I've had a bit of a search through the forum topics and haven't been able to find anything similar so I apologise if this has been covered already
I've had an Orion for almost a year now and for the most part I've been more than happy with the printer. Unfortunately I've recently uncovered a bit of an issue with printing parallel walls which has gone un-noticed until now when I've been trying to fit two parts together.
What I'm seeing is when I print a test block (100x3x5mm with the 100 long printed perpendicular to the z tower aka horizontal) is a deviation from one end to the other.
One end measures 3mm and the other end measures 3.3mm.
Now one 100mm long side (the rear most side) prints perfectly straight and the other 100mm long side (closest to the printer control screen) prints the first 30mm or so at 3.3mm, the last 30mm or so at 3mm and the mid section seems to taper between the two.
As the print head comes around the right hand side 3mm wide wall and turns 90 degrees to start the front 100mm long wall the print head seems to flare out forming a hump for the first 30mm or so and then back to normal.
Now interestingly when I print the same part at 90 degrees it prints near perfect (0.04mm deviation)...
I've been in touch with Seeme CNC support over the past few weeks and the help has been absolutely great however its proving a bit difficult to track down the issue.
We narrowed it down to a mechanical problem with a carriage and unfortunately after upgrading the arms and carriages to the ball cup injection molded components the problem still exists.
Thus far I've:
-Replaced the stock melamine carriages with the upgraded injection molded set and also upgraded the arms to the upgraded ball cup versions. This helped, it took about 0.2mm of error out of the prints (it was printing 3.0mm to 3.5mm over the 100mm) however it didn't solve all the error.
-Tried to maintain an even amount of belt tension on all three belts as this seems to account for slight errors if they are too tight or loose.
-Last weekend I individually swapped out each stepper motor (x y and z) with the extruder stepper motor to see if I had a dodgy stepper but they all seemed to print about the same.
-I asked Seeme CNC help to print my GCode which they did and got a slight variation (0.17mm)
I'm currently using:
-Orion with 0.91 firmware
-Upgraded cheapskates (now running the injection molded set)
-Upgraded Ball joints and arms
-Solidworks to create 3D data
-Mattercontrol and matterslice as the slicer
-Printing PLA at 210deg C.
So I guess the questions I'm asking are:
1. What sort of tolerances should I be expecting on vertical wall thickness? (my assumption is it should be better than 0.3mm, more like 0.1 or less, correct me if I'm wrong)
2. Has anyone else experienced anything like this and if so what was the problem?
3. Any suggestions on what I should be checking?
Anyway, any help to solve the issue (or potentially multiple issues) would be appreciated

Thanks guys