Trial truck Unimog (WIP)

[jorgeopesi]

A easy trial truck with 2 gears and steering with a small linear actuator, with Hispalug trial truck rules.

http://www.youtube.com/watch?v=3VGVS4XgWTk&feature=plcp

[Edwin Korstanje]

Looks very good so far Jorge.

Good slow steering, that's good for Trial and a lot off torq and 2 speed gearbox, can't wait to see the Unimog body

[jorgeopesi]

The body is the most difficult thing . I like to test with new steerings systems as you say this may be a strong one for trials but needs more room that a normal one, it isn´t possible to put a piece more in the front axle .

Edited November 27, 2012 by jorgeopesi

[AndyCW]

You might have it geared down too much. What are its current two gear ratios?

[timslegos]

I agree that there is not a large difference between ratios. Great frame otherwise!

tim

[jorgeopesi]

You might have it geared down too much. What are its current two gear ratios?

First gear 10´4:1

Second gear 6´24:1

You are right Tim, there isn´t a large difference but it was the smallest gearbox I can get, only 4 studs of gearbox between the Lego unimogs parts (Steering Ball Joint Large Receptacle) with the least possible number of gears, only 26 gears from both XL motors to wheels.

16 Tooth with Clutch X 7

20 Tooth Double Bevel X 2

12 Tooth Double Bevel X 1

16 Tooth X 4

20 Tooth Bevel X 2

12 Tooth Bevel x 2

8 tooth X 4

24 tooth X 4

Edited November 28, 2012 by jorgeopesi

[AndyCW]

Wow! That low gear is really low with 2XL motors. 5:1 on 2XLs is about right. It seems as though your second gear should become your low and your new second gear should become somewhere in the neighborhood of 4.2:1.

Disclaimer: I don't know the Hispalug rules for TT and all of my experience comes from building cralwers. This most certainly has some influence on any advice I may provide.

I suppose with a large enough body, the gear ratio may begin to make more sense.

[jorgeopesi]

Hispalug rules:

The vehicle

- The vehicle should look like a real one.

- All wheels drive.

- Must have cabin with seats and steering wheel (not functional).

- Must have a fake engine and make it work. Furthermore, the number of cylinders to be consistent with the type of vehicle.

- Rotation of the vehicle must be produced by steering wheels. In no step can be performed by changing the speed or direction of rotation of the wheels of different side.

- Tracks are not allowed.

- The all-wheel drive has to come from a single common transmission.

- Maximum permissible width including wheels 25 studs.

- The basic configuration of axles, steering axles, and relative distance between them must exist in at least an equivalent vehicle real.

- All wheel and tire combinations are allowed provided they are original LEGO pieces.

- All functions must be controlled remotely.

- Active suspensions by remote control are not allowed.

Electrical System

- Use appropriate original Lego motors always fed their nominal voltage (usually 9v or lithium)

- Only wireless systems can be used for vehicle control (PF, RC NXT or PBX).

- A maximum of 2 XL motors for traction regardless of vehicle size.

- It enables the use of up to 2 channels PF, or 4 independent functions in case of using NXT.

Parts not allowed

- Prohibiting the use of modified parts (cut, glued, painted or similar)

- Prohibited use of parts other than genuine Lego except: tires, ropes and cloth as decorative elements only.

[jorgeopesi]

I don´t like it yet, it is so big but is real... well... actually more a zetros that an unimog but still WIP . I have to put the yellow shock absorbers, the cabin has a lot of weight.

[Edwin Korstanje]

Well Jorge, it don't like a zetros either , but a good first try

Edited November 29, 2012 by VFracingteam

[AndyCW]

You might want to try the grey springs before you jump on the yellows. You want just enough spring to hold it up and upright without inhibiting articulation.

[jorgeopesi]

You might want to try the grey springs before you jump on the yellows. You want just enough spring to hold it up and upright without inhibiting articulation.

You are right, I will try first the grey ones. Building that awesome vehicle I am thinking of doing a real one, with ptos, differential locks, gearbox and everything that I can put in, it could be difficult but that is the challenge, with everything RC of course. Seeing that I can do it more studs wide and longer may be I have room enough.

Edited November 29, 2012 by jorgeopesi