Purchase from linearmotionbearings2008 is turning out to be a total disaster

[routercnc]

It has been many years since I bought my ballscrews (and they were from linearmotionbearings). Mine were maximum 120 0mm and arrived in a simple cardboard box like yours.

They were bent but not as much as yours. Probably helped that they were shorter. The worst one I sent off to a local company and they straightened them (~£40). The other one could do with straightening but was not too bad so I have left it. The $50 refund doesn't cover that but it is one option if you can find someone in Raleigh. He might budge a bit more if you get a straightening quote for all of them and he pays a fair portion (or 100%!) to save shipping costs and hassle.

A 'small' amount of bend is actually OK as the ballscrews are flexible and will be forced into line slightly by the ballnut. But I'm talking a few tenths of a mm or less. Obviously the more bent they are the more the ballnut will wear out. They are also noisy when even mildly bent.

As for the 'offset' machining. They might be accidentally machined with an offset - however you are measuring on the crest of the thread Vs the center line. Just to confirm it is better to put the nut on and measure on the outside of the nut as the balls will run along the bottom of the grooves, which is where they should be ground true. Or find a way to indicate to the bottom of the groove. That might be the same answer as your method, but worth a quick check to be sure.

I've since bought from Fred at Aliexpress and found a better quality of parts, plus better packaging. I've not bought long ballscrews from Fred though so can't be sure how he sends those out but in general his packaging has been good.

[JAZZCNC]

I've since bought from Fred at Aliexpress and found a better quality of parts, plus better packaging. I've not bought long ballscrews from Fred though so can't be sure how he sends those out but in general his packaging has been good.

I've had up to 3500mm screws from Fred and never had a bent one yet. To be honest this is why I stopped dealing with Chai at linear motion bearing and went with Fred because his shipping and packaging was much better.
If the screws are relatively long (1500mm+) they come in a wooden packing crate, if say under 1500mm they come in a cardboard box. However, usually it's a very strong thick-wall box and if the screws are over say 1000mm they are supported in the box with Cardboard braces to stop them bending.
Also, Fred wouldn't hesitate to replace or refund if they were bent and wouldn't ask for the old ones returning.

Edit: I will clarify this in that usually when I order from Fred it's for more than one machine worth of parts and often has linear rails etc so my packaging might be made slightly stronger than for say a single machine worth of screws etc. However, I have in the past had small rushed orders and the packaging as been good and strong.