Real-Time Shipping w/ "Boxing" Capability

Hi... I'm considering switching from an old version of Xcart to Opencart. The one feature I'm struggling with is shipping. In my current Xcart, I wrote a custom hack to calculate real-time Fedex shipping in a particular way.

I would like some opinions on how difficult it will be to duplicate my custom shipping method in Opencart. If there is an extension that will do this, great! If not, I would really appreciate some input on the feasibility of doing this extension. I'll try to explain...

The items in my store are not heavy, but they are oddly shaped, and somewhat fragile. A typical order will be 5 to 50 items. On average, I can get approximately 8 items per box without risking damage. So, if a customer orders 30 items, that will require 3 full boxes + 1 partial box. Most of my items are also fairly low-priced, and I don't want the cost of shipping to be a barrier to a customer's decision to purchase - and I also don't want to lose money on shipping! I found that ALL of the "traditional" shipping methods (flat rate, by total weight, by total quantity, real-time, per item, etc) resulted in either too high or too low of a shipping quote for many of my orders. The "multiple boxes" completely whacked up the standard real-time calculations, because three 5 lb boxes do NOT cost the same to ship as one 15 lbs box.

So, what I did in Xcart was hack the real-time shipping module to "box" the items in the cart. All I did was put a loop around the real-time shipping call that grouped the items into sets of 8. Every set of 8 items results in a call to the real-time shipping module with the weight for those 8 items + a tare weight for the packing material and box. The remaining partial box also gets a real-time call. The total shipping cost is the sum of the real-time cost for each box. This resulted in a total shipping quote that very closely matches the true cost to ship the items - no matter how small or large the order. My transaction volume is fairly low, so doing 4 or 5 real-time calls is not a problem on the performance of the cart.

So - what do you think? Is this sort of mod feasible for Opencart?

Thank you!!

I have a box packaging class that I am working on adding to my fedex real time shipping and modding it into UPS and USPS. I will see about getting that out sooner

Great!!! I'm anxious to see it - thank you!

If you would like any input on features, etc just let me know.

Edit: I just looked at your Fedex WSDL extension, and YES - I think that will work for me! The only thing I didn't see was the ability to set a standard weight for the box and packing material that is separate from the item weight. Having that allows even multiple small & light items to generate the correct total weight when you are shipping a partial box that is below the max weight. That feature is probably not a show-stopper for me - I can get close enough without it - it's just a nice to have. In my hack, I just had another configuration parameter that I called "tare_weight_per_box". That parameter was then added to the sum of the item weights before checking against the max weight and calling the real-time rates.

Thank you!

I'm intresting in this class too. We need to break up the cart per vendor/warehouse. I hope your packaging class can be fixed to use vendor designation instead of weight. When and how can we expect to see it?