Pwncnc spindle insight

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey John,

@JohnHewetson

I am thinking of going with a water cooled 220V version of the 1.5Kw but wondering if I should go with the 2.2Kw in order to future proof my set up.

independently of the power selection, I would recommend the 80 mm spindle because with 65 mm, it’s very tight inside. You have the squirrel-cage rotor, then the stator coils and then the water sleeve. That fits better into a 80 mm housing. Also with 80 mm spindles, you have the choice of ER-16 and ER-20 collets, the latter accomodate tools with 13 mm and half-inch (12.7 mm) shanks.

@Aiph5u

Once the Onefinity 80 mm spindle holder was released I ordered it and I came accross the question whether to buy a 2.2 kW spindle with ER16 or with ER20 collet. The first takes tool shanks from 1-10 mm and the latter from 1-13 mm, which would mean half-inch tools. But since at first I did not expect to use tools larger than 8 mm, I was unsure.
So I asked the manufacturer and he answered, the spindle with ER20 collet has larger bearings and a stiffier shaft. Larger bearings means longer life. Stiffier shaft means more precision. Also one should take into consideration that when using tools with a larger shank, the thicker the shank the stiffier the tool and so the longer the tools you can use – and thus the deeper the pockets you can mill into your workpiece. So I went for the ER20 spindle.

HFS-8022-24-ER20 2.2 kW 24,000 rpm water-cooled