Zerobricks Posted August 20, 2014 Posted August 20, 2014 Here's my attempt to add steering to the awesome UCS tumbler: Quote
S.I Posted August 20, 2014 Posted August 20, 2014 Nice idea. I hope that doesn't result in too much torque being applied to the remaining fixed connection. Quote
nikolyakov Posted August 20, 2014 Posted August 20, 2014 I think, back of the tire will touch the chassis. Quote
Rishab N Posted August 20, 2014 Posted August 20, 2014 That looks interesting. Looking forward to seeing it on the real thing Quote
Blakbird Posted August 20, 2014 Posted August 20, 2014 Having just built the Tumbler, I can tell you that this solution won't work. The problem is that the tire is much wider than the wheel and is already touching the support arm. In order to add even a little bit of steering, you'd have to move the whole wheel inboard one stud. To get a good steering lock, you'd have to move more than that which would throw off the scale of the model. To keep the wheels where they are, you'd have to change the support arm to be only one stud thick instead of two which would be too weak in torsion to support the weight. Quote
Paul Boratko Posted August 20, 2014 Posted August 20, 2014 Eric, are those Gold hubs just as wobbly as the LBG ones..? Our 2 sets are coming tomorrow... Quote
Rishab N Posted August 21, 2014 Posted August 21, 2014 Little OT but Shop@Home hasn't been working the entire day for me. Anyone else have the same problem? Quote
JGW3000 Posted August 21, 2014 Posted August 21, 2014 (edited) Rishab, I had the same problem, try logging out and then back in from the main Lego.com page Edited August 21, 2014 by JGW3000 Quote
Rishab N Posted August 21, 2014 Posted August 21, 2014 Rishab, I had the same problem, try logging out and then back in from the main Lego.com page Doesn't work I keep getting lines and lines of code and some sort of "http status 500" Quote
Lipko Posted August 21, 2014 Posted August 21, 2014 (edited) Having just built the Tumbler, I can tell you that this solution won't work. The problem is that the tire is much wider than the wheel and is already touching the support arm. In order to add even a little bit of steering, you'd have to move the whole wheel inboard one stud. To get a good steering lock, you'd have to move more than that which would throw off the scale of the model. To keep the wheels where they are, you'd have to change the support arm to be only one stud thick instead of two which would be too weak in torsion to support the weight. That's why I said in the Tumbler thread that increasing size actually makes incorporating steering harder than easier. Sariel's solution is the best I've seen so far, and it still looks a bit off. I'm struggling with this problem for a while now, built many versions, maybe I will have to give up the project. Edited August 21, 2014 by Lipko Quote
Zerobricks Posted August 21, 2014 Author Posted August 21, 2014 Too bad it does not work... Well I gave it a try... Quote
gmshades Posted August 21, 2014 Posted August 21, 2014 I wonder if there are pictures out there of how the real tumble steers? Maybe that will help in the design for the Lego Tumbler. Quote
Zerobricks Posted August 21, 2014 Author Posted August 21, 2014 The real one uses hydraulic arms to steer the wheels, simillar to my idea... Quote
gmshades Posted August 21, 2014 Posted August 21, 2014 I noticed in Jay Leno's video driving the Tumbler, it is similar to your design. However, the steering pivot on the real car is inside the wheel hub. Lego's pivot is outside the wheel. When will Lego fix this?! Quote
Technyk32231 Posted August 22, 2014 Posted August 22, 2014 I noticed in Jay Leno's video driving the Tumbler, it is similar to your design. However, the steering pivot on the real car is inside the wheel hub. Lego's pivot is outside the wheel. When will Lego fix this?! Never. Not even the 8448 wheels pivot in the center, and I doubt that Lego would use advanced steering geometry like kingpin inclination or multiple steering links that have an imaginary pivot point. Quote
Lipko Posted August 22, 2014 Posted August 22, 2014 (edited) I don't think the steering pivot is a huge problem with the Tumler, at least it doesn't have mudguards. Okay, the wheel can't turn as much before hitting the suspension arm. An exaggerated Ackermann would give decent turning radius while the outer wheel still wouldn't reach the suspension arm. Edited August 22, 2014 by Lipko Quote
jovel Posted August 22, 2014 Posted August 22, 2014 @Lipko Go ahead! I forgot to mention in my previous post - but I also think it is pretty clear - that if you want to use this system in the Tumbler, you gonna have to completely rebuild the whole front ( and also wil need to make some changes to the styling parts ). Quote
Zerobricks Posted August 23, 2014 Author Posted August 23, 2014 Thats a great solution with a nice virtual pivot point! Quote
drdesignz Posted August 23, 2014 Posted August 23, 2014 ...the tire is much wider than the wheel and is already touching the support arm. I just finished building this last night and the tires do not touch to support arm. The gap is about an 1/8" of an inch or so (4mm, I think). Maybe you installed the wheels backwards? Quote
Paul Boratko Posted August 23, 2014 Posted August 23, 2014 I just finished building this last night and the tires do not touch to support arm. The gap is about an 1/8" of an inch or so (4mm, I think). Maybe you installed the wheels backwards? Would it make a difference which way you install them..? I am looking at them now and it seems it wouldn't matter one way or the other as the wheel offset is the same inside of the tire... What about wobble from the hub...? Does that cause them to rub at all...? I know the play in these hubs is pretty bad... Quote
drdesignz Posted August 24, 2014 Posted August 24, 2014 Would it make a difference which way you install them..? I am looking at them now and it seems it wouldn't matter one way or the other as the wheel offset is the same inside of the tire... I'm not sure... I just removed the wheel and reversed it. The tire is now closer to the support arm, just barely touching with some play in the hub. I thought maybe the offset of the wheel was different, but it looks like it is the same and it's the tire itself that's not perfectly symmetrical. I took pictures. This image shows the wheel installed per the instructions. This one is reversed. You can see a slight difference in the gap. Quote
unicorn Posted September 5, 2014 Posted September 5, 2014 (edited) Just come up this idea. Not sure if it can really work as I don't get the Tumbler UCS yet. :) Edited September 5, 2014 by unicorn Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.