Loading

Excavator

by erdinger, published

Excavator by erdinger Mar 21, 2013

Description

Original is Volvo ec210
M about 1:20
And yes: there is sand at the teeth of the bucket out of my kids sandbox ;-)

I hope the pictures are descibing the project best. On pic SAM_4173 the lower part of the body is shown with holes for batteries. It was redesigned that a big pb battery fits now. The two servos in the arm have about 120 Ncm, the big one in the body about 260 Ncm.
In the tracks and for turnig there are the the cheapest servos ever in there for about 2,5€.
The servos in the tracks are hacked so that the pwm signal still works but they do it continously. Just search the web for "pwm servo hack"!
In the turnshaft i soldered the + and - of the servos togeter to reduce lines from 6 to 4.
The tooth gears are bought:
conrad.de/ce/de/product/297410/Zahnradsortiment-Modul-1
Maybe you can also print them, I can't.
The tracks are in fact a derivate from thingiverse.com/thing:36305
Thank you LoialOtter!

Recent Comments

view all

the center shaft is ground... 4 stacks would be too high. An hydraulic system would be cool, but expensive, yea. So I only used servos.

There will be pics and videos! i'll have to learn how to upload them on here. i printed the track tighteners and power wheel stabilizers before i saw the cutouts, so i'll make the cutouts with a dremel too. i kind of thought there might be washers in the slip rings but i couldn't tell for sure. good idea! did you also use the center shaft for the ground conductor? or is there four washers stacked up?
so far i have the arm built up (need to make new linkages, with tighter tolerances) and am controlling it with arduino joystick shield.
i used #0-80 x 1 1/8" screws for track pins, from mcmastercarr.com (you have to ask for them, about $20 for 100 screws)

I added some more pics to get you a clue of the construction of the slip ring... it is assembled with 3x washerSpacer.stl and 3x washer (Hornbach for Germany / Home Depot for USA). From the inside the wires are connected to the washers from the outside there are the sliding metal wires. I placed some tape between the different level of washer and washerSpacer. It is going full circle as often as you want (in theory... somewhere I have a shortcut in there I haven't found jet... too much different things).

I use 13mm (outer diameter) bearings. the cone is that it self centers when screwing.
I think that the middle wheels of the tracks do not really need bearings... I have them but the tracks are just sliding in most cases without movement of the wheels.

One other point I found out was that on the trackTightener.stl and pwrWhlSabi.stl you need a cutout for the screws I forgot to design. So I used my Dremel after printing... please find it in the picture with the blue arrows.

I expect a video or at least some pictures when you finished it!

More from R/C Vehicles

view more

Makes

Liked By

view all

Tags

License

Excavator by erdinger is licensed under the Creative Commons - Attribution license.

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag. Print Thing Tag

File Name

Downloads

Size

Comments

You must be logged in to post a comment.

isaac_alaska on Nov 13, 2013 said:

I am drawing the gears in solidworks, i'll upload them on here when they are finished.
a couple questions about parts i haven't got to yet:
how does the slip rings work for transfering power across the rotating main joint? i see some metal wire fingers sticking in there but they don't look like they go all the way around. can it work in a full circle?
another questions is about the drive wheels, i can't tell why the outer holes in them are tapered cone shapes instead of a place for a bearing to mount.
what size bearings did you use for the tracks to ride on? i'm planning to use 13mm (1/2 inch) outside diameter bearings and make axles for each set of two bearings.

erdinger on Nov 14, 2013 said:

I added some more pics to get you a clue of the construction of the slip ring... it is assembled with 3x washerSpacer.stl and 3x washer (Hornbach for Germany / Home Depot for USA). From the inside the wires are connected to the washers from the outside there are the sliding metal wires. I placed some tape between the different level of washer and washerSpacer. It is going full circle as often as you want (in theory... somewhere I have a shortcut in there I haven't found jet... too much different things).

I use 13mm (outer diameter) bearings. the cone is that it self centers when screwing.
I think that the middle wheels of the tracks do not really need bearings... I have them but the tracks are just sliding in most cases without movement of the wheels.

One other point I found out was that on the trackTightener.stl and pwrWhlSabi.stl you need a cutout for the screws I forgot to design. So I used my Dremel after printing... please find it in the picture with the blue arrows.

I expect a video or at least some pictures when you finished it!

rdh02 on Jul 18, 2013 said:

??,??????,???STL??????

Mendelbuild on Jul 12, 2013 said:

Anyone got alternatives to the gears ? it was like 50 euros total with shipping for a 6 euro kit of gears :/

erdinger on Jul 12, 2013 said:

I used these gears, because my print results are not good enough...
Maybe you can print some gears...

Mendelbuild on Jul 12, 2013 said:

Nice work ! :D

RossRobotics on Jun 17, 2013 said:

Absolutely amazing! Adding this to my "Gotta Make It!" list.

zebra_spots on Jun 10, 2013 said:

Do you have some pictures of how this went together? especially the track sections.

erdinger on Jun 10, 2013 said:

I uploaded 2 pics of the put together of the tracks but they are not displayed correctly (tried png and jpg). The best advice is to download freecad from http://sourceforge.net/project... and load the sources... there you can display and remove every part by pressing spacebar to see how it is assembled...

erdinger on Apr 21, 2013 said:

OK... Sun was coming out => the sand is not frozen anymore
So I uploaded: work.avi

fma on Mar 26, 2013 said:

I'm not sure how the global rotation is designed, but this thing may help to build a very rigid system: http://www.thingiverse.com/thi....
Just use a larger thrust bearing...

LoialOtter on Mar 26, 2013 said:

Okay, that is absolutely fantastic. Anyone else want to motorise it... *blinkblinks* Wait, it !Is! motorized... that is even more than fantastic, that's downright epic.

openhardwarecoza on Mar 23, 2013 said:

Agreed! Need some video!
And some more instructions please. This an Awesome thing

Walt on Mar 23, 2013 said:

Very nice! I can really appreciate the amount of time and effort that went into this project. Can't wait to see what else you'll make in the future.

fma on Mar 22, 2013 said:

Very impressive! I've always dreamed of such toy...

g00bd0g on Mar 22, 2013 said:

Cool!

visualkev on Mar 22, 2013 said:

totally cool project!

jpickens on Mar 22, 2013 said:

Needs me a video of this bad boy in action!

abobotek on Mar 21, 2013 said:

Very nice! Could you post FreeCAD source? Would love to tweak for some of the servos and electronics I have.

erdinger on Mar 22, 2013 said:

done

Greasetattoo on Mar 21, 2013 said:

nice..what software did you model it in?

erdinger on Mar 21, 2013 said:

updated the name... thank you

the software was/is FreeCAD: http://sourceforge.net/apps/me...
and blender for editing the tracks

cyclone on Mar 21, 2013 said:

Holy Wow!

Top