I will NEVER purchase another 3D printer that does not have automatic bed leveling, that is all…
Surprisingly, I leveled the bed of the turnigy replikator once and never had to think about it again. There are other problems but this works good for me compared to a famous reprap brand.
Because of the bow in the center of my heated build plate, I can either level and print right in the center, or level and print on the edges, but cant use the whole bed. I put a layer of glass on there which contours nicely to the bow in the aluminum, lol. To get a real great first layer you either need auto leveling or a very flat bed, of which I have neither, arg… Once I am past the first layer the printer is actually pretty amazing. Just getting going that will cause you immense pain.
Agreed. Bed levelling is ver challenging. Doable but definitely tricky
I got that with a reprap neo. Somehow it works now but i had many prints were I had to level the bed during the first skirt loops. Even with glasbed, the adjustment screws are just to loose.
You can try mesh leveling in marlin. It allows you to manually set the level for various points on the grid.
Works beautifully, except if you have a large variation on your bed, your prints will also be deformed in the same shape.
@Anthony_Webb I’m starting to agree with you on bed leveling. I used to be of the mindset on my HercuLien and Eustathios printers that all you need is a very rigid and repeatable system and bed leveling compensation is not needed. But after using the Delta designed by @Alex_Lee I’m learning to really love inductive bed level probe compensation. I’ve never had more consistent first layers than I am getting now using Alex’s printers.
what if, get this. some build a 3D printer that isn’t made from bloody chewing gum and cardboard and it’s solid enough to only need to be leveled every couple of months.
One thing manual adjustments doesn’t account for is thermal expansion of aluminum at different bed temps and hot end temps. The coefficient of thermal expansion is actually fairly substantial in aluminum. So switching from 60C bed / 220C hotend for PLA, then going to 110C bed / 245C hotend for ABS does require relevelling regardless of how precise and strong your bed is. That’s what changed my mind on bed compensation. I could run 6 months printing only ABS on my HercuLien and never have to adjust level. But changing materials did. Only a small amount, but enough if you really want a perfect first layer. Bed compensation means I never have to think about it at all, which in retrospect is pretty nice.
@Mark_Rehorst correct, the crowning in Z is caused by constrained expansion in x/y mostly… Along with temperature differences between plate center and plate edges.
@Nathan_Walkner my bed is mic6, so its not the bed flatness. I use feeler gauges under the nozzle. I can test it at 60C and then go up to 110C having never moved the bed. The feeler gauges dont lie. Then again my big printer bed is almost 17" x17"… So like all things 3d printer related scaling them up becomes problematic.
@Eclsnowman 1/4" mic6 doesn’t have amazing tolerances, .381mm is within tolerance according to alcoa. mind you i use mic6 on my printers 
another reason to use probing, linear rails that aren’t perfectly straight…
Odd – I set up the bed on my Mini Kossel months ago and its been printing pretty much every day since with no problems with bed alignment. When printing something wide on the bed I watch the first layer and sometimes give one of the three adjustment screws a quarter turn, but that’s all, and I don’t have to do that at all often.
Coordinate transformations result in rounding errors, which result in artifacts in the surfaces of prints. If you’re not seeing them, it’s because your print quality wasn’t high enough to begin with. I would like to see more printers using independently-driven 3-screw Z drive so that they can use a probe to mechanically tram the platform, but it’s not the cheapest solution.
A good platform should almost never need adjustment, especially if you print your first layer with taller AND wider extrusions, which are much more forgiving. I’ve had to argue with a bunch of different slicer developers to get the ability to do this implemented, but it’s in all the open source ones you’d want to use these days, so there’s no good reason not to do it.
I was concerned about artifacting but I haven’t really seen any and I’m fairly picky, but not the pickiest. It sure beats the headaches of bed leveling on a moving bed. Our um2 / craftbot etc def don’t need the auto leveling and are better for it.
An interesting idea would be to do z heigh compensation on a per part basis. say you had a dozen parts scattered on a build plate, locking the z to an averaged value per part, but adjusting as it went to the next part.
@Mark_Rehorst You seem to be talking about different things. If you’re using independently-driven Z screws AND using them for automated tramming, then you’re doing that each print, and it doesn’t matter if they get out of sync while you’re not printing. This is not the same issue as using multiple motors on the same driver, or with separate drivers but controlled by the same logic signals so that the software can’t move them independently of one another.
If any of your motors lose their position during a print, the print is ruined, and you have to start over, so it doesn’t matter if that results in the platform going out of tram as long as the next print will fix it. If you have a single Z motor and it binds and skips steps, your print is still ruined. The belt-synchronized screws arguably have fewer points of failure and are less likely to get out of sync, but if they do get out of sync, you need someone who knows how the machine is built and calibrated to set it right, whereas the 3-independent-screw system has a software routine that fixes it automatically.
@Brad_Hill You can see an example of the artifacts here: https://plus.google.com/+Whosawhatsis/posts/5Zq66r5kP7s
I have no issues with manual bed leveling. Adjust 3 screws until level and I’m good for 10-15 prints before I have to take another 60 seconds to re-level. It’s just too easy to even consider it a problem on my printer.