I2big47
I2big47 None
1/1/21 1:05 p.m.

I need to check my car weight in my garage. Thinking about getting a 400# rubbermaid digital scale for about 150$. Its 1.25 inch high. If I got suitable spacers at the three other corners, rotated the scale location for each wheel and record the weights. Is this feasible? Has anyone tried it?  

alfadriver (Forum Supporter)
alfadriver (Forum Supporter) MegaDork
1/1/21 1:13 p.m.

As long as it's all level, the physics says it would work.

Not sure if the 400lb scale would be enough, though.  For 50/50 distribution, that would max out the car at 1600lb.  And lighter as the weight goes away from balanced.

I2big47
I2big47 New Reader
1/1/21 1:58 p.m.

Thanks for your reply. In my case though without the driver it should not top 1600# but could get close with the driver. Per a 11/04 CM issue, a Series 2 Lotus 7 was 1125# without a driver. My target min. weight with the driver is 1455# 

Kubotai
Kubotai New Reader
1/1/21 3:34 p.m.

You can buy 440 lb electronic postal scales on Amazon for $35 each (Smart Weigh Digital Heavy Duty).  So, four would be less than the $150 scale you're looking at.  That is what I use for my car  and I don't have to mess with moving a single scale around.  

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
1/1/21 4:00 p.m.

Yep, and 300 lb bathroom scales are $2 or less at thrift shops.

Buy 8 scales and put 2 under each wheel (next to each other, maybe bridge the gap with a board, add the two readings together).

RX Reven'
RX Reven' SuperDork
1/1/21 5:05 p.m.
Robbie (Forum Supporter) said:

Yep, and 300 lb bathroom scales are $2 or less at thrift shops.

Buy 8 scales and put 2 under each wheel (next to each other, maybe bridge the gap with a board, add the two readings together).

If the boards flex, I believe some of the load will be lateral rather than vertical resulting in a falsely low reading (think force vector with the lateral component not being detected by the scale).

Also, make sure to deduct the weight of the boards.

Also, also, scales tend to be most accurate in the middle of their operating range so a scale rated for 800 Lbs. would be best although modern bathroom scales use load cells which may not have a linearity effect.  BTW, linearity is the proper term for this principle (i.e., how correct the measurements are across the instruments operating range).

alfadriver (Forum Supporter)
alfadriver (Forum Supporter) MegaDork
1/1/21 5:17 p.m.
Kubotai said:

You can buy 440 lb electronic postal scales on Amazon for $35 each (Smart Weigh Digital Heavy Duty).  So, four would be less than the $150 scale you're looking at.  That is what I use for my car  and I don't have to mess with moving a single scale around.  

Or 550lb scales-https://www.amazon.com/EatSmart-Precision-Extra-High-Capacity-Extra-Wide/dp/B01ATYK3M6/ref=sr_1_5?crid=36GKLDWVB47P4&dchild=1&keywords=heavy+duty+bathroom+scale&qid=1609542986&sprefix=heavy+duty+bathro%2Caps%2C195&sr=8-5

 

Wayslow
Wayslow Dork
1/1/21 5:31 p.m.

Assuming you drive onto the scale it should work fine. Jacking a car up and lowering it back down will change the the loading on the suspension.

90BuickCentury
90BuickCentury Reader
1/2/21 7:09 a.m.

If your goal is just to see total weight, drive it to a scrap yard or similar place and park it on their scale.

If trying to accurately figure out the weight distribution per wheel, 4 identical scales would make more sense.

iceracer
iceracer MegaDork
1/2/21 6:38 p.m.

Depending on the car, individual weight can exceed 800 lbs, even on a 2400 lb. car.

I2big47
I2big47 New Reader
1/3/21 4:11 p.m.

Well I appreciate all your input. This is my first GM/CM forum or any forum. Since I have two projects in my garage; one F/P Midget that needs to lose wieght and one vintage racing Lotus Seven that needs to gain wieght, I'm inclined to get 4 - 440# smartweigh postal scales from wallmart.com at $34.95 each.  They also have 2 year factory warranty per betterbasics.com

I should confirm there is not a problem using them near the top of the range from Smartweigh.

The ulimate test, if with a suitable rigid board to bridge two scales was used , (to reduce the force vector with the lateral component), would be to weigh one or both of the 1000 -Lb. Sisters from TLC. 

 

 

 

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