JJ2 Posted February 14, 2016 Posted February 14, 2016 (edited) Hello, I noticed that the performance of the original 9398 was not very good so I decided to do this mod including 5 motors. IMG_0086 by JJ2Sam, on Flickr I kept the body original and suspension except shock placement and drive and did extend the wheelbase but kept the original width. The suspension has about ~45* of flex and is responsibly soft and responsive to bumps. I used 2 XL motors in the back, 2 L motors in the front and replaced the servo motor with a M-motor for steering and added 1 pair of headlights. IMG_0116 by JJ2Sam, on Flickr IMG_0117 by JJ2Sam, on Flickr The front axle has a kingpin incline making the wheel pivot near the inside of the wheel making it easier to steer and makes it have less stress on the steering motor. You may be wondering about the use of 2 different motors in the dive chain causing problems in speed differences but your worries can be put to rest because a L motor geared 12/20 is almost the same as 1 XL. IMG_0121 by JJ2Sam, on Flickr Thank you for reading-watching! More pictures on my flickr https://www.flickr.c...6592@N04/albums Edited February 14, 2016 by JJ2 Quote
Zerobricks Posted February 14, 2016 Posted February 14, 2016 How do the 12 tooth bewel gears hold up to the torque of the XL motor? Too bad you didnt use XL motors on all axles while you were at it. Does the angled kingpin noticably help? I love the color combo, lime green is awesome! Quote
Lox Lego Posted February 14, 2016 Posted February 14, 2016 That is solid! I like the double gearing for the XL motors, I'm assuming so the gears don't grind? Also, recreating the same tilted top is a cool feature. What siZe tires are those? Thanks for sharing Quote
JJ2 Posted February 14, 2016 Author Posted February 14, 2016 How do the 12 tooth bewel gears hold up to the torque of the XL motor? Too bad you didnt use XL motors on all axles while you were at it. Does the angled kingpin noticably help? I love the color combo, lime green is awesome! They held up great! I would have used 4 XL's but I only have 2 of they so I had to use L's, Yes the kingpin helped, before I put it in it was impossible to steer even with a servo, after I added it, it worked fine, so I replaced it with a M motor to get a greater steering angel That is solid! I like the double gearing for the XL motors, I'm assuming so the gears don't grind? Also, recreating the same tilted top is a cool feature. What siZe tires are those? Thanks for sharing They do not grind but the front axle does... I am going to fix that before I make instructions, they are 1,9 Ansmann tires Quote
Leonardo da Bricki Posted February 15, 2016 Posted February 15, 2016 Terrific modifications! I might (read: will definitely) use your axle on one of mine. Quote
JJ2 Posted February 15, 2016 Author Posted February 15, 2016 Terrific modifications! I might (read: will definitely) use your axle on one of mine. Thanks! I am going to start making the instructions when I have time... TO MUCH STUFF TO DO! Quote
Rockbrick Posted February 15, 2016 Posted February 15, 2016 i'd be concerned on how strong the ball joints are after a few fast and hard descents... but for careful crawling should be ok Quote
Major_Ton Posted February 15, 2016 Posted February 15, 2016 Dit you use an additional batterypack to power all those motors? Quote
JJ2 Posted February 15, 2016 Author Posted February 15, 2016 I'd be concerned on how strong the ball joints are after a few fast and hard descents... but for careful crawling should be ok the ball joints were fine in the front axle (if those are the right ball joints) Dit you use an additional batterypack to power all those motors? I did not use an extra BB to power the model and it seemed to work fin so I did not add an extra. Quote
Leonardo da Bricki Posted February 18, 2016 Posted February 18, 2016 I totally understand having to much stuff to do. I still haven't had time to photograph and post ANY of my models yet. BTY, instructions is beyond me, except maybe photo-sequence. That I can do. (probably, maybe, not likely.) Quote
nerdsforprez Posted February 18, 2016 Posted February 18, 2016 Great build. But how do you gauge if the front and back tires move at the same speed? They not only have different speeds but different torque output as well. Quote
JJ2 Posted February 18, 2016 Author Posted February 18, 2016 I totally understand having to much stuff to do. I still haven't had time to photograph and post ANY of my models yet. BTY, instructions is beyond me, except maybe photo-sequence. That I can do. (probably, maybe, not likely.) The instructions are actually done but I need to do edit them, make a parts list, submit to rebrickable, and upload them of course Not that hard... Great build. But how do you gauge if the front and back tires move at the same speed? They not only have different speeds but different torque output as well. I used Sariel Gear chart to calculate it, there is about 2-4 RPM difference but when driving on dirt that makes little to no difference. Quote
nerdsforprez Posted February 19, 2016 Posted February 19, 2016 Gotcha....although the gear chart only gives values that are under no load. Because they have different torque, these rpms will change as you drive on different terrain. Sariels gear chart is static whereas driving in real time with different motors will be dynamic. Probably not to a huge degree..... But it is there...... Quote
JJ2 Posted February 19, 2016 Author Posted February 19, 2016 Gotcha....although the gear chart only gives values that are under no load. Because they have different torque, these rpms will change as you drive on different terrain. Sariels gear chart is static whereas driving in real time with different motors will be dynamic. Probably not to a huge degree..... But it is there...... Yes you are right. I have completely finished the instructions so, edit them, make a parts list, submit to rebrickable. Quote
JJ2 Posted February 20, 2016 Author Posted February 20, 2016 I have uploaded the instructions to flickr https://www.flickr.com/photos/136426592@N04/ Quote
JJ2 Posted February 24, 2016 Author Posted February 24, 2016 Everything is done now The rebrickable is in the description Quote
JJ2 Posted February 24, 2016 Author Posted February 24, 2016 Awesome, love the black and lime!! Thanks! Quote
BrianGT Posted February 25, 2016 Posted February 25, 2016 Awesome mod to the model. I built up one of the 9398 sets yesterday and was disappointed with the performance of it as it comes from the box. Looking to replicate a stronger drive train, and was wondering if there is an advantage to using 4 XL motors? Looks like it would be harder from a packaging standpoint to fit them in. Will have to look at Sariel's gearing calculator as well. Thanks for posting up this project! The 9398 should have come this way. (how much would they have charged for it though...) -- Brian Quote
JJ2 Posted February 25, 2016 Author Posted February 25, 2016 Awesome mod to the model. I built up one of the 9398 sets yesterday and was disappointed with the performance of it as it comes from the box. Looking to replicate a stronger drive train, and was wondering if there is an advantage to using 4 XL motors? Looks like it would be harder from a packaging standpoint to fit them in. Will have to look at Sariel's gearing calculator as well. Thanks for posting up this project! The 9398 should have come this way. (how much would they have charged for it though...) -- Brian Using 4 XL motors means you have a lot of power and you can make your crawlers have decent speed. The XL motors are not hard to build in you just have to worry about the torque breaking your pieces so I recommend portal hubs or planetary reductions. On another note if you haven't already look at Zblj's stuff or Sariels hummer to get examples of XL moror uses. Quote
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