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Gallery, Projects and General => Project Logs => Topic started by: John Hill on October 14, 2010, 01:05:01 AM

Title: Weighty project!
Post by: John Hill on October 14, 2010, 01:05:01 AM
(http://farm5.static.flickr.com/4105/5079874379_0f5be3aeb0.jpg)
Turn a chunk of round scrap and make two big buckets of swarf...




(http://farm5.static.flickr.com/4092/5079874653_48051a32db.jpg)
Turned another piece to be a cosy fit and cut a groove in it for an o-ring.


(http://farm5.static.flickr.com/4003/5079875649_9823824310.jpg)
Put the two pieces together and fill the gap with oil.

(http://farm5.static.flickr.com/4107/5080470578_ec337bff7f.jpg)
Put the ensemble under the end of this shipping container.

(http://farm5.static.flickr.com/4022/5080470276_753526e6e7.jpg)
There is a 100Bar pressure gauge on the end of that copper pipe!

The piston is 114mm in diameter and according to my calculation and indication of 100Bar would be 10 tonnes, here we can see a much lower reading showing this end of the container weights about 1.4 tonnes,  I will need to do the other end too and add them together but I am guessing this fairly empty container weighs 3 tonnes.

This is useful information as it shows I can put 3 tonnes of my treasures in there and still get it shipped to our new house at the lowest freight rate!
Title: Re: Weighty project!
Post by: Trion on October 14, 2010, 02:26:10 AM
Good thinking, will keep this in mind if i ever need to weigh something that large! :thumbup:
Title: Re: Weighty project!
Post by: Stilldrillin on October 14, 2010, 03:48:14 AM
Well thought through John!  :clap:   :thumbup:

As someone used to say.... "Think literally. Think laterally".

David D
Title: Re: Weighty project!
Post by: AdeV on October 14, 2010, 04:18:00 AM
Hmmm, I like that a lot.... where did you find the calculations (or are you just extremely brainy...)? I can see this being adapted to make a low-cost set of corner scales for a race car, for example...
Title: Re: Weighty project!
Post by: John Hill on October 14, 2010, 04:48:13 AM
Hmmm, I like that a lot.... where did you find the calculations (or are you just extremely brainy...)? I can see this being adapted to make a low-cost set of corner scales for a race car, for example...

Hi AdeV



Calculations are not difficult, I used an on-line circle calculator to find the diameter for a particular area.

Say you want your load cell to weigh 500Kgs, so choose a gauge with a scale of, or some multiple of, 0 to 500.  Lets say 500 KPa.  (Thats about 75 PSI)  Looking up an online converter I find that 500KPa is equal to 0.05098 kgs per square millimetre.  So we divide our 500Kgs by 0.05098 = 9808 sq mm required for our load cell.

Look up a handly online circle calculator and I find a circle of 9808 sq mm area has a diameter of 111.75mm.

Cheers
Title: Re: Weighty project!
Post by: tony ennis on October 14, 2010, 07:54:20 AM
What keeps the oil from squirting out from between the two pieces?
Title: Re: Weighty project!
Post by: Stilldrillin on October 14, 2010, 08:01:20 AM
What keeps the oil from squirting out from between the two pieces?

The O ring, mentioned in the 2nd pic...... :thumbup:

David D
Title: Re: Weighty project!
Post by: ozzie46 on October 14, 2010, 08:05:28 AM



  I thought all shipping containers  had their empty weight marked on them?

   Ron
Title: Re: Weighty project!
Post by: tumutbound on October 14, 2010, 09:02:37 AM



  I thought all shipping containers  had their empty weight marked on them?

   Ron

John had already started loading his Lego before the decision to weight the container. (http://madmodder.net/index.php?topic=3667.msg39699#msg39699)
Title: Re: Weighty project!
Post by: dsquire on October 14, 2010, 11:43:09 AM
John

Very good John. Leave it to the Artfull Dodger to come up with the solution to the problem. That is definitly thinking outside the box. (no pun intended). How does this weight compare with the Listed tare weight on the container?  :doh:


I don't envy you with all the work involved in the move but I am sure that once you are settled in your new place it will have been worth it.  :)

Cheers  :beer:

Don

Title: Re: Weighty project!
Post by: fatal-exception on October 14, 2010, 04:40:19 PM
Hmmm, a hydraulic pancake loadcell. Nice work, and probably well accurate enough for what your intended use is.

If you have a scale company around that calibrates loadcells, they could probably confirm your pressure reading against a known deadload.

Good thinking.  :beer:
Title: Re: Weighty project!
Post by: John Hill on October 14, 2010, 07:44:21 PM



  I thought all shipping containers  had their empty weight marked on them?

   Ron

Yes it did Ron, since painted over.  Besides, this was a refrigerated container and that equipment has been removed so the tare weight would no longer be applicable, plus there is quite a bit of stuff in it already.

The real aim of this exercise is to avoid loading it past the weight for the cheapest shipping rate .
Title: Re: Weighty project!
Post by: John Hill on October 14, 2010, 07:46:12 PM
Hmmm, a hydraulic pancake loadcell. Nice work, and probably well accurate enough for what your intended use is.

If you have a scale company around that calibrates loadcells, they could probably confirm your pressure reading against a known deadload.

Good thinking.  :beer:

I can not think of such a place right now but I could easily take it to someone with a workshop press and confirm I am not grossly out of range.
Title: Re: Weighty project!
Post by: AdeV on October 22, 2012, 11:05:16 AM
John,

I'm just about ready to make some of these, but unfortunately your pics have gone missing..... any chance they could be resurrected?

Ta in advance!