board problem

Hello..
I'm a newbie on this area..
It's "my" first 3d Printer. A friend lent me the printer.
A Kossel mini Delta with a mks v1.2 board.

My big problem.. I never had any issue from updating firmware marlin to the printer...

Everything ok..
After a few days of very hard calibration e manage to put the printer working not so bad..

But now it can't comunicate with the board..

I plug the usb, uses "com5", the pc detect the board the marlin also detect the "com5" the blue led on the board blinks and turns on the lcd...
But it dosen't comunicate with the board..

Using repetir:
No start signal detected - forcing start
Communication timeout - reset send buffer block

Using marlin:
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

What can it be?


And another thing...

I print a stl file that the object is 32mmx32mmx17mm..
When printed..
22.44mmx22.44mmx17mm

Does this have to change anything from firmware?
If so...
That's really bad...

Edited 1 time(s). Last edit at 04/05/2018 02:25PM by Lc1975.

Did you check the solder job around the USB port of the MKS board? There might be a problem.

The real part is smaller in X/Y than the .stl file means, your set diagonal rod length is too long. ( by ~30%)

Hello.

Yesterday i was messing in the printer with the settings...
The rod was at 80 now i put it at 107.49..
And the was convex.. Difference more then 6mm from center to the max of X and Y.. Now is way more better..
Now the printer goes to 85mm radius..
Before that never went more then 60mm and the nozzle after 10mm distance hit the table..
I think that now is much more better..

The board i talk here with a friend and he told that can be the bootloader problem or hardware.. That is not with me.. I don't understand that much.. Next week i'm going to take the board to him..

Thanks for the tips.



Edited 1 time(s). Last edit at 04/06/2018 05:35AM by Lc1975.