Look at the power label on each tool. Those that say 50Hz/60Hz (and I think that is most of them now) will work just fine with a step up transformer. If they only say 60Hz, then you could run into some issues with timing and full power. If you have a battery charger that is only 60Hz, you can use a Festool EU model to charge your batteries without a problem. The current chargers I have are dual Hz and I have used to charge my 18V batteries off of a transformer with no problems. (When I'm in Germany).
Suggest you buy transformers on Amazon prior to going to the EU. They are very expensive in Europe...even in the military exchanges. Much better pricing from Amazon for higher wattage transformers. Make sure you buy a "STEP-UP" model, not a Step-Down version. The latter is for EU 220V tools used in the U.S.
Most of Europe is on 50Hz cycles. The U.S. is 60Hz. That is the only issue that you need to focus on. Electric clocks, microwaves, electric timers, etc.. will all have errors if the Hz is not matched to the product. Heat is another potential issue if the Hz frequency is different. That being said, many manufacturers now produce products that have auto-switching frequency...and most newer computers and related equipment can be used from 100V-220V with auto voltage switching as well. The Mac I'm writing this on is being charged by a standard Apple charger plugged into Nigerian 220V, 50Hz power without a transformer necessary. Wish ALL electric product manufacturers would do the same with their tools and machines!
![Blink [blink]](https://www.festoolownersgroup.com/Smileys/default/blink.gif)
Good luck,
Frank