Search the Community
Showing results for tags 'praga'.
Found 1 result
-
Hey everyone! For the first time Toronto, Canada is going to have a Truck Trial race . This is my WIP topic for my entry - a 6x6 truck based on the Praga trial truck, as seen below: The goals for this model are as follows: Performance prioritized over looks - a bulkier or uglier design that is more robust will be favoured over a cleaner design. The primary goal is the best possible offroad performance Highly robust transmission and steering - I want to make sure that none of the mechanical functions are going to fail under pressure 6x6 drive with diff locks on all 3 axles 2-speed gearbox Winch My plan for this MOC is to reuse many of my successful design ideas from my most recent Unimog U5000, but with a couple of key improvements: Reusable ideas Robust transmission setup - by gearing down the transmission close to the wheels, pressure is reduced on sensitive components such as universal joints and differentials Gearbox - the gearbox design, based on @Sariel's heavy-duty gearbox idea, was very reliable Pneumatic diff lock mechanism - this was also working very well Features needing improvement Steered hub robustness- the steering hubs on the Unimog were too weak Steering strength - the small linear actuator used for steering turned out to be too weak under the weight of the finished model, as @nerdsforprez originally anticipated (if only I had listened ) The first decision I have to make is how to power the model. Although I was happy with the power output of 2 XL motors with BuWizz on the Unimog, this MOC will be even heavier, so I can either gear the motors down further or power it with 4 XL motors and 2 BuWizz (which is the more fun but more expensive option). I also have to decide how I am going to build the robust front axle I want. I'm leaning towards using the LEGO Unimog portal axle hubs. Despite their poor turning radius, they are probably going to be more robust than any custom portal axle I could possibly build, but if anyone disagrees I would love to hear your arguments . As for the steering mechanism itself, I am thinking of either using a large linear actuator, although it will be difficult to fit in the limited space without limiting turning radius, or alternatively, a large rack and pinion with a worm gear setup. I am leaning towards the latter, but this will be a bit more tedious due to the extra gearing to reduce the speed and the fact that I would like to add a clutch mechanism of some kind so as not to break any components. Here is some WIP for the front axle: I am looking to make this my best trial truck yet, so all comments are welcome and appreciated! I'm looking at you @Zerobricks, you said there was room for improvement on the Unimog and you could give me some advice on my next MOC , so please feel free to do so!