e-savage robot project

[Bjorn]

Hi guys,

I'm a guy from Belgium looking for a new project and some advice. I have 2 esavage trucks laying around so I tought lets build a robot. To make things worse I had the brilliant idea to merge them together in order to turn by driving left and right in the opposite direction. So lets see if my idea was actually that brilliant.

After looking at this and then trying , I bumped into a few problems.

1) The shocks are nowhere near powerfull enough to hold its own weight let alone with the actual load (at least 8 extra pounds). Thats why you see no shocks in the picture.

2) The gearsbox ratio is to high. I want more control in the lower rpm's. In other words reduce the max speed.

3) The diffs are not working anymore because I cut the savage in half. So I had to mount the
4 shaft ends of the savages to the chasis which is not that nice because you hear them moving and clicking when you power the motors.

4) the wheels are too flat at this point to drive.

So my question is do you guys have some advice or can you point me in the right directionto modify the savage in order to use it this way. If the advice is to get another platform then you may be right .

Anyway thanks in advance!
Cheers

 

[Bauerdog]

Hi guys,

I'm a guy from Belgium looking for a new project and some advice. I have 2 esavage trucks laying around so I tought lets build a robot. To make things worse I had the brilliant idea to merge them together in order to turn by driving left and right in the opposite direction. So lets see if my idea was actually that brilliant.

After looking at this and then trying , I bumped into a few problems.

1) The shocks are nowhere near powerfull enough to hold its own weight let alone with the actual load (at least 8 extra pounds). Thats why you see no shocks in the picture.

2) The gearsbox ratio is to high. I want more control in the lower rpm's. In other words reduce the max speed.

3) The diffs are not working anymore because I cut the savage in half. So I had to mount the
4 shaft ends of the savages to the chasis which is not that nice because you hear them moving and clicking when you power the motors.

4) the wheels are too flat at this point to drive.

So my question is do you guys have some advice or can you point me in the right directionto modify the savage in order to use it this way. If the advice is to get another platform then you may be right .

Anyway thanks in advance!
Cheers

Wow! love your Frankenstein work so far. That kind of width I'd expect duboling up on big bores. Just to keep it close, lst2 shocks perhaps . Don't give up! Looks wild, can't wait to see vids of it running!!

 

[Bjorn]

I think I found a solution for problem 3 and that is locking the diff. At this point the power of the motor goes to the wheel with the least resistance and this is ofcource the axis with no wheel attached to it. ( You should've seen my face we I powered up this setup everyting was turning exept the wheels) If I lock the diff, both axes should receive equal amount of power. Or am I wrong?

 

[Bjorn]

@Bauerdog: Tanks for the reply. These shocks are massive . I wonder if they fit!

 

[Jam Racing 1]

To answer your question yes locking the diffs will send power to both wheels equally, providing the center differential is also locked down if so equipped.....

also to stiffen the shocks you can also try very heavy springs and oil to help or as suggested use either some big bores or losi lst shocks with heavy springs and oil...

Good Luck with the project and keep the pics coming...

 

[mikelh]

That is a wild looking contraption! Very cool!

 

[Rmadrid7]

I like the fuel you are posting in the pics...Jack Daniels, Johnny Walker...etc. are they 25% nitro? with this tipe of fuel you will able to build 4 Savages...

 

[francis Labarbara]

Can I have the bodies? It doesnt look like you will need them

 

[Bjorn]

Can I have the bodies? It doesnt look like you will need them

no can't do that sorry, If the setup does not work in the end I just convert everyting back to normal.

 

[Bjorn]

have a look at these ( sorry its in dutch):
https://www.toprc.nl/losi-front-sho...YSJCJs-YhRIYpDVnurVMdjTqu-tqd9zmZEaAqc98P8HAQ

https://www.toprc.nl/losi-rear-shoc...9Nbggsa-JiZGWyUNA6Bl8u-qCR5SS-fjtwaAmmj8P8HAQ

these are 1/5 shocks made for the losi dessert xl buggy. I realise I have to somehow come up with a connection plan to mount it on the arm and the tower.

 

[Bjorn]

So just to tell what i'm doing now.

Just to have an idea how big it is .

I have 4x 4000 mah battteries 30C. So this should give me a peak power of 120 Amps.

I'm preparing the motor power connection to be compatible with the LiPo batteries. Just need to go to the store and get some shrink protection.

This should be my control unit. the bottom pcb is an old lynxmotion SSC32 with 32 servo channel (motor controllers and servo's). The left pcb is a breakoutbord for the wifi bluetooth gumstix processor which is running linux and on the right of course the playstation 3 controller. In the future I need to amplify the range of the controller ( By using a 433 or 866 Mhz transmittor or something ). If everything goes well I should have a running truck video this weekend with the stock controller.

I disabled the steering servo at this point. So in order to turn I need to power the motors in opposite direction. I hope the diffs can handle the torque. I have a vague feeling that this won't work and need to go back to the steering servo's. Future will tell...

 

[Rmadrid7]

Are you working on a project for NASA? Wow!

 

[francis Labarbara]

Even if the diffs can handle the torque you will quickly remove the tires from the wheels.

 

[Bjorn]

Yeah I know, we'll see. I got everything working now. It's doing what I want. I will post a video later this day. It's raining outside at the moment.