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Pad 4 Wheel Scales use

Shocks, Springs, Brakes, Frame, Body Work, etc

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j-c-c
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Pad 4 Wheel Scales use

Post by j-c-c » Sat Jun 29, 2019 8:32 am

Two questions:
1. How sensitive are the weights measured realtive to the scales being level?
I mean are we talking a2 lbs or 20 lbs or more with how much off level on say a 3000 car?
Additionally, is it water level the goal, or all the scales on the same plane a more important goal?

2. On the 15" Alum billet scales, if no individual leveling device is part of the system used, it seems tentative to just sit the pretty shiny alum pad bottom directly on a rough concrete surface, and all the resultant abuse it will suffer over time.
Anyone add a layer of thin rubber/surface protector, to also add some grip and protection, and if so, what?
Seems less compressibility the better based on #1 above.

midnightbluS10
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Re: Pad 4 Wheel Scales use

Post by midnightbluS10 » Sun Jun 30, 2019 9:20 pm

Most of the good systems can accurately measure weight on an uneven surface. The rugged stuff can accurately weigh in any weather on any surface. It seems like having them all on the same plane is a non-issue. Each operates independently of the others and their weights are used in formulas to find total weight, percentage front/rear, etc...
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MadBill
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Re: Pad 4 Wheel Scales use

Post by MadBill » Tue Jul 16, 2019 12:36 am

I have to partially disagree. As long as the scales individually are level and are level left to right across each axle, a minor difference in front to rear height will cause only an inconsequential error in front to rear percentage, ditto left to right but if one pad, for example the right front, is even 1/8" high, it and the left rear will read too high and the others too low. Especially with stiff springs, the error could be 50# or more when you might be looking to balance to ± 5#.
A good illustration of this sensitivity is to set the car up on the pads, take scale readings then bleed a pound or two of pressure out of one tire and note how the readouts change.
Vinyl tiles make pretty good shims/cushions. If you have a preferred spot, after you've dialed them in once you can mark the locations and code the shims for each.
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Jeff Lee
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Re: Pad 4 Wheel Scales use

Post by Jeff Lee » Wed Jul 17, 2019 6:03 pm

Accounting for a slope in the concrete pad, what would you suggest as the easiest way to level the scales?
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MadBill
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Re: Pad 4 Wheel Scales use

Post by MadBill » Wed Jul 17, 2019 8:42 pm

I use a digital level (~$50) and a top quality 10' drywall level, but any straight length of square or rectangular tubing will do.
o First I search out the most level available floor space and position the pads so the tires will be well-centered on them.
o Then I check to ensure each pad is level, adjusting with sheet metal if need be.
o Next I lay the tube across two pads and position the level in it's center. (to ensure the inevitable droop is equally distributed)
o I use large thin vinyl tiles and possibly sheet metal pieces to shim the pads as needed to register 0.0° on the level. By way of insurance, check diagonals also.
o I mark the location of each pad on the floor and store each shim stack separately.

There's lots more to getting the corner weights where you want them, way too much for an S-T post, but Google is your friend.
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af2
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Re: Pad 4 Wheel Scales use

Post by af2 » Wed Jul 17, 2019 11:12 pm

MadBill wrote:
Wed Jul 17, 2019 8:42 pm
I use a digital level (~$50) and a top quality 10' drywall level, but any straight length of square or rectangular tubing will do.
o First I search out the most level available floor space and position the pads so the tires will be well-centered on them.
o Then I check to ensure each pad is level, adjusting with sheet metal if need be.
o Next I lay the tube across two pads and position the level in it's center. (to ensure the inevitable droop is equally distributed)
o I use large thin vinyl tiles and possibly sheet metal pieces to shim the pads as needed to register 0.0° on the level. By way of insurance, check diagonals also.
o I mark the location of each pad on the floor and store each shim stack separately.

There's lots more to getting the corner weights where you want them, way too much for an S-T post, but Google is your friend.
=D> Exactly why my son and I spent 4 hrs getting the 4 post BendPack dead nut level when you lower it on the stops just so we didn't have to mess with it every time we scale a car.
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