1/12 John Deere 870G
 

So this is my first scratch build after converting a bruder excavator, its made from steel, 50mmx50mm box for track base, cant remember what gauge the boom steel is, tracks are made from 1/2 inch roller chain with every other tooth removed from sprocket, the track pads are carpet gripper cut into bit and bolted through every other chain link.

I know people like to see the universal scale coke can to get an idea of the size but we couldnt find 1 so i had to use the universal pint glass :D

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Re: 1/12 John Deere 870G
 

Nice start! It's gonna be big...SWEET! What kind of valve is that???

Reg

Re: 1/12 John Deere 870G
 

the valve block is from fumotec

Re: 1/12 John Deere 870G
 

wow! Monster build fella! Do you have only one bolt holding the cleats onto the tracks? No fear of them skewing around in use?
Glenn

Re: 1/12 John Deere 870G
 

Nice metal work ,looking good so far ! ,look forward to seeing more of this build.
Do you have a build thread for your bruder excavator?

Re: 1/12 John Deere 870G
 

Rckiwi : yes there is only 1 bolt holding the cleats this owrried me to start with also but the aluminium is soft and bites into the chain once the bolt is tight and cant be twisted.

Pumptech : i cant take credit for the metal work that was my dad, i cut the shapes out and he welded it for me when i was at work :) didnt make a build thread for my bruder to be honest i struggled with the screwdrives they didnt seem to have any power, we got it working i moved some sand with it then it got shelved and i started building this.

Re: 1/12 John Deere 870G
 

.

Pumptech : i cant take credit for the metal work that was my dad, i cut the shapes out and he welded it for me when i was at work :) didnt make a build thread for my bruder to be honest i struggled with the screwdrives they didnt seem to have any power, we got it working i moved some sand with it then it got shelved and i started building this.[/QUOTE]

Well, you and your dad are off to a good start :), looks to be thin gauge sheet metal ,seeing the heat coloration ,have to be speedy welding that.May have to beef up the boom were it meets the arm a little (pivot point) ,just a thought.
As for the Bruder ,had my troubles with mine in the beginning, finally got it where I want it,finding the right servos,made a metal bucket for it,digs sand ,loose dirt ok.

Re: 1/12 John Deere 870G
 

A great start that both you and your dad have done. :cool:

Is your dad as ambitious about this hobby as you? The two of you could build alot of great models together. :D

Re: 1/12 John Deere 870G
 

Joe: Im not sure hes as ambitious as i am but he was an engineer before he retired so he doesnt mind helping with a bit of welding, i think he can see the practical uses of it to do work in the garden :)

A few updates from yesterday, track base is tacked together i think its slightly crooked so may have to knock it apart and straighten it , still need to find some bolts for the top rollers so i can connect the tracks together.

Dropped the base plate on top to see what it would look like height wise, its made from 5mm steel.
http://img198.imageshack.us/img198/2120/imag0143ie.jpg
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my sister came back just as i was taking photos so i got her to stand on it to show better scale

http://img804.imageshack.us/img804/6855/imag0154ww.jpg

Rob

Re: 1/12 John Deere 870G
 

update! she rolls, bought some cheap escs from ebay then realised the were forward only :D powered by 2 12v drill motors running at 7.2v

http://www.youtube.com/watch?v=9XzrYqIGpYE

http://www.youtube.com/watch?v=eUxneBpI1VM

Re: 1/12 John Deere 870G
 

Great idea with the carpet gripper.

Re: 1/12 John Deere 870G
 

slew drive finally in place, used an old car trailer hub we had lieing around stands a bit tall but didnt pay for it so cant complain really, slew motor is fitted temporary, the shaft needs shortening so it fits better

http://img233.imageshack.us/img233/4002/imag0213v.jpg
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some video testing the extra weight it now weighs 25kg, might want to turn the sound down a bit camera picks up alot of background noise

http://www.youtube.com/watch?v=J13Y6En4ayM

Re: 1/12 John Deere 870G
 

Looks good. What did you scoop the gears from? They look like motorcycle parts...

Reg

Re: 1/12 John Deere 870G
 

RCP57: i couldnt find anything suitable in the workshop so got the gears from technobotsonline, they were on sale so quite cheap, finished the swing drive today, i think its got some nice power http://www.youtube.com/watch?v=QlS8KPnAJoY

Re: 1/12 John Deere 870G
 

Like the home brew angle:D:D:D Keep up the creativity!

Cheer's, Neil.

Re: 1/12 John Deere 870G
 

i bet you this machine will dig better then any store bought digger!!!
that is some heavy duty machine

Re: 1/12 John Deere 870G
 

Im with bigford, this is a right piece of ironwork, i cant wait to see this digging up paving slabs.
What soet of money has it cost you so far?

Re: 1/12 John Deere 870G
 

If you feel that it is a little high, maybe you got enough room to let the body hang down below the car body platform, kinda split the difference. Looks good. Fred

Re: 1/12 John Deere 870G
 

Bobcat : about 250quid maybe not counting the valve block, but thats including motors bought by mistake would be cheaper if i knew what i was doing.

Had a go at making a cab over the weekend, failed woodworking at school so didnt expect a masterpiece

http://img16.imageshack.us/img16/6738/imag0223ib.th.jpg

Re: 1/12 John Deere 870G
 

Looks good to me... Reminds me of the machines they use for logging with it high up like that.

Reg

Re: 1/12 John Deere 870G
 

nearly finished, i am missing the bucket cylinder that will hopefully arrive this week, just needs a coat of paint and some tidying done then can install the plumbing.


Caution images contain graphic agricultural welding!




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Re: 1/12 John Deere 870G
 

hydraulic test

http://www.youtube.com/watch?v=h3vfs7y4cEA
http://www.youtube.com/watch?v=YMDPbLjHOt0

running at 28bar it wont drag itself with the stick not sure if it should?

Re: 1/12 John Deere 870G
 

Looking good!

Re: 1/12 John Deere 870G
 

Sweet! It's about time you posted pics and video! I doubt that any of them would have the power to drag themselves across grass. Lookin good! How fast are you spinning your pump? I bought an infared tach a few days ago and found out that the pump in my Volvo is turning at 5900+rpm:eek:.

Reg

Re: 1/12 John Deere 870G
 

Reg i tested a bit more today it dragged itself across concrete no problem but on grass it just stalls the stick, according to my calculation the motor shouldnt run any faster than 4200 unloaded on a 4s lipo, maybe i will get a tach to check what speed mine is doing, 5900 its pretty quick! arent the pumps only rated for 5000rpm? hasnt stopped raining all day so havent be able to test outside, hopefully over the weekend i can give it a proper test drive.

Re: 1/12 John Deere 870G
 

Sounds like it is similar to my volvo for power. I'm not sure what the production machines are capable of though(more/less)? I know that my pump is spinning way faster than I would like! It could stand to turn a little slower but not too much. I think a larger pump would have been much better for my machine. Hopefully you get the weather to try it out some more, and of course post more video!

Reg

Re: 1/12 John Deere 870G
 

couple more videos, doesnt dig very well the soil is heavy and sticks to the teeth, also i think my bucket geometry is slightly wrong
http://www.youtube.com/watch?v=IaFfVZTRV0c
http://www.youtube.com/watch?v=9GswNyT77bI

Re: 1/12 John Deere 870G
 

Dude that excavator is huge! Awesome! Looks to me like it is digging pretty well. It looks like the ground is pretty hard and like you said sticky, so I doubt most would even scratch the surface.... You've inspired me.... I'm goin to film a video of what I've been up to today... Thanks!