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View Full Version : OT? Weigh a crate with bathroom scales..



The Artful Bodger
09-10-2012, 09:58 PM
I am exporting an old motorcyle and need a weight to determine the freight to charge the buyer..


http://farm9.staticflickr.com/8445/7974836512_c32d4236e9.jpg (http://www.flickr.com/photos/58195047@N04/7974836512/)
weigh crate (http://www.flickr.com/photos/58195047@N04/7974836512/) by MrJohnHill (http://www.flickr.com/people/58195047@N04/), on Flickr

It is very simple really...

Chock up one end of the crate..

Put a lever under the other end taking note of the length of the lever and the position of the fulcrum.

Put one foot on bathroom scale, other foot clear of the floor. Adjust position so that scales read your weight.

Press down with other foot on the end of the lever until the crate lifts.

Make sure hands are not touching anything and you are balanced on the scale and the end of the lever.

Read scale and note this.

Relax and lower crate to the floor.

Subtract scale reading which will give you the weight you were applying to the lever.

Calculate weight of that end of the crate.

Repeat for the other end and add together.

According to my exercise my crate weighs 320Kgs which is very close to my estimate.

Paul Alciatore
09-10-2012, 11:37 PM
Sounds like a clever method and nothing wrong with it in theory. One thing to watch out for is the crate should not be tilted at any noticeable angle when either end is checked or the opposite end may get more than it's share of the total. The angle of the crate should be the same when checking both sides. I would modify one step of your procedure as follows:

Press down with other foot on the end of the lever until the crate lifts AND BECOMES LEVEL.

Also, the foot and the crate both need to rest on a single point on the lever. Otherwise, it is not possible to know the actual length of the two lever arms (crate and foot sides). A small piece of round stock welded or otherwise fastened across the ends of the lever would accomplish this.

I have one of those new, digital bathroom scales and it is quite accurate. But it does not read below about 15 or 20 pounds. When I need to weigh smaller packages I first weigh myself (twice for accuracy) and then myself holding the package (again, twice for accuracy). The difference is the package weight, +/- 0.4 lbs. (least count on the scale is 0.2 lbs). This usually checks quite closely with the PO or UPS scales.

oldtiffie
09-12-2012, 12:49 AM
Why not use a certified commercial weigh bridge?

First weigh your trailer empty and then with the crate on it.

You will get two certificates of weight which should be accedptable to all/most freighters.

I would bet that you shipper checks it against his scales anyway.

Any error in your bath-room digital scales will be multiplied by the mechanical advantage of the bar you use with it.

The Artful Bodger
09-12-2012, 01:01 AM
Why not use a certified commercial weigh bridge?

First weigh your trailer empty and then with the crate on it.

You will get two certificates of weight which should be accedptable to all/most freighters.

It is not on my trailer and the shipper will pick it up from here but before that happens I want to know what the freight will cost so that the buyer can pay me before the bike leaves here.

oldtiffie
09-12-2012, 01:14 AM
If I recall correctly, you have a heavy beam over you garage door opening for heavy lifts.

Hire an analogue/digital scale from your local hire firm - ask if it is certified as correct - that can be suspended from the beam and suspend the crate from the scale.

I would bet that you shipper checks it against his scales anyway.

Any error in your bath-room digital scales will be multiplied by the mechanical advantage of the bar you use with it.

The Artful Bodger
09-12-2012, 01:24 AM
Thats why I was careful to take several readings and average them.

oldtiffie
09-12-2012, 01:41 AM
The cost charged by the shipper will be for the weight on his scales.

So there is a risk that if you charge the buyer less than the shipper charges you, you will be out of pocket - but if the reverse applies you may have to decide what to do with the excess amount you charged the buyer.

danlb
09-12-2012, 02:04 AM
I like the idea. Thanks for sharing it. If the weight is close, then that's enough for most purposes, like buying / renting a hoist.

As for the question of over/under charging the buyer, I like the concept that if the buyer agrees to a price for shipping, then it does not matter what the real cost is. As an example, when I agree to pay $22 for an end mil, it does not matter what the seller's cost is. I've accepted the $22 price.

Dan

The Artful Bodger
09-12-2012, 02:06 AM
It is going by sea freight, not air, volume determines the cost, but the shipper still asks for a weight before issueing a quote.

I dont think I will bother with this topic any further. I posted this to show how easy it is to get a reasonable weight with the equipment a typical home shopper may have on hand.

elf
09-12-2012, 03:30 AM
It is going by sea freight, not air, volume determines the cost, but the shipper still asks for a weight before issueing a quote.

I dont think I will bother with this topic any further. I posted this to show how easy it is to get a reasonable weight with the equipment a typical home shopper may have on hand.

It would be interesting to find out how accurate the method is (if the shipper weighs it).

Mcgyver
09-12-2012, 08:21 AM
well done AB. Ignore the noise, the post is appreciated

sasquatch
09-12-2012, 08:57 AM
Agreed, i thought this was quite an interesting topic.

Mr. Negative, (No matter the topic, always "spouts" off many times just to have something to blabber on about.)

Guido
09-12-2012, 12:34 PM
Reminds me of the farm boy showing us how to measure a longish length of stiff 2 inch rubber hose which had been neatly coiled and securily tied. He stood the coil on its edge, then slowly rolled it across the floor for exactly four and a half revs, since he eyeballed four and a half coils in the roll.

The floor was tiled in 1 foot squares, so it was only a matter of counting the number of tiles which required the four and a half revs of the untied coil, to duplicate it's length.

Thinking outside the box, makes for a keepable employee.

--G

cameron
09-12-2012, 01:21 PM
Yes, but did you check the certification slip issued with each of the relevant tiles and make the proper correction for its deviation from the one foot standard?

Alistair Hosie
09-12-2012, 01:54 PM
why not try tjhis old English method developed by sir J Stevenson take the bike to pieces every nut bolt etc weigh them all individually then add them up and rebuild should take no longer than a month or so.It sounds bizarre but it will be the most accurate way er weigh er way.:D NaLISTAIR

The Artful Bodger
09-12-2012, 03:59 PM
For ..... sake! All this quibling, I took the ..... crate out to the pool and tossed it in, exactly 360 litres of water came out the overflow!;)

Yes, I did make allowances for the salinity of the water, the water temperature and the atmospheric pressure.

The Artful Bodger
09-12-2012, 04:03 PM
why not try tjhis old English method developed by sir J Stevenson take the bike to pieces every nut bolt etc weigh them all individually then add them up and rebuild should take no longer than a month or so.It sounds bizarre but it will be the most accurate way er weigh er way.:D NaLISTAIR

According to the shipping company the old Douglas should be back in England about Guy Fawke's Day so maybe Sir John will get a chance to do exactly that! Hmmmm, I am not sure he is a Duggie man, he might forget to put it back together!

http://farm7.staticflickr.com/6230/6300800601_07430e701c.jpg (http://www.flickr.com/photos/25239206@N06/6300800601/)
P1010017 (http://www.flickr.com/photos/25239206@N06/6300800601/) by aardvark_akubra (http://www.flickr.com/people/25239206@N06/), on Flickr

http://farm7.staticflickr.com/6188/6121634918_128b551f0e.jpg (http://www.flickr.com/photos/25239206@N06/6121634918/)
IMGP3179 (http://www.flickr.com/photos/25239206@N06/6121634918/) by aardvark_akubra (http://www.flickr.com/people/25239206@N06/), on Flickr

Paul Alciatore
09-12-2012, 04:17 PM
You guys...!

armedandsafe
09-12-2012, 07:14 PM
You guys...!

It appears that some are changing your sig to "Have a fit," eh? ;)

Pops

sasquatch
09-12-2012, 07:25 PM
Beautiful restoration , nice interesting bike!!

That one escaped getting "BINNED!":rolleyes:

The Artful Bodger
09-12-2012, 08:30 PM
But now it is lying at the bottom of the pool...:(

sasquatch
09-12-2012, 08:41 PM
Well now, that is the stupidist way to BIN anything that i've heard of!!:p

oldtiffie
09-12-2012, 08:51 PM
I thought it was going "accross the pond" (as it were) to the UK.

Didn't get far.

A box/crate can/could be seen as a sort of bin and if so the bike was "binned".

Guido
09-12-2012, 09:06 PM
If'n bike/box is lying at the pool bottom, the displaced and measured volume of water and it's weight, does not equal the true weight of the bike, only equal to the volume of solid materials used in building the bike.

If'n the bike/box floated with no air entrapped, then ain'tcha ready to say the weight of the displaced water volume is equal to the weight of the bike/box combo, sans any trapped air volumes????????

--G

oldtiffie
09-12-2012, 09:39 PM
For ..... sake! All this quibling, I took the ..... crate out to the pool and tossed it in, exactly 360 litres of water came out the overflow!;)

Yes, I did make allowances for the salinity of the water, the water temperature and the atmospheric pressure.

That makes you quite a tosser AB.

sasquatch
09-12-2012, 09:40 PM
Depending on the type of wood used to BUILD the box, the actual true weight of John's box---(The one with the bike in it,!!)- will be approx. 23.8937 heavier above water level than when submersed.
Estimated drying time enroute to the shipper should be calculated taking this into consideration,and allowances be made percentage wise for Chlorine contamination, (Unless a signed affidavit from John is available stating he never "Pees" in his pool.):confused:

The Artful Bodger
09-12-2012, 09:40 PM
After the air leaked out of the crate and the crate sank I was able to measure the quantity of water required to refil the pool and thereby calculate the average density of the bike and the crate. Unfortunately I mislaid my slip of note paper so I cant tell you exactly what it came out as.

oldtiffie
09-12-2012, 10:07 PM
Pull it out of the pool and toss it in again.

This is turning into quite a tossers picnic.

oldtiffie
09-12-2012, 11:06 PM
The box will displace its own weight/mass in water if the box is sealed with no water getting in.

The box will sink until it has displaced a volume of water equal to its weight/mass and it will then float.

Determine the volume of the displaced water (in litres).

The mass of water is 1 kg per litre. Number of displaced litres = mass of the box and contents in Kg (whichis theunit of measurement for shippping - volume is in m^3).

(1,000 litres = 1 tonne = 1 cubic metre).

Easy.

Now toss the tossers (back?) in.

http://en.wikipedia.org/wiki/Bouyancy

http://www.google.com.au/search?q=buoyancy&hl=en&rlz=1R2IRFC_enAU360&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=TU1RUNH3CsaaiAex5oCYDg&sqi=2&ved=0CCkQsAQ&biw=1920&bih=851

http://www.google.com.au/#hl=en&gs_nf=1&cp=5&gs_id=i&xhr=t&q=buoyancy&pf=p&output=search&sclient=psy-ab&oq=bouya&gs_l=&pbx=1&rlz=1R2IRFC_enAU360&fp=1&biw=1920&bih=851&bav=on.2,or.r_gc.r_pw.r_qf.&cad=b

The Artful Bodger
09-13-2012, 12:25 AM
http://farm9.staticflickr.com/8319/7981595010_f5209c86f6.jpg (http://www.flickr.com/photos/58195047@N04/7981595010/)
... (http://www.flickr.com/photos/58195047@N04/7981595010/) .. ... (http://www.flickr.com/people/58195047@N04/), on Flickr

All dried out and on the way to the new owner!

oldtiffie
09-13-2012, 04:42 AM
And after all that - just what did it weigh? By AB and the shipper?

The Artful Bodger
09-13-2012, 03:34 PM
360kgs by my method, I doubt the shipper will ever tell me what his scales read.

cameron
09-13-2012, 04:59 PM
All this talk of water reminded me I used a similiar method to weigh a boat I built over fifty years ago . Since we were too poor to own bathroom scales, had to walk to school 10 miles uphill each way, etc, I put containers of water on one end of a plank and calculated the volume of water.

oldtiffie
09-13-2012, 06:47 PM
360kgs by my method, I doubt the shipper will ever tell me what his scales read.

I would have thought it would be on the invoice and any other shipping paper-work from/by the shipper. The client as receiver might be intersted as well - as might Customs.

Measuring the water displacement on a box or any other regular shape is simply marking/noting the "water line" distance from the base in metres and then multiplying it by the length and width to get the volume displaced (in metres) to give cubic metres. One cubic metre = 1 metric tonne.

So if the box was water-tight its weight could have been determined as before - in the pool.

The Artful Bodger
09-13-2012, 08:15 PM
I would have thought it would be on the invoice and any other shipping paper-work from/by the shipper. The client as receiver might be intersted as well - as might Customs.

Measuring the water displacement on a box or any other regular shape is simply marking/noting the "water line" distance from the base in metres and then multiplying it by the length and width to get the volume displaced (in metres) to give cubic metres. One cubic metre = 1 metric tonne.

So if the box was water-tight its weight could have been determined as before - in the pool.

All the shipper is interested in was what size truck to pick it up otherwise shipping by sea is by volume provided the weight is less than the "dimensional weight".

oldtiffie
09-13-2012, 09:22 PM
Quite so - I forgot that lot.

malbenbut
09-14-2012, 09:48 AM
Borrow another set of bathroom scales from next door put wheel on each of scales an add the two reading together.
MBB