1/4 Scale R/C F1 (Regarding Chassis and suspension)

[newyorkkopter]

Thanks guys for your input.

Sorry, it´s not meaned in an offensive way, I doubt you have the technology and knowledge to use honeycomb core, for your project yet.
That´s nothing to be ashamed of, but you will need to walk, before you can run.
So do yourself a favor and start small/simple (no core construction), but start and learn your lessons along the way, while you are doing things.
You will have a better understanding, of what the challenges are, when you have laminated a part or two.
Try to produce some simple things, make a form of an cheap model car, or any other geometric shape, just to learn the technique. (form making, layout etc.)

Thanks for putting it in a nice way. I think I'm going to go with that(more or less).
So instead of a 1/4 r/c I'm planning on switching over to doing a 1/4 scale model.
It doesn't absolutley have to be superdetailed like the pros do it, but still, hopefully it'll be useful in learning about composites, painting, mouldmaking, and how an F1 car works.
1/4 scale seems easier to work with than 1/24 or even 1/18 when it comes to detailing.
Sorry about the honeycomb thing
And I almost forgot, thanks for the pics!

[747heavy]

Hi newyorkkopter,

I don´t want to offend you, nor want I discourage you, far from.
But I feel that from time to time, it´s good to do a "reality check" for whatever
project you want to do. ( it applies for myself as well, sometimes you just have to admitt, that you don´t have the knowledge or the means (money,equipment, time etc.) to do what you would like to do).
I just don´t want that you are hugely disappointed, when it does not work out the first time around.
To do a honeycomp cored CFRC monocoque is no small feast, and you need a considerable amount of know how, infrastructure (that is not a "kitchen table" project) and time, apart from some money as well. You will need at least a two part mould, which has it´s own challenges. So that´s why I recomended to start simple and learn the processes. This is a craft, so there is only so much you can learn from books or on forums like this.
At one point, you will need to bite the bullet and get your hands dirty, so to speak.
you will see, what the challenges are, and it will help you to ask "better" questions, and in general, you will learn a hell of a lot.
The general process and the mould making is the same for fibre glass and for carbon fibre. Fibe glass (E-glass) is cheap, so you can start out with this material, and learn your craft. It´s cheaper to throw a fibre glass part in the bin, then a carbon part -> and it will happen, that´s just the way of things.
To become a master, you have to practice, there are not many shortcuts on the way.

Nevertheless, good luck on the way, and I´m sure most hee are still happy to help, if the ycan - I am. Keep us posted!!

P.S.: I agree that at 1:4 or 1:5 model is a bit easier to start with, as far as details go.

[mep]

Why you always think a mould is needed?
Can't you also build a wooden frame and glue the carbon/glassfiber on top of it?
So the wood gives you the shape, increases the strength on openings (where you will use stronger and thicker wood) and can act like a core.

I think you should test this. Build just a chassis without caring about the rest of the car and then test the strength of it. So this chassis will be destroyed.
Then you can build another one and learn from your gained experience.
Other things you don't have to care about then. This will make things much easier.

[newyorkkopter]

747, thanks again man.

Can't you also build a wooden frame and glue the carbon/glassfiber on top of it?
So the wood gives you the shape, increases the strength on openings (where you will use stronger and thicker wood) and can act like a core.

yeaa I could try that.
I was thinking about using a wooden chassis in a large scale rc supercar
Maybe I could do resin bonded plywood, I remember reading an article about a gokart regarding something like that.
But this would be for rc car right?
Because with a scale model I could probably get away with less stronger parts
But then again doing it on a scale model might have benefits, like learning about making chassis.
Either way, thanks mep!

[flynfrog]

747, thanks again man.

Can't you also build a wooden frame and glue the carbon/glassfiber on top of it?
So the wood gives you the shape, increases the strength on openings (where you will use stronger and thicker wood) and can act like a core.

yeaa I could try that.
Maybe I could do resin bonded plywood, I remember reading an article about a gokart regarding something like that.
But this would be for rc car right?
Because with a scale model I could probably get away with less stronger parts
But then again doing it on a scale model might have benefits, like learning about making chassis.
So yea, thanks mep!

it will pretty heavy

[newyorkkopter]

heavier than steel tubes?

[flynfrog]

heavier than steel tubes?

in honestly depends on the design just look at the fsae teams using a good layup are not a whole lot lighter than the moly frames

[Carlos]

This thread references a 3mm plywood monocoque - Marcos of England used it in road sportscars, Le Mans prototypes and F2 - also mention of paper composite airplane monocoque:
viewtopic.php?f=6&t=7142&hilit=wood+monocoque&start=0

Two inexpensive books:

Understanding Aircraft Composite Construction - Zeke Smith

Composite Construction For Homebuilt Aircraft - Jack Lambie

[marcush.]

wet layup technique is completely useless for a project incorpoarting CF and sandwich technique.
You will never get close to a useful resin content with debulking methods on a wet layup so if you are not willing to go the complete road ..just stop here and instantly and buy a ready made whatever is available.

To get down to resin contents of under 50% you need to go to infusion or prepreg /resinfilm systems both are entirely feasible to do at home with some gearing up:You need a vaccum pump and some bagging hardware + an oven (that could be customized kitch oven(!) or to be fancy some basic initial testing could give you surprisingly perfect examples with a microwace oven !(as you will heat the object through from the start and not from the outside..

Moldmaking and moldmaking IS fun and of course you need to put your brains into it to arrive at something usable...in engineering the attitude to go straight to the result without tooling more than a hammer and a saw is very rarely going to give you the desired result... So we are technically minded ,aren´t we ?

having a proper mold will give you a lot of opportunities ,believe me...and it will enable you to produce quality,precision and reproduceability as well .

[marcush.]

we have reached a point in another thread were we are discussing topics of interest
but unfortunatelly being for too offtopic to have any relevance to that very thread.

So I would like to open a discussion about the challenges of suspension related kinematics detail design and the pro´s and cons of different solutions.

First of all I think we should be clear what exactly to discuss here.Is it useful
to exclude geometries (in terms of toe,camber etc )or dynamic charecteristics (camber change/ackerman/anti prodive/squat /elastokinematics ...)and just define the load cases and the possible solutions we have seen /are willing to share or do you think it is restricting the view too much to start discussing focussing ourself so much into the very detail right from the start?

Suspension kinematics detail design challenges

[newyorkkopter]

To get down to resin contents of under 50% you need to go to infusion or prepreg /resinfilm systems both are entirely feasible to do at home with some gearing up:You need a vaccum pump and some bagging hardware + an oven (that could be customized kitch oven(!) or to be fancy some basic initial testing could give you surprisingly perfect examples with a microwace oven !(as you will heat the object through from the start and not from the outside..

Moldmaking and moldmaking IS fun and of course you need to put your brains into it to arrive at something usable...in engineering the attitude to go straight to the result without tooling more than a hammer and a saw is very rarely going to give you the desired result... So we are technically minded ,aren´t we ?

having a proper mold will give you a lot of opportunities ,believe me...and it will enable you to produce quality,precision and reproduceability as well .

ahh the right tooling can be helpful means. thanks!

"This thread references a 3mm plywood monocoque - Marcos of England used it in road sportscars, Le Mans prototypes and F2 - also mention of paper composite airplane monocoque:
viewtopic.php?f=6&t=7142&hilit=wood+monocoque&start=0

Two inexpensive books:

Understanding Aircraft Composite Construction - Zeke Smith

Composite Construction For Homebuilt Aircraft - Jack Lambie"
hey man thanks for that!

So I would like to open a discussion about the challenges of suspension related kinematics detail design and the pro´s and cons of different solutions.

That could be useful
I think would be easier for beginners to follow if geometry and dynamics were excluded at the beginning of the thread
Maybe they can be worked in to thread abit after discussing loads?

[747heavy]

ceramic bearings

[Peter-RC]

ah the traxxas revo car... as far as i know you'd want the shocks to displace more then the pushrods (higher motion ratio)... but this is exactly the otherway around.
Good thing the pushrod+damper mounts are in double shear, most R/C car makers use single shear mounted stuff a lot.

[747heavy]

some photos of F1 components, maybe not 100% related to your project - sorry

this is an machined insert (aluminium) which goes inside the tub (hardpoint), where
later the engine stud is secured to connect the engine with the chassis.
note the many small holes for good resin penetration and bonding.



machined rockers out of solid titanium billet



machined front wishbone insert - titanium

[mep]

There is a article about scale race cars in racecar engineerings november issue.
I haven't read it yet but it looks good.

(Btw. first time I got the mag send to my home, it just feels better to read from real paper than from the screen)