
Last Christmas my wife got me a big cheap Double Horse co-ax helicopter. I was instantly hooked. The helicopter on the other hand was quickly destroyed. So I ordered another big, cheap helicopter. This time a Double Horse single rotor, fixed pitch. This helo so far has survived. Plus it taught me a lot about flying. Unfortunately, there is not a lot of room for follow on projects with the Double Horses. They don’t lift very much and they are hard to control.
So I set out to find the next step. For me that was building from scratch a 450 Trex clone. For those who don’t know a 450 Trex is the Honda Civic of the RC helo world. Basically you can go into any hobby shop and they will know exactly what you are talking about and have parts. Furthermore the parts are dirt cheap (although they get expensive when added together).
So in my process of trying to understand this whole new world of helicopters and trying to select the right parts from among that world, I discovered Hobby King. Hobby King is a online retailer of VERY cheap Chinese made RC parts. Basically they copy everything Horizon makes and sell it at 1/4th the price.
This downside of this (other than notable quality issues), is Hobby King is plagued by backorders. I think at any given time, if I made a basket of things I wanted, half would be on backorder. When you ask Hobby King about those backorders their stock answer is 7-30 days. If you press them (via their 24×7 chat support, which is cool), they will say 1 of three things: 1) 7-30 days 2) 1-4 months and 3) never/unknown.
So being frustrated with these answers, I did what I normally do. Which usually involves reading every word on the site and often looking at the source. I discovered that they had an API that allowed you to check inventory levels. Furthermore their API returns text. Ah ha! I have been wanting to learn the php/mysql fu but I had yet to find the right project. Other possibilities required me to learn xml or json parsing, which made the learning curve to steep. But with my recent arduino adventures, php was starting to feel safe so really I would be just bolting on the mysql component.
Essentially the core questions when shopping at hobby king are, when will this item be back in stock and how fast are they selling. One can be answered with historical data, the other can be predicted by knowing how often shipments come in.
What followed was a weekend of PHP/mysql tutorials, frustration and hobbyking-watch.com. In short I designed a site and series of databases that aim to track Hobby Kings prices and inventory on a daily basis. For now, I am just reporting data. Hopefully, in a few weeks I will have enough data to start making predictions and performing analytics on Hobby King’s performance.
I submitted the link to hobbyking-watch.com to Reddit and got a lot of great feedback. The first suggesting I implemented was coloring the cells on the main page to indicate hobby king’s inventory level and backorder status. Lots more to follow.
Anyway, it was a hobby weekend. For the time I was not building the big silver 450 trex, I was working on a website to help others build theirs.
