[MOC] 4x4 retro car help

[Un_Dac]

Hello evry1,

I'm attemting to build my first MOC. What I'm aiming for:

- something like a retro / vintage / classic car, two seater cabrio. Like the Catherham Seven or what this guy made

- 4x4, motorized with independent suspension;

- the gear shifter will manually shift between neutral (only the fake engine will work), 2x4, 4x4 and 4x2 (yeah, i'm going to need some help with this one)

- in the future I intend to attach a go pro to an arm. the arm must turn the camera 360 and lower or raise the depression angles.

Currently I have the following sets:

- 2 x 8838 Shock Bike; these two sets will supply the wheels, suspension and chain;

- 1 x 42050 Drag Racer; i will use the fake V8 engine from this set;

- 1 x RC Tracked Racer Set 42065 - from this one i will use the two M motors (stearing + drive), battery box, IR receiver and remote;

- 1 x Arctic Truck Set 42038 - this set has a switch with gears which i want to use to switch manually between N, 2x4, 4x4, 4x2.

- 1x Fire Truck Set 8289 

- 9392 Quad Bike Set

- 3 differentials, universal joints (cardan), verious gears and miscellaneous parts.

This being my first MOC, I have some questions:

1. are the two M motors enough or do I need to get an XL engine for te drive. I expect the set to be large and I dont know if one M engine will be enough to power the fake engine along with the 4x4 drive train?

2. how do i make the manual switch between N and traction settings? Theser are 4 options, the switch I have only has three settings. 

3. the transmision will be: M motor > central differential and the fake engine (the motor will turn the fake engine at all times) > from the central diff to the front and rear differentials > wheels. Is this ok?

Thank you!

Bwt, do I need to gear down the motor?

Edited December 14, 2017 by Un_Dac

[Milan]

If this is your first moc, I would suggest you to take it slowly, and maybe with a bit reduced/more achievable goals. 4x4, independent suspension, and drive option selector may be too much for the first moc.
Your best bet is to explore mocs done by veteran builders in details, examine official sets both via instructions and as you build them, and finally, try for yourself to build something smaller and lighter, as a start.

Starting your own build and presenting it here, literally from the very first step is also a very good decision. We will be happy to help you as you go, but it is much easier for us if we see images, you preferred building style etc.

Anyway, welcome to EB and happy building your first moc!

[Un_Dac]

Thx,

I'm sure I can get the independent suspension, stearing, and 4x4. I'm not sure how to make the the drive selector...

Anyway, i'll build and maybe ask you guys as i go along.

This is the progress so far after 30 min :)

The two motors will be on the left and right side. The one that will power the drive train will be on the right and will be connected to the central differential from the sides.

 

LE: this 100Kb limit for uploaded pictures... :( have to risize them...

Edited December 12, 2017 by Un_Dac

[Milan]

Ok, now it is better! Keep building and when/if you are stuck, ask, we are here!

 

9 minutes ago, Un_Dac said:

LE: this 100Kb limit for uploaded pictures... :( have to risize them...

No, you just have to upload them to image hosting site and link them here. Before that, please take some time and read our Guidelines, and also, here is some image posting help.

[Un_Dac]

Ok, so i ran into truble when i started making the front stearing system.

The thing is, i dont have the input shaft nor the suspension arms in order to make the articulated arms and drive axels to the wheels. So i had to find a way around it and i came up with this:

https://ibb.co/ksKgEb

https://ibb.co/gOhtub

I had to make sure that the articulation for the drive is just over the universal joint and it works fine. We have FWD.

Now I have to find a way to attache the suspenison. Question: Which is better: to have the articulation for the suspension closer to the body or closer to the wheel? And why?

My guess is the closer the articulation to the center of the body => more off road capability.

Edited December 12, 2017 by Un_Dac

[Jurss]

RightClick on the picture, select "copy image address", then paste here

I suggest to use bricksafe.com, there You can select also links to resized images (at the moment it is not a problem with Your picture)

u joint center should be at the articulation center.

With this design You will get pretty massive suspension. It will be also pretty hard to make independent front suspension with steering and drive with parts You have.

14 hours ago, Un_Dac said:

42038 - this set has a switch with gears which i want to use to switch manually between N, 2x4, 4x4, 4x2.

I'm afraid, that it wont be enough. You can make there neutral and two modes.

 

[Un_Dac]

6 hours ago, Jurss said:

With this design You will get pretty massive suspension. It will be also pretty hard to make independent front suspension with steering and drive with parts You have.

Challenge accepted.

Yeah, without this pice + input shaft, I imagine it will be hard to make a FWD with independent suspension and steering. But not impossible. It wont be compact though.

I'm also rethinking the drive switch. I think i'll make it with only two options: N and AWD and I'll see from there later on.

Edited December 13, 2017 by Un_Dac

[Technonsense]

You can use something like this for your front suspension:

 

[Un_Dac]

@Technonsense, Thanks! I had a look at that video. Also this one is interesting, however they are working with two motors and no differential.

 

Anyway, after 3 hours of trial and error, I think I naild the front stearing and suspension, This is my porgress so far:

My issues so far:

- the gear rack i need for the steering has to be 11 studs. I have 13 and 8...  so that's face palm no 1. The next thing I'll do I have to solve this.

- the suspension I used in the above pics is not working as I expected. If you push down on the car, it will not bounce back to its initial position. If I push the car hard engough it will touch the ground with its belly and will stay that way. I changed the suspension and I got better results with these ones, however I have a hard time fitting them and the wheels will form an angle:

 

Maybe if I add a second flexible arm behind the suspension to suport the wheel it will be better.

Edited December 14, 2017 by Un_Dac

[Jurss]

5 hours ago, Un_Dac said:

If I push the car hard engough it will touch the ground with its belly and will stay that way

That's because pins with friction are used

 

5 hours ago, Un_Dac said:

- the gear rack i need for the steering has to be 11 studs. I have 13 and 8.

combine that shorter rack with that 11L beam

Or, if You have 

or

then You can use long rack

this also could be used with long rack

or 

with 2l axle

 

 

Suspension/steering system is interesting. For parts You have, pretty OK.

[Un_Dac]

2 hours ago, Jurss said:

That's because pins with friction are used

If I replace the pins with axels with stop at one end, will it be better?

 

2 hours ago, Jurss said:

combine that shorter rack with that 11L beam

Or, if You have 

Thanks! I was actually thinking of something like that. I want to keep the 13 stud rack and replace the arms with the parts you mentioned in order get the flexibility for the suspension. I'll see.

 

2 hours ago, Jurss said:

Suspension/steering system is interesting. For parts You have, pretty OK.

Thanks a lot! Its more fun when you don't have the exact parts and you need to improvise, it forces you to be more creative. When I started building,I  was thinking "I'll see when I get there". For example, I did not know the articulations for the steering / suspension have to be just under the universal joints in order to work together. I found out the hard way, but you get this moment of "Aha!" when you figure it out.

Edited December 14, 2017 by Un_Dac

[Jurss]

12 minutes ago, Un_Dac said:

If I replace the pins with axels with stop at one end, will it be better?

Yes, axles also doesn't make significant friction.

but you will get more wobbly suspension and steering

[Un_Dac]

Regarding the drive option, I plan to use the 3 selector switch and add a 4th for neutral like this:

Instead of coupling the different drives, I want to uncouple the front or rear or all together:

- In Neutral position the switch will uncouple the motor from the central differential and the motor will only turn the fake engine;

- In center position it will couple the motor to the central differential and all wheels will turn (AWD) along with the fake engine;

- in forward position, it will uncouple the front drive (the transmission between the center diff to the front diff) and only the rear wheels will turn (RWD)

- in the back position, it will uncouple the rear drive (the transmission between the center diff to the rear diff) and only the front wheels will turn (FWD)

the switch will be located between the seats like a gear shifter.

On paper, that's the plan, but I have a long way so I'll see when I get there:)

[Jurss]

With that one "switch" (driving ring and clutch gears) You have, I would say, that it is impossible.

Maybe if you make some pure mechanisms with gears, close to the real gearbox mechanisms ...

good luck!

[Un_Dac]

didn't have time to work on it, small update - finished the steering. It now has steering, independent suspension and 4WD. 

I don't mind that it's massive and I like how it turned out, especially those steering angles:

couldn't help myself adding the motor to the chassies for a test drive. It works ok, it drives over obstacles, however, I think an XL motor will be better.

 

[Milan]

1. It is never good idea to use parts that can slide off, in the steering system. As soon as a wheel meet an obstacle, and you engage steering, your black connectors will slide off that gray 3l axle. Always use one piece parts, that cannot be separated, in these sections.

2. You could continue to use the M motor, if the vehicle will remain in the chassis phase, but it needs some gearing down (I guess it is also a bit too fast now). XL motor(s) is a must for a vehicle this size.

[Un_Dac]

I'm aware of problem no 1, however i don't have a simple solution around it for the moment. I need an 11 stud rack to use the one pice arms or I can use an 11 studs beam + 3 of simple pice racks attached to that:

 

the down side to this is that i have to move the engine up a stud or two and will make the hole thing taller.

 

regarding the M engine, its not that fast. I dont know if the engine is struggling or the bateries are running out.

Edited December 17, 2017 by Un_Dac

[Un_Dac]

This is the alternative steering with the 11 stud custom rack:

another downside is that the steering angle is not so wide anymore.

[Milan]

And it easily push and rotate the connector on the steering arm?

[Un_Dac]

Yes, it works ok, you can feel very little opposing force. The rack dosen't get stuck or enithing.

This is alternative 2. I used a normal beem, not a brick with holes. However, this will not be an option, first of all, the teath from the two racks do not cover evenly the beam. Second, when you turn the steering all the way, the beam will fall into the chassies.

Out of all, I liked the results from the first steering system despite the parts which will slide off.

I looked for an 11 stud steering rack, however for some reason, this pice dose not exist

[Jurss]

10 hours ago, Un_Dac said:

I'm aware of problem no 1, however i don't have a simple solution around it for the moment

You can use there simple 5L beam.

 

10 hours ago, Un_Dac said:

another downside is that the steering angle is not so wide anymore.

also connection closer to wheel are not fixed, which is much bigger problem. steering geometry will change after each turn.

9 hours ago, Un_Dac said:

I looked for an 11 stud steering rack, however for some reason, this pice dose not exist

As I wrote previously, yo have 2 of these

combine it with 13L rack, and you have 11L rack at the same time

[Un_Dac]

@Jurss,

You mean to connect that piece to the axe whole on the side of the 13L rack?

[Jurss]

yes. And in this You can insert that pin with ball.

[Un_Dac]

1 hour ago, Jurss said:

yes. And in this You can insert that pin with ball.

Thanks Jurss!

Now I'm like why I didn't think of this earlier... thing is I hardly noticed the axel holes on the sides.

[Un_Dac]

what does a clutch gear do?