fresko Posted February 24, 2013 (edited) Dear Eurobrickmembers, I made a new MOC, the Quad Crawler. It's my first own-made crawler, so I haven't got much building experience with design/building crawlers. I build this MOC because I want to prepare me for the Belgian Outdoor TruckTrail this summer. I wanted to learn some building techniques and receive driving experience. In this moc I use 2XL-motors for propulsion (gear ratio 1:1), and 1 M-motor (gear ratio 1:0.2) for steering. It also has the V2 receiver. The Batterybox lies very low (but the ground clearance is still good), so the model won't capsize fast. The suspension works very well, as you can see on this photo: I was afraid it won't perform good, because I used differentials. Still, it performs much better than I thought (indoor and outdoor) I made a nice video: http://www.youtube.com/watch?v=jmdHidAWGzs More photo's (when folder is made public): http://www.brickshel...ry.cgi?f=523374 I'll upload LDD instructions soon! I'd like your opinion and advice. Greets, Fresko Edited February 24, 2013 by fresko Share this post Link to post Share on other sites
legolijntje Posted February 24, 2013 Nice moc. I don't really like the big gear at the front, but it's Lego Technic, so gears need to be there for a reason . Please note that images on EuroBricks may not be larger than 800x600, as stated in the guidelines here. Please resize them, or make link to the images Share this post Link to post Share on other sites
AndyCW Posted February 24, 2013 (edited) Great first build. It is better than my first crawler. They only get better from here. Understanding fullscale crawler design and the reasons behind them will improve lego cralwers. -Caster angle -Kingpin inclination -Ackerman geometry -Pinion angle -RTI http://en.wikipedia....mp_travel_index -Steering angle -Turning circle Etcetera v/r Andy Edited February 24, 2013 by AndyCW Share this post Link to post Share on other sites
Johnny P Posted February 24, 2013 (edited) hey frederic your moc looks really nice .a nice detail would be that the steeringbar also turns when the wheels turn.but thats just detail. and i think for trial your speed is a little high for precision driving. i also see that you are using diffs. are they limited slip or lockable in a way?because otherwise diffs are not done in trial. another problem for the belgium outdoor trial is that when you use 2 XL motors for drive you MUST use 2 bat boxes. Edited February 24, 2013 by Johnny P Share this post Link to post Share on other sites
fresko Posted February 24, 2013 Thanks for the nice comments! Understanding fullscale crawler design and the reasons behind them will improve lego cralwers.-Caster angle -Kingpin inclination -Ackerman geometry -Pinion angle -RTI http://en.wikipedia....mp_travel_index -Steering angle -Turning circle Indeed, I search a lot of information like steering angle, turning circle and Caster angle before building this MOC. I didn't know the RTI and Pinion Angle, but they looks interesting and it will surely improve my next crawler. your moc looks really nice .a nice detail would be that the steeringbar also turns when the wheels turn.but thats just detail.and i think for trial your speed is a little high for precision driving. i also see that you are using diffs. are they limited slip or lockable in a way?because otherwise diffs are not done in trial. another problem for the belgium outdoor trial is that when you use 2 XL motors for drive you MUST use 2 bat boxes. I has the same idea for a woorking steeringbar, but I thought that I would use another extra motor (best servomotor). I realised me that, if I should use another motor, the batterybox would run out of power faster. You're right, the speed a little high for a Trail verhicle. In this MOC I use differentials without limited slip or even lockable, and I'm surprised about the performance. It isn't bad at all. I'm convinced when using differentials, the drivings is smoother (especially when you steer). But, if i should drive in sand or another outdoor (uneven) surface the differentials would slip. Remember I build this MOC just for understanding building techniques and driving skills, and I have learned much out of this (next time I won't use differentials. I didn't know the rule of 2 BatteryBoxes, thanks for explaining, in this MOC I can fix that in 5 min I'll suerly use your ideas for improving next time! Greets, Fresko Share this post Link to post Share on other sites
fresko Posted March 3, 2013 The instructions for my Quad Crawler are available! Go to http://www.brickshelf.com/cgi-bin/gallery.cgi?f=523695 and chose the .LXF file! Please take a look at the pictures in that folder. They show how you have to fix the building errors in the .LXF file. There is also a complete part list on rebrickable: http://rebrickable.com/mocs/Fresko/quad-crawler Greets, Fresko Share this post Link to post Share on other sites
