Luke11CNC Build Log ,I'm so naïve

[Jonathan]

I am going to order my ball screw set from the above ebayer as most people on here seem to rate him for price but is the product any good and what is the service like

I've bought from him on 3 separate occasions - couldn't afford to buy it all at once! It's generally quick to arrive, and generally good products. Make sure you get his supported linear bearings/rails. The 25mm rails are better than the 16mm and 20mm as they have another row of balls. I found there was a bit more play in the 20mm. When you've worked out what you need email him and he will list what you need.

It looks like you've chosen 20mm ballscrew for the X-axis. The critical speed of 16mm screw, with the bearing blocks he sells, for 1000mm long is about 2000rpm, 20mm screw is 2600rpm, so with 5mm pitch that is 10,000mm/min and 13,000mm/min. Both are probably plenty ... I would either get the RM2005 or RM1610 as the bigger pitch will halve the rpm. I used RM1610 on my Y-axis (750mm long axis) with a 3nm motor and it'll do 12,000mm/min easily. The backlash in his ballscrews is very low.

(My build log: http://www.mycncuk.com/forums/showth...outer-building...)

Watch out for customs charges ... he puts a low value on the item so it's not too bad, but you still have the £10 handling fee from Fedex

With one set of bearings for the x axis for now

For a 600mm wide gantry you will certainly want two ball-screws to prevent it racking. Or cables in a cross shape like on a drawing board slide ruler to keep both sides moving together.

Ballscrews are the way to go. they will be much better than screwed rod.

Yep, using them increased my feedrate on Y-axis by a factor of 2.5 and X-axis by 4. Not entirely comparing like with like there ... but in general they will go much faster due to the higher efficiency.

[wiatroda]

but you still have the £10 handling fee from Fedex

From my last invoice - DHL administration fee- £1.25 + 20% vat as value stated on invoice - sometimes you may pay custom duties if custom officers fancy it :). What is a justification of charging £10-Fedex if somebody else can handle the parcel for £1.25-DHL ????