Festool Owners Group

FESTOOL DISCUSSIONS => Festool Tools & Accessories => Topic started by: Mythic on May 04, 2021, 04:43 PM

Title: CT MIDI (2019+) clean function.
Post by: Mythic on May 04, 2021, 04:43 PM
Hey everyone,

I have a CT MIDI and a CT36AC. I’ve started noticing when using the semi-auto filter cleaning function on the MIDI (covering the hose, pressing down the lever) dust blasts out of the outlet ports of the vac. I never really thought about it, but I never noticed the same with my CT36 in the AC cycles.

Is this normal with your MIDI devices? The more I think about it, it seems to make the HEPA certification useless. Is there an issue with my MIDI/Filter?

Thanks in advance.

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Title: Re: CT MIDI (2019+) clean function.
Post by: Magpal on May 26, 2021, 02:31 AM
I have the same issue with my MIDI. I have never used an semi-auto vac before, and therefore just assumed that this was normal, although a bit dissapointed by the behaviour. Would be interested in knowing if this is a trade-off only for the semi-automatic cleaning or if this is inherent to the cleaning function.
Title: Re: CT MIDI (2019+) clean function.
Post by: mino on May 26, 2021, 05:04 AM
This is normal.

You are supposed to only very shortly push the level to give the bag a bit of a shake. Not to keep it pushed.

Also, the effect on the main filter is severely limited - you need a proper cleaning mechanism like on the CT 26/36 AC series for that.
The manual clean is mainly to help de-clog the bag which does not need much besides a bit of a shake.

If you have an AC vac, you can notice the cleaning action is just very short "bumps". Short-enough that the air stays in the vac/hose.

I do not believe it makes much sense to close the hose when manual cleaning. It will increase the effect but that is questionable to me.
It will anyway not clean the main filter "enough" and for bag de-clogging a short shake with an opened hose is enough.