Thierry-GearsManiac

I've vaguely heard of Let'sEncrypt from my friend who enabled HTTPS on my personal Web space ; however I'm rather "dumb"(unskilled) in this area of computer science, so that I don't exactly understand everything you are saying, except that it is positive.

This reminds me what one of my former bosses told me almost twenty years ago about the future of the Internet (heavily plagued by E-Mail spam at that time) : Internet would evolve towards a two-tiered, two-class, double standard system where you would either be free/independent but exposed to malicious actors (pirates, spammers etc...), or gain access to some degree of protection at the cost of becoming dependent on commercial/big actors (it also reminds me Benjamin Franklin's famous quote "If you give up your freedom for safety, you don’t deserve either one" (and will lose both)). And it's exactly what happened, first on E-Mail hosting, where it was so complex for a server to prove its credentials (in order to avoid being blacklisted) that only a few actors remained (or at least servers managed by very skilled sysadmins). And now, as you say, so many regulations put a lot of legal accountability on content providers that it has become a nightmare.

Don't worry, I perfectly understand this last point (I thought about it when using the word "volunteers", but I wasn't explicit). Finally, I can live with simple links for referencing videos (I'm happy as long as people can see them), and having them embedded would only have been a "nice-to-have" feature.

Exposing the problem to my local hackerspaces' friends, they told me that this kind of attack against forums is already possible with simple integrated images because they can be linked from any source, no matter the domain (the only requirement is now HTTPS, as I learned 1-2 months ago). And they indeed confirmed that the only way to recognize reputable sources (which would have moderation) would be by a list of domain names ; however, this list would need to be managed in order to add new server instances or remove dead ones from time to time. And this list would also need to be large enough in order to spread the load on different servers (they are managed by volunteers / non-profit groups). Therefore, I have another question to raise : with such decentralized providers, users have more ease to move their account from one to another (unlike on proprietary centralized platforms where switching costs are a concern, keeping users locked in). Then they are responsible to maintain/restore their links when moving. For me, I'll indeed have to update my few own ones after recently leaving Diode Zone for Interhacker Space : either I'll be able to edit my old posts (and explain why in the adequate field), otherwise I'll have to add new messages to the related topics, taking the risk of "resurrecting" them, which may break the usual online code of conduct. I need an advice...

@aFrInaTi0nYou indeed understood and explained the philosophy of PeerTube I didn't or forgot to mention at the very first time, which is the reason why there isn't a single domain. I indeed purposely avoid having an account in the Google ecosystem (thus YouTube) because they violate my privacy (here is the price we overlook : we usually say that it's not "free as in freedom"). Vimeo could perhaps be a bit better, as long as they don't undergo enshittification (Wikipedia link) too. However, I want to support and help ethical online services to grow in popularity. And also, the decentralized nature of the Web is its core original philosophy (which also makes its strength/resilience), isn't it ? And dead links are an unfortunate byproduct. Closed user accounts, bankrupt/disappeared platforms etc... can also lead to dead links. If YouTube, AWS, Meta etc... were to collapse at some time (nothing is too big to fail), the remaining Web would still work.

As PeerTube (open-source YouTube competitor) is becoming popular, would it be possible to support video embedding for PeerTube links through BBcode too ? Here is a personal video I would have liked to embed : https://tube.interhacker.space/w/gqKyoBSjnsTPRqCokexgZM Unfortunately, the only currently proposed way for embedding it is HTML code, which is restricted on forum posts for obvious security reasons. <iframe title="LEGO telescopic doors" width="560" height="315" src="https://tube.interhacker.space/videos/embed/7cedc633-becf-4cff-baaf-39d5a47aeb3b" frameborder="0" allowfullscreen="" sandbox="allow-same-origin allow-scripts allow-popups allow-forms"></iframe> Thanks in advance...

After building two other variants and upgrading the existing ones, I thought it would be better to show everything in video : PeerTube link (not yet supported as embedded player) : https://tube.interhacker.space/w/gqKyoBSjnsTPRqCokexgZM (it is my very first video editing attempt : it was tedious and it's probably far from perfect)

@Mr JosImpressive warehouse center (I myself can't achieve such big designs) ! Clever heavy-duty and compact rail design for allowing the intermediate cart and the platform to partially disengage on both sides. And also clever chain design (crossed chains on both sides) for the linear differential (stroke doubler), so that the stroke can be achieved on both sides. Not counting that chains are a bit hard to work with (matching the axles' distance on a stud pitch, with respect to the chain pitch, in order to get the right tension). @MinusAndyI don't understand : on which part will the worm gear be mounted, as well as the static gear (probably acting as the "moving nut" of the worm-based linear actuator) ? For which function exactly inside the whole thing ? Driving one of the two panels or moving one with respect to the other ? Meanwhile, I upgraded the cable-based movement to 3 panels (but I reduced the door width to 8L instead of 9 in order to avoid modifying the chassis too much) : This mechanism could also be easily fit into this big door design from Brick Experiment Channel for achieving a true telescopic movement (and the driving cable is also shared with the linear differential on the "2/3" panel).

Been amazed by automatic sliding doors mechanisms since I was child, I of course got interest in this subject when it comes to building them in LEGO. But after some research, until now, I haven't seen yet the telescopic kind (two or more overlapping door panels moving at different speeds in the same direction). I guess it's because they can hardly be integrated in MOCs because, as I tried to experiment, the mechanism is always bulkier than for symmetric doors (this one is really unbeatable : https://www.youtube.com/watch?v=Wpqx9xFL59c). However, I find the challenge of reproducing such mechanisms motivating : below are my first prototypes, followed by all the mechanical brainstorming involved : First, my first prototypes as pictures : First attempt :Really not terrific (wonky, not strong enough) Unfortunately, axle guiding reveals too wonky ; studless<->bricks interfacing not terrific, although trying to stay "legal" (no stud -><- Technic hole assembly, avoiding Technic bricks and their holes' tiny vertical offset). Second attempt : Large door, traditional bricks, vertical "linear differential" mechanism, use of "door rail" bricks/plates : works well ; possibility to drive the fast door panel from above ; possibility to cascade a third door panel (but at the cost of an overhang in front ; perhaps possible to rebuild this mechanism upside down, eliminating the overhang). Horizontal and rather compact (still gear-based) linear differential. Could duplicate it symmetrically... but still needs room above for the drive mechanism. ... And now a cable-based linear differential, like on real-world doors. A 3rd panel might be possible, at the expense of some more height for the second linear differential. (the two bushing-terminated friction pins on the left act like violin keys for adjusting the string tension and mechanical offset between the two panels). And still a lot of technical recipes combinations to try !... Now comes all the thinking : Where to install the mechanism ? Above (like in real world but almost always too bulky) or below (easier to hide but creates a gap in the ground) ? Should we drive the slow or the fast panel ? Or even both, eliminating the need of a linear differential ? Linear differentials variants : scissor-based (as seen on a GBC module with telescopic stairs), gear-based, string & pulley-based ? Orientation of the linear differential mechanism : horizontal or vertical plane ? Assembly method : studless, studded, mixed ? (I guess that the door panels themselves will be brick-based, allowing more flexibility for aesthetics) Door panel thickness : 1L (more compact but more complex as well) or 2L (much easier but less usable in MOCs) ? Door panel mechanical guiding : usually close to the mechanism (prevents pitch backlash that would jam the panel), axle-based or door rail brick-based ? The second gives really excellent results and not too muck yaw backlash. Panel drive mechanism : rack & pinion (rack would be too long if on the fast panel) ? String & pulley / chain & gear (compact but needs tension adjustment) ? Leadscrew ? Linkage ? Scotch-Yoke ? Even more complex : 3-panel door ? Double (symmetric) 2-panel door ? (combinatorial explosion, but fortunately a lot of impractical or impossible combinations get discarded at an early stage)

This does highlight the philosophy differences between a construction game and "real world"/"industry" etc... (I don't know how to name it) : in construction games, multipurpose parts are often preferred : cheaper (a single part) but less performance, as it is the case with the double-bevel gears (a central spur section and two beveled sizes)... and even with the single-bevel ones in real world usages, performance is the first requirement, hence the specialized parts like, for example, pairs of truly conical gears for a defined ratio/angle, special teeth profiles for meshing with worm gears etc... Therefore, is it really a good idea to demand high performance to a construction game, at the expense of parts multiplication ? And a little word about beveled gears from LEGO (as well as in some other construction or educational games) : rather than true conical gears, they could better be considered as crown gears with 45° teeth because, like regular crown gears (with 90° teeth), they can mesh with several different gear sizes at once.

Thanks for the diagnostic. Meanwhile, when looking for information at my local hackerspace (where there are many computer & network security experts), I got the same explanations. I'll try to fix it later... ... Fixed 20241114 : all my HTTP image links work again on the whole website, thanks to enabled HTTPS + redirection from HTTP.

"the 24z gear sticks out" : do you mean that its outer diameter is too big for building close to it (it indeed doesn't fit into à 3L space) ? Or do you mean that its teeth do skip too easily, even in the presence of a half thickness spacer (bushing, thin liftarm) ?

What about a zero-backlash clutch ring-like part ? By fitting clutch gears at each end of such a part, we could also build compound gears which can rotate freely on axles : useful for gear stacking in advanced and more compact mechanisms like clock movements. (Currently, only the Z16/Z24 combination already exists as the v.2 differential body (6573)).

@Peppermint_M My own personal web space has no deeplinking restrictions : I just checked it. (by the way, I wondered about deeplinking rules nowadays, knowing that it is a bad practice for the reasons you mentioned ; however I had seen lots of deep links targeting Bricklink for showing parts, and someone told me that it seems no longer to be such a problem : do you confirm ?) In fact, the problem seems to come from the forum software itself, because even my old posts no longer display images, but rather their filenames instead, like in this one : I also reproduced this problem yesterday (using the response text area and the preview feature for testing), and I even reproduce it below in this post : instead of using the user interface, I insert an img BBcode tag : it will only display the filename, too. @Jim URL example : http://www.mgtx.fr/LEGO/Divers/69762_45deg.jpg The same as manually entered img BBcode tag : (EDIT20241114 : HTTPS support (+ redirection from HTTP) now enabled on mgtx.fr ==> problem indeed solved everywhere on the forum) Hope this helps...

Hi. Also a similar problem, see Trying to link images in my post thanks to [Insert other media] [Image from URL] fails to work : in the modal dialog box, clicking [insert into post] results in a link validation failure (the input box turns red) : why ? Non-secure HTTP not allowed ? Personal domain rejected ? IP ban I may not be aware of (I don't engage in illegal activities) ? Some 3rd-party scripts blocked on this browser ? (therefore I had to work around and post my images as simple links instead) Thanks in advance.

Recently getting some 69762 gears (from the 42168 John Deere 9700 Forage Harvester), I wondered if, despite their design for a single use case, they could be meshed in another way : what if we tried to mesh two of these gears together ? Because they can mesh really better (thanks to their true conical shape and bigger teeth) than double beveled gears. The optimal angle of the two axles would be 2 * arctan(14/22) = 65° approximately. Therefore I tried, for several angles close to this value, how to mesh these gears as closely as possible (mitigating/eliminating backlash) without putting pressure on them (they must spin freely) : I built these test benches in order to eliminate tilt backlash for the axles (they are guided on some length) as well as the flexibility of the structure. In each case, a specific height adjustment was necessary 45° (135° axle hole connector) : needed 0.8L = two plate heights : 53.1° (bent liftarm) : 0.5L = half brick width : 60deg (120° triple axle hole connector) : 0.2L = one stud height (look at the stud-terminated pins) : 67.5deg (112.5° axle hole connector) : needed 0L : Therefore, would there be any use cases ? Sci-fi doors, orreries etc...

Just a little note about it : impossible to assemble with three (Z8) planet pinions at 120° exactly (teeth phases constrained by the ring won't match with the sun). Only assemblies with two or four Z8 planets are possible. (the general rule states that the sum of the teeth on the sun and the ring must be a multiple of the number of (evenly spaced) planets).

I just wonder how such a part can be used after inserting the pin, i.e. if there's still some room for attaching other parts on it without interfering with the end of the pin... perhaps cylindrical 1*1 bricks (3062a or 3062b) or conical ones (can't find the reference quickly) because they're narrower at their ends. Other possibilities ? Extra possibilities would exist if the studs were hollow.

The mechanism in the video is one possible implementation of a circular translation movement. I'm not sure that this is what will help the most (not counting that the 2nd Z8 idler pinion in parallel doesn't correctly align its teeth with its adjacent gears, building stress and friction). However, why not build the output cranks by the help of Z56 or Z60 turntables ? The "axle" of rotation is therefore very sturdy, with low backlash, and the torque at the pinion driving the gear part of the turntable will be lower (and the crank and gear won't be heard "suffering"). Two drawbacks : your driving gear train will have to spin faster because of the speed reduction caused by the pinions+turntables (at worst 1:7 with Z8+Z56), and I don't know where you'll have room for the aesthetics (colored background plate).

@XG BC:Hyperlinks to doctor-brick.de unusable (login required)...

In other words, slowly moving away from the concept of multipurpose/versatile-but-less-efficient gears (often found in construction sets) to efficient, specialized, industry-like ones (hence the separation between spur and truely bevel gears).

I'm sure that Akiyuki will fix the torsion of the central axle soon : he already faced this kind of problem, as showed in this video from himself : https://www.youtube.com/watch?v=drmlBqzqJSo Although he can't build a thick axle here, between the output gear and the "rotor", there are possibilities to add 2 or 4 supporting structures between the Z40 output gear and some of the axle-made beams (which hold the vertical rails) in order to relieve the central axle. As an extra option, we can also use a bigger output gear like a turntable or a ring of banana gears, attaching it the same way on the "rotor".

And, as a thoretical reminder, a rule of thumb I found once somewhere on a LEGO-related website states that the tolerance for gear distances is +-0.05 stud. (therefore, in this case, with sqrt(2) = approx. 1.41, VS the optimal distance of 1.25, we have 0.16 more, which is way too much)

Z12, Z20 pure spur gear variations, including the clutch variant... ... but when will LEGO complete the Technic gear range with the Z32 size ? It currently only exists as a custom design. (I can't imagine/mention all new use cases it will cover, beginning with easy 1:4 ratios, despite the half stud spacing)

It reminds me this variant of a locker-based Geneva mechanism : I noticed this principle long time ago in several door lock types, but I never thought about implementing it in LEGO for intermittent rotation.