Technic General Discussion

[Technyk32231]

Pics of your setup would be helpfull.

It's just a regular trailing arm setup. I think I will just add a tensioner wheel.

[Doc_Brown]

The longest one that I can think of is the Elphinstone road train by 2legoornotto2lego.

Thank you very much blakbird! Just what I was looking for. Cheers

Another question!

How do you work out scale? For example my model is 41cm long and in real life its 7700cm long, What scale is that?

[aol000xw]

7700/41 => 1:187 ?

[Technyk32231]

You know how LDD lacks a lot of the technic parts that many people use? I've been trying to figure out how to add parts to it, and I think that I may be on to something.

On a windows computer go to Computer > Program Files(x86) > Lego Company > Lego Digital Designer, and there is a .xml file titled "ldraw". It lists a whole bunch of parts, and I think if I modified it correctly, it would be possible to get the whole Ldraw parts library in LDD.

[Blakbird]

You know how LDD lacks a lot of the technic parts that many people use? I've been trying to figure out how to add parts to it, and I think that I may be on to something.

On a windows computer go to Computer > Program Files(x86) > Lego Company > Lego Digital Designer, and there is a .xml file titled "ldraw". It lists a whole bunch of parts, and I think if I modified it correctly, it would be possible to get the whole Ldraw parts library in LDD.

No. That file is used for mapping LDD parts to LDraw parts when you select "Export" from LDD. It doesn't control anything about parts in LDD itself.

[Lakop]

That road train is fab. I've not seen it before.

H

[Doc_Brown]

7700/41 => 1:187 ?

Thanks!

So would 7700/82 be 1:094? or 1:94:

[Technyk32231]

No. That file is used for mapping LDD parts to LDraw parts when you select "Export" from LDD. It doesn't control anything about parts in LDD itself.

Oh, I thought it was the other way around. My bad.

[Alasdair Ryan]

Has any one built any cool sounding lego plane engines?

A Saab 340 turbo prop sounding one would ideal...

I never brought down any buggy motors with me but I can buy L and XL motors if required.

Edited January 5, 2014 by Alasdair Ryan

[quilkin]

Looking for help with driving a turntable with an 8-t gear.

The photo may help; I have removed some strenghening parts to show more detail. The 8-t is directly mounted on the XL motor, on a 3L axle passing through one of these.

It runs OK until the load increases, then the gears slip. Normally it's necessary to have both sides of a gear firmly mounted but this isn't possible when driving a turntable.

The motor is mounted very rigidly and is not moving , all the play appears to be in the turnatble itself or the 3L axle.

I would try using 2 (or even 4) 8-tooth gears spread around the circumference, driven in parallel, to share the load, but there's a fixed 'axle' (15-hole bricks joined with plates) going right through the 'hub' which gets in the way of sharing the load like this.

Any ideas?

[NevynPA]

What if you mounted the motor "off-board" and used chain links to connect it to the turntable? Would that get in the way of the function?

[quilkin]

Interesting idea which I think may lead to a solution . Chain on its own might still slip but combined with direct drive like this:

could help hold tings together. Anyway by observing this assembly under load I have seen where I can strengthen the superstructure to stop things moving as well. Thanks Nevyn.

[z3_2drive]

I wanted to add a little bit of info to my description of nicjasno's custom wheel hubs. When I got them I took my car through a lot of bashing, and after enduring the torque, jumps, and 10-12 mph speeds one hub came apart at the glue layer, and of course broke the dark bley hub piece. This will never happen to anyone's MOC because my vehicles are the most insane of any Lego RC MOCs, but I think using a specialized plastic-bonding glue would be stronger than multi purpose super glue. And regarding the Outdoor challenger-I really wish TLG would bring back the 11.5l Shock absorbers!

[nicjasno]

z3_2drive: if you can't repair the hub, give me your address again and i'll send you a replacement.

[z3_2drive]

z3_2drive: if you can't repair the hub, give me your address again and i'll send you a replacement.

Thanks, I don't need it now so I'll fix it on my own time soon. If I can't I'll let you know

EDIT: You sent me 4 for the price of 2 anyway, so if anything I owe you

Edited January 8, 2014 by z3_2drive

[nicjasno]

I did? Haha, my mistake. Did you order only 2?

Also, can you post a pic of what happened and a pic of your r/c car?

Edited January 8, 2014 by nicjasno

[z3_2drive]

Yeah I wanted 4 but ordered 2 after I saw the price, and it turned out nicely since I only used two for the car and had two spares when one broke.

Here's some quick pics of the beast:

Here's the broken hub:

[nicjasno]

That should be easy to repair. stick an axle through the hub, put a pulley on the broken off part and stick an axle through that (to get it all centered) and glue back together.

[z3_2drive]

Exactly what I had in mind Although I may not need it for a while, I ordered some chrome wheels and may do one more video before I take it apart and start the Ripsaw project.

[NevynPA]

Interesting idea which I think may lead to a solution . Chain on its own might still slip but combined with direct drive like this:

could help hold things together. Anyway by observing this assembly under load I have seen where I can strengthen the superstructure to stop things moving as well. Thanks Nevyn.

If you put extra gears on the 'inside' and 'outside' of the chain loop to act as both tensioners and guides, that'd probably reduce the risk of slipping at the cost of increased parts/complexity. Sounds like you've got a good solution planned!

[captainmib]

Here is a question for you that i really want to solve.

I am building a sequential gearbox and want to do manual gearshifting with a stick that returns to centre by elastic band.

The thing is, i want to build a single mechanism that can shift forward and back by turning a knobwheel 45 degrees.

So, pushing the selector forward will 'grab' the knobwheel, turn it 45 degrees, releases the knobwheel (so it stays in that position) and returns to centre.

It has to be able to shift forward and back, so turning the knobwheel 45 degrees in both directions.

I hope you guys understand what i'm saying. I could not find a real life mechanism so far, so if you can find an example and show it to me, thats ok aswell.

If i need to explain more, please ask.

[NevynPA]

Have the 'fingers' on the sequential stick push on a cam lever that's attached to the axle of the knobwheel?

[captainmib]

And how does the cam reset so yo can push or pull it again?

I'm not sure if I understand what you are saying.

The gearbox i'd like to use i this one:

And I want to switch the m-motor for a lever, so that you can shift manually.

The knob-wheel is turning 45 90 degrees. (i'm a pancake, it needs to rotate 90 degrees, not 45)

Edit:

I think a found a solution, will try this setup:

http://www.mocpages.com/moc.php/239686

Edited January 11, 2014 by captainmib

[Dooftastic]

Does anyone know when the 2014 sets will be available from the Lego online shop to customers in the US?

[legomania94]

a question at all, when it comes out a decent bucket for an excavator or 8043 zorex etc?