Bruce Seidner
03-10-2012, 9:41 PM
I am building a Thien top that for the 1.5" duct from my power hand tools. The top hat will be "powered" by a vacuum motor because it just seems redundant to have a separate shop vac and I don't need another one and have no space in my small shop. So, the plan is to run the 1.5" duct from the tool to the top hat and I am curious what the thinking would be in terms of the size of the inlet.
For instance, one option would be to create a 4" rectangle inlet and use a round to round transition ahead of the top hat to transition from 1.5" to 4" round duct which would then transition from 4" round to a rectangle of a larger volume to create a nice column of air to drop through the slot of the Thien baffle slot. The top hat will be powered by a vacuum motor typically used in commercial shop vac's. I will make the top and bottom so that I can fit different height sides and experiment with the volume of the top hat. I am interested in seeing how this works.
So what does the group consciousness suggest in terms of the size of the inlet. The choice is native 1.5" or a more typical 4" inlet that has the transition accomplished in the duct prior to entering the top hat.
For instance, one option would be to create a 4" rectangle inlet and use a round to round transition ahead of the top hat to transition from 1.5" to 4" round duct which would then transition from 4" round to a rectangle of a larger volume to create a nice column of air to drop through the slot of the Thien baffle slot. The top hat will be powered by a vacuum motor typically used in commercial shop vac's. I will make the top and bottom so that I can fit different height sides and experiment with the volume of the top hat. I am interested in seeing how this works.
So what does the group consciousness suggest in terms of the size of the inlet. The choice is native 1.5" or a more typical 4" inlet that has the transition accomplished in the duct prior to entering the top hat.