Posted September 9, 20159 yr My goal here is to provide a big vehicle for some robotic application. - length 75cm - width 47cm - height 28cm - wheels 27cm - weight 1,750kg Edited September 9, 20159 yr by oracid
September 9, 20159 yr Looks really good ! like how you used the angled connectors and flex axles for the wheels
September 9, 20159 yr Wow, that performance while climbing that slope! I wonder how can such wheels get a good grip. Anyway, great concept. I'm looking forward to see some robotic attachments :)
September 9, 20159 yr Nice, totally looks like a micro mars/moon rover chassis. I think it will do relatively well on dirt with tons of this in the wheels for traction https://alpha.bricklink.com/pages/clone/catalogitem.page?P=11478#T=C
September 9, 20159 yr Author Thank you everyone for your enthusiasm. Here are some details. Below you will find images of a wheel. The perimeter of the wheel is constituted by axles 16 coated with a silicone tubing between two ½ Bush. Silicone provides excellent grip to the ground, but prohibits lateral rotation. It is for this reason that I have inserted the Bush ½ yellow wich has a slightly larger diameter, which allows the lateral rotation. Sorry, PROlego, I do not understand your idea. Can you clarify?
September 9, 20159 yr Very nice project. It looks so light. Have you tested the wheels with more weight?
September 9, 20159 yr with regards to the wheels , take the tracks from 42028 and join them all in one revert "track" you will get a quite big wheel. Question is if it would not be too expensive... and still you will need to make a rim for it.
September 10, 20159 yr Author Very nice project. It looks so light. Have you tested the wheels with more weight? BIG is ... big! I think if it had been smaller, its capacity would have been lower. with regards to the wheels , take the tracks from 42028 and join them all in one revert "track" you will get a quite big wheel. Question is if it would not be too expensive... and still you will need to make a rim for it. I think I understand what you mean. I have tried many solutions but this one seemed the most effective to me. I have another idea which I will speak later for future release. Edited September 10, 20159 yr by oracid
September 10, 20159 yr Great model! It looks like a bridge on wheels Sorry, PROlego, I do not understand your idea. Can you clarify?I think, he means about replace Bushes ½ to this details: https://alpha.brickl...age?P=11478#T=C
September 10, 20159 yr Great model! It looks like a bridge on wheels I think, he means about replace Bushes ½ to this details: https://alpha.brickl...age?P=11478#T=C Yeah, that's it, but it will maybe be way too expensive, probably if you already have some and put one every two half bushes instead of in everyone it can be affordable. Kinda like the small paddles in the wheel of the not as famous as it should be Lunokhod. Edited September 10, 20159 yr by PROlego
September 10, 20159 yr Very nice. I wonder though, Do the shock absorbers really work? It looks like their length would not change, unless I need to look at pictures from different angles.
September 10, 20159 yr Very nice. I wonder though, Do the shock absorbers really work? It looks like their length would not change, unless I need to look at pictures from different angles. Last picture provides required view. As you can see, absorbers arent parallel to the vertical axis - bottom pin is shifted by one hole sideway. That creates just a little bit of compression and causes both quite soft suspension and very wide range of movement.
September 11, 20159 yr Last picture provides required view. As you can see, absorbers arent parallel to the vertical axis - bottom pin is shifted by one hole sideway. That creates just a little bit of compression and causes both quite soft suspension and very wide range of movement. Thank you, I knew I was missing something rather obvious :)
September 11, 20159 yr Author @PROlego. I understand what you mean now. Don't forget that the main thing is to have enough grip to the ground. I am not shure this piece help much instead of silicone tube. The 1/2 bush are here, not to grip, but to allow sided rotation. This because silicone grip to much and prohibits sided rotation. To understand what I mean, please look at this http://www.thingiverse.com/thing:638687 Thank you WINNER for explanation. @DrJB. Yes, of course, the shock absorbers work very well as you can see in the video. Thank you everybody.
September 11, 20159 yr Yeah, I meant for traction in dirt, which is the typical place where a Moon or Mars rover would be
September 11, 20159 yr That's a lovely machine! I have been experimenting with various designs for large wheels for some time. I am surprised by how sturdy these appear to be. Great work!
September 12, 20159 yr Author Yeah, I meant for traction in dirt, which is the typical place where a Moon or Mars rover would be Yes, on Mars, maybe it would be nice ...but on Earth, I tried several things like this and it was not very effective, but I study a new principle that I hope you will appreciate, I will come back on this problem. That's a lovely machine! I have been experimenting with various designs for large wheels for some time. I am surprised by how sturdy these appear to be. Great work! it's a shame that Lego does not make a very big wheel. For robotics, I think Lego should consider a larger scale. Great model! It looks like a bridge on wheels I think your point is very important. This bridge-like structure is at the root of the rigidity of the rover.Perhaps you've noticed that I had already used for Porcupine, http://www.eurobricks.com/forum/index.php?showtopic=110044&hl=porcupine Edited September 12, 20159 yr by oracid
February 16, 20205 yr On 9/9/2015 at 10:18 AM, oracid said: My goal here is to provide a big vehicle for some robotic application. - length 75cm - width 47cm - height 28cm - wheels 27cm - weight 1,750kg  Hi we spoke on youtube please see attached image  the 2 parts in circles and the 1 with the arror pointing to it . what are the bits called . and what is the total diameter of the wheel it self best regards james Â
February 17, 20205 yr Author Hi. Here some pictures and links those I hope they will help you. The wheel diameter is 27cm. Each yellow bush are separated with soft silicon tube. https://www.bricklink.com/v2/catalog/catalogitem.page?P=32034&idColor=86#T=C&C=86 https://www.bricklink.com/v2/catalog/catalogitem.page?P=10288&idColor=120#T=C&C=120 https://www.bricklink.com/v2/catalog/catalogitem.page?P=6538c#T=C https://www.bricklink.com/v2/catalog/catalogitem.page?P=4265c#T=C https://www.bricklink.com/v2/catalog/catalogitem.page?P=43093#T=C Â Edited February 17, 20205 yr by oracid
February 19, 20205 yr Wow, just saw the video (had not seen the original post from 2015). This is crazy ! It is ingenious ! A lot of discussion happened for the wheel, obviously. But I feel the whole build is educational. Very economical usage of parts as well.
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