Better Cooler Drain Plug (RubberMaid Cooler) with o-rings.

thingiverse

I lost the plug for this darn cooler long ago, in a galaxy far far away. Since then I've made several plug replacements. I even made one out of duct tape! This time I decided to finally make the plug to end all plugs and design and 3d print one. So this is my latest iteration. I'm confident to declare that you can not buy a better plug for your cooler than this. It's better designed and better made than the plug that came with the cooler and it's also better than the replacement plugs you can buy. The hole on my cooler is right at 9.7 mm at the hole. I'm pretty sure this will fit quite a few coolers from different makers. But I've included my design files so you can adjust it for your needs. I made this with grooves in it to put two rubber o-rings on to ensure a water tight seal. I got an assortment set of o-rings on AliExpress just for these types of projects. So the o-ring that I intend to use for this is labeled 9 x 2 mm. I also filleted all the edges, which is trivial in FreeCad. Which is the primary reason I use it. I mean other than it being FREE, and it runs on Linux. UPDATES I have printed this object a couple of times now. I printed it on a PrintrBot Simple Metal, and it works, but you will want supports, and a brim. It took about an hour at highest resolution. Then I printed it on a Zortrax and it printed at high resolution in only 33 minutes. So I decided I'm having an affair with the Zortrax printer now. The slots for the o-rings in the model ended up being a touch too shallow. So I've made them 0.4mm deeper and I'm printing the updated plug now. But without the o-rings the plug fits quite snugly. I may want to make the handle bigger to make it easier to put on and pull off. The files are now on revision 3. Update I printed rev 3, and it was too tight initially. However I put a little vaseline on the o-rings and they slid in perfectly tight. Now I'm pretty sure vaseline is NOT the appropriate thing to put on o-rings (and I think mine are nitrile o-rings). But I was in a hurry and wanted to see if all it needed was a little lubricant. And that was the ticket. Now I'm pretty sure the thing I should have used should have been silicone grease. Which I have in my tackle box for my fishing reels. UPDATE I've decided that even with the lubrication it's still just a touch too tight. So I've redesigning the slots for the o-rings to be a little bit deeper. I've increased the size of the base so it's easier to grab with my big hands. I'm reprinting it soon. So this latest version is Rev 4. Rev 3 worked and I will keep it as a backup plug. But Rev 4 is the gold standard for now. Latest Revision is Rev 4. I've printed and tested Rev 4 on a printrbot and a Zortrax at high resolution, out of ABS. It fits like a dream. First I coated the o-rings with the proper silicone grease. It only takes a smidge. Then when inserting it into the drain hole, it resists at first, then snaps right in all the way in. I have yet to fill the cooler with water to test for water tightness, but I'm pretty confident its going to work perfectly. Actually this plug is better constructed than the original that came with the cooler and the replacements that they sell online. I field tested the Rev 4 this weekend and it didn't leak ONE drop. So I consider this a huge success and I can finally put this project to rest. I took the cooler on a 3 day fishing trip last weekend, and not one drop did it leak. The bottom of the cooler was a dry as a bone. I printed a second one to duck tape to the inside of the lid as a backup. Print Settings Printer: Zortrax Rafts: Yes Supports: Yes Resolution: High Infill: 30 Post-Printing Remove raft/brim and supports. I designed this to use two, 9 x 2 mm rubber o-rings. How I Designed This I designed this in FreeCad using simple Geometric Primitives.