Day: September 24, 2011

Saturday, 24 September 2011

11:08 – I installed Zen Cart yesterday, and spent some time playing around with it. It’s an e-commerce/shopping-cart package, and it reminds me a great deal of the hosted e-commerce package that Maker Shed uses. Which is to say that I have no clue how it works in terms of setup and administration. I don’t intend to bring up a storefront right away, but I figured it was time to dip my toe in the water. Zen Cart is free (as in speech and beer), and it appears to have more than enough capability to do anything I’d want to do in the foreseeable future. Critically, it appears to work seamlessly with PayPal, which will allow me to accept credit cards without having to establish a merchant account or worry about keeping people’s credit card information secure, since I’ll never see it.


I got a delivery from one of my wholesalers yesterday that includes most of what I need to assemble a dozen biology kits. Over the next couple of weeks I’ll spend some time doing what amounts to a 3D jigsaw puzzle, trying to figure out what size box to use for the kits.

For the chemistry kits, I use Priority Mail large flat-rate boxes, which cost about $15 to ship whether the destination is next door or in Alaska or Hawaii. Those boxes have a weight limit of 70 pounds (~ 32 kilos), which is much more than the kits weigh. But USPS also offers regional-rate boxes, which cost anything from about the same as flat-rate boxes to several dollars less to ship, depending on destination zip code. They’re limited to 20 pounds, which isn’t a problem for the biology kits.

The problem is, there’s a size difference. The large flat-rate boxes are 12″ x 12″ 5-1/2″, or 792 cubic inches (about 13 liters). The large regional-rate boxes are 12-1/4″ x 10-1/2″ x 5-1/2″, or 707 cubic inches (about 11.6 liters). The chemistry kits as currently packaged simply won’t fit the smaller regional-rate box, but the biology kits might. In fact, to keep the price down, I may make some changes in the contents of the kits, if necessary to fit the box. Any changes I make won’t compromise the utility of the kits, but it’s often possible to make substitutions that provide equivalent functionality but fit the jigsaw puzzle better.

Once of those changes will be in chemical packaging. The chemistry kits currently use a styrofoam block that contains 44 15-mL PP centrifuge tubes. The six vacant positions in the block are filled with glass test tubes for protection during shipping. For the biology kits (and eventually for the chemistry kits) I’m going to substitute a mix of plastic dropper bottles for liquid chemicals, wide-mouth plastic “pharma packer” bottles for most solid chemicals, and coin envelopes for some items such as tablets, seeds, and so on. The bottles are actually significantly more expensive than the centrifuge tubes (which aren’t cheap to begin with), but they’re also easier and quicker to fill and seal. The coin envelopes are much cheaper than tubes or bottles, typically three to eight cents each, depending on size and type.

Of course, that leaves me with the question of how to pack test tubes for the biology kit. If I don’t have the foam block to protect them, the obvious answer is to wrap the half-dozen test tubes in bubble wrap. Doing that is time-consuming, and it also yields a bulky component that would have to be fitted into the 3D matrix. It occurred to me that I could bump the number of 50 mL PP centrifuge tubes included in the kit from four to six, and pack each glass test tube in a 50 mL centrifuge tube. That bumps my total cubic for 50 mL centrifuge tubes from about 0.2 liters to about 0.3 liters, but reduces the cubic by the volume that would otherwise have been needed for the bubble-wrapped test tubes.

As usual, solving one problem creates another. I have been using 15×125 mm glass test tubes in the chemistry kit, but those are too long to fit into 50 mL centrifuge tubes. So, part of what’s in that order that showed up yesterday is a couple gross of 16×100 mm glass test tubes, which do fit into the 50 mL centrifuge tubes.

One thing about starting a small business is that it’s forced me to learn to deal with details, which is not my strong suit. Well, it is when I’m writing or working in the lab, but not in my personal life. Running a small business, especially what amounts to a small manufacturing business, leaves no option but to deal with details. I’m doing it, but I’m still not very good at it.

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