Linear Rail X Axis Mod for Ender 3

thingiverse

This mod is for adding a linear rail to the Creality Ender 3. I have these versions installed on my machine, and they are working well. Is this a necessary mod? Probably not. The Ender 3 is a well-built machine as it is. It's something that you can do to gain a small improvement and probably fewer headaches down the road when the wheels and bearings start wearing. I tried to keep it as simple as possible. The required parts are few, the largest being the 300mm long linear rail itself. At the time of this writing, it was about $30.00 US on Amazon. It's cheaper by ordering it weeks away from China, but with the quality on these things, I spent the little extra so I could get it replaced if necessary. Notes: 1. The hardest part of this project is to drill out the X gantry plate that holds the hot end on. The thing that worries me is that Creality will change the plate a little. I made the Drill Guide patterned after mine. The first thing you should do is check to see if the drill guide aligns with your plate. Print the drill guide. Measure the 4 C holes to verify that they are 20mm apart to make sure it's properly to scale. If you have a bearing block, attach it with long (12mm) screws to verify; if not, just measure it. Use the two 5mm screws and nuts that hold the top wheels on to fasten the guide to the plate (pictured). There are two things to check here: The first is that there's about a 1mm gap between the straight edge of the guide and the two belt-holding pieces that stick up from the plate. The guide edge will represent the edge of the bearing block. The gap is just to keep the block off of the curved part of the plate so it will sit flat. The second thing is to check that the two threaded lugs that the fan housing screws fasten into are centered in the B holes. If all is as it should be, then go ahead and drill the C holes through into the plate with a 3mm or 1/8" drill bit. 2. The only kludgy/unplanned thing I had to do on this mod was use a couple of 4mm nuts as spacers under the fan housing mounts to hold it away from the plate. The screws that hold the bearing block to the plate are in the way, so... It doesn't seem to affect anything, but I don't know. If you have another fan mounting method, you'll have to check for interference. 3. The limit switch spacer is obvious. The X gantry plate comes out 9mm, so the limit switch will also have to come out. The 40mm screws holding it all together need to be replaced with 50mm screws. 4. The hole in the plate that the bottom wheel goes through is 7mm, so I used a 7mm screw/bolt to hold the belt extension on. It appears that 7mm is an odd size for metric bolts. I had a hard time finding one. I finally found the 15mm long one at Ace hardware. If you have trouble with finding one, a 1/4" screw should work fine. I like using nylock nuts for things like this; they stay tight without having to over-torque them. 5. I had problems with the first design of the belt adapter. It was not strong enough and broke easily. So, I replaced it with V2, which is stronger and has a better orientation for printing in the "flat" plane for strength. If you only have one printer, it's a pain to print a new part when the old one breaks. BOM: 1 x 300mm mgn12 Linear Rail with mgn12H bearing block. I got mine from Amazon. 1 x M7x15mm bolt or screw 1 x M7 Flat Washer 1 x M7 Nylock Nut 4 x M3x50mm flat head screws to replace the 40mm screws holding X servo on 10 x M3x8mmm Cap Screws 10 x M3 T-Nuts 2 x M4 nuts (Only used as spacers; use any 3mm thick spacer.) Rev History: 8.27.18 - Replaced the Belt Adapter with V2. V2 is stronger and has a better orientation for printing in the "flat" plane for strength. 12.18.18 - Replaced Drill Guide V1 with V2. It's the same exact size and function; I just repaired the STL file. Some were having problems printing it. 12.28.18 - Replaced Belt Adapter V2 with V3. V3 is a little stronger, and the STL is a little cleaner.