Doc_Brown Posted April 21, 2013 (edited) Hello everyone! I started work on this, with the goal of having independent suspension and gearing down after the differential. I have hit a snag, hard to see, but the gearing "cracks" after the diff, because it can move from each other. Its really bad and when geared with 12t and 20t will not even move on level ground under its own power! When geared with 8t and 24t it will move but slightest bumps will cause it to grind gears. There is just no room between the gears and universal joints for reinforcement. You will also probably spot the plastic washer I made to stop the diffs from being torn to a pulp. Many wont approve of this, but I only have 2 good ones left! And need to protect them as they are a little pricy to replace. This does work very well tho. Has anyone succeeded in gearing down after the diff on independent suspension before? Any ideas or advice would be greatly appreciated, at this point I'm going to scrap this and start again, perhaps forget about gearing down after the diff. Thanks Edited April 22, 2013 by Doc_Brown Share this post Link to post Share on other sites
pint14 Posted April 21, 2013 I think you should change the diffs and use knobs or other gears.But there is a solution that you put both sides the 24gear(you have already playced one), just put it on the other side too, i think it will stabilize the diff.(hope you understand me). Good luck with building!! Share this post Link to post Share on other sites
Doc_Brown Posted April 21, 2013 I think you should change the diffs and use knobs or other gears.But there is a solution that you put both sides the 24gear(you have already playced one), just put it on the other side too, i think it will stabilize the diff.(hope you understand me). Good luck with building!! Yes I understand you, thank you! I have a set of gears both sides of the diff. I'm going to make this in lego designer and hopefully its easy to see. Share this post Link to post Share on other sites
Zerobricks Posted April 21, 2013 Those Cv's cant carry the torque required to such big wheels... Share this post Link to post Share on other sites
Doc_Brown Posted April 21, 2013 (edited) Those Cv's cant carry the torque required to such big wheels... Yes, already destroyed 2. Haha This will not be a serious off roader, more of a display piece. But still has to move on level ground!!! Just made this. lego by Doc_brown1, on Flickr Where the arrow is it grinds, just can't think how to reinforce. The universal needs to be there. Edited April 21, 2013 by Doc_Brown Share this post Link to post Share on other sites
pint14 Posted April 21, 2013 Well i used same solution in my previous crawler, just without diff. U need to put piece top of the 12 gear to stabilize it.(the axles on top of the diffs must be 1 sutd longer. You could use this part for top of the 12 gears: Share this post Link to post Share on other sites
DLuders Posted April 21, 2013 Your Lego model of the Patria AMV 8x8 will be cool when you finish it: Share this post Link to post Share on other sites
cgg199 Posted April 21, 2013 This is what i have come up with. I don't know if it'll work for you, but it's worth a try. Share this post Link to post Share on other sites
timslegos Posted April 21, 2013 You might have too much friction in all the gearing which might contribute to the problems. Of topic but you always have really nice pictures, what camera do you use? tim Share this post Link to post Share on other sites
Lakop Posted April 21, 2013 I have had a similar issue with a mini remote model I was working on. In my case the motor would "pop out" taking the small gear with it. Using the right gears in the right place for the size of wheel etc is very important. In your case I would make my own diff with bigger gears. Look forward to the completed model and lots of nice pictures. H Share this post Link to post Share on other sites
Doc_Brown Posted April 22, 2013 This is what i have come up with. I don't know if it'll work for you, but it's worth a try. Thats fantastic! Thank you very much for that idea will have a go. I have had a similar issue with a mini remote model I was working on. In my case the motor would "pop out" taking the small gear with it. Using the right gears in the right place for the size of wheel etc is very important. In your case I would make my own diff with bigger gears. Look forward to the completed model and lots of nice pictures. H Thank you. I use a Canon 550D with standard 18-55mm lens. I got it for an insane price of $600 (elsewhere were 1000-1100) On Australia day sales last year. Your Lego model of the Patria AMV 8x8 will be cool when you finish it: Yes I really hope so! I have 2 containers full of grey Lego plates, never been used just waiting. I'm so excited about detailing it too, can't wait! Share this post Link to post Share on other sites
Doc_Brown Posted April 22, 2013 This is what i have come up with. I don't know if it'll work for you, but it's worth a try. This worked! Thank you so much, I'm very excited. 1,000,000 points to you! Share this post Link to post Share on other sites
cgg199 Posted April 22, 2013 YES!!! Feeling like a legend. I'm glad it worked, and if you need anymore help, just hit me up. Share this post Link to post Share on other sites
Someonenamedjon Posted April 22, 2013 I bet it will look AWESOME when it is done!! Share this post Link to post Share on other sites
Paul202 Posted May 2, 2013 Yes, I loved 8x8 Military Vehicles, however very few people make then. :( I tried to make a BTR-80 about a year ago, however it can't scrapped due to my lack of building skills. If this is successful then I may reattempt to build it. Share this post Link to post Share on other sites
Boxerlego Posted May 3, 2013 You will also probably spot the plastic washer I made to stop the diffs from being torn to a pulp. Many wont approve of this, but I only have 2 good ones left! And need to protect them as they are a little pricy to replace. This does work very well tho. WOW! This is excellent. I definitely approve of this. How did you make the plastic washer and is the plastic flexible? Great job on the 8x8wip. Share this post Link to post Share on other sites
Doc_Brown Posted May 4, 2013 (edited) WOW! This is excellent. I definitely approve of this. How did you make the plastic washer and is the plastic flexible? Great job on the 8x8wip. I make the washers from the top of an old tumbler ware lid. I found its the perfect thickest of 1mm. Yes it is flexible, but I feel if it were more stiffer it would perform better. It does make a heck of a difference tho, but unfortunately under very high stress will still grind gears, but does save a lot of wear and tear on the diff. :) YES!!! Feeling like a legend. I'm glad it worked, and if you need anymore help, just hit me up. Thanks again, Hopefully I will get a chance to. Unfortunately the new wheel hubs are kinda crap IMO. So I have switched to the 8070 set ones. They turn and dont "lock up" at all. Much better. Lost the gearing down after the diffs tho. :( I bet it will look AWESOME when it is done!! HAHA thanks, I sure hope so too. Yes, I loved 8x8 Military Vehicles, however very few people make then. :( I tried to make a BTR-80 about a year ago, however it can't scrapped due to my lack of building skills. If this is successful then I may reattempt to build it. Sweet! Can't remember if the BTR of the top of my head is independent or like pendulum. How did you try yours? still waiting on my orders. Geez I hate waiting when I have so many things to do and make. Edited May 4, 2013 by Doc_Brown Share this post Link to post Share on other sites
efferman Posted May 4, 2013 why you not use my planetary gear rims? you can use it for independent suspension too and you would have an 4 to 1 reduction within the rims 100_0459 von efferman auf Flickr Share this post Link to post Share on other sites
Paul202 Posted May 4, 2013 Sweet! Can't remember if the BTR of the top of my head is independent or like pendulum. How did you try yours? still waiting on my orders. Geez I hate waiting when I have so many things to do and make. The BTW has independant suspension. The farthest I got in my moc was only 1 axle, however I am reading through Sariel's book so when I have another attempt it will be better. Share this post Link to post Share on other sites
Doc_Brown Posted May 5, 2013 why you not use my planetary gear rims? you can use it for independent suspension too and you would have an 4 to 1 reduction within the rims 100_0459 von efferman auf Flickr This is awesome! I just followed the LDD, and its great, unfortunately I just don't have enough turntable parts. But many thanks tho! Share this post Link to post Share on other sites
Imanol BB Posted August 28, 2015 hi, i saw this topic, and i tried to make a more stronger transmission, i used the planetary hub idea from Efferman to make this, it is supossed to use the 8 teeth universal joint (marked in green), so, the reduction from the diff is 4:1 instead of 1:1, i hope you like it and thanks to Efferman for the planetary rim idea: Share this post Link to post Share on other sites
Doc_Brown Posted August 29, 2015 Thanks for sharing that! It looks pretty cool, I might have time tmr to build it and test it out. Would you mind sharing the file? :) Share this post Link to post Share on other sites
Technic Jim Posted August 29, 2015 Thanks for sharing that! It looks pretty cool, I might have time tmr to build it and test it out. Would you mind sharing the file? :) Are you still building this model then? Share this post Link to post Share on other sites
Doc_Brown Posted August 29, 2015 (edited) Are you still building this model then? ImanolBB's Axle? Yes. The actual AMV, I finished ages ago. :D Edited August 29, 2015 by Doc_Brown Share this post Link to post Share on other sites
Imanol BB Posted August 29, 2015 (edited) i forgot it, sorry, here is the file: http://www.brickshel...ry.cgi?f=558594 Edited August 29, 2015 by ImanolBB Share this post Link to post Share on other sites
