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-   -   Build an Excavator from Scratch (https://www.rctruckandconstruction.com/showthread.php?t=13935)

pufferfish 02-07-2022 02:59 AM

Re: Build an Excavator from Scratch
 
Hi,

you've convinced me :D
I wonder, why this forum isn't using such simple quick-response buttons as a "like". Its quickly made for you without spamming the thread and a response for the thread opener. thereby the opener hasn't the feeling to write soliloquies.

A little sideeffect for me of writing in an english speaking forum is to improve my written english with non-trade-affected terminologies. I'm programmer by trade and the vocabulary of ibm books is restricted :D

So I'll try to write more about my thougths why I do something so or not.

----------
Let's go back to the barrel tank. Looks good but it has some imperfections. I've forgotten a oil level indicator and a ventilation.
I can add them outside, but a second point is more important. A kind master of hydraulics told me, that with my "big" pump
and the small usual hoses I'll ran into problems with cavitation (pitting in the pump).
The pump offers a g1/8 thread instead the usual m5 threads.

to compare the hose sizes (top down):

normal pressure hose id 2,5mm od 4mm
normal pressureless hose id 4mm od 6 mm
the new pressureless hose id 8mm od 10mm

this reduces enormous the flow speed and avoid cavitation.

https://blog.rb-fotos.de/wp-content/...r/img_6536.jpg

Unfortunately, the hole for a g1/8 thread is bigger than the doublings in the tank.

So i've decided to build another tank with all the needed holes and threads.
This time a cubic form to get a feeling wich form is easier for me to build.
I've not noticed significant differences, thus it will be simple a question of style in the future.

The result. oil proofed and mounted. Ready to use.

https://blog.rb-fotos.de/wp-content/...img_6575_0.jpg

kerst 02-07-2022 06:14 AM

Re: Build an Excavator from Scratch
 
Thank you, I have been reading your posts with much interest!

Kerst

Jared 03-24-2022 11:37 PM

Re: Build an Excavator from Scratch
 
I'm glad you changed your mind!

pufferfish 03-30-2022 03:26 PM

Re: Build an Excavator from Scratch
 
Hi,

I haven't been lazy whilst the long break here.
A short summary jump to the actual standing:

the work on the monobloc has begun
https://blog.rb-fotos.de/wp-content/...img_6664-2.jpg

an intermediate stand together with a bit of cardbord aided design
https://blog.rb-fotos.de/wp-content/...r/img_6678.jpg

the monobloc body is ready and bending the hydraulic pipes begins
https://blog.rb-fotos.de/wp-content/...r/img_6711.jpg

pipebending is done and the first cylinders of the second genereration are done.
some issues on the first generations forced my to do so.
https://blog.rb-fotos.de/wp-content/...r/img_6804.jpg

30 kg ballast lead arrived
https://blog.rb-fotos.de/wp-content/...r/img_6771.jpg

a new dimension of metal handling for me: 1,5mm stainless sheets. very stable and very hard for me and my little tools. but at least the first simple bucket is done
https://blog.rb-fotos.de/wp-content/...r/img_6902.jpg

pufferfish 03-30-2022 03:56 PM

Re: Build an Excavator from Scratch
 
stick, bucket and bucket mechanic
https://blog.rb-fotos.de/wp-content/...r/img_6903.jpg

the very noisy pump gets a leadfilled cover.
https://blog.rb-fotos.de/wp-content/...r/img_6966.jpg

an overview of the deck with all the hydraulics and electronics. this is the almost final view. only minor changes will happen
https://blog.rb-fotos.de/wp-content/...r/img_6967.jpg

and then? then there was a very shocking moment. with a thoughtless movement of the superstructure i've pushed a former build from its rest. :jaw:
result: a 100% total loss. :mad:
https://blog.rb-fotos.de/wp-content/...r/img_6987.jpg

the base , a traxxas trx6, ist still useful, maybe a following project.

parallel to all these steps i've made some trials and errors to get a reproducible method to build a proper hull.
a first success was my first pretty 3d corner

https://blog.rb-fotos.de/wp-content/...r/img_7012.jpg


today , a big milestone has reached. the drivetrain is done and a first driving lesson occurs.

jerry56 03-30-2022 04:06 PM

Re: Build an Excavator from Scratch
 
WOW that thing is huge !!!! it will be a monster... nice to see it progressing...

pufferfish 03-31-2022 12:44 PM

Re: Build an Excavator from Scratch
 
At the beginning of my research for an excavator i've found a flyer from liebherr. There was the model 966 noticed as a perfect fit for 30 tons dumpers. My dumper is a 30 tons one. Thereby the 966 became my model for principal sizes.
Later I was surprised too that you need a monstrous excavator to load a small dumper :D

------
Todays work were the operators gangways.

https://blog.rb-fotos.de/wp-content/...r/img_7099.jpg

https://blog.rb-fotos.de/wp-content/...r/img_7100.jpg

https://blog.rb-fotos.de/wp-content/...r/img_7102.jpg

Jared 04-01-2022 11:34 PM

Re: Build an Excavator from Scratch
 
Very nice pipe work. What is your method for bending without kinking them?

frizzen 04-02-2022 01:25 AM

Re: Build an Excavator from Scratch
 
Looks like a lot of progress! Shaping up into a very impressive machine

Was the totaled truck something like an Airport Fire engine, or a Trial Truck? Atleast the ejector seat worked.

skeeter 04-08-2022 12:38 AM

Re: Build an Excavator from Scratch
 
AWESOME project!
This thing should be a beast of a machine once completed!

pufferfish 04-09-2022 02:44 PM

Re: Build an Excavator from Scratch
 
Quote:

Originally Posted by Jared (Post 171929)
Very nice pipe work. What is your method for bending without kinking them?

Thank you. I've choosen the easy way. 6x1mm stainless pipes are not easy to bend but with the right tools it's possible and up from 15mm radius without any kink. I'm using a "RIDGID 600 series lever bender" for 16mm radius.
with the enclosed examples you are quickly enabled to make reproducable multi-angle bendings.

Quote:

Originally Posted by frizzen (Post 171933)
Looks like a lot of progress! Shaping up into a very impressive machine

Was the totaled truck something like an Airport Fire engine, or a Trial Truck? Atleast the ejector seat worked.

It was called "s.o.f.t. superfast offroad fire truck" and should be a quick response bush fire truck.

"ejector seat" :D:D

Quote:

Originally Posted by skeeter (Post 171980)
AWESOME project!
This thing should be a beast of a machine once completed!

indeed.
----------

After a short vacation I've save up enough point on my patience account to begin with the last two hydraulic cylinders. Patience is needed because me and turning internal threads are not friends.
fortunately, this time it works at the first attempt and some other parts are build too.
Pistons and guide rings from brass, rod and cylinder from stainless and the cylinderhead is from aluminium. (nothing to weld on the head and very easy to turn)
https://blog.rb-fotos.de/wp-content/...r/img_7129.jpg

The head is the most complicated part. Internal thread and a recess for the guide ring on the inner side. thereby the guide ring is oil lubricated.

https://blog.rb-fotos.de/wp-content/...r/img_7128.jpg

On the outside are three grooves for o-ring sealings.
https://blog.rb-fotos.de/wp-content/...r/img_7127.jpg

Threads will be sealed with loctite 542.

pufferfish 04-10-2022 01:54 PM

Re: Build an Excavator from Scratch
 
Todays work: The completion of the stick cylinder.

After applying the orings i've prefilled the cylinder with oil

https://blog.rb-fotos.de/wp-content/...r/img_7133.jpg

The thread was filled with loctite

https://blog.rb-fotos.de/wp-content/...r/img_7134.jpg

after 4 hours the glue isn't 100% but for a first little test tight enough
but before, i've made a hose-guard from 5x0,3 stainless for the hose to the front

https://blog.rb-fotos.de/wp-content/...r/img_7137.jpg

the last cylinder for the bucket is prefilled too and can't wait to mount him

https://blog.rb-fotos.de/wp-content/...r/img_7138.jpg



The cylinder and stick in action you can see in this little clip (self hosted)

https://blog.rb-fotos.de/wp-content/...es-stick-1.m4v
(moving from the nineth second on)

trucker n 04-10-2022 02:41 PM

Re: Build an Excavator from Scratch
 
man very nice and smooth

skeeter 04-10-2022 11:03 PM

Re: Build an Excavator from Scratch
 
Great job with them cylinders!

pufferfish 04-12-2022 03:02 PM

Re: Build an Excavator from Scratch
 
thank you guys.

the temporarely used threaded rods will be switched into much more stylish bolts with circlips.


https://blog.rb-fotos.de/wp-content/...r/img_7160.jpg

https://blog.rb-fotos.de/wp-content/...r/img_7162.jpg

And the driver makes a visit. A good thing to see the dimensions of this rig.

https://blog.rb-fotos.de/wp-content/...r/img_7159.jpg

https://blog.rb-fotos.de/wp-content/...r/img_7158.jpg

https://blog.rb-fotos.de/wp-content/...r/img_7161.jpg

pufferfish 04-13-2022 01:33 PM

Re: Build an Excavator from Scratch
 
After six months of almost daily work at this project, all mechanical todos are done :bounce:

Parking position
https://blog.rb-fotos.de/wp-content/...r/img_7173.jpg

max Height over ground approx. 130 cm
https://blog.rb-fotos.de/wp-content/...r/img_7175.jpg

max Depth ca. 100 cm
https://blog.rb-fotos.de/wp-content/...r/img_7177.jpg

Next big steps are learning to operate it and building the hull and the cabin and 347586 other little things.

Lil Giants 04-14-2022 08:17 AM

Re: Build an Excavator from Scratch
 
Great work on the project to date Ralf, well done :cool:

What is the ground level reach?

Learning to operate it, I would suggest getting a big bag of rice or pellet dog food & a couple of cardboard boxes, transfer from one box to the other & back again inside the comfort of your house daily. :D

pufferfish 04-14-2022 10:13 AM

Re: Build an Excavator from Scratch
 
Thank you. Thats a good Idea, but too late.

The first loading of my Dumper happens in my garden .

https://blog.rb-fotos.de/wp-content/...tbuddeling.m4v

some issues found but nothing worse (i hope :D )

Have a nice easter weekend

Lil Giants 04-16-2022 09:10 PM

Re: Build an Excavator from Scratch
 
Watching your dig video, perhaps if you lowered your EPAs of swing & valves then your movements wouldn't be so quick & twitchy. Takes more radio stick throw to make something happen making far less sensitive.

Also, with your hyd motor running continually at a very low speed, as low as possible so the motor doesn't chatter trying to run & using valve mix to speed up movement helps to smooth out movement too. And it helps keep your pump motor esc from over heating too from additional stall current start ups.

pufferfish 04-17-2022 01:25 PM

Re: Build an Excavator from Scratch
 
Thanks for the advices, Joe. I appreciate them and will give them a try at the next dig.

But due to a complete disassembling of the excavator this will take some time.

Disassembling for fixing issues , improvement and so on.

Til waiting for easter brunch with the family I've made the cables for the working lights on the monobloc.
Simple wires are bending in very unpredictable ways.
To tame them I've used a simple but effective method.

Whilst the hole procedure take care that the wires laying flat side by side.

Two single wires are bound with a very thin stainless wire
https://blog.rb-fotos.de/wp-content/...r/img_7214.jpg

This thing pulled through a heat shrink tube.

https://blog.rb-fotos.de/wp-content/...r/img_7207.jpg

After shrinking the wires get more stiffer and bends reproducable nice way

https://blog.rb-fotos.de/wp-content/...r/img_7217.png


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