Baffle Clearance for Center Pipe

Started by Hobkirk, September 14, 2008, 12:08:00 PM

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Hobkirk

I am finally doing this - I solved the damning issue of where it can fit. I have a Sears 16 gallon vac and a 20 gallon can. I made a special trip to Rockler to get the nice fittings (worth the hassle - thanks). I have some 2" PVC pipe and an elbow. I've routed and am waiting for the paint to dry. All is wonderful. Except...

I've been watching your progression for quite a while. Your front page is much more effective since you added the new illustrations and the more detailed design specifications. But what happened to your center pipe, Phil? It used to reach near the baffle, and it appears as though it might be completely gone now. I am interested in catching as much as I can, including fine dust, so it seems like close to the baffle would be best, but you are the man! What do you suggest?

Thanks for being such a dedicated nut case - people like you make the world a vastly more interesting place.

What's your PayPal address?

PS - You could start other forums for your other projects, like the controversial doweling jig, one for particle measurements, etc. One forum for each project.

PPS - Is it possible to determine that the catch can is full w/o looking? Does suction drop off? Does noise change? Do I need to add a window to the can? Thanks

Hobkirk

#1
I used a center pipe protrusion of 1.5" and about 1/4" clearance from the 2" inlet elbow to the baffle plate - should it be tight?

I plugged everything in and turned on the vac, located in a lean-to shed on the other side of a window. No extra noise, no fuss - just the baffle lid pulling down a little. Seems like about the same level of suction. HOORAY!

I sucked up 1-2 # of sawdust, mostly from sanding. All the bigger debris and most of the very fine dust stayed in the baffle can, but there was still enough to lightly coat the filter and sides of the 6.5HP Sears vac. REALLY COOL! Now I can radically decrease the number of trips to the vac itself (outside in the shed).

QUESTION: Is there any way to decrease the fines getting to the vac? Smaller/larger baffle width? Longer/shorter center pipe? Baffle tight against elbow, even shaving the bottom of the elbow for the tightest possible fit? Shape the outlet on the elbow?


THANKS! This baffle is very, very impressive! It took quite a while, but I am green - this was the first time I cut circle dado or cut a circle using the router. And painting the lid took time (2 coats on top, 1 on bottom, very damp weather).

phil (admin)

Toss a bag in the vac to control the super-fines that get through.

Also, you can experiment with a flexible diverter to reduce short circuiting of fines.  This is a small piece of flexible plastic that goes between the inlet and outlet and helps the incoming debris enter the cyclonic rotation without getting a chance to short-circuit right into the outlet.

But I find that using the bags in the vac is my preferred solution especially because when using tools with small ports (like the 1" on my sander) that there is never going to be sufficient airflow to separate out all the fines.

phil (admin)

Quote from: Hobkirk on September 14, 2008, 12:08:00 PM
I've been watching your progression for quite a while. Your front page is much more effective since you added the new illustrations and the more detailed design specifications. But what happened to your center pipe, Phil? It used to reach near the baffle, and it appears as though it might be completely gone now.

Poor photo, so it doesn't show up.  I'm going to need a better photo and I may put some SU art on the page.  But I'm so busy at work I'm not getting much of a chance to get any of this done.

Quote from: Hobkirk on September 14, 2008, 12:08:00 PM
I am interested in catching as much as I can, including fine dust, so it seems like close to the baffle would be best, but you are the man! What do you suggest?

I like a little space there, yours is perfect.  Without it some stuff with catch between the baffle and the inlet and eventually accumulate.

Quote from: Hobkirk on September 14, 2008, 12:08:00 PM
Thanks for being such a dedicated nut case - people like you make the world a vastly more interesting place.

What's your PayPal address?]

That would be phil (at) cgallery (dot) com.

Quote from: Hobkirk on September 14, 2008, 12:08:00 PM
PS - You could start other forums for your other projects, like the controversial doweling jig, one for particle measurements, etc. One forum for each project.

The controversal doweling jig, I LOVE IT.  I have a name for it now.  LOL.

Quote from: Hobkirk on September 14, 2008, 12:08:00 PM
PPS - Is it possible to determine that the catch can is full w/o looking? Does suction drop off? Does noise change? Do I need to add a window to the can? Thanks

The suction doesn't drop off much, no.  When I first started my prototyping I was checking it very often to see how it was working.  But then I did a couple of projects where I wasn't concentrating on it and I did fill it a little over the top of the baffle.  Still very little made it through to the vac because I caught it just in the nick of time in both instances.  There are some designs for photo-based sensors for cyclones, I don't see why one couldn't be adapted to the separator lid design.