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locost way to weigh car?
2b_pablo - 22/2/08 at 12:29 PM

any locost ways to weight my kitcar? in situ in the garage rather than using weighbridges etc.

cheers


02GF74 - 22/2/08 at 12:31 PM

yes, drive into a large bucket of water and collect all the water displaced, pour into smaller containers or a one of known volume since you can assume that 1 litre = 1 kg and add it all up.


2b_pablo - 22/2/08 at 12:33 PM

right, where can I get a 7 sized bucket?


Macbeast - 22/2/08 at 12:34 PM

Assuming it floats.


02GF74 - 22/2/08 at 12:35 PM

B&Q in the garden pond department. Water is usually found inside your sink tap.


Mr Whippy - 22/2/08 at 12:37 PM

quote:
Originally posted by 02GF74
yes, drive into a large bucket of water and collect all the water displaced, pour into smaller containers or a one of known volume since you can assume that 1 litre = 1 kg and add it all up.


Your plan is flawed as this would only work for parts that were the same density as water, plus the air in the tires would make it even lighter. Sorry to be picky


RickRick - 22/2/08 at 12:38 PM

i think so long as it floats then it'll be correct


Mr Whippy - 22/2/08 at 12:47 PM

quote:
Originally posted by RickRick
i think so long as it floats then it'll be correct


A floating ship will displace only the water equivalent to its own weight. But a submerged ship will displace the same amount of water whether it's made of metal or foam. Therefore your right it has to float.

Anyone tried a 7 in the water? I think it should float quite well. I always wanted to get my buggy sealed up to make it amphibious as it's like a bath with wheels.

[Edited on 22/2/08 by Mr Whippy]


ditchlewis - 22/2/08 at 12:54 PM

how about 4 sets of bathroom scales. they read up to say 120kg, so unless you have a porker of a car should work. see if there are any scales in your local pound shop

if the scales are to cheap you may still be left guessing what the weight is

ditch


Dangle_kt - 22/2/08 at 12:57 PM

what happens if you STACK scales? You could test it by weighing soemthing you know the weight of (you) and calebrate the scales so you know what equates to what (as long as it doesn't work exponetially or similar...)

Then buy 8 scales (£4 ea in tesco) and try it out.

I only needed four as the rolling chassis was not too heavy.


RickRick - 22/2/08 at 01:08 PM

i'm fairly sure if you put one on top of the other, and for isntance put 100kg on it, the top one would read 100kg the second would read 100kg + the weight of the scale above


DaveFJ - 22/2/08 at 01:14 PM

quote:
Originally posted by RickRick
i think so long as it floats then it'll be correct


If it floats doesn't that mean it weighs the same as a duck? And if that is so doesn't it mean that it must be made of wood? and therefore it should be burnt......

I'll get my coat


Richard Quinn - 22/2/08 at 01:14 PM

quote:
Originally posted by Dangle_kt
STACK scales?
Are they the ones with the max weight tell-tale???


Richard Quinn - 22/2/08 at 01:16 PM

quote:
Originally posted by 02GF74
yes, drive into a large bucket of water and collect all the water displaced, pour into smaller containers or a one of known volume since you can assume that 1 litre = 1 kg and add it all up.
If you want it really accurate, bear in mind that this should be at 4 deg C!!


2b_pablo - 22/2/08 at 01:41 PM

PMSL @ some of the responses! Bought a set of £20 scales from B&Q go up to 150kgs so should be ok.

will let you know how it goes


02GF74 - 22/2/08 at 01:41 PM

I was thinking of using air as another method. For example place a block of wood on two 2 litre Tesco value water bottles filled with air and then drive car on top.

The bottles should flatten and by measuing this, it should be able to work out the wieght either by calculating or by calibrating.

To stop the car from sinking, put it inside a largre polythene bag.

[Edited on 22/2/08 by 02GF74]


2b_pablo - 22/2/08 at 01:45 PM

I could also use Prof Frinks "De-biggifier" and shrink it x100. then pop it onto my wifes cooking scales and "re-biggify" it once I get my reading.

Multiplying the result by 100 of course


james h - 22/2/08 at 01:48 PM

quote:


If it floats doesn't that mean it weighs the same as a duck? And if that is so doesn't it mean that it must be made of wood? and therefore it should be burnt......

I'll get my coat




This should help you work it out!


DaveFJ - 22/2/08 at 01:49 PM

One of my colleagues has just suggested stripping the car down to it's littlest components and then standing on a pair of bathroom scales holding each part and subtracting your weight.. then just add up all the results.....

He got his own coat.....


Fred W B - 22/2/08 at 01:52 PM

Secure a plank to a piece of pipe or something as a pivot so that 12” sticks out one side, 48” on the other. Put the 12” side under the front of the car, put a scale on the end of the 48” side. Push down on the scale with your foot and note the mass just as the car lifts. Times by four to get the mass at that end. Repeat at other end of the car, add together. Should be good enough for jazz

Cheers

Fred W B.


02GF74 - 22/2/08 at 02:13 PM

quote:
Originally posted by 2b_pablo
I could also use Prof Frinks "De-biggifier" and shrink it x100. then pop it onto my wifes cooking scales and "re-biggify" it once I get my reading.

Multiplying the result by 100 of course


that would work but you would need to mltiply by 1,00,000 as object is a solid 3 dimensional.

ofcourse it may be quicker to bigify the scales.


Phil.J - 22/2/08 at 02:40 PM

If It's super light I've got an accurate hanging scales I want rid of, weighs up to 600 lb/ 300 Kg. Yours for £40.


2b_pablo - 22/2/08 at 02:42 PM

wouldnt have anything to hang from sorry mate.


MikeCapon - 22/2/08 at 02:45 PM

This is a wonderful forum. You can even tell what day it is. From this thread it's obviously Friday afternoon


james h - 22/2/08 at 02:47 PM

Personally the best way by far is to go to sea level and time the frequency of an oscillating pendulum (with simple harmonic motion).

Repeat with the pendulum next to the car and measure the difference in the time period. With this you can work out the effect of the car's mass and thus derive its weight.

James

p.s. just don't ask me for help


novacaine - 22/2/08 at 03:37 PM

if you have a barometer my method might just work.....


ok, so have a sealed room of a known volume,

Measure the pressure in the room when it is empty then you can introduce your car into said room through an airlock then measure the change in pressure
(make sure temerature stays the same


do a bit of maths and you will then be no where nearer your goal as you just slap your head in an exclamation of stupidity as you realise that the rather time consuming method you have just used in fact finds the volume of the car, not the weight, you then return to the computer to tell us all about it on this forum.....

you then decide to put said barometer inside a rather large sealed plastic bag of a known volume (large) you then place your car on top of this bag and measure the change in pressure, a bit more maths then you know how much your car weighs


NS Dev - 22/2/08 at 03:42 PM

I think its all psychological!!

if you are worried about how much it weighs, its probably too heavy. lose a few bits and bobs that you don't need then see if you are happy with it.

repeat until happy. if car no longer works you've gone too far.

if it does, bingo, light car

How light?

Who knows, but, as I always point out to people handing me their problems at work, "only ask the question if you can do something to change the answer"


2b_pablo - 22/2/08 at 03:44 PM

I think you get one of these:

gyrate
gyrate


then get 5 of her pals

gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate


then keep adding them to a big bar on the far side of the car until they balance the car.

Then jump on top of one and try to gauge her weight and multiply by the number required to balance the car.


02GF74 - 22/2/08 at 04:05 PM

Sorry but you are missing the point now - the original question was asking for a locsot method, I'll bet she and her identical friends are gonna be pretty high maintenance.

quote:
Originally posted by 2b_pablo
I think you get one of these:

gyrate
gyrate


then get 5 of her pals

gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate


then keep adding them to a big bar on the far side of the car until they balance the car.

Then jump on top of one and try to gauge her weight and multiply by the number required to balance the car.


2b_pablo - 22/2/08 at 04:08 PM

lol you only replied so you could quote and get 5 more


blueshift - 22/2/08 at 06:34 PM

back to slightly more serious: stacking the scales vertically (in series) would not help, as someone said they'd read the same + weight of scales on top of them.

however if you exceed the range of one scale you could put two side by side, something appropriate to spread the load (bits of wood etc), zero the scales with the load spreader on, put the car wheel down in the middle and add the weights on both scales to get the corner weight.

Note you have to make sure the suspension is loaded up evenly, if you raise one wheel at a time and leave the others dangling you'll overread the weights.. 4 scales and do both back wheels at the same time then both fronts will be pretty accurate.

[Edited on 22/2/08 by blueshift]


carpmart - 22/2/08 at 07:00 PM

where does one purchase the scales at a good price but accurate enough to be worth the effort?


2b_pablo - 22/2/08 at 10:05 PM

150kg scales worthless, went straight off scale


carpmart - 23/2/08 at 07:15 AM

quote:
Originally posted by 2b_pablo
150kg scales worthless, went straight off scale


How many did you buy?


Schrodinger - 23/2/08 at 02:24 PM

My wife tells me that this wouldn't work as they would not tell you their true weight, you would only know it weighed more

quote:
Originally posted by 2b_pablo
I think you get one of these:

gyrate
gyrate


then get 5 of her pals

gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate
gyrate


then keep adding them to a big bar on the far side of the car until they balance the car.

Then jump on top of one and try to gauge her weight and multiply by the number required to balance the car.


Dangle_kt - 23/2/08 at 04:15 PM

I bought Tesco Value scales.

I checked each one was accurate enougth my weighing me, and any that over read/underread was adjusted so it was accurate. I knew that no wheel (on my rolling chassis) would weigh significantly more than I do, so knew if it weighed me ok then 4 scales at £4 would be fine.

To further refine it you could buy 4 more and do as has been mentioned with two scales side by side on all four wheels. 8*£4 isn't tooo expensive really.

quote:
Originally posted by carpmart
where does one purchase the scales at a good price but accurate enough to be worth the effort?


jono_misfit - 23/2/08 at 09:01 PM

Take your car to the local scrap yard (metal scrap etc.) and ask if you can stick it on the weigh bridge.

Our local one lets us do this for free plus they are fairly accurate (ish). Takes about 20 seconds.


carpmart - 23/2/08 at 10:12 PM

Can you send me a link to these? Cant find them on Tesco's web site?

Thanks

quote:
Originally posted by Dangle_kt
I bought Tesco Value scales.

I checked each one was accurate enougth my weighing me, and any that over read/underread was adjusted so it was accurate. I knew that no wheel (on my rolling chassis) would weigh significantly more than I do, so knew if it weighed me ok then 4 scales at £4 would be fine.

To further refine it you could buy 4 more and do as has been mentioned with two scales side by side on all four wheels. 8*£4 isn't tooo expensive really.

quote:
Originally posted by carpmart
where does one purchase the scales at a good price but accurate enough to be worth the effort?


carpmart - 23/2/08 at 10:13 PM

quote:
Originally posted by Dangle_kt
I bought Tesco Value scales.

I checked each one was accurate enougth my weighing me, and any that over read/underread was adjusted so it was accurate. I knew that no wheel (on my rolling chassis) would weigh significantly more than I do, so knew if it weighed me ok then 4 scales at £4 would be fine.

To further refine it you could buy 4 more and do as has been mentioned with two scales side by side on all four wheels. 8*£4 isn't tooo expensive really.

quote:
Originally posted by carpmart
where does one purchase the scales at a good price but accurate enough to be worth the effort?


MikeCapon - 24/2/08 at 10:53 AM

You don't need to buy 4 scales. Just find 3 wooden blocks the same height as the one set of scales and measure each wheel in turn. done this before and v accurate.


2b_pablo - 24/2/08 at 02:28 PM

yes i bought on st only and would have went round each wheel


mad-butcher - 1/3/08 at 01:57 PM

£2.99 a set from tesco Rescued attachment corner weight setup.JPG
Rescued attachment corner weight setup.JPG


blueshift - 1/3/08 at 08:33 PM

Good work, that sack of sand did a pretty neat parking job there