2GodBDGlory

Oh, cool! I'm obviously not familiar enough with Bionicle parts!

I'm pretty happy with the progress I've made since the last update! I have: 1. Installed a battery. Space is tighter than I was expecting, so I was forced to use an old 9V train battery (and go buy a 9V battery!) under the floor. In order to hook it up to PF receivers, I'll use an old trick and run one from an output, and then run the second one from on top of that, avoiding the normal incompatibility at the cost of one port. 2. Installed a drive motor. Again, space was tight, so I could only fit a PF M-motor. It runs two long shafts on universal/CV joints with extending segments to reach both rear wheels. I had always planned on using a differential, but in the end I didn't have space. I also forgot about hooking it up to the micro piston engine, so I'll have to take a look at it later. 3. Installed the transformation motor. I had planned on using a PF L-motor, but it didn't have enough torque, and I lacked space for gearing, so I used an Xl instead. It seems to be struggling now, so perhaps some kind of modification is in order. 4. Tweaked the jet-engine deployment. Although the Defender rim looked good, it was too large to work reliably, and got jammed regularly, so I changed it to a Racing Small rim. I changed the mounting point of the cover, and added a small rubber band to make it easier for the engine to push the cover up. I also changed the linear clutch in this mechanism to a ball-joint design I shared yesterday in the General Technic Discussion thread. 5. Added the central section of the roof and its lowering ability. A 3L pin with the axlehole is used to make a linear clutch here, allowing two 2L beams to use linkages to pull the roof down a single stud to get it out of the way when contracting, and to get it back to normal height when expanding. One issue here is that when the Xl is turned off after reaching the end of its travel and stalling, it unwinds itself a little once power is shut off, which often lowers the roof back down. Using the speed control remote, however, seems to mitigate this. 6. Built the sides of the body. This section was very easy to do, and lacks really any detail. I had held off on installing it to keep access to the inside easy, but I decided to put it in now, making it look much more complete. 7. Redesigned the sides of the wing. Originally, I had the sides of the wing fixed upright and the top part sliding freely when contracting. This kept binding up, however, because the linear actuators were too far below the wing and thus didn't pull it straight. To avoid this, I have now fixed the top of sides to the wing with a hinge, and hinged them at the bottom, causing to to go from an | | shape to a \ /. This did mean that I had to sacrifice the elevator that was going to be built in to the wing, but I was doubtful that I'd be able to hook it up to anything at this point, so it was somewhat inevitable. I think I'll be able to keep the rudders, though. I'm reaching the home stretch on this model, I think, with only a few things left to do! These are: 1. Install the steering motor 2. Install the receivers 3. Design some control mechanism for the flaperons. 4. Hook the rudders up to the steering. 5. Hook the piston engine up to the drivetrain 6. Increase the ground clearance at the rear spring mount 7. Decrease the length of the flaperons so they don't collide with the body 8. Make adjustments to many parts of the transformation mechanism for greater smoothness and reliability

Very cool!

Yeah, I've got a stack of those (2x8, 2x4 and 1x2) that I got years ago at a garage sale. They can be quite useful in anything involving the old 9V system, but nothing like it was ever made for PF, presumably because of the totally different plug design and potential for damage if polarities were reversed.

Thanks! I just took a look, and am pleasantly surprised with how cheap they are! They look very useful, so I'll make a point of picking up some should I be ordering from a seller who has them. Looking at the images on Bricklink, it seems that the rubber continues inside and rubs the ball, adding friction. Is this correct? I had assumed that it was just weird decoration, but maybe not.

Sounds good! I've already thought of a promising alternative, proving once again that constraints catalyze creativity.

Yeah, it's perfectly reasonable to not want lubricant; after all, Lego would never do it! The area I was hoping to use it is in the top of the spoiler on my car. In it, the top section has to slide on transverse axles as the car contracts, but because it is so much higher up than the actuators, it usually binds up. I'm not quite sure how else to build it, but I expect I can think of something, though it may involve compromises.

Working on my [TC21] entry, I found myself needing a small yet tight linear clutch that engaged more smoothly than the official one. Inspiration struck, and I built the one seen below: I haven't seen this design before, though it may have been done, so I thought I'd share it. I reckon this would work and be more compact, but I don't own the socket part, so I can't test it. It could maybe also work as a linear clutch/CV joint combo, I guess.

It does look very nice and light! Do you think removing the rear differential would cause too many problems? As it is, I'd expect that it could get into trouble a lot while off-roading, thanks to the open diff.

It does rather seem like this mold was needed to make this locking function work properly, since there cannot be an axle permanently inside it holding the parts together, because the key has to be able to fit. I'm still not sure where it would be useful in Technic, but at least it's designed for that possibility, rather than making it a blatantly single-use part.

Yeah, I agree. It'll definitely have to be a small set!

Interesting challenge! I kind of want to try in Stud.io. Could you clarify the "rules," though? Does every single part need a unique color, such that a 100-piece set would need 100 different colors, or does just every different mold have to have a unique color, so that all doubles of a given part can be the same color?

At least Lego isn't that fanatical about color coding yet!

Thanks for the thoughtful comment! I'd like to build more colorful stuff, but currently my desire for color is less than my desire to save money... [EDIT] My inspiration won't work after all On another note, I just had a stroke of inspiration for two of the transformation functions: the jet deployment and the roof lowering (not built yet). Both of these need to work immediately when contracting and at the very end when expanding. My idea is to put put these functions going the wrong direction but much faster, so that when expanding, one taps the contraction direction for just a second at the very end of the transformation and when contracting, one taps the expansion direction for a moment right at the start. This ought to prevent binding, if it works as expected. I can't wait to get out of class and work it out practically!

Yeah, that's entirely possible, and while it lacks the precision of a gear it's probably more reliable. There are still gears though, just inside the pullback motors!

Or something square like the 3L axle extender with pinhole (or the axle-based version)? Should I take this to mean Jim had a review copy in hand?

Yeah, that's great! I'll keep it in mind!

I'd expect the pullbacks to have at least one gear for the launch mechanism's ratchet, but your point still stands.

Thanks! I haven't taken any video yet, but I'll think about making one. Yeah, there certainly won't be any interior on this one! Today's build session revealed that I had less space than I was expecting, so stuff will be probably be crammed in desperately. I may have to drop some auxiliary functions, too.

It makes my brain hurt too!

Nice, clean, and simple, with some relatively "big-set" parts in a very little set.

Nice work! I recall seeing concrete pumps at work last summer and thinking it would be cool to see a Technic model of one, what with the huge number of boom joints. I look forward to seeing it finished!

Thanks! I'm glad you like it! You're absolutely right that a different color would make it look way better (Azure, orange, red, or now lime green are all good candidates with the wheel arch available), but of these red is the only color I have any significant number of parts, and even then I'm far from where I'd need to be. I could always order parts, but it'd be a lot, and I'm cheap.

I wouldn't be surprised if there are two pullback motors. The Porsche appears to, at least. As for the focus groups, I expect you're right. The two main audiences for a set like this are kids looking for a play model (where pullbacks are great) and adults looking for a display model (where a lack of real functionality isn't missed, though displaying a model with the wheels steered is nice.) The only audience that really loses out here are those who want their Technic sets to reflect real-world engineering, regardless of the looks or play value, but those seem to be the minority...

Like the Zetros? What would it even show in a set that simple?