[mrosso]

What are your opinions of the HGH15 blocks they sell on Ebay versus the ones from Automation4less? Are the Ebay blocks counterfeit or cheap copies? What about these https://www.amazon.com/HIWIN-HGH15CA...6493029&sr=8-4. Too good to be true?

[DubMFG]

How long did you end up buying for your rails? I'm estimating somewhere around 500mm?

[joemusso]

How long did you end up buying for your rails? I'm estimating somewhere around 500mm?

Just measure the surface your mounting the rail to and multiply it by 25.4

The G0704 column was about 630mm = 24 13/16" that's what mine worked out to be

[Uguessedit]

For others that may come by and read and to comment to what length rail they should use I usually order rails that are two inches longer than actual travel needed. There is typically no need to run rails the entire length of the column. If you have 17” of travel than consider 500mm rails which covers you but doesn’t give you so much rail you sacrifice any potential accuracy or worse getting damaged during shipment. Longer rails are more prone to bend. So IMO shorter is better. Usually I trim them further to fit. Same with ball screws so I keep those short as possible. You get smoother operation, less chance of screw whip, besides your wasting space that can be utilized another way and again longer ballscrews May be apt to show more inaccuracy. Regardless what they like to claim. Don’t short yourself you build a Novakon. The. You need a vice to hold everything. Ideally you want to be able to machine off the table surface when needed. If you always use a vice then it don’t matter essentially the rail length allowing the spindle to come in near contact with the table and not so far you need 4” long end mills.