Help with your MOC

[Jim]

HELP WITH YOUR MOC

This is a topic where you can ask other members for help with your MOC. It's linked in the Technic and Model Team Index.

GUIDELINES FOR ASKING A QUESTION AND POSTING AN ANSWER

Description

Please be as clear as possible describing your problem. Reread your question and ask yourself whether someone without prior knowledge will understand your question.

Picture

A picture is worth a thousand words. Please try to include a picture with your question. This will make things more clear for other members.

Tip!

If you don't have storage online for storing a picture, please checkout Bricksafe. It's a great site for sharing pictures of your Lego creation. Alternatives are Brickshelf, but it will take some time before your pictures will be visible to other users and Flickr, which is pretty self explanatory.

Remember to deeplink an image with a normal resolution, like 800x600. Whatever you do, don't post images that are over 1024x768 pixels (or 768x1024 pixels for pictures with a portrait orientation), which is stated in the site guidelines.

Posting an answer

When posting an answer to a question, please make sure to add the name of the member to whom to you are replying. Even better would be quoting one of his/her posts. When quoting a member please remove the images from the quote, unless it's really necessary to include them.

[MrNumbskull13]

How can I make a four link live axle stronger using 6L links? Mine seems to twist and steer the car when driving.

[Alasdair Ryan]

How can I make a four link live axle stronger using 6L links? Mine seems to twist and steer the car when driving.

What about a central pivot (axle)?

[therealjustin]

Excellent idea for a topic!

I need help with my MOC but sadly it would take an entire novels worth of advice! I'd like to build my first Technic supercar with the parts from both 8070 and 42000 but I have no idea where to even begin. There are some excellent modular ideas out there but when it comes to adding a gearbox my mind goes blank. Nothing too crazy either, something like a 5+R transmission and rear wheel drive in a rear engine platform similar to the Porsche 918 or McLaren P1. The Aventador by Francisco Hartley would be my dream supercar build in terms of chassis and suspension but my fear is that I'll only get as far as the chassis and get stuck because of a lack of experience. I'm also pretty terrible at reverse engineering.

Edited September 11, 2013 by therealjustin

[Junpei]

How about something completely different, like a Dakar truck? It can keep the 5+R gearbox and engine, but with crazy suspension with all the a-arms and F1 links, and maybe something that uses the LA's. There are definitely enough panels for something big, but the wheels might be too small. If you just don't care, put a V16 in it or something.

If it has enough functions, it could still be considered a supercar like Sheepo's Land Rover Defender 110. Not technically a supercar, but a supercar nonetheless.

[weavil]

You could search the forum for "transmission". Their are different types, shapes, sizes and discussion of them. Would link but using my phone and it a mess to try doing a link.

[Alasdair Ryan]

Once you decide on what to build I would recommend starting with the gear box.

[jantjeuh]

@therealjustin: have you built the supercars of the likes of Nathanaël Kuipers, Crowkillers, Jurgen Krooshoop, etc.? Those might give you some good ideas on how to handle stuff like the chassis, suspension, gearbox, etc.

[Junpei]

I think this is a great topic, but as soon as somebody else poses a question, the question before it might tend to be forgotten... I know it creates many more topics than one, but maybe just individual topics?

[Marcel1980]

Need a design of a tatra a chassis. The hubs, no problem. But the 2 drive axles in the chassis... Just cant get it right... Just to many liftarms to supoort it....

[Junpei]

You might need to be a little more specific, although I get what you're saying, I tried to build a Tatra once. Are there really no pics in this topic yet? Be prepared to be asked a thousand questions about my first rock crawler tomorrow. My post is gonna be loaded with pictures.

[Hrafn]

I think this is a great topic, but as soon as somebody else poses a question, the question before it might tend to be forgotten... I know it creates many more topics than one, but maybe just individual topics?

I agree - the thread is a good idea but problematic in the implementation. It's already becoming hard to follow the different topics.

[Lipko]

I agree with the problematic thing. I didn't feel that the forum was clustered with technical questions so I don't think a topic like this is necessary. Maybe a sub-forum under the Technic forum would be better than this solution.

[captainmib]

No, this is a very good topic, I always feel this section of the forum drowns in simple questions in seperate topics.

The thing is, if we update the first post with the questions asked, add a link to the question, make a nice table of contents, we will have a nice overview.

People are able to see if their question is asked before and if yes, have an answer without posting a new topic.

I like it.

Maybe we need a format for questions aswell...

Edit: oh, i forget to add: rename the topic to "Simple questions, Simple answers" - and pin?

just my $0.02

Edited September 12, 2013 by captainmib

[GuiliuG]

Personnally, I don't think that this topic is very usefull. When you are building a MOC and have some troubles creating what you want to get, why not simply post a topic of your creation and explain your problem ?

Edited September 12, 2013 by GuiliuG

[nicjasno]

Also, without pics, any question is useless.

[Jim]

I agree that the topic in this form might not be the best solution. Let me consult with some regulators and moderators to see what's the best course of action.

Having an index in the first post is a nice idea, but the answers will still be given in the middle of other questions etc. Not ideal either.

I also agree that a certain format for a question might be useful....especially including a picture.

To be continued...

[Jim]

Okay, for the time being we will let this topic evolve and see what happens.

I have included a short description in the first post, explaining how to ask a proper question. If there is something missing, please let me know.

Of course it's not forbidden to start a separate topic if you feel that your problem needs it.

[Sebeus I]

I'm looking for 6-wheels motorized vehicles (or 8-wheels), something in the nature of a 9398 Crawler but instead of 4x4 it's 6x6.

I'm building one myself and I'm having trouble finding a good sollution for the suspension.

I don't think my english is good enough to provide a decent explanation of the problem so It's probably better if someone could give me (some) links to older MOCs featuring 6 or wheel Trial Trucks.

Edited September 12, 2013 by Sebeus I

[Hrafn]

I'm looking for 6-wheeled motorized vehicles (truck trial style), I'm building one myself and I'm having trouble finding a good sollution for the suspension.

Forgive me for asking, I don't hang around in the Technic forum a lot, but I can't find the MOC index (only one that contains only two mocs but I assume there must be a bigger one ).

Are you looking to do 6x6 or 6x4? 6x4 would be easier, since integrating steering, suspension, AND power into a robust front axle can be tricky.

There are a number of possible suspension types out there: Tatra (swing-axle), live axle, etc. Some real-world trucks (like my favorite ugly duckling, the Scammell Explorer/Pioneer) have a "walking beam" suspension for the rear 4 - on each side, a beam is mounted on an axle, and the wheels are then mounted at the ends of the beam. This allows for considerable vertical motion, but then the wheels aren't independent.

Sariel's book (The Unofficial Lego Technic Builder's Guide) has some good instructions, and his site (sariel.pl) is good for inspiration.

[Sebeus I]

Are you looking to do 6x6 or 6x4? 6x4 would be easier, since integrating steering, suspension, AND power into a robust front axle can be tricky.

Thanks for the link,

I want a 6x6 with axles equally spaced, both front and rear axle would be steer-able, I have a pretty good Idea about transmitting power into the axles (it involves 5 differentials and 2 XL Motors).

For front and rear axle I use live axles but it's mostly the suspension of the center wheels I'm struggling with, I was thinking to use independant suspension for the center wheels but I'm not sure if that's appropriate for a heavy duty vehicle.

Anyway, I'll check out some MOCs first to see how others do it, thanks again.

[Hrafn]

Thanks for the link,

I want a 6x6 with axles equally spaced, both front and rear axle would be steer-able, I have a pretty good Idea about transmitting power into the axles (it involves 5 differentials and 2 XL Motors).

For front and rear axle I use live axles but it's mostly the suspension of the center wheels I'm struggling with, I was thinking to use independant suspension for the center wheels but I'm not sure if that's appropriate for a heavy duty vehicle.

Anyway, I'll check out some MOCs first to see how others do it, thanks again.

Do you have a particular real-world vehicle in mind? If so I'd try using whatever that vehicle uses for center suspension. Otherwise, pendular suspension is relatively straightforward and robust, especially if you use turntables for the central pivot.

Take a look at the Unusual Locomotion site, too - they have pages for 6x6 trucks, both medium and heavy, plus a lot of other information about different kinds of vehicles.

I'd also take a look at some 6x6 armored personnel carriers, though the ones with 2-axle steering seem mostly to steer the front two axles.

[Jim]

I am working on my Wheel-E (or Wheel-EV3) robot and I need to work with axles through a turntable, much like the 8043. See the image below, nothing out of the ordinary.

There is much slack in/between the gears (especially) when reversing direction. I am using motors to power the gears, but when I reverse direction it takes a while for the Driving Ring and Driving Ring Extension to connect/link (not sure how to call this, but you should know what I mean). Using two extensions obviously worsens this problem. Since I am using gravity as a counter force it probably won't be a real problem, but I am wondering is there is a way to achieve this without the Driving Ring and Extensions, so there's no slack in the gears.

Preferably the solution should not involve glue

[efferman]

why not use the older diff case with the 24 tooth gear?

[Jim]

why not use the older diff case with the 24 tooth gear?

Because you never told me... until now.... (just kidding)

Now that you mention this, I have seen this solution and it might work. Have to change some things, but at least the slack will be gone.

Thanks for the tip, I will see if this fits