[WIP] Pajero Pinin

[unimog123]

Oh, well that's good. I also think the upper part of the V4 looks a like a supercharger, which doesn't seem to fit in with the rest of this model.

[piterx]

ok :

after the 3rd re-build of the gearbox, wich had some troubles when too much torque was applied on the 2nd gear, now every gear can make the motors stall.... FINALLY lol

I also added a white gear indicator to know wich gear is engaged to avoid starting the car in 4th gear...

Another good thing is that as the gearbox is more solid than it was it seems that the shifting is smoother.

Immediately after the gearbox you can see a rubber wheel wich is the braking system...i've tried to put disc brakes on the rear axle but it wasn't coming that elegant as it was oversized...

So i decided to put it on the main shaft...it's pretty strong and it will do its work as it can make the motors stall even in 2nd gear :)

The rear live axle needs the panhard rod to avoid side moving...and i also need to reinforce the beam wich is holding the suspension as at the moment it bends

Hope you like it!

if you have any suggestion on things that i could do in a tidier way they're welcome :)

now i just need to give a second built to the shifting mechanism just in order to see if i can make everything tidier

[unimog123]

Well done. What motor are you using for the brakes? I would also put some axle connectors and axles in front of the rear shock absorbers to help stabilize the setup.

[timslegos]

I would love to see a more detailed explanation and recreations of the final gearbox as well as the shifting mechanism. It looks like a great system!

tim

[piterx]

Well done. What motor are you using for the brakes? I would also put some axle connectors and axles in front of the rear shock absorbers to help stabilize the setup.

for the brakes im gonna use a third servo that just arrived at my place :D

i have to fix the rear suspension setup yet...i need it softer than it is now...i might change something

I would love to see a more detailed explanation and recreations of the final gearbox as well as the shifting mechanism. It looks like a great system!

tim

yeah of course i will...i think i'm gonna make instructions for it as i'll probably want to use it for other vehicles in the future :)

[legomuppet9]

i think i'm gonna make instructions for it as i'll probably want to use it for other vehicles in the future :)

I'd sure like instructions for this, it's very nice

[MrNumbskull13]

If you angle the springs in the way a bit more (like in the front) it should feel a little softer... or use softer springs...

[PG52]

Hi, very interesting project ! As all of yours Piterx. The gearbox looks very compact compared to classic gearboxes.

I think that the original creator of this type of gearbox control is NFL77, a french MOCer : http://www.techlug.fr/Forum/topic6787.html?

[piterx]

yeah he's the guy who made the 90° rotation mechanism! very clever idea...i've tried hard to make something different but it's just like the front suspension that nicjasno did...perfect xD

yeah the gearbox is absolutely compact and mainly is stronger than classic ones..the only problem is that its un-synchronized but you can deal with that :)

[JM1971]

Are you doing pictures for instructions when you eventually take it apart.

[piterx]

ahah of course i will XD

so now it's tidy and effective finally!

but the problem is always behind the corner....the autoclutch tends to stop working when too much torque is applied :\

as you may notice i've changed the two L motors with two XL geared up...

edit: problem solved...

the statement is:

"run the clutch and the gearbox at the highest RPM and lowest torque possible"

:)

Edited March 1, 2014 by piterx

[unimog123]

How did you fit 2 XL motors in the same space as 2 L motors? Nicely done, though.

[piterx]

Chassis finished :)

Time for finetuning....wich means dismounting the chassis to move the gearbox 2 studs up -_-

I'll explain what's happening:

as 2 XL motors have a lot of torque, whenever the wheels get into an obstacle, all the torque is spreaded along the clutch and the gearbox's shafts causing dismounting or deforming...that is bad obviously :)

what i've done is gearing up 3 times the motors to have more RPM and less torque (wich are inversely proportional)

the problem is that, at this stage, the gearbox is transferring to the wheels a lot of RPM but such a small torque that the two XL motors are overstressed when i engage the 4th gear...

It means that i need a final reduction after the gearbox to bring back all the torque i want on the wheels...

i really hope this will solve all my problems im so tired of dismounting and re-mounting this chassis...

edit:

ah! the braking sysem works great :D

Edited March 2, 2014 by piterx

[AndyCW]

I learned the same thing when I built my four speed crawler. Reduce the torque input (= increase rpm) and gear down after the transmission.

Are you going to use a single battery and RX to power the 2 XL motors? This will limit their power output.

v/r

Andrew

[piterx]

yeah i think i'm gonna use a single lithium battery...exception made for the steering and the engine every motor is activated alone...

anyway i could consider adding a second lipo battery if the final weight won't be a problem once i fix the driveshaft :)

[HorcikDesigns]

Love it, love it, love it! :D

Will you show how you solved the front axle?

[piterx]

The chassis is DONE

finally...because i was really getting sick of fixing it in the multiple issues it had!

now it works fine, the completely recharged lipo gives enough power to start the car even with the 4th gear...wich is pretty fast!

the gearbox is sturdy and the clutch doesn't get stuck anymore.. and a lot of things are tidier than before wich is something i really like

it weighs 1270g ...

now it's time to build the body, but i think i'm gonna go light as usual, so flexible axles and tubes, and some details more where it needs to have them

do you wanna see a WIP for the bodywork as well or shall i keep it secret till the end so it will be more like a surprise :P?

[timslegos]

I think you should make it a surprise! Also, I am surprised you have so many gears in the steering system. When I introduced gears into the steering system in a truck that I am working on I got major backlash, and the wheels never quite returned to center.

tim

[piterx]

i have 4 gears in the steering system...and yes...they don't return to center as there was only one but it works fine anyway :D

ok so i'll go for surprise :P

i'll just make another thread once i'll finish it :)

[Zerobricks]

Sneak peak would be nice :) And yeah keep it light!

[unimog123]

I would like it a surprise as well, but why make another thread? Do you think a completed model by itself will attract more attention than a WIP?

[Meatman]

Yeah, I would just keep it in this thread.

[piterx]

I would like it a surprise as well, but why make another thread? Do you think a completed model by itself will attract more attention than a WIP?

hmmm yeah i quite think so... just a few of you are following this thread :P

after all this was just a development thread to show you how i've done things in order to give you some ideas

even for a simple tidyness thing, i'd prefer having all the pictures and description in the first post without asking people to find it at the 3/4th page of a wip thread :P

Sneak peak would be nice :) And yeah keep it light!

i might consider that...as long as it doesn't reveal too much :D

[Doc_Brown]

Looking good man! Can't wait to see the body work.

[unimog123]

Maybe you should do a teaser video or picture, like efferman did with his Mercedes G.