Planetary Wheel Hub - Please Help

[PlanetaryHub]

Hello,

Having played extensively with LEGO Technic as a youth (I still have the original 853 Car Chassis Technical set), I now find myself playing with LEGO Technic with my son! I am a vehicle design engineer by trade and this combined with the time spent playing with LEGO Technic resulted in an idea for a new Technic compatible part. After this idea had knocked around in my mind for some time and refused to go away, I decided to design in properly using 3D CAD and present it to the Lego Group to see what they thought.

I put together the following video and sent it by e-mail to the LEGO Group several months ago, but I have had no success in getting them to take an interest in the proposal:

My design cannot be submitted through the LEGO Ideas web site, because new part designs are specifically excluded. However if I can get to at least 10,000 views on YouTube (the LEGO Ideas review threshold), I think LEGO Group may be prepared to give serious consideration to producing these new parts. If you like the idea please help by sharing this video on social media, in forums and with friends.

Thank you for your help.

Edited January 22, 2016 by PlanetaryHub

[RohanBeckett]

Very cool concept, and excellent presentation!

A lot of us in here would like more complex parts/sets from Lego Technic (a lot of people dislike the 1-part-per-step instructions of this generation)

But I feel that while this is unlikely to be created by TLG... but it WOULD be an excellent candidate for people to 3D print themselves.

Have you browsed Effermans' amazingly long thread?

http://www.eurobricks.com/forum/index.php?showtopic=91294

[Sylvian]

Though your effort and presentation is awesome,.. a planetary hub reduction in this size can be made allready without custom parts,.. even a steered axle with the steering pivot next to the wheel.

Offcourse without the sprocket.

[allanp]

I really like the idea. but I don't think getting 10'000 views is the same as getting 10,000 votes on Lego ideas. I think the best thing you can do is state your case. Why does TLG need to produce this? What new possibilities does it open up for them? Why will it make them more profits? Yes it is definitely great and I would love to see it made in an official Technic set. Imagine it with some massive new tyres with the chevron pattern treads and there are 4 of them which act as the basis for the 4 wheel drive of a massive pneumatic back hoe. Oh yeah baby! I don't think you need to sell us fans on that. However TLG is a business so you need to state your business case. When I argued for longer pneumatics.... (my original design below)

http://www.brickshel...umatic_long.jpg

....I not only had to build a case for longer pneumatics, but for pneumatics over LAs in general because at the time, aside from one or two sets, pneumatics was hardly ever used anymore. I said how Technic sets are getting larger and so it makes sense that these components also be made larger. As they were, they wasn't really showing the full potential of the pneumatic system. As for their advantages over LAs from a business perspective, (this is NOT meant to start debate, this is only for an example for the sake of the new guy who hasn't already read all this from me before ) well they require less parts to operate (pump, valves, a few hoses) which means that even if the pneumatics themselves cost more to make, you don't need as many parts to operate/support them so they can be cost effective in the long run. Gear trains not only need the gears and axles but the surrounding structures to support them. So with pneumatics you can save money by not needing all that, or you can still have all that and use it to power even more functions which increases the desirability of the set. They are also far more reliable than LAs at transmitting power to where you need it. Long gear trains can sap so much power that there is very little left when you get to the LA (the stabilisers in 42009 could barely move). Whilst LAs are more powerful under perfect test conditions directly coupled to a motor, in real world applications their gear trains waste most of that power leading to unreliability of performance as seen in 42009 and customer complaints, not what TLG wants. Pneumatics would have been a much better solution here. They are also more authentic to real life mechanics. You touched upon that in your presentation but it helps greatly if you say why that is a good thing. Being closer to reality makes it feel more like the real thing. It makes it feel less like a kiddies toy and more like a serious working model for grown ups. Kids don't want toys because they are toys made for kids. They want to be grown ups. Offer a kid a toy car and he'll like it. Offer him a real car and he'll crap himself with excitement! So in making it more authentic you make it more like the real thing which taps into that excitement. In the case of pneumatics vs LAs, you can see the hoses and you can see that it is working on the exact same principals as the real thing. This will drive up the desireability of pneumatic kits among TLGs target audience over kits with the less realistic LAs. There is a number of other factors in favour of pneumatics and I made many many long winded posts and a few topics stating my case (much to the annoyance of some people in the community ) but remember, I am not trying to start up that debate again here. I am only posting this to serve as an example of how I put forward my case for longer pneumatics, which we finally got in the Arocs. And having said all that, I have no idea if my writing had anything to do with their finally deciding to give us what we wanted. But with the designer saying in the designer video for the Arocs that the pneumatics were probably the most wanted new parts from the fans and their final design looking very much like my own, I think chances are good that it might have had something to do with it. So yeah, I think it is possible to get what you want and you have made an excellent video. But now you need to accompany that video with a LOT of words which speaks from a business point of view. you should also know that your design won't be the final design but it will be better in some way from TLGs point of view. It may do away with the ball bearings to make it simpler and cut down on cost to make, and friction is dealt with in some other way. It may use a single inner piece as opposed to a two piece clicked together with 3 pins which might be a failing point. Good luck

Edited January 22, 2016 by allanp

[PlanetaryHub]

Thanks for all your kind words.

In case you missed it on YouTube (the description text is not very obvious), the key design features are:

1) Planetary gear train built into a standard 56x34 rim - the gear train provides a 3:1 speed reduction and a corresponding 1:3 increase in torque. The output torque is generated at the internal gear and transmitted directly to the rim and from there to the tyre or track, therefore it does not pass through any axles.

2) Integrated 14 tooth track drive sprocket - increases potential applications, the rim flanges provide lateral support on the underside of the track segment plates. The sprocket is hidden when a tyre is fitted.

3) 4-point universal mount - this is designed to accommodate: rigid axle, rigid axle with steering, suspension or suspension with steering set-ups, all utilising standard components. The pivot point is positioned to allow the use of either a one part universal joint or a 2 part cardan joint.

4) Rolling element bearings - provide authenticity, tight rim location with little free play and also give low rolling resistance.

[Victor Imaginator]

Very nice part this will be if TLG will ever do it... But i don't believe they do( Anyway, better to print it first for testing. 3 pins for bracing is enough? Looks like weak point for me.

[PlanetaryHub]

If I dare ask, any suggestions as to which other forums I should post this request for help on? - USA?

[Tommy Styrvoky]

It's a great idea, but I think there would be too many new parts involved in it for TLG to produce it. I also think there would be issues with the 2 halves coming apart under horizontal stress on the wheel, though this could be solved if a 4L axle with stop is used. A 3D printed version would work great, though I am unsure of how it would work with the ball bearings.

[zux]

Design looks very clever, I like. However I doubt it would be very useful in long term - dust would kill plastic covers and ball bearing pretty quick.

[Dafgek81]

Keeping this from coming apart can also be achieved by putting a rigid 3mm hose through the centre of the pins.

This will prevent the ends from squeezing together and come out.

[ARXD]

I will buy this part even if it is not made by LTG, perfect in any way.

[Blakbird]

A planetary gearset has been on the top of my wishlist for Technic functionality for a long time. You've done a great job and made a really compelling video. Personally, I'd like to see an epicyclic set that is a bit more generic and not just limited to a wheel hub. For maximum educational possibilities, you should be able drive the sun, the planet carrier, or the ring gear and likewise use any of the three for output. This really shows how just changing which portion is fixed can totally change the gear ratios. I also think it would cool to be able to use planet and sun gears which are not all the same size.

I'd be very happy if your design were to appear in a set. In my opinion, the thing that makes this least likely is the rolling element bearings. While these would be fantastic for minimal friction and structural strength, they would presumably need to be metal. Apart from the cost, they are probably too dangerous as a swallowing hazard for kids. I suppose they could technically be plastic and have lower load capability but more safety.

[efferman]

have you thought about to upload it on shapeways?

[Saberwing40k]

What program did you use to render this and the other parts? I'd like to find out. Also, I have a couple of suggestions.

• The roller bearing are probably not necessary, at least at this scale. I don't know if bearings are needed at all, but they would be nice to have.
  
• If you want to have the bearings, I'd suggest using simpler to make and assemble tube bearings rather than ball bearings. If you could find a way, you could actually make use of the 1L pin joiner in this manner, which would make it a better sell for Lego.
  
• Finally, it would be really helpful and solve a number of problems if you had the inside of the drive, the part that connects to the steering or frame, lock into the rim. That way, the rim can not walk off of that part, and the other side only keeps the gears in.
  

Overall , though, this is a great design. I only wish Lego had some kind of direct to consumer program for stuff like this, in addition to motors and stuff. It would be good for parts such as this that are not really practical for use in sets, but clamored for by fans.

[SevenStuds]

Very nice to see the good technical skills you have! Well done on your video!

The best way forward, in my opinion, is to print it and simply build an amazing MOC with it.

Since making new parts is what nearly threw LEGO off the financial cliff in 2003, I can understand why you're having a hard time in getting them to give you the response you're expecting. The way I see it, LEGO makes sets first, and only makes new parts when that particular set really requires it. According to this article (https://www.quora.com/How-much-does-it-cost-for-Lego-to-make-a-completely-different-block-for-1-or-2-sets-only) it takes £50-100K to create a production mould for one new part. The article also mentions that it can take as long as 9 years for a part to go from concept to stores.

I personally love new parts, but I'd rather not spend 9 years hanging around hoping and waiting for LEGO to listen to its fans when I can print it and have it at my doorstep in 9 days thanks to services like Shapeways.

[tripletschiee]

Very cool design and superb video! Congrats!

[PlanetaryHub]

Thank you for all your thoughts and comments. If you like the parts and have not commented please do so, it could help win TLG over!

Some specific replies:

Dafgek81: Not sure it is a technique that LEGO would approve of, but yes I have also pushed a rod down the centre of Technic pegs, which keeps the ends splayed and thus stops them pulling out!

Blakbird: I think plastic would be fine for the ball bearings in a production version. (Plastic balls made of materials such as Du Pont Delrin are used in some real world bearings; I am not suggesting that anything that sophisticated is needed here!)

efferman: I feel that It would be best for everyone if TLG could be persuded to produce the parts in injection moulded ABS, so I would like to stick with that option at present. Clearly if there really is no hope of TLG listening and taking an interest :( , then I am happy to consider alternatives - I do not want to see my design "go to waste". If this is the case perhaps you could help me(?), but I really would like to stick with trying to get TLG to take an interest at present.

Saberwing40k: I used OpenSCAD for model generation and rendering, it is freeware :) www.openscad.org

SevenStuds: (please see reply to efferman above)

Are there any other LUG forums I should post my request for help/support to? Any other ideas to gather more support?

Thanks, I like this forum, you are all so helpful and friendly!

[nerdsforprez]

I, like others, enjoyed your presentation and concept of idea. I would also love to see this as an actual piece available from Lego. But.... like others, also think that it is best to just print the parts out yourself.

Why it likely will never be produced is because we are still dealing with a child's toy. That is, IMO, the larger issue that everyone is alluding to. As long as TLG sees this as a child's toy they are not likely to pay much attention to our desires as adult builders.

I don't think this is as off-putting as it sounds. I think we are making strides, as the adult community, in having TLG hear our voices. We are having near-3,000 piece flagship sets new......nearly 1,000pieces more than 7-8 years ago. Wonderful sets, with although there is still so much more to go in terms of complexity, personally, I think we have at least seen gains. Perhaps one day TLG will see the potential of the adult market, and then I see requests like yours a viable option foe TLG. But until they make that switch, I don't see it happening. If they did, do they have the infrastructure to deal with all the new submissions that people would undoubtedly place? We have members on this site who for years have been making similar pieces. The adult community would tsunami TLG with submissions........

[roppie11]

i like that it is compatible with tires and tracks. TLG should make that as well.

[Dafgek81]

Wy should Lego disapprove putting a rigid hose through the centre of a pin, nothing illegal about that, they use it themselves to.

On the 8285 tow truck, they've put the antenna through the hole of a light holder.

[PlanetaryHub]

Wy should Lego disapprove putting a rigid hose through the centre of a pin, nothing illegal about that, they use it themselves to.

On the 8285 tow truck, they've put the antenna through the hole of a light holder.

...you are correct, so OK by LEGO :)

[sonar]

i like that it is compatible with tires and tracks. TLG should make that as well.

My thoughts exactly. The combination of wheel hub and sprocket into one part is a very very good idea.

[PlanetaryHub]

have you thought about to upload it on shapeways?

@efferman Your Technic parts on Shapeways look great. Please can you help me with some advice on correct tolerancing for printing successfully in fused nylon (strong & flexible) at Shapeways?

[efferman]

when you make a part wich have to rotate in a other printed part you need 3 tenths of a mm between the parts in your cad file. holes should have 4,9mm in diameter and in the printfile they should oriented vertical to avoid oval holes. Crossholes are 4,9mm in diameter too. the cross is in the file 1,85mm thick. And you should avoid thick walls around crossholes or they will be highly possible to tight. my walls are mostly 1mm thick, on high load situations 1,2 bis 1,5mm.

when you make your printfile make a connection between the parts to save money. I use for this afull circle 2,9mm bolt with 5mm disks at the ends, and this is inserted into pinholes.

[PlanetaryHub]

when you make a part wich have to rotate in a other printed part you need 3 tenths of a mm between the parts in your cad file. holes should have 4,9mm in diameter and in the printfile they should oriented vertical to avoid oval holes. Crossholes are 4,9mm in diameter too. the cross is in the file 1,85mm thick. And you should avoid thick walls around crossholes or they will be highly possible to tight. my walls are mostly 1mm thick, on high load situations 1,2 bis 1,5mm.

when you make your printfile make a connection between the parts to save money. I use for this afull circle 2,9mm bolt with 5mm disks at the ends, and this is inserted into pinholes.

@efferman Thank you for your help.

1) Just to confirm that I have understood you: if I had an 8.0mm diameter rod, it would need to be in a 8.6mm diameter hole to rotate freely...?

2) Do you just use unpolished nylon? Is this to avoid the dimensions changing unpredictably during polishing?

3) Last year I did print off a small test part in nylon at Shapeways (added to an order for something else not LEGO related). The CAD file had a 4.9mm diameter hole, but the hole in the actual part was smaller. When I find the test part, I will post the actual dimensions.

If this discussion is boring everyone else, I could revert to PM's - let me know.