Anyone open up their HF DC to a 6" inlet on the fan housing and have cfm data?

[Kooshball]

I am considering opening up the inlet on my HF dc to a 6" inlet but I am concerned that at this size it might be too big for this machine.  Has anyone tried this and is there any cfm data to proofs that it moved more air?

Thx

[polarys425]

If i had a way to measure the CFM's i could tell ya.....

[Don_Z]

I have the HF model and the best advise I can give you is DO NOT OPEN IT UP. I did and had to re-fabricate a new part to put it back to 5" because the drop in performance was immediate and horrible. I purchased the machine out of the spirit of doing the whole Thien experiment from scratch and didn't really care if I failed then all I would be out was a cheap $150.00 vs buying a $800.00 Powermatic or something. For the HF model, you have to design everything around a 5" system because of the smaller impeller. My next build will be either off of a Powermatic or Grizzly ( I don't have the space for a cyclone just yet.)

[Kooshball]

That is what I was afraid of. I assume that there is an ideal ratio of inlet diameter to impeller diameter and given the size of the one that is on the HF, I wast sure of 5" was the max...

Thx

I will probably just install the thien baffle and leave it alone at 5" until it breaks and/or I can justify a mobile 3hp cyclone.

[polarys425]

I've read conflicting information on this......

I made a new 6" takeoff for the impeller housing for mine, and kept the original 5" opening plate intact. I couldn't find 5" pipe when i did my ductwork.

I'll have to test it sometime.....

[Rick T]

There was a thread here  http://www.jpthien.com/smf/index.php?topic=470.0 earlier this summer on the impeller size on HF units. I don't know that there was any conclusion reached other than HF impellers aren't all the same and in some cases the Griz impeller, which can be ordered, may work but it isn't cheap. Seems it's sufficient to move a suitable volume of air to support 6" pipe. It's 12 3/4" dia. radial fin design.
I don't have either of these units so no personal experience with either. Just info.

[Don_Z]

It's a 9.75" impeller.

[dbhost]

It's a 9.75" impeller.

Depends on the specific model. My #97869 impeller measures out at 10.5"