looking for as small as possible front axle for 4wd micro truck

[scj]

Hi friends,

I'm looking for as small as possible front axle for my 4wd micro truck. I decide to ask You, because I'm stuck on developing my own for few months. Please, share links/know how. I will be very happy for all suggestions.

scj

[gor Ipsa]

Hi friends,

I'm looking for as small as possible front axle for my 4wd micro truck. I decide to ask You, because I'm stuck on developing my own for few months. Please, share links/know how. I will be very happy for all suggestions.

scj

which tire/wheel combination do you want to use?

Kind regards

Igor

[DLuders]

nolnet created a small (7-studs-wide) Lego Power Functions 4WD Mini Truck, and posted details on his Flickr photostream, Brickshelf gallery,

, and

. As seen in the bottom two pictures below, he used a 5119 9V Micromotor "Illustrating the micro-motor-direct-to-steering-technique. The 3L technic liftarm grips firmly onto the motor's stud."

[Zerobricks]

Dluders, he said 4x4

What about this:

[mahjqa]

More pictures: http://www.flickr.com/photos/28134808@N02/sets/72157623112621657/with/3419434996/

[bricky300]

I think this is the smallest ever: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=3481185 it is Not made by me and I don't know if it works

Edited May 2, 2011 by Rico Geller

[T_Tank]

I think this is the smallest ever: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=3481185 it is Not made by me and I don't know if it works

Looks like its kinda similar to Nico71's lada but its using a combination of this steering part 4261 , 2 12t double bevels, 4 12t bevels, 2 20t bevels, 1 8t, all driven by a worm gear with the steering gear (16 Tooth with Clutch) riding on the drive axle. Pretty smart way of making a super compact steer axle.

Edited May 2, 2011 by T_Tank

[SNIPE]

hi, i spent the last few days building in LDD and made up a front axle unit that i am quite pleased about (whether it works in real life or not is another thing but you can still try to change the assembly to get it to work.)

here is an image, for a 360 view you can download the LDD file here and this will help to build it too

note that where the red ball joints are, they should attach to the red axles, i recommend using the 3L or 4L technic steering arms as i am sure they will fit but if they don't just replace the ball joints with a pin or axle and use something that can be attached to the other default axle such as a technic beam.

if you want the option to make it 4wd,2wd or idle wheels, you can attach the clutch or make one yourself that drives the front diff, it can either make it 2, 4 or no wheel drive if you attach the drive shaft to both of the dark grey gears that mesh with the clutch. (the axle joining each of the two gears by another gear should be separate to each other other so they don't move the other axle when you did not set the clutch to do that)

the front diff only a single slip diff meaning that only the drive shaft can move both front wheels at the same time and in the same direction and the front can also drive the rear if you use the clutch and if it is set in the right position)

the specs are:

4WD/2WD/idler vehicle configurations

independent suspension and universal joint axles for two pivot motion per side

working steering that can have HOG compatibility

disk brakes (not functional of course)

torsion beam suspension and wishbones

diff case and drive shaft angle adjustment

steering shaft angle adjustment

wheel camber angle adjustment (depending on if the rims and tires are big enough to leave a ground clearance to attach them in which case the camber adjustment beams can then be attached and function.

steering sensitivity can be adjusted by adding a larger gear on the same axle, after the small gear then attaching that to the driver (such as a motor or your hand (HOG)

***NOTE*** the height between the wishbones at the end where the diff is (not the spindle and disk brakes) can be adjusted but it will mean taking apart a lot of the assembly and modifying it so that it will fit and still function properly, since this is meant to be a small design i left out the additional parts such as the camber beams and clutch.)

rims and tires i left off for clarity and because i assume they are already specified by the creator of this thread)

here is the LDD file of the assembly

http://www.brickshelf.com/gallery/finneykris/mfr/micro_front_unit.lxf

here is the LDD file of the clutch, and wheel camber adjustment shafts)

http://www.brickshelf.com/gallery/finneykris/mfr/micro_front_unit_with_lutch_and_camber_adustment.lxf

image of it here: http://i52.tinypic.com/v5a73l.png

the blue axle in the camber represents a threaded technic axle of the same length, and the yellow spacers on that blue axle represent technic nuts to adjust the camber)

these are color coded for reference and as mentioned , the red parts in the LDD file of the main assembly represents link points for the suspension link arms.

any adjustments are up to you, it should need to be mounted for-fully which means you need to attach the assembly to the vehicle in the right places in order for the parts to work.

****NOTE**** that if the clutch is set to the middle position it enables 4wd, the other two positions are to select whether its front or rear wheel drive, if you want idle move you have to attach another two grey gears onto of the original two with split axles.

EDIT: here is another image but with different wishbone axle to chassis mounts.

http://i54.tinypic.com/2ed2jy1.png

edited parts are highlighted in green

also the suspension is mounted sideways now to save unneeded height (also in the above image) and i attached some bottom axles to the wishbones as a marker of where it could be mounted to the chassis.

*****NOTE***** here is an image of a longer steering rack,

http://i51.tinypic.com/nn40us.png

also if you attach a larger gear onto the same axle as the original steering spur gear it will control the movement of the original spur gear which means you can adjust the sensitivity of the steering and how much the wheels steer when you turn the axle that holds the spur gear.just as long as the larger gear is connected to what moves the axle. (motor or bevel gears for a vertical HOG steering dial for example)

Edited May 11, 2011 by SNIPE

[Brickend]

The above design won't be able to steer due to the position of the UJ relative to the turning point of the Upright. Nor would the suspension function as you would need two UJs in the space where you only have one.

[efferman]

how wide should be the axle and could it be a portal axle?

13 studs wide (without wheel)

eight studs (without wheels)

Edited May 12, 2011 by efferman

[SNIPE]

the wishbones would move up and down but the wheel will be cambered (tilted) though the ball joints do allow the wheel to tilt the opposite way to it is less cambered.

i don't know if it will work the only way to know is to build it and try it

i dont think you have to have two uk joints as one is making sure the diff does not tild with the wishbones and the other is making sure that the wheel does not tilt with the wishbones

mine only keeps the diff in check but the front ball joints which allow the steering to work by tolding the spindle left and right, can also tilt the spindle up and down so that the wheels will not be as cambered.

the steering might not also work but it can only be verified for certain again by building it and trying it out, this is why i said in the original post that you can move the wishbones further apart (not at the wheel end but the diff end of the wishbones) so that the universal joints have more space to work

i am building a front assembly for my project but i am not as limited to space and the one i built is similar to this one but it has less parts for less to go wrong but it is longer than this one

Edited May 12, 2011 by SNIPE

[RohanBeckett]

I can confirm the steering won't work.

I built a smallish FrontWheelDrive a few months ago:

http://www.eurobricks.com/forum/index.php?showtopic=51830

I skipped the suspension, to keep it simple..

I used the CV joints from the 8297 OffRoader - they work OK, but have a fair amount of friction in them, when the wheels are turned

I don't think there's any legit way of using the steering parts you've selected as drive-able.. they are designed for freewheeling only

I had issues with my steering arms, having to be angled forward, to avoid hitting the differential

The suggestion from Allanp, in my thread helped a lot, as it negated the need for a rack and pinion.

My finished MOC doesn't have perfect return to centre steering, due to to the axle/gear geometry - the self centering ends up being 1 tooth out, so it's not perfectly straight.

It's still fun to drive, though!

RB