Engineering project, leaving cert 2012

mousi · 13-10-2011 9:45pm #1

What does everyone think about the project?

Mayo_Boy · 13-10-2011 10:00pm

We haven't got ours yet :eek:

fullback4glin · 14-10-2011 5:13pm

Can the title of this thread be changed to Engineering Project, it's misleading because there is a Junior Cert subject that is called Metalwork and has a Project too...

Ya, this year they've to make a Lunar Roving Vehicle (LRV), our school got the Brief today.. my first impression was that it was ok, until I realised that it has to be steered and powered by the front wheels. And each wheel has to be able to move independently.. so you'd be looking at three motors, all powered by 9V.

For me, that's the most difficult part. It's going to have to be light- acrylic or sheet metal. Looking forward to it though, it's not entirely different to the Snowmobile last year.

Bbbbolger · 14-10-2011 7:41pm

I was expecting it to be a lot worse after the snowmobile last year. It'll be a challenge but it leaves a lot up to your own design. Plenty of scope for creativity.

ImpossibleDuck · 16-10-2011 2:48pm

fullback4glin wrote: »

And each wheel has to be able to move independently.. so you'd be looking at three motors, all powered by 9V.

Ahh no? At no point does it say each wheel has to be able to move independently. It says the two front wheels have to be powered individually. I suggest having a wee read of the brief again before ye start building :P

Leftyflip · 17-10-2011 4:24pm

Got the brief today and already know exactly how I'm gonna do it, too much time spent on RC cars...

fullback4glin · 17-10-2011 5:42pm

Leftyflip wrote: »

Got the brief today and already know exactly how I'm gonna do it, too much time spent on RC cars...

Care to share it with us?

Leftyflip · 17-10-2011 5:57pm

fullback4glin wrote: »

Care to share it with us?

Sure

Chassis, wheels, track, motor.

:pac:

TheRealRail · 17-10-2011 7:00pm

i got th brief there and was wondering do the front wheels have th be able to turn even thow it has to be front wheel drive.. or could you steer it from th bck instead???

Leftyflip · 17-10-2011 7:15pm

TheRealRail wrote: »

i got th brief there and was wondering do the front wheels have th be able to turn even thow it has to be front wheel drive.. or could you steer it from th bck instead???

"Include a steering mech. for the front wheels" front steering.

Mayo_Boy · 17-10-2011 7:53pm

Gonna be a challenge

conorfitz · 17-10-2011 7:53pm

Can anyone put up a photocopy of the brief?
Or even write out all the details which it must include please!

Much appreciated,

conorfitz

Leftyflip · 17-10-2011 8:01pm

Brief: Design a model of a Lunar Roving Vehicle to the general specifications outlined below.

The LRV should:
a) Have propulsion units to provide individual drives for both front wheels;
b) Incorporate a central switching console to operate the front wheels;
c) Include a steering mechanism for the front wheels;
d) Have seating capacity for the driver only.

Presentation of the completed project should ensure that:
a) All main operating features are clearly visible without dismantling;
b) The longest dimension of the model must not exceed 350mm;
c) Electric power does not exceed 9V.

Will throw the rest up later!

conorfitz · 17-10-2011 8:08pm

Thanks a million :-)

partyatmygaff · 17-10-2011 8:52pm

God I would have loved this instead of the snowmobile I had to design/make last year.

A handy tip:
Get your brief finished over the mid term break, otherwise you'll be under huge pressure come March/April.

Mayo_Boy · 17-10-2011 10:08pm

Am I right in sayin' it has to be done for March 2nd?

Edit: anyone no where to get a sample brief for some ideas?

fullback4glin · 17-10-2011 10:39pm

Ya March 2nd

Bbbbolger · 17-10-2011 11:09pm

Got my snowmobile from last year back today. Broke my heart thinking about having to do another project this year! As someone who did it last year as well I have to second what partyatmygaff said. Get your brief done. Do it as you do your project or you'll be under unnecessary pressure near the end of the year.

mousi · 17-10-2011 11:51pm

sorry about the wrong heading for this i completely forgot.

but a quick question, i know the brief says "incorporater a central switching console to operater the front wheels" but i was wondering if i made a wireless remote control and have the switch on that would that be good enough to satisfy the examiner?

cheers
mousi

fullback4glin · 18-10-2011 12:00am

That would absolutely satisfy the examiner! I was just gonna make a simple remote control, but wireless now that's interesting! How might one achieve this??

mousi · 18-10-2011 12:12am

my metal work teacher was telling me to take a part a rc car and get my barrings from that and see what i would need to put into it and see how much work would have to be done, but he said that it would be very do-able..
would we get docked mark if we copied a design of a rc car remote control?

cheers
mousi

partyatmygaff · 18-10-2011 12:16am

fullback4glin wrote: »

That would absolutely satisfy the examiner! I was just gonna make a simple remote control, but wireless now that's interesting! How might one achieve this??

FM Radio and servos.

Leftyflip · 18-10-2011 4:21pm

partyatmygaff wrote: »

FM Radio and servos.

Stop giving people my ideas!
Was toying with this idea myself last night.

cnlhernon · 18-10-2011 4:46pm

So the wheels have to be able to turn with a steering mechanism?. But do the front wheels have to be powered by two seperate motors?

Mayo_Boy · 18-10-2011 8:03pm

cnlhernon wrote: »

So the wheels have to be able to turn with a steering mechanism?. But do the front wheels have to be powered by two seperate motors?

Yes and Yes.
Did you not read the brief at all?

TW Mr Tayto · 18-10-2011 9:24pm

Double post, sorry guys.

TW Mr Tayto · 18-10-2011 9:24pm

This seems very Scrapheap Challenge, if only!

What materials are people thinking?
Obviously engineering is seen as a follow-on from metalwork; but most of my plan is plastic ATM.
I'm having Aluminium mud-guard looking things on the back, for now.

Billtop · 18-10-2011 9:56pm

The project can have no hidden parts - all visible - so clear perspex base might be a good idea, maybe 6mm thick. That would make attaching easier plus adds a bit of structure. You can't go wrong with 1.5mm aluminium for other parts.

Mayo_Boy · 18-10-2011 10:21pm

Billtop wrote: »

The project can have no hidden parts - all visible - so clear perspex base might be a good idea, maybe 6mm thick. That would make attaching easier plus adds a bit of structure. You can't go wrong with 1.5mm aluminium for other parts.

Would having to look underneath the chassis of the project to see it parts count as being visible or do they have to be seen from the top?

Bbbbolger · 18-10-2011 10:25pm

As long as nothing has to be dismantled to be seen you're ok.

Darth Frodo · 18-10-2011 10:31pm

Hello, I just got the brief today. I have a couple of questions and suggestions.

"Incorporate a central switching console to operate the front wheels"
I have no idea how to intemperate this for my folio. Would anyone care to elaborate please. Does this mean that the 2 front wheels need to be completely independant of each other?

"Electric power does not exceed 9 volts."
Please correct me if i'm wrong but i think i remember doing something in physics last year, that no matter how batteries you have in the system, the power does not change.
It's sort of 2 9v batteries put ou 9v but an 18v battery (if it exists) puts out 18v?

Lastly I see people looking into RC and wireless... why?
I mean this machine wasn't RC from earth by NASA (or those sneaky Chinese). It was driven like a normal car only powered by electricity. The astronaut drove it. My idea for the propulsion was simple, batteries powering 2 motors.

partyatmygaff · 18-10-2011 10:46pm

A central switching console is just that. A control panel of some sort that controls both power and steering of the front wheels.

As for your power question... Say we have two identical 9v batteries with a maximum current output of 200mA.

Wired in parallel your power supply will be:
9v
400mA

Wired in series your power supply will be:
18v
200mA

Darth Frodo · 18-10-2011 10:53pm

But what if the batteries are completely independent of each other. ie one battery and one side another at the other side. What if they're not wired in a parallel or series circuit??

partyatmygaff · 18-10-2011 11:00pm

Well if they're completely independent of each other there's no change whatsoever to their power ratings.

It won't look too good from a design point of view though. I'd avoid more than one power source as it just adds excessive weight and adds more points of failure.

Darth Frodo · 18-10-2011 11:02pm

Great! Thanks for your input! Much appreciated!

partyatmygaff wrote: »

A central switching console is just that. A control panel of some sort that controls both power and steering of the front wheels.

When you say this do you mean to say that they must be steered independently?

partyatmygaff · 18-10-2011 11:08pm

Darth Frodo wrote: »

Great! Thanks for your input! Much appreciated!

When you say this do you mean to say that they must be steered independently?

No. Sure what good of a steering system would it be if the wheels pointed in different directions? :P

They're just asking for a central control panel of sorts where you can adjust the power and the angle of the wheels. I had one on my snowmobile last year as a matter of fact.

Darth Frodo · 18-10-2011 11:11pm

So when it says "central switching console" what does the switching refer to?

partyatmygaff · 18-10-2011 11:27pm

Darth Frodo wrote: »

So when it says "central switching console" what does the switching refer to?

Switch: To change the direction of something where "something" is your set of front wheels.

It's an odd way of using the word but it's perfectly valid too.

Darth Frodo · 18-10-2011 11:29pm

EXCELLENT!!!!!
Thank you very much. I can now finish off my analysis.

IIIAcHmEdIII · 19-10-2011 9:53pm

Hi guys just wondering if you used two rheostats (variable resistors) on the two motors in the front to steer . This way you could speed up one wheel and slow down the other to turn my interpretation of it would be that im using an electrical mechanism for steering . Would make it a fair bit easier .

Thanks

partyatmygaff · 19-10-2011 10:18pm

It wouldn't work very well unless you had both the back and front wheels connected to the motors. Even at that it'd be very user unfriendly and difficult to use.

Trying to rotate a four wheeled car about its central axis by just rotating a single front wheel is nigh on impossible.

IIIAcHmEdIII · 19-10-2011 10:31pm

Thanks for the reply but my idea does not consist of 4 wheels so i was hoping this would count as my steering mechanism and the switching console and just use the two rheostats and a DPDT (double pole double trow) switch in a wired controller to control it . Thanks

partyatmygaff · 19-10-2011 10:46pm

Well the brief specifies "front" wheels. That implies you'll need wheels at both longitudinal ends of the vehicle.

I'd say just stick to a four (Or more) wheeled front wheel drive vehicle so you don't lose any marks for not meeting the conditions of the brief.

IIIAcHmEdIII · 19-10-2011 10:58pm

partyatmygaff wrote: »

Well the brief specifies "front" wheels. That implies you'll need wheels at both longitudinal ends of the vehicle.

I'd say just stick to a four (Or more) wheeled front wheel drive vehicle so you don't lose any marks for not meeting the conditions of the brief.

Thanks i was thinking along the ines of more than 4 wheels anyway but dont want to give away to much coz the design i have is very out of the box thinking =P but yet the simplest i can think of . Thanks

laoch na mona · 19-10-2011 11:06pm

it seems grand it only took one class brain storming session for everyone to have it figured out more or less

laoch na mona · 19-10-2011 11:13pm

TW Mr Tayto wrote: »

This seems very Scrapheap Challenge, if only!

What materials are people thinking?
Obviously engineering is seen as a follow-on from metalwork; but most of my plan is plastic ATM.
I'm having Aluminium mud-guard looking things on the back, for now.

aluminium and plastic at the moment

joe mc mahon · 20-10-2011 6:08pm

anybody have a portfolio from last year in which they would like to email it to me ?

Cuppa tae · 20-10-2011 7:30pm

partyatmygaff wrote: »

A central switching console is just that. A control panel of some sort that controls both power and steering of the front wheels.

I understand the central switching console to have nothing to do with powering the steering.

I took the central switching console to mean the ability to adjust the speed of the individual wheels independently.

Nowhere in the brief does it say the steering must be motorised

partyatmygaff · 20-10-2011 7:37pm

Cuppa tae wrote: »

I understand the central switching console to have nothing to do with powering the steering.

I took the central switching console to mean the ability to adjust the speed of the individual wheels independently.

Nowhere in the brief does it say the steering must be motorised

No one said that a "central switching console" need be completely electronic either...

Basically, to put it in much clearer English they're just looking for a centralised user interface. One place for all the controls.

One important thing to note about the two motor set up you'll have to use for your front wheels. Use the same type of motor for both wheels and make sure they both receive equal amounts of power. Having one wheel rotate faster than the other is going to cause you all sorts of problems.

Cuppa tae · 20-10-2011 9:59pm

So would i lose marks if i had a completely manual steering system?

The only electronics would drive my two front wheels

mousi · 20-10-2011 10:15pm

Cuppa tae wrote: »

So would i lose marks if i had a completely manual steering system?

The only electronics would drive my two front wheels

No you wouldnt because all the brief says about the steering is that it should hace "a stteering mechanism for the front wheels" it doesnt say it has to be electric or manual, so it can be either.

Engineering project, leaving cert 2012

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