FWD Lego Model

[Legotyres]

Hi All,

im currently in the throes of building a transverse fwd Lego moc. It’s in its early stages at the mo, it it has an ultra 4 speed gearbox, engine and differential all mounted transversely. 

 

Ive still to do a bit of work on the gear selector to make it a little easier, but here’s a small video of it in its current state 

 

if if you see bits of your Lego Design in this model, thanks for the inspiration

 

 

[veryrusty]

Very nice indeed. I'd be interested to see more photos of your gear selector.

[Legotyres]

the rotation selector works really nicely, it's the linkage after that that I'm having fun with at present. I've just built the v3 modded Porsche gear selector and still a little clunky for my liking. Was a nightmare to build too as the lxf program completely messed the instructions up 

It's something to do with those weird gears with four nobbles on them. I tried another system with them earlier and they were just as bad. If I use normal gears, and my fingers as the selector, it's damn perfect 

so, it's back to the drawing board for the linkage selector  

[Legotyres]

An earlier version with the linkage for you, sorry it’s not in wide screen 

 

 

[Legotyres]

Mk6, some major alterations due to the gearbox selector being a little to tensioned for any of the gear-levers. 

So, it’s a massive changed whilst still retaining the original project guidelines which were, it had to uses macpherson struts as it’s a FWD, all the running gears from the differential to the engine had to be transversely mounded. The model also had to use Ackerman steering. There is still a lot of work to as the video is only shows a chassis front end. Apologies on the video quality too, ill change this once I’ve added added the gearstick and lower body part

 

 

[Legotyres]

Hi All, MK6 FWD Transverse has a working gear stick and rather crude chassis. Enjoy a slightly better video

 

 

If you see your designs in this MOC, thanks for the inspiration as I couldn’t have done it without your ideas 

[Aventador2004]

I think it is too short for its width, try extending a little.

[Didumos69]

I like the concept and it seems to be working . One thing I noticed: At timestamp 31 the speed of the big gear at the left side of the gearbox oscillates. This indicates friction. Perhaps you could address that. I suppose the chassis is not done yet, so I won't comment on that.

[Legotyres]

Yeah, it’s a bit short (it’s just a template chassis to show it working ) and yeah I’m not totally happy with the gear ratio, but it’s a working transverse fwd Lego car (well kinda).

One thing which others maybe able to help me with, I’ve yet to find a proper FWD out on the web, most seem to use a longitude differential or the gearbox. With this model, everything is transverse mounted even using an older style differential to keep it true

[Didumos69]

7 minutes ago, Legotyres said:

One thing which others maybe able to help me with, I’ve yet to find a proper FWD out on the web, most seem to use a longitude differential or the gearbox. With this model, everything is transverse mounted even using an older style differential to keep it true

I suppose you mean something LEGO. I only know about @Rudivdk's 7-Seater, but it has a longitudinally placed gearbox.

[Legotyres]

Aye, that 7 seater model is awesome. One of the best builds I think I’ve seen 

[Lucullus]

Hi, i'm currently building a WRC car with the same engine/gearbox/front axle layout as yours (there are some early WIP pictures in the axle collection thread). I think the reason for that layout being so rare is that lego gearboxes (and fake engines) are much out of scale in smaller cars and if you want to position the gearbox next to the engine (as it is done in real cars) it will be even harder at a small scale. My car uses Unimog wheels and it is still very narrow in the engine bay.

[Legotyres]

3 hours ago, Lucullus said:

Hi, i'm currently building a WRC car with the same engine/gearbox/front axle layout as yours (there are some early WIP pictures in the axle collection thread). I think the reason for that layout being so rare is that lego gearboxes (and fake engines) are much out of scale in smaller cars and if you want to position the gearbox next to the engine (as it is done in real cars) it will be even harder at a small scale. My car uses Unimog wheels and it is still very narrow in the engine bay.

Have you any pic’s. Be interested in seeing someone else’s design. 

Ive the Unimog hubs with some low profile tyres on it which should give you an idea how big the model is. 

Edited May 14, 2018 by Legotyres

[Lucullus]

Current state of my wrc car:

As you can see, the gearbox doesn't use selector rings as the "official" Lego gearboxes do. It works a bit like the one in 8860 with an idler gear that can slide along an axle to connect the gears. For that reason it doesn't shift very well when the gears aren't moving. The good thing is, that it has a realistic cone shape.

In my previous post i forgot to mention that this is of course an awd drivetrain, but as this car doesn't have a central diff (due to FIA rules), its front axle/gearbox is identical to an fwd one.

[Legotyres]

That’s awesome and makes mine look a little naff 

 

i really like the gearbox idea. I’ve sorted the ratios for the gearbox on mine, although I got to figure out how to even put the drive from differential to the gearbox. That’s where the friction is coming from. Looks like the ratios are creating two much of a friction when first gear is selected. 

Have you seen my instructions for a mechanical correct macpherson strut. I’ve posted photo instruction on here via flicker. 

I cannot take credit for then as it’s evolved from other versions I’ve seen and been able to incorporate into it

[Lucullus]

Yes i've seen your macpherson suspension but i haven't tested it yet. Did you notice any difference between small and large springs regarding the play between the two tubes of a spring? It seems that at least the large springs have a tendency to bend/wedge instead to compress as they should. I also had the idea to use two big springs connected in opposite direction to improve it but i think this won't work with the wrc's geometry.

Edited May 15, 2018 by Lucullus

[Legotyres]

If you use the smaller 62mm tyres, they’re not perfect although they work. Using wider tyres ensures they do not taper outwards at the bottom though. Although it’s not massive. It’s a little bug-barer

With the springs, you don’t need to use the yellow ones. I’ve two models shown in my posts which use the large springs. These only require grey or black one. The yellow ones as just to strong and are not required. It the same with the small springs, light or dark grey ones are perfect.

im pleased with the springs, I cannot take credit for them as they have evolved over the models and when I’ve seen another option, I’ve seen if it will work better than another. If it did, it replaced the original design and if not, it stayed to same

Both spring types  work fine though

Looking at how wide your engine bay is, this macpherson solution will not work due to the angles required to give the springs there strength. It’s only 13 wide at the top which is what dictated where the gearbox sat

Edited May 17, 2018 by Legotyres

[Legotyres]

Well, I gave up on the last one and since then, Lego have introduced some new parts. So I’m in the very very early stages of trying another transverse Lego Technic MOC

I’ll post some better images soon. Unlike the last one, I’ve managed to add a F-N-R and the sequential side is a four speed

Still got to add the steering and suspension, so please don’t get to excited 

 

First and reverse have the identical ratio to which is nice
 

Edited March 26, 2022 by Legotyres
Trying to upload images