ATC spindle with iso30/bt30 or hsk63f

I've had good luck with the HSK63F tool holders and spindles we use.

But I don't really have any experience with the BT/ISO taper tool holders (the only real difference is the pull studs I'm told) I've heard that there can be significant problems with them sticking in the spindle if the spindle is left to cool with the tool holder in, especially when used at high speeds.

For 9-12kw spindles I've payed between $8000-$15000. from HSK, Omlat, Andi and Hiteco. The Hiteco ones have been the most cost effective for us. They have been almost half the cost of the Omlat spindles I'm replacing with them (with as good or better longevity.)

Also for a machine that sees more than 50% duty cycle (spindle running more than shut off) I'd strongly recommend liquid cooled vs just a fan. (But many CNC routers aren't used that hard.)

Thx for the info.

I don't have any water cooling installation on the machine. So that would be another extra. That's why I would opt for an air cooled spindle.

It's a 1000 USD extra for the hsk holders. For what I hear, I should opt for the more expensive one. As all I hear is hsk is the way to go for long term. Sad thing is all is more expensive the holders everything.

Cheapest would be the iso30. I have the impression that is used most actually on routers

On large production machinery, builders have been using HSK tooling almost exclusively since about 2002. Just look at the spindles offered on machines from SCM, Biesse, Komo, Heian, Mortibelli, Northwood, Anderson. If any of them even offer the option of ISO/BT tooling any more it is only on their lowest end bargain machines, or to give the option of machining up with existing tooling a shop may already have.

One of the reasons the HSK spindles and tooling is more expensive is because of higher/more difficult machining tolerances that the spindle/holder interface must be ground to. The other is probably royalties and licensing that fees that must be paid to patent holders.

The hsk is less likely to get sucked into the spindle from Rpm and thermal growth because it is dual contact. On a bt or cat taper the tool can get stuck and it will make a clunk as it is removed with the atc arm(or jam I've had to tap cheap machines with a hammer)

Big Kaiser makes a dual contact holder for BT but those cost more

True there are dual contact BT holders. But I've had my doubts about their usability on every spindle. I can't see how you could guarantee that all BT spindle's tapers and faces are ground perfect enough for use with a dual contact tool holder.

Todd wrote:

True there are dual contact BT holders. But I've had my doubts about their usability on every spindle. I can't see how you could guarantee that all BT spindle's tapers and faces are ground perfect enough for use with a dual contact tool holder.

Yes, the spindle needs the big Kaiser grind.

It would not surprise me if having that special grind done on a new spindle would take a pretty big bite out of the cost difference between the BT and HSK. But it would go a long way to reducing the deficiencies of one vs the other.

But back to the original subject for router with a spindle in the 12kw class, I still think it would be a no brainier to go with the HSK. For a lighter machine running a 5-8kw spindle it is harder to harder to justify the cost difference.

I would setup a pin to block spindle rotation without a tool clamped as it can damage the drawbar on a hsk spindle.

All of the routers I've used with HSK have and monitor the sensors that detect if a tool is inserted and correctly clamped before enabling the spindle to start, and shut it down if the clamping isn't correct. They also usually have sensors that detect if the spindle is fully stopped before allowing the tool to be released as well.