Prints is ok in one side, terrible in other side,

it is printed from my mendel prusa, abs, 240 degree, 90 degree heat bed. no fan is turned on.
the print of columns from back side looks terrible, it looks twisted with close look. the the columns in front looks alright.
I am totally at lost, please, any one show me the magic, give me some ideas to try to improve this. thanks

I've been struggling with the same thing for some time now. I am fairly certain it's heat related and I think the heater block is at fault. In your print is the end of the heater block (where the resistor or heater cartridge is) on the side with the bad print?

Try printing at a lower temp, like 10-20c lower.

I ended up lowering my heat bed temperature, and putting some ceramic cloth insulation over the heater block and it reduced the problem by 90%. Still not perfect but don't know what else to do. I can get better looking prints by lowering my hotend quite a bit but then I lose layer adhesion strength.

No offense but I am glad to finally see I am not the only one with this issue.

Oh, one more thing, print faster. It seems the slower you print the longer the heater block is over a section and thus makes the issue worse.

So to summarize, lower temp of hotend and build platform (try 80c on platform), print faster (80-100 mm/s seems good) and insulate the heater block from heating the layer below it.

Each of these should show some degree of improvement but put them all together for better results.

Let me know if this helps you.

Edited 2 time(s). Last edit at 07/02/2014 06:07PM by tmorris9.

Could it be because of the position of the printed part on the platform? It's kinda hard to explain without pictures, but if the belt is not straight the printer might have difficulties being precise at certain position.

One way to test it out would be to position the printed part in the direction where it prints better.

I think what you mean by "twisting" is a result of warping so the other layers are not sticking where they should. If this is PLA, then you should check where your print fan is and make sure it is not only cooling one side of the print, but everything evenly. Based on the pictures, if this is PLA and you have a print fan, then it is mounted in the front and the back is not recieving any air.