trouble calibrating the h1.1

[burro breath]

so i have trouble calibrating my h1.1. i am not sure at this point what my issue is. i am using sprinter and repatier host for software. when i put my calipers on the x and y axis and measure how much it moves for a 10mm command it actually moves 10mm. but when i go to print things they come out larger then they are supposed to. also it doesnt make perfect circles. i know it is never going to make a perfect circle but it should be alot closer then it is. i print ovals:( i have included pictures of a galaxy s3 car mount. the car mount came out about 3/8 of an inch too long in the y length. also if you notice the holes are not circular. any help would be great. thanks.

[Polygonhell]

The circle issue is classic backlash, looks to be worse in Y than X, you're Y bely is either too loose, or it's rubbing badly on something, probably the former.

[burro breath]

so i tightened the belts and it definetly helped. now the question is how nice should my prints be coming out. i see the prints of the rostock max and its amazing? should i be able to produce prints of that quality? what are some tricks to getting the best prints possible?

[mhackney]

You should absolutely be able to make prints as nice as the Rostock - just not as big!

The basic steps are:

1) mechanical calibration - X, Y, Z movement and Extruder. You have started to do this. It should be spot on. If you say print a circle 2" in diameter you should get a circle 2" in diameter!

2) extruder/hot end calibration - this will likely take most of your time to work out. First is the extruder. Make sure it is calibrated. Search for info here to learn how of you don't know. The extruder needs to move the filament 10mm if told to. Also, it must not slip. This is a bit of an art so I recommend reading the posts here. Also the hot end, you need to find the best or a good temp for your specific filament.

3) your slicer parameters. With the above working, now you can start doing calibration prints and tuning things like retract, lift, extrusion multiplier, etc. This is very slicer specific so read and search here on the slicer software you are using.

You can do these in order or do them all sort of at the same time. I'm methodical and find doing it in this order takes less time and less aggregation!

cheers,
Michael

[burro breath]

is there a single place where i can read up on what every function of the extruder does. like what retraction and extrusion multiplier means?

[mhackney]

Your best best for absolute beginners is to pick up a copy of Practical 3D Printers. It at least talks abut the mechanical and electrical subsystems and has a pretty good treatment of the software tool chain. It spends a little too much time (almost half the book) on using OpenSCAD to design 3D objects to print, but even that is worthwhile. It covers basic terminology, etc. Otherwise, the RepRap.org site is an open Wiki that has much of the same information if you are willing to wade through it.