Engineering project 2013

daz801

So we were told what the project was today. For those who haven't been given the brief yet here it is. Not to bad really although I do think it's harder than the last few years projects.

Copper_pipe

Ya , I would have preferred if it was some sort of vehicle

denis0000

anyone have any ideas on the mechanisms that can be used to grab the table tennis ball?

spurious

Reminding people not to upload any photos or details of anything that will be submitted to the SEC. Thanks.

Copper_pipe

denis0000 wrote: »

anyone have any ideas on the mechanisms that can be used to grab the table tennis ball?

I presume you can't tamper with the ball

denis0000

could you put a magnet in the ball or on the grab and lift it that way.

daz801

Had the same idea of using a magnet in the ball but decided against it. Have my project fully designed already. Just need to do up the drawings.

denis0000

can a hoover be used in conjuction with the project as the suction technique or what can be used

Copper_pipe

daz801 wrote: »

Had the same idea of using a magnet in the ball but decided against it. Have my project fully designed already. Just need to do up the drawings.

Have a fair idea myself, Just doing it up on solidworks now. Only thing im worried about is programming it

iFreeley

Programming it? Jesus.

MrBigPauL

i heard from a secret source tat u can actually put a hoover on top of a frame and u get full marks, if it dosent work u cn get attempt marks,,,,,YESSSSSS LAADDDD

Copper_pipe

iFreeley wrote: »

Programming it? Jesus.

How else do you think of doing it

iFreeley

Em i havent really thought it through yet, but how would you programme it? like would you not have to control it by a joystick of some kind?

denis0000

the ball can be lifted grabed, or sucked up. was thinking of doing this a number of ways:
1:some sort of grab system like when your lifting timber using links and springs.
2:use a sort of spiral/auger sytem to lift the ball up a certain height and then leave the ball roll down a maze, kind of like a track on a roller coaster. you could use a rotating bar with a spiral/auger on the outside to lift the ball.
3:use a crane system to lift the ball using a fishing line and some sort round shaped feature on the end of the line with bristles off a tooth brush attached to the round shaped grab. this round grab would fit down over the ball with it getting logded in the bristles and lifting with it.
Does anyone else have any other ideas of how to lift the ball.

spurious

From the SEC:

General directions to candidates
1. The project you design, make and submit for examination must be unique and be your
own individual work, carried out in the school under the supervision of the teacher.

Your own individual work is intended to include the intellectual activity of design
along with the practical activities of making the model and compiling a folio.



I've already advised against what some forum members are doing in this (and similar threads).
Please, think about what you are posting.

denis0000

Sorry didn't read your message properly first time around. thought it only said no photos of the project was aloud. didn't think you weren't aloud to share ideas.

spurious

The quote in my last post is from the link outlining the brief.
It's the SEC instruction.

The SEC have contacted boards previously in relation to exam material being discussed on the forum, so it's just a heads up that discussing exam work in detail on an internet forum (before it has been assessed) might not be the best thing to do.

General discussion is not a problem. It's when people get into specifics that the problem arises.

Copper_pipe

Will you lose marks if it needs to be connected to an air compressor

marky1994

just wondering what are people designing to pick up the table tennis ball

Copper_pipe

I'm using suction, Ran my idea by my teacher today and he gave it the all clear

daz801

Copper_pipe wrote: »

Will you lose marks if it needs to be connected to an air compressor

Not too sure but you only loose five marks for going over the size restrictions anyway which is less than 1% over all so it's really not to big of a deal.

Copper_pipe

What about if it had to be connected to an external air compressor so the suction could work

marky1994

i was thinking suction to but a claw would nearly be easier to fit

Copper_pipe

You'd need to make sure it wouldn't crush the ball

marky1994

true im not sure of the suction idea tho gettin a small enough suction pipe would b hard

MrCraigButler

what is the best thing people have come up with for the lifting mechanism ? and also what are people using to move it ? .. anyone who wants to share ideas with me message me if you want and il give you some of my ideas in exchange:)

Sean Lad

Hello, Having a bit of trouble with the Engineering Project So i though i might try here for help . So basically we have to build one of those claw crane things you see in arcades, it can only run off a 9v battery. i have a rough idea how to move it up and down and across but i have no clue how i will pick up the table tennis ball any one have and ideas it has to be either suction grab or lift ?? Thank you.

jamo2oo9

Remember, you can use as many batteries as you wish but it must be under 9V.

As for the claw, ask your teacher to guidance on that. Also look for claws that don't need any mechanisms involved like mine. Keep it simple, don't make it complex. I'd advise against using a suction device, this has a lot of wiring involved unless you are good with electronics. You could create a forklift type of crane and work your way from there or design something else.

kirving

I did my project years ago. I was just thinking that you could use a solenoid connected to a bellows type thing? Sounds like a nice little project.

If it was me, I'd be going with a crane arm type arrangement instead of an overhead track with a descending grabber.

I wondr could you set up the control mechanism with a number of resistors so that a forward movement of a joystick could move a number of motors so the suction cup moves only horizontally? I know that's a bad description!

mondY65

I done my leaving cert last year, and i think this project is much more difficult. My teacher gave me one really sound piece of advice last year and it was to keep it simple. Of course i didnt listen, and i was lucky things turned out ok. But it added serious amount of extra time, effort and hassle. Simplicity is really the essence of engineering, I realise it now that I'm studying it in college.
Also another thing is to be individual, use your own ideas, think outside the box. Do your own thing and don't listen to anyone (well maybe your teacher, occasionally). If you have your own idea, stick with it as It will look much better when an examiner comes into a room, your project will instantly stand out.
Anyone need any help, I'll gladly help. I also have a load of really good(a1 standard) theory notes of anyone wants them, contact me.
Good Luck!

padraig100

a hoover that runs off 9 volts?? good luck son..

kirving

Don't go with a hoover attachemnt. It might work, but you've used something else to solve a problem. While this is generally a great idea in engineering(keep it simple), the task here is to solve a problem yourself, showing off as much engineering innovation and workmanship as you can.

I'd be using a bellows, connected to a piston powered by a solenoid. The air line would be flexible and the piston would not move. It would have to be very refined to work, but it's doable.

chloe04

i didnt even do metalwork for the junior cert, flying with the higher theory but havent a clue what to do about the project at all, help

Wils110

Mini USB Hoover thing for office desks

chloe04

Wils110 wrote: »

Mini USB Hoover thing for office desks

doubt thatd work, suction is too weak

Wils110

Engineering....ramp it up wouldn't need much suction it's only a table tennis ball

partyatmygaff

Potentially a very difficult project compared to past years. Depending on how you hack it, it may need a lot of fine-tuned and precise motor control.

Suction is an option but it's fraught with complications and very difficult to achieve enough suction with just 9V. Not only that but you still have to design a mechanism capable of moving around in at least two axes.

Personally, i'd start looking in to two solutions:
A)
Get four high torque servo motors and make a three-fingered "grabber" than can move in three axes and close/open with four potentiometers/555 timer servo controller circuits.

One geared to a chain/belt to control the X axis, another to control the Y axis and another with a rack and pinion (Or something similar) control movement along the Z axis. Then devise some kind of mechanism to open and close the three-fingered grabber and control that with the fourth servo.

It's not a very elegant way of doing things and you'll need to center your design around the mechanism to prevent problems down the line but it's definitely functional.


Do something similar but with stepper motors and a PIC/AVR microcontroller and a tennis-ball sized scoop rather than a fingered grabber. Link the X, Y values of a joystick (Like this) to the stepper motors controlling the X and Y axes of your mechanism. Once you've got that sorted, get a switch and program that switch to drop the scoop by a variable distance. What I mean by that is if you need your scoop to drop by 50mm to successfully pick up a ball, program the microcontroller to lower the scoop by 10-20-15-30-25-40-50cm depending on your number of attempts and then release it over the hatch. Essentially what you're doing is making it successfully pick up the ball 1/7 times.

It's very elegant and quite a bit easier to work with from a mechanical point of view but definitely not for everybody. Without any experience, you'll have to learn it as you go along using internet tutorials and the like. Doable but unless you're already familiar with some of the fundamentals you'd be better off sticking with discrete components and at most simple ICs like the 555.

Supermensch

Just to clarify, all the electrical constraints entail is that the potential difference at any two points in the circuit does not exceed 9 volts. The brief is rather misleading with its' "Electric power does not exceed 9 volts", mainly because voltage is not a measure of electric power :rolleyes: , but also because when people see the 9 volts they think one nine volt battery. 9 volts is only the largest potential difference you are allowed to have in your circuit, so it is permissible to have a number of 9V batteries in your design, or indeed to connect a number of 9V batteries together in parallel.

Can anyone find alternative existing claw crane designs? All I can find is the standard square container with the claw sitting on rails design for my research for the Investigation of Solutions bit.

chosen1

padraig100 wrote: »

a hoover that runs off 9 volts?? good luck son..

It's not that difficult to achieve that suction on 9v. I have a working model done up already that lifts the ball.

TheHardyViper

Just a reminder, the brief says there has to be skill involved, so if your project involves suction you'll need some kind of objective other than turning on and off a pump

chloe04

i really think suction would be the hardest option, im choosing grab for mine, the over and back will be grand with 2 different switches, but anyone have any idea how ill make it move down and grab the ball?

TheHardyViper

I think a motor with a pulley is the simplest option for how to make it move down. As for grabbing, that's pretty difficult. Something designed to simply 'pick up' the ball might be easier

iFreeley

How long is everyone elses claws? Afraid i wont have much room for moving up and down?

DMC1230009

anyone know where to get a 9 volt vacuum pump?

Supermensch

DMC1230009 wrote: »

anyone know where to get a 9 volt vacuum pump?

Have a look at USB Vacuums. The USB standard is 5 Volts, and 500mA (I think).

Quick search on Amazon;
http://www.amazon.com/CablesToBuy-Black-Powered-Vacuum-Cleaner/dp/B000VXOPLQ/ref=sr_1_1?ie=UTF8&qid=1352505768&sr=8-1&keywords=usb+vacuum

iFreeley wrote: »

How long is everyone elses claws? Afraid i wont have much room for moving up and down?

Height of a ping pong ball is about 50mm. Full raised, the claw in my design is only 100mm above the area where the ball sits.

DMC1230009

thanks but i dont think it would be powerful enough.

chloe04

i chose to use something to scoop up the ball instead, the lowering and scooping up will be fine but does anyone have any ideas how to drop the ball?

EoinLoook

I'm using a suction mechanism that actually seems to be the simplest option regarding circuitry. I've tried a simple fan and motor job in a plastic bottle or tube works perfectly. It works off 9v of power too.

DMC1230009

That would be good but how could you harnass it to use in the project?

BrendonB

So what is everyones take on the scoring system?

BrendonB

chloe04 wrote: »

i chose to use something to scoop up the ball instead, the lowering and scooping up will be fine but does anyone have any ideas how to drop the ball?

How are you lowering and scooping the ball? If you are using a motor,im sure you can reverse motion and drop the ball? just a suggestion.