[Gulfcoast Robotics] MGN12 Linear Rail Precision Motion Kit for Ender 3 Pro and Ender 3 V2 (Dual Rails, Ender 3 V2)

I bought this for my ender 3 v2 neo as the stock bed was crazy bent. The initial order had a bad rail but the company replaced that in no time! I was in direct contact with them and basically the source the rails from another company, so they themselves didn't do QA on the rails. I was told that they used to, but people kept thinking their package was used because the rails were opened. After this mishap they said they were going to start doing QA again but repackage the rails. They really care about their product and it showed from the communication I had.Def get this, you wont be disappointed!

Bought this kit to replace my V-wheel and original bed frame with something better. The new bed frame is more rigid and has helped me create the flattest bed I've had yet. It also has an option to go to 3 knobs with an adapter, but I would set that up before applying a magnet to the heated bed. When printing, it's not much louder than the original bed setup after adding some Super Lube (lithium grease) to the rails and moving the bed back and forth a few times.

Decent kit, not for the price.The rails have 12 bolt holes each(24total), they only 12 screws/t-nuts. A little annoying having to skip every-other bolt hole knowing that I paid premium.Clean the rails of all original grease/oil with alcohol. Reapply lubricant.Had to drill 3 holes since my ender 3 extrusion is thinner than what this is designed for.Biggest thing is to assemble correctly.First, I bolted & tightened adapter brackets to rails, then I secured bed(I suggest you ream the bolt holes bigger so it doesn't flex and cause tension on the bearings). Lastly, the rails were bolted up. The center bolt had tension while the rest were loose. I rolled it back and forth numerous times delicately torque the bolts inward out. It's important to torque the bolts sequentially. The rails will microscopically buckle.Last thing, the end stop micro switch will not touch. I had to modify the bracket and flip it upside down to contact the aluminum adapter.Other than that, its an alright kit. The $90+ really buys you the custom brackets, linear rails are subpar.

One of the rails was straight up trash. After I cleaned and lubed it one had a several spots that the cage would straight stick. The other one had a bearings missing. I didn't want to send it back because the rest of the parts where great, so I just ordered new rails.

Works on the Ender 3 if you’re willing to drill some holes. Measurements are in my pictures. This makes for a very tight and precise y axis. I replaced my springs with silicone spacers at the same time and haven’t had to touch my bed level in the last several prints

Firstly they charge you for shipping. Secondly the rails come over lubricated and it causes the ball bearings to fly out after about spending 30 minutes getting them back into place I put them on the rails only for it to happen again. Thirdly it doesn’t move on the rail it just gets stuck, one’s moves but the other doesn’t. I would like to see this company make things right. Overall though I will most likely be returning this I’ll give the company a week to make things right.

The media could not be loaded. Why no 5? In a premium kit such as this, I would have expected a printed alignment jig to center the rails during installation. Since I had no working printer, I had to buy aluminum jigs from China.Other than that? EXCELLENT quality and precision machining.Some may complain about the overall quality of the rails themselves but ANY rail that comes at this price point needs work before use.I completely disassembled each carriage, soaked all bearings in 91% ISO. Used an old vibrating toothbrush and scrubbed the insides of the carriages while the bearings were soaking. This removed all packing grease.I counted the 3/32" bearings in each carriage and reassembled. I lost 3 during this process. I ordered another packet of 100 from Amazon. I made a mistake in "assuming" that replacing all the stock bearings with new ones would be a better option. I killed another hour doing that. MISTAKE! The new bearings (after lubrication) were grittier then the originals so yeah, I reversed all that and only replaced the 3 I had lost originally. I used Super Lube liquid pen oil with PTFE in the grease holes located at each end of the carriages.MUCH BETTER!So aside from the jig thing, a resounding 5 (if my peeve isnt yours).NOTE: On the Ender 3 Pro, I experienced severe drag on one rail after installation. I contacted GULF COAST and they were extremely helpful in identifying my issue. Seems Creality is known for having an ever-so-slight twist on the 4040 "Y" axis extrusion. Mine did as well. I have reordered a replacement piece from Ender Extender in Texas to replace the original. I will need to drill my own holes to bolt it to the frame and to attach the belt tensioner. The video shows the severe drag I mention after installation trials.

Great kit and fit and finish on everything was awesome. It was a little hard to get both rails lined up so there was no binding but its not really the fault of Gulf Coast. I only wish they offered it with a black anodized finish.I also bought the replacement bed with 24v\250w silicone heater and its equally a good product. I print Nylon\ASA and the bed heats up to 110C much faster than it did before.