New Filament Feeds – now out of Beta.
Still not fully ready for Prime Time, but “mostly working”…
What’s changed.
After Prime Day the old filament feed stopped picking up Prime Exclusive pricing altogether, and old (list) pricing for a whole lot of items. Prime Exclusive items are typically about a 1/3 of what’s on sale for filament. Old price is necessary to calculate the price drop for an item.
It’s far from totally useless in it’s current form, but it’s not what envisioned when i set it up…. so i adjusted.
New feed (the main feed) now picks up all the Prime Exclusive, coupons, old prices etc.
Here is how it works:
It picks up the first 15-20 pages of what Amazon has in the All Discounts section for filament, with some parameters preselected. Basically, the same stuff that you can find at this link. It then applies all the coupon logic and resorts by lowest price after coupon. Then it cleans up all the garbage that tends to make it’s way into that section, like dryers, spool holders, resin, etc. The final 200 or so results go for another spin to get more data.
In the second round it goes out and picks up all the missing details for each item (like Prime Exclusive and Lightning Deal pricing). Then it checks a historical database of Amazon prices to find the average 30 day price for each item. That average is then used as the old price, and is what’s used to calculate the percentage drop. So don’t be surprised if the old price you see for an item in the feed does not match what you see on Amazon. I use the average, not some fantasy number some seller’s intern made up as the list price.
Once all that data comes back, it goes for another round of cleaning. This time all the junky brands and sellers are eliminated, along with some other logic to keep the list clean from bullshit listings. Finally, everything that had at least a 10% drop gets uploaded to the site.
By the time everything is said and done, there are usually about a 100-150 items left over from the original 350-400.
All prices are accurate within 5 minutes of update (that’s kind of how long it takes the function to run and create posts). Does not pick up variations. Picks out the lowest priced item per listing, not always the best deal (think same listing with 1kg of PLA for $10, and 2kg for $13 – it will return the $10 item, since it’s the lowest priced).
Alt Feed:
Checks historical price database to see which items are currently showing as being at least 15% off (before coupon), and grabs all the filament it can find (including variations). This data can be a bit “stale”, and can be anywhere from 1-12 hours old. This is especially true for anything Prime Exclusive or listings with coupons. Results are then cleaned to remove junky brands, etc. Usually ends up with around 200-300 results.
Currently main feed updates every 2 hours, alt feed every hour. But that will change in the next few days when other feeds finally go live.
Every half hour the site checks the feeds for items that are either a medium drop (35-50% off), or high drop (50%+), and sends notification to Discord. That part was a bit buggy for a few days, but it looks to be fixed now (no more duplicates over and over again).
In fact, i’m proud to say that today’s one and only post so far (the Polymaker 40% off) came from a notification that popped up on Discord 🙂
I had this post as draft for almost two weeks now. Every time i sit down to finally publish it, something breaks, and i spend the next couple of days fixing it.
Nothing has really broken in the last few days, so…………. let’s see how it goes 🙂
Thank you for all the work you put into this! I really can’t believe how far you’ve come since I first found this site. I’m glad your vision recovered sufficiently for you to carry on with this. I noticed there isn’t very much activity in the comments, and maybe 3D printing people are just shy or something, but I can’t be the only one who appreciates this effort you have put forth.