Festool vac question?

Re: Festool vac question?

Rick Christopherson

It's been a while since I fully disassembled a CT vac, but to the best of my knowledge, they do not use vacuum air to cool the motor. However, the only way I can be completely positive about it is to pull one back apart and check for air channels.

One possibility that is well worth looking into is the possibility of a source for static buildup. The most common source for this is with older versions of Dust Deputies that were not conductive. However, that is not the only place where static can build up.

The key to this problem is that you either need to be completely non-conductive, or completely conductive, but most importantly, not a mix of the two. If you have a mostly conductive airflow path, but have a short section that is non-conductive, that short section will build up an upstream charge until it gets large enough to jump the gap into the downstream path. When that happens, a spike will be sent down the conductive portion of your airflow/hose, and the sudden spike can damage the control board.

These static spikes seem to affect the autostart circuitry the most.

Re: Festool vac question?

Barry Irby

Mine is a CT 26 I believe and it lives in the bottom of a cart that passes for a workbench in my shop. One side is completely open and one has a large hole for access to the controls and port. It is about four years old and has been in that or a similar space for most of it's life. The floor of the cart is metal and the walls wood and plywood.

It's does blow off some heat. On hot days I notice it. It's usually runs in short bursts, connected to the Domino or perhaps a sander. This was it's biggest/longest workout.

The Leigh Router support and Dust pickup did not work well with the plywood, but it was the fault of the plywood. There were chips and shards, some four inches long. They clogged the port and stopped the air flow. I did not notice it and kept on going.

The Vac has been working well since I cleared the hose and went back to my usual use.

Thanks for the help.

Re: Festool vac question?

Rick Christopherson

A blocked inlet presents a no-load condition for the motor, and that is why you hear the motor speed up. What could cause overheating in your situation would be the loss of exhaust air no longer circulating air inside your cabinet.

On a separate issue, you should consider opening up the cabinet some more, or at least providing an easier path for the exhaust air to get out without heating the whole cabinet. Because the vacuum motor compresses the air as it passes through, it will heat that air. This is also one of the reasons why they don't use vacuum exhaust air to cool the motor--it's already hot air.