Calculating load (N) exerted by a 1000 litre drum
Calculating load (N) exerted by a 1000 litre drum
(OP)
Hi,
I'm looking to select some caster wheels for a trolley. It's going to carry a drum that can hold 1000 litres of fluid. I need to know what force in Newtons this will exert in order to select suitable caster wheels? Is there an engineering formula for this or some sort of tool that can be downloaded to calculate the force exerted?
God bless,
Phil.
I'm looking to select some caster wheels for a trolley. It's going to carry a drum that can hold 1000 litres of fluid. I need to know what force in Newtons this will exert in order to select suitable caster wheels? Is there an engineering formula for this or some sort of tool that can be downloaded to calculate the force exerted?
God bless,
Phil.





RE: Calculating load (N) exerted by a 1000 litre drum
A.
RE: Calculating load (N) exerted by a 1000 litre drum
RE: Calculating load (N) exerted by a 1000 litre drum
You won't find a formula for converting Litres to Newtons (not done often enough to be worth printing) - so you'll need to do this in two stages (serials 2 and 4 below).
I'd use "kilograms" as my intermediate step.
1. Confirm the size of the drum (1000l seems a bit big to be moving on a trolley with caster wheels) - or are you just going to move empty drums? If that's the case, make sure you have some way of keeping it that way, then skip step 2.
2. Convert litres to kilograms (need to know the density of the fluid you're carrying to do this)
3. Don't forget the weight of the empty drum and trolley frame
4. Convert kg to newtons (there's just under ten of them to the kg in this corner of the galaxy)
5. Don't forget to allow for the number of wheels you're fitting - or for the fact that the load might not be equally shared between them.
6. Don't forget to check whether the floor will bear this sort of load once it's concentrated on the small contact patch the wheels will give you.
7. Don't get between the trolley and wherever it thinks it wants to go. A tonne of liquid skating around on casters might be a bit wilful. Don't forget to post a video.
A.
RE: Calculating load (N) exerted by a 1000 litre drum
2) make sure you're using the MASS density of the liquid, and not the WEIGHT density (how much a liter weighs) ... a 1000 lt of water weighs 1000 kg (i think) which would be 4540N.
4) becareful with your units ... the mass of the liquid and the MASS of the frame (tho' most likely you'll have the weight of the frame, probably in kgs (that'd be kilogramforce ... 1kg = 10N)
5) multiply the resultant weight by a factor, 2?, 4?
then divide by the # of supports
7) how do you plan to brake this beast ?
RE: Calculating load (N) exerted by a 1000 litre drum
Why does this simple problem lead to so much confusion.
Everybody knows that 1000cc of water weighs 1 kg or about 2.2 lbs and 1kg is 9.8 N. So you can call 1Kg mass (or weight as a practical matter). What does it matter?
It's the physicists that cause all of this.This problem is located on this planet, not Mars.
RE: Calculating load (N) exerted by a 1000 litre drum
RE: Calculating load (N) exerted by a 1000 litre drum
No I'm not a student but thanks for the humour (laughed at 'post the video'. Not actually going to be transporting the 1000l schutz container around. It's stationary and used to fill 15 gallon drums instead which will be portable. So then, won't be much fun making a video of those.
Will follow the advice given. Thanks very much all.
God bless.
Phil.
RE: Calculating load (N) exerted by a 1000 litre drum
Given:
Size of drum = 15 Gallons / approx 57 litres (working in metric as I'm Irish)
Density of monomer = 1kg/litre
Weight of drum approx. 3kg
Weight of frame approx. 10Kg
57 * 9.8 = 558.6
3 * 9.8 = 29.4
10 * 9.8 = 98
Total = 686
Multiply by factor of 4 = 2744
$ wheels therefore load of 686N/Kg
RE: Calculating load (N) exerted by a 1000 litre drum
That being said, unless you need to have a static-dissipative rubber wheel or a shock absorbing wheel almost all of the casters in Misumi are rated around 700N and above.
If you were actually moving the 1000 liter tank the weight would be something close to 20x the 700N weight (assuming a similar allowance for tank and frame weight) or about 14,000N. In that case you won't be able to get a safety factor of 3, but CKZJ100 is rated to 9,000N. If you again assume a worst-case 3 wheels carrying the load, you have 27,000N capacity, which is a safety factor of 27,000/14,000 or about 2.
RE: Calculating load (N) exerted by a 1000 litre drum
what is a N/kg ? you've calc'd a load of 686N per wheel (with a safety factor of 4). handleman is pointing you towards some wheels that lift this; that the wheel allowable is very close to your load can be defended by your relatively high safety factor.
but wouldn't 15 gallons be 15*4.54 = 68 lt ? which would throw your calc's out a bit, but i think you could still use these 700N wheels.
RE: Calculating load (N) exerted by a 1000 litre drum
Imperial Gallons - 4.54 l
US Gallons - 3.79 l
Handleman's advice looks pretty sound.
A.
RE: Calculating load (N) exerted by a 1000 litre drum
RE: Calculating load (N) exerted by a 1000 litre drum
RE: Calculating load (N) exerted by a 1000 litre drum
m x a = f
1000kg x 9.8m/s***2 = 9800 Newtons
RE: Calculating load (N) exerted by a 1000 litre drum
RE: Calculating load (N) exerted by a 1000 litre drum
RE: Calculating load (N) exerted by a 1000 litre drum
rho = 1000 kg/m^3 [water]
W = (1000 kg/m^3)(1.0 m^3)(9.81 m/s^2) = 9810 N
Take this weight and divide by total number of wheels intended to be used on the trolley. I would multiply that by 1.5 just as an additional safety factor against dynamic loading or shock loading. This is the rating of the caster wheels intended for usage with a water medium.
If the fluid is mercury (Hg), then rho = 13546 kg/m^3 so that W = 132886 N. You follow the same logic as the water computation. Done.
Awesome observation Zekeman, yes, this planet and not Mars. But if the application was on Mars, then use castors rated for 3810 N using water, 51610 N using Hg.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Calculating load (N) exerted by a 1000 litre drum
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Calculating load (N) exerted by a 1000 litre drum
Also, the OP is looking to spec casters from a catalog, not design them from scratch. All you need to do is calculate the expected static load per caster. The caster mfr. has already taken normal use (shock loads, normal vibration, etc) into account when giving that rating. Unless your use conditions are unusually severe (high speeds, high-grit environment, extreme temperatures, severely uneven floor surface, high risk to life and limb, etc.) can you not pretty much go by the catalog rating?
RE: Calculating load (N) exerted by a 1000 litre drum
2. The static load per caster is exactly what is calculated.
3. Give the manufacturer the static value; he will suggest a castor product.
4. Read the fine print in the catalog, but probably yes.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada