Good evening all.
I introduced myself to the forum few weeks ago and gave a brief description of build so far (http://www.mycncuk.com/threads/14348-New-Member-Build). I am now after some advice on ball screws, after researching the forum I believe I have purchased the wrong ball screws for the size of the machine (1605). And after more reading, I have seen some members mention problems with whip on long screws.
My machine needs a minimum of 1365mm ball screws on the X axis and 1500 on the Y axis and will need to shift a heavy 80160 gantry. I currently have 3Nm steppers and ideally will use pulleys on the Y & X axis as the steppers can be placed neatly. I am in a position to order the new ball screws but would like to be sure I order the correct size, I have read that some members have used 1610 and also 2020, there is a huge price difference from BST on aliexpress so hoping someone can advise on this prior to ordering.

Thanks for reading.