# Improved Zero Clearance Insert for Tablesaw



## Sideways (1 Aug 2019)

Sharing an idea that I think is simple but innovative (at least to me).
A DIY woodworker from the Netherlands has improved the simple MDF zero clearance insert for his tablesaw to give better dust extraction.
He has a youtube channel H.O.W. "Hooked On Wood" so I'll let him speak for himself :
https://www.youtube.com/watch?v=0boQ01NF508


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## Droogs (1 Aug 2019)

interesting and easy to make. will give it a go and subscribed to see what else he comes up with.


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## Rorschach (1 Aug 2019)

Sort of what I did on my insert, expect that I just drilled a load of holes in it. I think it helps with the dust extraction.


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## AjB (29 Sep 2019)

I did exactly this and it worked great!


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## transatlantic (29 Sep 2019)

Not sure I understood what he meant at the end of the video in regard to better extraction within the cabinet itself. I thought you wanted to seal up any air vents to improve extraction? not create more air vents?


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## Simon_M (29 Sep 2019)

transatlantic":7pqsp5ni said:


> Not sure I understood what he meant at the end of the video in regard to better extraction within the cabinet itself


He shows that you need to let air in from above, for his extraction to suck dust out of the cabinet. If you run a table saw with a blockage, you quickly realise the importance of not blocking the airflow. Not everyone has a hood as effective as his above the saw blade.

His approach is very scientific and he shows by example what works. You could also clear the dust in the cabinet by stopping the saw and removing any insert and running the saw again but the extra holes let in sufficient air to allow a good airflow as shown by the video.


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## Inspector (29 Sep 2019)

You can't pull air out of a machine if there is none replacing it. Ideally there should be at least two to three times the area going in as out. So a saw cabinet with a 100mm duct (380 sq mm) should have openings totalling 760 to 1140 sq mm.

Pete

Note the math error. Should be 7,854 mm2 with openings totalling 15,708 mm2 to 23,652 mm2. See below.


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## transatlantic (29 Sep 2019)

Ah interesting.

I always thought that these machines would have plenty of gaps in the construction and if anything, you'd be trying to seal them.

Always learning!

Sent from my SM-J510FN using Tapatalk


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## Steve Maskery (29 Sep 2019)

Inspector":qupdhlw6 said:


> You can't pull air out of a machine if there is none replacing it. Ideally there should be at least two to three times the area going in as out. So a saw cabinet with a 100mm duct (380 sq mm) should have openings totalling 760 to 1140 sq mm.
> 
> Pete



A 100mm diameter duct has an area of 7850mm2 not 380...


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## Inspector (29 Sep 2019)

I sit corrected. :roll: I shouldn't do metric math before my morning cocoa especially when I usually use Imperial. :wink: Edited the post to add the corrected values.

Pete


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## DBT85 (1 Apr 2020)

A small bump with an updated video and him actually building one and showing more detail on why it works better.

https://www.youtube.com/watch?v=R3K3RKn7yis


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## Steve Maskery (1 Apr 2020)

Very good in many respects, good job.
I don't use DX on my TS, mainly because my little extractor doesn't make a lot of difference. I let it build up and then shovel it out. Not the best idea, I know. I think he must have a rather more powerful DX system than I do.
Full marks for raising awareness of the importance of this.


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## DBT85 (2 Apr 2020)

He's "only" running a 2hp dx so not terribly huge.

The whole thing is an interesting point that I think most overlook. We think we need to seal up the gaps and focus all air flow through that slot area and it ends up choking the vac no matter the power.


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