Help with your MOC

[Jim]

Is there any way to extend the proposed solution. I need 5L instead of 4L.

[jantjeuh]

Doubt it.

[Jim]

Doubt it.

Me too.

Fortunately gravity is working for me, so it won't be a problem this times, but still I would like to know if there's a better solution for this problem.

[jantjeuh]

I've been thinking a bit, and I really can't come up with anything. So either you have to start gluing, or settle for 4L ;-)

[Alasdair Ryan]

Would 6L work?

[Jim]

Would 6L work?

Yes, that would work. 5L is the minimum. Maximum can be up to 12L or something.

[Jim]

Ps it's 6L now, so that would be perfect.

[jantjeuh]

I'm really curious about this 6L solution without backlash!

[weavil]

close to what i did not to long ago...

I never put on LDD before I took it apart so its hard to remember exactly how it was. LXF

[Alasdair Ryan]

I'm really curious about this 6L solution without backlash!

My solution is using a diff going through the middle,that same Effe suggested.

[jantjeuh]

My solution is using a diff going through the middle,that same Effe suggested.

Yeah, but that's 4L isn't it.

[GuiliuG]

Just extend the diff with a driving ring extension and another 16t clutch !

[jantjeuh]

Yes, but that introduces a LOT of backlash! And that's what he's trying to avoid ;-)

[Alasdair Ryan]

Yeah, but that's 4L isn't it.

Yes a diff is 4 long but that would work on it's own like what Weavil posted.

This type of backlash always appears when you have more than one axle going through a turntable.

[weavil]

But when you add gears to the axle going through the different, it becomes at least 6L without any spacing. If you put diff then beam then gear it becomes 8L.

[lukeandahalf]

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.

I think your English is very good! Nico71 has a very good design for a mini 6x6 on his website :) a place to start anyways!

[Jim]

close to what i did not to long ago...

I never put on LDD before I took it apart so its hard to remember exactly how it was. LXF

Thanks a lot! I will take a look.

Yes, but that introduces a LOT of backlash! And that's what he's trying to avoid ;-)

Indeed

The driving ring extension is a major no no

[quilkin]

Not sure if this post belongs here or should start a separate thread! I am looking at ways to make a large beam (cross section approx. 3 x 3 studs) as strong as possible. I have come up with these ideas, in studful and studless (these are 'opened' to show the construction) but wonder if anyone has better ways. The studfull appears stronger (in terms of bending and torsion) but is much more difficult to assemble since the whole of one side needs to be fixed at once across a large number of pins. This is a pain when trying to sort out how the ends of the beams are joined together. To see what I'm trying to do, there are more photos of the application (a W.I.P.) here . If I can decide on the best method I'll need to order a whole load of new parts, but don't want to order parts for the wrong method - and if I can't make the beams stronger than they are now I think I'll have to abandon the project!

[Jim]

Hi!

This is the right topic!

Is 3x3 the limit?

You could use a 2 x 4 liftarm:

http://www.bricklink...tem.asp?P=32140

Or even better....the 3x5 liftarm:

http://www.bricklink...tem.asp?P=32526

Like this:

[quilkin]

Thanks Jim. I have tried the 3x5 liftarms but the results seem similar to using the pin connectors. The cross-section could bigger at 4 x 4; but 3 x 3 seemed a good size to use for the long pins and other available parts. 4 x 4 would be tricky in studful, it would need to be 4 x 5 or even 5 x 5. I'll do some experiments - if it works it will be costly at Bricklink!

[Jim]

Using the 3 x 5 liftarms will probably be stronger, since you have some lateral connections as well.

5 wide you can use the 5 x 7 Open Center Frame Thick, which will result in a very sturdy frame.

http://www.bricklink...tem.asp?P=64179

[Blakbird]

The best way to make a beam strong is to use diagonal connections. You should be able to use a 3-4-5 triangle to help support your beam.

[quilkin]

I did think about these but there are no holes across the centre (in the right direction!) for the middle three layers of liftarms. This wouldn't matter so much for connecting sides made of studded bricks, because the middle layers are held by the studs. Anyway I have made a 5 x 3 version of both and the studded version is considerably stronger when trying to bend the beam (in the vertical direction , which is most important). (ignore the 'bend' in the photo, that's due to the camera lens!) .... thanks Blakbird, just seen your comment after posting mine. Yes, triangles are strong but the diagonal (5) needs a 6-hole liftarm doesn't it? -not available in thick and expensive in thin. The 5x3 liftarms are a good compromise.

Edited September 23, 2013 by quilkin

[quilkin]

OK, thanks guys. Tests with the 5x3 cross-section made with (studded) bricks and joined with 5x3 liftarms are good, so I'll go with that. I'll need about 100 12-hole bricks, 50 or so 5x3 liftarms, 200 long pins and I haven't yet worked out how many 8x1 or 6x1 plates as spacers. The colour scheme will be better than my test constructions! Careful planning will be required to ensure I can fit the two half-sections together for each of the three beams; that'll be up to 60 pins to push home at the same time.....I wonder if they'll ever come apart?

[Hrafn]

OK, thanks guys. Tests with the 5x3 cross-section made with (studded) bricks and joined with 5x3 liftarms are good, so I'll go with that. I'll need about 100 12-hole bricks, 50 or so 5x3 liftarms, 200 long pins and I haven't yet worked out how many 8x1 or 6x1 plates as spacers. The colour scheme will be better than my test constructions! Careful planning will be required to ensure I can fit the two half-sections together for each of the three beams; that'll be up to 60 pins to push home at the same time.....I wonder if they'll ever come apart?

If you're using any normal-length (2L) friction pins, make sure none of them are the old ones (the ones without center slots)! Those are hard enough to pull out one at a time.