HI REJSHARP,
the OD is 68mm but you can, of course change to anything you want. If you need something made let me know I might be able to knock one out. Buying a 3D printer is not an easy (or cheap) undertaking despite what they would have you believe. The more consumer orientated, the more restricted they are in usefulness. And lets not mention drawing in 3d is not a basic skill regardless of what package you use, tinkering is fine but creating something you exactly want takes time and a steep learning curve. Downloading prints and fiddling with them is easy. If you are prepared to put the hours in on both the drawing and a printer then it’s rewarding. I have a giant delta printer, a heavily modified boots industries BIv2.5. Great ideas, badly executed and rubbish company to deal with (took 6 months to manufacture and 12 months to deliver-long kickstarter story). Still, using other resources, upgrading key bits and advice from some very helpful people it’s now singing and can print a giant 300mm diameter 400mm tall. I can print ABS+PLA, I could probably print just about any thermoplastic with a modified head and an extruder to make filament, but that’s another project (packaging to filament). I’m in the UK. If I was going for one now I would buy someone else’s abandoned project (super cheap on ebay), there are many people who give up with them when they can’t print a full colour boba fett 10 minutes after taking it out of the package.