design questions

[CRD]

Hi Phil

I found your site from surfing the Canadian Woodworking site. Great stuff here Phil, nice work! I'm currently working on a new shop in my basement and will be incorporating your ideas eventually.

I have a couple of questions regarding design.

1. I see the outlet pipe in the center always extends down below the lid. Why is that and is there an optimum distance? Is this distance related to the diameter of the pipe?

2. I was thinking that if this pipe were flush with the bottom of the lid and a cone was mounted on the baffle directly below the outlet it may improve flow. The cone could be plain, with straight sides, or even have a curved side to promote the sharp turn in the airflow required to exit the can. Have you tried anything like this?

TIA
Claude

[phil (admin)]

Yeah, you absolutely need an outlet tube.  Anything around 1" to 1.5" is fine (I just use a coupler that I remove the inside ridge from using my router table and a flush-cutting bit).  Without the tube, the outlet port is directly coupled to the top, and it ends up working sort of like a funnel.