Technic Parts We Would Find Useful

[gyenesvi]

20 hours ago, Aleh said:

I've faced in practice that the most usefull would be 2L clutch compatible with new diffs (with 5 gears inside).

Yeah, that's something I'd like too. I think it would be possible like the old 2L one, but with its small teeth replaced with the ones like on the new 3L one, and the inner ridge made shorter so that it can slide into the new clutch gears. I have checked that the length of the teeth are the same, and the gap between the two outer rings in the middle is also the same, so it could even work with the orange selector (the ring diameter would have to be decreased slightly like on the new 3L one). Furthermore, the old 2L one can slide smoothly on a new type 2L connector that has no ridges, so that would also work fine with the orange selector when no clicking to place is required. It could look like this.

[2GodBDGlory]

2 hours ago, artemisovsky said:

For example, pneumatic motor should be cheaper than an electric one

I kind of doubt that it would be able to be any cheaper. In a sense it ought to be, being quite a bit simpler than an electric one, but we're at a point where little electric motors are being mass produced, allowing them to be a lot cheaper than they would be otherwise. Because pneumatic motors would be so niche, they wouldn't be able to benefit from that scale.
They sure would be cool, though!

[allanp]

I have often wondered about how to do a pneumatic motor, or more specifically, an axial piston pump type compressor which could also possibly be used in reverse as a motor. It would be a sweet replacement for motors where in real life a hydraulic motor is used (for example excavator track drives, grabber rotation, etc), but just that on it own certainly wouldn't justify the development costs. But if it's main use was as a 6 bore (like a stack of 3 x 0.5 pulleys) axial piston pump, 6 pumps in about the size of a pf medium motor, that could also be back driven as a motor, well that would be totally sweeeeeeeeet!!!!!

[msk6003]

Speaking of pneumatic, I always wanted electrical valve. Considering it only need 3 position and spike essential's 3x3 light matrix, one C+ port can control least 9 switch at once. And same way, PF-C+ converter also need to control 9 motor at once.

And similar to pneumatic motors, if we have a rotary pneumatic pump (approximately 3x3x5 in size?) it will be much easier to integrate the pump into the motorized model.

Motors with shafts coming out of both sides, or motors that are water-tight, are also useful.

A small solenoid actuator operated by an electromagnet with a stroke of about 3 studs (equivalent to a 5L v2 cylinder) would also be useful, but I don't know what to use right now.

Edited January 30, 2023 by msk6003

[artemisovsky]

15 hours ago, 2GodBDGlory said:

I kind of doubt that it would be able to be any cheaper. In a sense it ought to be, being quite a bit simpler than an electric one, but we're at a point where little electric motors are being mass produced, allowing them to be a lot cheaper than they would be otherwise. Because pneumatic motors would be so niche, they wouldn't be able to benefit from that scale. They sure would be cool, though!

I'm not sure if you're right, that pneumatic motor would have a very simple construction (I'm not an expert though). If it would be used in pneumatic sets, will go to mass production which lowers price. However, I see disadvantages - tightness is difficult to obtain, low efficiency and therefore low power. Anyway, I wish had that motor but know it will never be implemented.

[Davidz90]

3 hours ago, artemisovsky said:

I'm not sure if you're right, that pneumatic motor would have a very simple construction (I'm not an expert though). If it would be used in pneumatic sets, will go to mass production which lowers price. However, I see disadvantages - tightness is difficult to obtain, low efficiency and therefore low power. Anyway, I wish had that motor but know it will never be implemented.

A pneumatic motor would either need one or several pistons (like the mentioned axial piston pump; howevet, it comes with all the complications of making them airtight) or some sort of turbine (but that would be extremely high speed/low torque unless large gearbox is added). Since nothing else really uses pneumatic pistons (as opposed to electric motors which are off the shelf parts packed in Lego casing), it would not be exactly "mass" production and certainly much more expensive than electric motor.

Besides, it would really be useful only as a pump, unless used with significantly larger air tank than the one currently available. Or electric motor driving a pump, but then why bother?

[HydroWorld Outlook]

Thank you so much for starting this discussion. I will add my proposals here. Although such parts would be a bit more specialized than others mentioned here, I strongly believe that we need some more rotor and propeller blades added to the LEGO Technic building system. I know we already have the 89509 fan blades as well as the 65422 and 99013 helicopter blades for large propellers, but these two existing pieces alone do not serve our needs well for building air, water, and wind/fan-powered vehicles that use ducted-fan or coaxial propeller systems; the 89609 fan blades are too small and are only produced in one direction, while the 65422 and 99013 helicopter blades have surfaces that are way too thin. Additionally, the helicopter blades cannot create air unless they are securely fastened to the hub at an angle, which is very difficult to accomplish with Technic pieces without the risk of centrifugal force pulling the entire assembly apart, especially for variable-pitch systems.

To fix this issue, my proposal is to produce new propeller blades that are wider and more aerodynamic (preferably with leading and trailing edges), as well as new rotor hub elements that allow these blades to swivel or remain stationary (depending on whether or not the propeller is fixed- or variable-pitch) while still keeping them fastened to the hub. The propeller blades themselves should be made in different sizes (to allow for different sizes of vehicles) and designed with neutral, symmetrical airfoils, like the one displayed in the attached image, to allow for use of the same part in both clockwise and counterclockwise rotational directions. This will save on cost when producing the new rotor blade, because only one new element for each size rotor will have to be fabricated rather than two blades exclusively optimized for different directions of rotation. Pin or axle holes on the flat blade tips would also allow a ring to be constructed around the blades to reinforce them while rotating or drive them from the outside, if found necessary.

Additionally, the blades should have connectors with circular protrusions that fit in the circular grooves of the propeller hub, as well as axles that allow bevel gears to be mounted inside the hub for variable-pitch systems. This would mean that the hubs would have to be produced in two halves: one for the bottom and one for the top, so that the pitch-changing mechanism would be secured inside the hub with the protruding ends of the rotor blades. This would likely mean producing the propeller hubs with central pin holes rather than axle holes, so that the axle controlling blade pitch could rotate freely for variable-pitch propellers. In that case, driving the propeller assembly itself would would require a standard turntable to connect the rotating blade assembly with the vehicle's static structure around the propeller pitch control axle. For fixed-pitch propellers, the structure built inside the rotor hub would be far simpler, as securing the blades would only require using axle connectors and axle pins to lock the blades to the hub. By securely fastening the blades into the propeller hub, the propeller can operate at much higher rotation speeds without the risk of centrifugal force disintegrating the entire assembly and injuring someone who may be standing nearby when the model is turned on.

A possible alternative to bevel gearing would be to provide circular "swashplate" pieces (kind of like mushroom-shaped elements) that connect around the central drive axle and are two studs smaller in diameter than the propeller hub itself. The mushroom elements could have bars extending from their bases that allow them to be reciprocated by either pneumatic cylinders or linear actuators. This system would allow the propeller hub and blades to rotate around the mushroom swashplates, while the mushroom pieces themselves remain stationary with the rest of the build. 

Unfortunately, the propeller hubs themselves are the biggest catch because different molds of them will have to be fabricated for different numbers of blades. For example, if you need a large 9-blade propeller for let's say, a 1:4 scale model of the Vonmercier EV Sports Hovercraft, you will need a propeller hub that has 9 socket attachments for 9 rotor blades. Or if you're building even bigger like me and you need an even larger 15-blade propeller for a 1:3 scale model of the GE9X, then you will need a larger diameter rotor hub with 15 blade sockets.

I know it all sounds a bit complicated, and I understand that such parts may never be feasible, but I strongly believe that adding such parts to our inventory will increase the flexibility and efficiency possible when constructing aircraft, watercraft, and other propeller-powered vehicles with the LEGO Technic building system.

Edited January 30, 2023 by HydroWorld Outlook

[artemisovsky]

44 minutes ago, Davidz90 said:

A pneumatic motor would either need one or several pistons (like the mentioned axial piston pump; howevet, it comes with all the complications of making them airtight) or some sort of turbine (but that would be extremely high speed/low torque unless large gearbox is added). Since nothing else really uses pneumatic pistons (as opposed to electric motors which are off the shelf parts packed in Lego casing), it would not be exactly "mass" production and certainly much more expensive than electric motor.

Sounds reasonable. Earlier I thought that something similar to multi-groove wheel closed in a case would be sufficient. Thanks for the explanation.

[Davidz90]

2 hours ago, HydroWorld Outlook said:

I know it all sounds a bit complicated, and I understand that such parts may never be feasible, but I strongly believe that adding such parts to our inventory will increase the flexibility and efficiency possible when constructing aircraft, watercraft, and other propeller-powered vehicles with the LEGO Technic building system

Yes to this, with one caveat: at the small scale/speed Lego models are operating, typical airplane-like profile as depicted is not optimal. Very thin, curved surfaces (like in first airplanes such as Wright flyer or small birds) are better. If symmetrical profile is used (for reasons you described), a flat, thin plate may still be better than "proper" airfoil, but overall zero curvature profile all the way from blade tip to root would severely hurt performance.

[mla2]

I've been working on building CADA set C63004 with current TLG parts only. This set uses many of the parts listed on the first page of this topic. Replacing them with current TLG parts has been ok so far but there was one very special part which is not listed on the first page but seems very interesting and was harder to replace. It's like a mix of a 3L beam and a technic cam, adding a compact way to create a half stud offset. Luckily I've only encountered 1 step using these so far

[1gor]

@mla2 could this one be usefull for you?

https://www.bricklink.com/v2/catalog/catalogitem.page?P=11272#T=C

 

 

[mla2]

51 minutes ago, 1gor said:

@mla2 could this one be usefull for you?

https://www.bricklink.com/v2/catalog/catalogitem.page?P=11272#T=C

Thanks but this creates the offset into a different direction? I replaced it by two technic cams after changing other parts to make space for that.

[gyenesvi]

1 hour ago, mla2 said:

It's like a mix of a 3L beam and a technic cam, adding a compact way to create a half stud offset.

That would be a nice part to have indeed. Sure, the cam can replace it if there is enough space.

I’m curious which parts are available by Cada from the front page? I only know about the flip-flop beams and the beams with pins on the end. Anything else you found?

[mla2]

9 hours ago, gyenesvi said:

I’m curious which parts are available by Cada from the front page? I only know about the flip-flop beams and the beams with pins on the end. Anything else you found?

4L pins and 10L axles with stop.

Also it has pins with towball sockets (I thought those were mentioned in this topic but don't see it now), a modified version of 71708 which has 4 axle holes on the long side like the part I mentioned above and panels which look like smaller versions of 67142.

Finally its 5x7 and 5x11 frames are made of 2 separable parts.

Edited January 31, 2023 by mla2

[gyenesvi]

2 hours ago, mla2 said:

4L pins and 10L axles with stop.

Also it has pins with towball sockets (I thought those were mentioned in this topic but don't see it now), a modified version of 71708 which has 4 axle holes on the long side like the part I mentioned above and panels which look like smaller versions of 67142.

Finally its 5x7 and 5x11 frames are made of 2 separable parts.

10L stop axles sound interesting! Yes I remember the pins with towball sockets, but I could not make them in part designer yet.

Do you know how the separable frames work? What is their advantage?

[msk6003]

14 minutes ago, gyenesvi said:

10L stop axles sound interesting! Yes I remember the pins with towball sockets, but I could not make them in part designer yet.

Do you know how the separable frames work? What is their advantage?

Normal frame can use differential only with normal axle but those frame can use with 5.5 stop for stronger wheel connection.

[gyenesvi]

18 minutes ago, msk6003 said:

Normal frame can use differential only with normal axle but those frame can use with 5.5 stop for stronger wheel connection.

Oh, okay, that sounds interesting, but where does the frame separate? I guess it has to be split longitudinally then. And doesn't that make it weaker? I think one key property of the frame is that it's a single part that can be a strong core for a floating axle for example, keeping the two sides together without the need for further reinforcement. In a larger scale where it can be reinforced or in independent suspension it could still be useful though.

[mla2]

31 minutes ago, gyenesvi said:

where does the frame separate?

[efferman]

1 hour ago, gyenesvi said:

What is their advantage?

it was mostly made to avoid copyright problems, so they replace the old 5x7 and 5x11 frames.

[gyenesvi]

8 hours ago, efferman said:

it was mostly made to avoid copyright problems, so they replace the old 5x7 and 5x11 frames.

Good to know, thanks for the info and @mla2 for the picture.

[Saberwing40k]

i was building something, and there are several parts I would find useful.

Most prominent is a variant of 55615,LegoTechnic, Pin Connector Perpendicular 3 x 3 Bent with 4 Pins

i think it would be great to have one that is 2x2 instead of 3x3.

[astyanax]

49 minutes ago, Saberwing40k said:

i think it would be great to have one that is 2x2 instead of 3x3.

You mean  but with 2 pins?

[Saberwing40k]

Basically, yeah.

[2GodBDGlory]

A while back in this thread, @Zerobricks was showing some sweet 3D-printed versions of the "Racing Small" rim, with much more offset. Anyways, I've been starting planning a small off-roader (Somewhat inspired by @gyenesvi's Bronco), and I was thinking it would be fun to print myself some more accurate rims in that size. The trouble, of course, is that for a 4x4, you essentially need to have some kind of driven, steered hub for the front axle, and the Racing small rim, at 43mm total diameter, really can't quite accommodate them. In order to get around this, for my custom design, I mildly increased the diameter to ~47mm, which is about the minimum I figured I could get away with while maintaining strength and fitting the planetary hub. I've now printed one of them (with more to come), and I think it looks quite promising! Because of the diameter increase, there are some limitations to its use, though: Based on my testing with the three compatible tires I have, I found that the 81.6mm balloon tire works effortlessly (It's always been soft and loose on rims, so I was pretty confident it would work), the 68mm balloon tire works tolerably, and the ~56mm street tire can be jammed on there, but looks weird (though I was testing with a clone one, which might be a bit stiffer).

Anyways, though, for actual 4x4s that are going to be using the larger tires, I think it should work fine!

As far as hub compatibility, it will work fine with planetary hubs, the old LBG steered hubs with integrated towballs, unsteered hubs, and the old-school black hubs from 8070. Portal hubs work tolerably by my standards, but there is some rubbing. Unfortunately, the new-style black driven/steered hubs won't work, because of the large axle hole parts. (The BMW motorcycle fork hubs won't work either, but they hardly work with anything anyways).

I understand that this isn't a solution Lego would use, but I think for fan models it can be a very pleasant compromise.

Spoiler

If anyone is interested in printing some of their own, let me know and I can post the file on Thingiverse! Also, Cura's Iron feature is awesome for making a nice top surface!

[phildc]

Train wheels to run LEGO build trains on DUPLO train tracks.

I just designed the following prototypes to print in 3D:   (the STL files are free)

LEGO trains on DUPLO tracks by phildc - Thingiverse

Additional wheels for LEGO trains on DUPLO tracks by phildc - Thingiverse