August 20, 20231 yr Author 55 minutes ago, SaperPL said: Can't the last design, the one on the bottom, be used here though? If the steering selector stick is put into the top right hole like in the photo, it'd be inconvenient to pull it out when it's blocked onĀ all 4 sides.
August 21, 20231 yr The suspense! I hope you will make the deadline and come up with a fix for the steering modes!
August 21, 20231 yr Author I will make it in time!Ā Crane is already built and works perfectly. Steering mode works perfectly. I even came up with an improvement during the build. Will show later. Currently digging through my sets to get the pieces I need.
August 21, 20231 yr Author Here it is! Ā Sorry for the potato quality, I don't really have photograph equipment with me. Usually I'd book a professional photography session, but given the tight deadline I'd have to make do. Ā Edited August 21, 20231 yr by Ngoc Nguyen
August 22, 20231 yr Author It's daytime in my place now so there is more light. That allows me to take some photos of this model in a more flattering light. Look how cute this is.
August 22, 20231 yr Author A study of a compact 3 mode steering structure. Ā 1. Front axle Front wheel steering is connected to a liftarm running parallel to the chassis. Ā This liftarm is connected to two 2L liftarms in the back. One 2L liftarm isĀ above the spine connected to the axle going through the turntable, serving as a HOG. Ā One 2L liftarm is below the spine and connected to the cam piece through the 3L axle in the middle. The cam piece serves as one half ofĀ the selector mechanism. Ā 2. Rear Axle Rear axle steering rack is also connected to a 2L liftarm above the spine. Ā Ā 3. The Lock Position. The Lock Position ensures that the transmission from the HOG doesnt affect the rear axle, and at the same time prevent the rear axle from steering. Given the slack in the liftarms and frictionless pins, that is impossible, but at least the lock position restricts the steering of the rear axle. Ā 4. The Selector Mechanism The selecter mechanism has two parts. The first part is the cam piece mentioned above. The second part is this red submodel. Ā It has four holes, and the bottom left hole is connected to the rear axle steering. Movement from the HOG will reach the cam piece beneath the red submodel, and the cam piece will connect to the red submodel if aĀ selector piece is put into one of the top two holes: - Top left hole allows crab steering - Top right hole allows 4 wheel steering. Bottom right hole fixes the selector to a horizontal line, so it locks the rear axle steering, so this allows front wheel steering only. Given that the red submodel is connected to two points at a time at most, and both of them are loose connectors, and if no steering mode is chosen then the red submodel can rotate around the bottom left pin hole and , there should be another connecting point to stabilize it. Since it's gonna move back and forth during the steering, I decided to let it slide along an axle. Ā 5. The Selector Piece and the lower half of the selector mechanism. Even though the final solution is straightforward, it took a lot of thinking to get it right. There are lots of constraints to take into account. - It must not be too long, because the cabin when rotated backwards will be above it. - It must not be too shortĀ so that pulling it out is not too difficult. - It must not be 1L thick so that there is room for movements during steering. It should also ideally: - Be held firm enough to not fall out during play - Be held not too firm to make pulling it out too difficult. Ā Ā The selector mechanism has two halves, as mentions above. The upper half -Ā the red submodel -Ā design is finalized, so only the lower half can change. A couple of options: Ā - Piece 98585 with pin hole underneath + Axle 3 with stop: Result: Axle falls out too easily. Also too short so pulling out is a struggle. Ā - Piece 98585 with axle hole underneath + Axle 3 with stop. Result: Axle is held firm, but pulling out is even harder. Ā - Piece 98585 with axle hole underneath + Axle 4 with stop. Result: Axle is held firm, pulling out is slightly easier. But it's not the degree of ease that I want. That was when I thought of using the cam piece, and only one of it. The cam piece still has axle so it can still hold the axle, but it's made of a softer plaster, and there's only one of it, it has a slightly looser grip. And that's my final design choice. Ā And that concludes that study. Thanks for reading.
August 22, 20231 yr Seeing the mechanism in the original Claas set, then in Nico71's mini and now this one. Each a little different from each other, but each working very well. The whole concept of this mechanism still amazes me and how you figure this out to make it smaller is no small feat. Kudos. Ā Ā
August 22, 20231 yr Nice model and that steering mechanism is just brilliant. Really well done, especially for a (somewhat) last minute model!
August 23, 20231 yr Author Even though the contest entry has been submitted, there are still a couple of features I'd like to work on before I publish this model. Help wanted: I need suggestions for the fender. When I built this model in Studio, there's a gap between the fender and the tyre. Ā But in real life due to the weight the tyre will rub into the fender. The same happens to the front fender.Ā Ā One solution that I tried is to cut back on the thickness of the fender and move the wheels outwards by 0.5 stud. The wheels no longer rubbed against the fender, but the tractor looks weird. The wheel are too far from the body, and the fenders dont even look like they will do what fenders will do. Ā I can't really raise the fenders because the front one will interfere with the hood during steering and the rear one will interfere with the cabin rotation. I also did try the middle Technic panel 2x3, but that piece is still 1 stud thick at the axle holes so the wheels still rub. Also there's no way to fix it in place for the front fender. Ā So I think this problem can only be solved with System pieces, as they allow lower thickness. The problem is that I have very limited knowledge of System pieces, so I can use some suggestions. Ā This is one solution that I came up with, but I'm not quite fond of it because I'd like the fender cover to be slightly lower, like in the middle of the row. Also it's just 1 stud thick, and it'd look better if it can be longer to the outside to cover the wheels properly. Ā Any idea? Edited August 23, 20231 yr by Ngoc Nguyen
August 23, 20231 yr You found a very nice solution for the three sterring modes. It took me quite a while to understand it. I never was a big friendĀ of the original mechanism in 42054 because of the huge slack and inconvenient operation. Just a suggestion to reduce the remaining slack: You could replace the 2L liftarm above the spine for the rear axle by twoĀ thin liftarms with axleholes. So you could use a blue axle pin withĀ friction (or a tan axle pin without friction ; just try both) instead of the grey pin without friction, which is responsible for a part of the slack. Maybe a red 2L axle could deliver good results as well. Edited August 23, 20231 yr by Timewhatistime
August 23, 20231 yr Author 4 hours ago, Timewhatistime said: Just a suggestion to reduce the remaining slack: You could replace the 2L liftarm above the spine for the rear axle by twoĀ thin liftarms with axleholes. So you could use a blue axle pin withĀ friction (or a tan axle pin without friction ; just try both) The problem with slack is mainly the slack in the rear axle, while your approach only increases the friction for the HOG and the front axle steering though.
September 10, 20231 yr Author The instruction is online! https://rebrickable.com/mocs/MOC-158407/nguyengiangoc/mini-42054-claas-xerion-5000-trac-vc
September 30, 2024Sep 30 Author I shared this model in a Facebook group for Lego Technic and among the likes I got there is one from none other than the legendary himself!Ā Ā (I did check the fb, it looks like it's real)
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