USPS shipping module / tare weight

This tare weight is driving me nuts.

zen cart version 1.3.8a

Goal: Set up USPS shipping module using tare weight so multiple orders in the same session do not compound packaging materials weight

IE: I want to set it up so that the tare weight is added only one time into a total multiple purchase weight.

My average packing supply weight is about 7oz or .4375

When I add a product to the catalog I enter its actual weight, not the packaged weight.

I have my product weight entered as pounds and ounces in the decimal point system.

IE:

Book 1 weighs 10 oz = .625
Book 2 weighs 6 oz = .375
Book 3 weighs 1lb 6oz = 1.375
total weight 2lbs 6oz = 2.375

I test the shopping cart for product weight calculation per item.

I add a book to the shopping cart. Above the item it shows how many items and the how much it weighs.
The weight shows correctly. I add the other two books to the cart, one at a time to see if the weight is calculated correctly for each addition. The weight is correct for each addition.

In shipping/packaging > the "Small to Medium - added percentage:weight", I'm thinking to set a percentage figure with weight set at 0 is the way to accomplish what I want. I have tried adjusting the percentage weight until the cart shipping estimator total lines up with USPS website calculations.
This worked until I added in a third book and then the tare weight goes higher than expected. So I back the tare percentage down until it again lines up with USPS website calc.

The problem is when I add just one book to the cart I get offered first class mailing when I know once packaged it will be too heavy for 1st class.

I hope this explanation makes sense. Anyway with the weight figures I've given and my goals what should I be doing with the tare to get things correct?

Has anyone else had success with this?

If I set the Tare to 0:3 then I add 3 lbs to the Total weight of the Order ... not per product ...

What are your settings in the Configuration ... Shipping/Packaging ...

What are your settings in the Configuration ... Shipping/Packaging ...<<

Package Tare Small to Medium - added percentage:weight 35:0

Book 1 weighs 10 oz = .625
Book 2 weighs 6 oz = .375
Book 3 weighs 1lb 6oz = 1.375
total weight 2lbs 6oz = 2.375

2lbs 6oz is more than 13oz ...

13 oz is 0.8125 ...

.625 + 35% is 0.84375
.375 + 35% is 0.50625
1.375 +35% is 1.85625

Kinda makes it hard to keep in the 13oz rule with that Tare setting ... :cry:

Kinda makes it hard to keep in the 13oz rule with that Tare setting ... <<

It sure does.

Suggestions welcome from anyone who worked something out along the lines of what I'm trying to do.

Set the Tare to 0:0 and there isn't a Tare added ... :cool:

Do you need the Tare weight? Or, could you manage it with a Handling charge?

Or can you explain better when you do or don't need a Tare Weight added?

I sell books.

The tare is to account for the average weight of packing materials used to ship one book.

for instance:

A packaged book weighs 1lb 3oz. Shipping by media mail.

The Media mail rate for a package weighing over 1lb but not over 2lbs will cost $2.58.

Another paperback or two may be able to ship in that same package at the same rate providing the weight does not go over 2lbs

I need to be able to charge for just one container weight.

If a buyer purchases 3 books in one order I don't want them to be charged a shipping weight for 3 container weights.

I am not sure where you are getting the 3 package Tare weights ...

You take an order of 7 lbs and add a 3 lb Tare ...

If the order is made up of
1 Product A @ 2lbs = 2lb
4 Product B @ .25lb = 1lb
1 Product C @ 4lb = 4lb
Total weight 7lb + 3lb Tare = 10lbs

There is just one Tare applied here ...

Sorry if my explanations are confusing.

I'm still trying to understand how this is working and maybe I'm not getting it.

This

I am not sure where you are getting the 3 package Tare weights ...<<

comes from

if I don't do the tare as a percentage, but instead do it as weight, 0:3 for example , then the tare weight would be added to each item in a multiple purchase?

Just when I think it's coming clear I'm confuzzled again :cry:

I set the Tare to 0:3 which adds 3lbs ...

I add to the order a Product at 1lb and will get 4lbs ...

I add 2 of the same Product to the order and get 2 x 1lb = 2lb + 3lb = 5lbs ...

I add 3 Products of varying weight to the order in varying quantity ...

I put them all on the Weight Scale and it comes out to 12lbs ... then I add a 3lb Tare to that for 15lbs ...

Ajeh:

I set the Tare to 0:3 which adds 3lbs ...

I add to the order a Product at 1lb and will get 4lbs ...

I add 2 of the same Product to the order and get 2 x 1lb = 2lb + 3lb = 5lbs ...

I add 3 Products of varying weight to the order in varying quantity ...

I put them all on the Weight Scale and it comes out to 12lbs ... then I add a 3lb Tare to that for 15lbs ...

LOL .... I sometimes make thing overly complicated for myself. Thank you Ajeh!

Not a problem ... hoped this helped get you back on track ... :smile:

I am having somewhat of the same problem...

for international rates is there a way to set the Tare to always be 12 or 13 oz? I don't have weights set for each item so i was trying to figure out a way to have the tare come out to be an equal shipping charge for international orders (so that I can ship first class instead of priority)

If I set it as 0%:1 that is too high for first class mail. But I tried to type 0%:.75 or something along those lines and that doesn't work either. First class still does not show up as one of my USPS options (yes, its checked off in the shipping module)

hmph!

The Tare is set with numbers without the percentage key ...

0:0 for no Tare and 10:3 for 10% plus 3 lbs ...

Can I make domestic shipping go by the USPS rates.... and international shipping have zone rates?

Set a Zone for what you consider to be the US on the USPS shipping module ...

Set a Zone for the Rest of the World on the Zone Rates zone shipping module ...