-fotos.de/wp-content/...r/img_9182.jpg

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

it runs smooth and hold the arm with load even if the body is tilted
https://blog.rb-fotos.de/wp-content/...r/img_9186.jpg

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

Re: Build an Excavator from Scratch
 

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...

Re: Build an Excavator from Scratch
 

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 :)

Re: Build an Excavator from Scratch
 

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

Re: Build an Excavator from Scratch
 

Impressive!

Kerst

Re: Build an Excavator from Scratch
 

thank you guys.

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

https://blog.rb-fotos.de/wp-content/...r/img_9283.jpg

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
https://blog.rb-fotos.de/wp-content/...r/img_9257.jpg


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)

https://blog.rb-fotos.de/wp-content/...r/img_9261.jpg


Additionally I've made better fitting pistons

https://blog.rb-fotos.de/wp-content/...r/img_9263.jpg

https://blog.rb-fotos.de/wp-content/...r/img_9265.jpg

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

https://blog.rb-fotos.de/wp-content/...r/img_9272.jpg

https://blog.rb-fotos.de/wp-content/...r/img_9273.jpg

close but works

https://blog.rb-fotos.de/wp-content/...r/img_9274.jpg

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

https://blog.rb-fotos.de/wp-content/...r/img_9281.jpg


the cylinderhead is still sealed :bounce:

https://blog.rb-fotos.de/wp-content/...r/img_9284.jpg

Next step: upgrade the other cylinders.

Re: Build an Excavator from Scratch
 

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

Re: Build an Excavator from Scratch
 

Indeed :)

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

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

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

Re: Build an Excavator from Scratch
 

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

https://blog.rb-fotos.de/wp-content/...r/img_9314.jpg

https://blog.rb-fotos.de/wp-content/...r/img_9315.jpg

https://blog.rb-fotos.de/wp-content/...r/img_9316.jpg

https://blog.rb-fotos.de/wp-content/...r/img_9317.jpg

https://blog.rb-fotos.de/wp-content/...r/img_9318.jpg

Re: Build an Excavator from Scratch
 

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

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.

Re: Build an Excavator from Scratch
 

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


-Shawn-