This is the page for my Standard sized spool holder... This is for a specific size of my universal spool holder... The main page for this universal spool holder can be found below... That page has every size needed to fit 99% of the spools currently on the market... Main Page - http://www.thingiverse.com/thing:1001312 If you're on this page, you've probably already been to the main page and decided the size you needed (which I assume is this size) so I won't go into too much detail here. But here is the instructional video on how to print and put the spool holder together https://www.youtube.com/watch?v=zG1CFx9aUIk The instructions to get a good fit are pretty simple.... 1st Find a spool you want a holder for. In the center of the spool there will be a hole... This hole will have the top rod going through it. You need to figure out which sized top rod you need - a big one or a small one - most spools (90%) have a hole of around 50mm in diameter... However, some (like hatchbox) have a smaller hole of around 30mm... If your hole is less than 50mm but greater equal to than 30mm - you're going to need a Small Top arm pair... If your hole is greater than or equal 50mm - you're going to want a Big Top arm pair... (This will be most spools) 2nd Now you're going to need to figure out what sized arms you should use... Take your spool, lay it flat, and now measure the full outer diameter of the spool from end to end... All the files needed are on this page - but I'm going to give you direct links to the individual pages so you don't accidentally get the wrong one. If your spool is less than or around 160mm - you're going to want to print the Small size... Link - http://www.thingiverse.com/thing:1001360/#instructions If your spool is greater than 160mm but less than or around 200mm - you're going to want to print the Standard size... (This will be about 90% of spools on the market) Link - You're already here If your spool is greater than 200mm but less than 270mm - you're going to want the Oversized size... (This is the size for the big Makerbot spools) Link - http://www.thingiverse.com/thing:1001359/#instructions CheckPoint Now that you know what sized top you need and what sized arms you need... You should be good to go on the arms... But just to be sure... If you measured and decided you need a Big Top and Standard sized arms... You will need two files for your two arms Standard_BigTop_BaseArm & Standard_BigTop_SpinnerArm If this makes sense - you're all set. Now you can move on to the next step which is rod length 3rd Now, like I said above, you need to figure out what sized rods you should use... But first you need to understand how the rods work. I have two rods... BigRod & SmallRod If you determined that you have a BigTop in the first step - you will need to print 2 Small Rods and 1 Big Rod of equal length If you determined that you have a SmallTop in the first step - you will need to print 3 Small Rods of equal length Now to determine length... Lay your spool down on its side and measure the height of the spool from end to end... (If the spool was upward, it would be the width)... Whatever measurement you get (in metric) - add 10mm to that... So if your measurement was 65mm from end to end - you're going to want 75mm rods... The extra 10mm is to account for the 7-8mm lost when the rod screws into the base arm... I did this to add strength to the holder... But you have to keep it in mind and account for it... All of my rods are in 5mm increments from 40-110mm in length... So, 40,45,50,55,60,etc... So if you get an odd measurement like 63mm... You'll add 10mm to get 73mm... What you will need to do is simply round up and take the 75mm rods... The exception to this rule is Hatchbox - I made a specific 63mm rod for Hatchbox and it is annotated in the file name of the STL... Well that's it I hope you enjoy the spool holder!!!