5" to 6" intake modification?

[Carpenter Mark]

Hello everyone,
First, big thanks to Phil for this site and for sharing his design;funny how you don't realize what you're missing till you stumble upon it, I was looking at cyclones when I found the link to here. I haven't built my separator yet but I'm looking forward to it.
So far I've ordered a Wynn filter kit and have gotten my barrel(s) together. I have a Grizzly 2 hp 1029 DC with a 5" inlet(12" impeller) and I'm planning on expanding my system using 6" pipe. I was wondering, would it be advisable to cut out the 5" tube on the inlet cover and increase it to 6" and do the same on the outlet?.  Would this decrease the blower performance?

[dbhost]

Folks do something similar with the Harbor Freight DCs... However they simply replace the impeller cover / inlet with a plywood, or MDF cover with a 6" S&D nipple for an inlet port. Your Grizzly should perform a bit better due to the larger impeller...

[Carpenter Mark]

Yes, I've seen that modification. I've been wondering how critical the inlet to impeller ratio was to cfm; if I increase the volume will I lose too much pressure or would it be the same as choking it down 6" to 5" after the separator-which I plan on installing upstream of the dc. I have a buddy who's a tinknocker right down the street so the metal work will be easier. I guess just trying it out  might be an option too. ( I too get glassy eyed when the engineering math gets heavy. ;) )
The reason I ask about this is that I plane a fair amount of soft maple. The chips are usually long,curly and straw-like and they tangle up in 4" flex pipe( which I have a 3' piece of from my planer to the 5" trunk I have now) fast if you don't keep the air moving pretty quick. It's why i think I might make the drop slot in the separator a full 1-1/2" too.

[dbhost]

How much flex hose are you using? Each rib in the flex hose is a loss of air flow, so the more you use, the more you lose... You might actually try making the run with 4" S&D and see how that works for you, Doesn't have to be a dedicated system yet.

FWIW, I am using 10' of 4" flex and plane a LOT of maple, walnut, and cedar, only issue I have had so far is sucking up a plastic bag that managed to bypass the baffle, continue on to the impeller and get stuck at the cross piece in the inlet...

[bridger]

The chips are usually long,curly and straw-like and they tangle up in 4" flex pipe( which I have a 3' piece of from my planer to the 5" trunk I have now) fast if you don't keep the air moving pretty quick. It's why i think I might make the drop slot in the separator a full 1-1/2" too.

maybe consider a separate collector bin with the wider slot for the planer . position it as close to the planer as you can and with only smooth wall pipe between. that way the main separator can remain with the small slot so you still catch the fines from other machines. you will get a performance hit at the planer, but it will be at the planer only.

[Carpenter Mark]

My Grizzly is an older model with a 5" intake, 12" impeller. When I plane 6-8" wide maple, the chips will often come off the stock the full width of the stock being planed; when a 5-6" long chip gets turned in a piece of 4" flex(only 3' long), it can clog even when it's the only machine on the system. I'm running a Powermatic Model 100 and considering having my tinknocker buddy make me a 5 or maybe a 6" hood for it,so that's why I asked about pressure loss with increased volume.
BTW, it seems that a newer model 6" intake plate fits the older models so I won't have to make one. Read about it on the 'creek.

[dbhost]

If you've read my post, "A reminder the baffle doesn't get everything." at http://www.jpthien.com/smf/index.php?topic=302.0 you will see that I have had a similar problem with certain things such as shopping bags getting into the system, bypassing the baffle, and jamming the DC up, causing a HUGE drop in flow... Don't stop up the flow through the system, or it will sort of suck everything where you don't want it...

Full width planer shavings shouldn't be a problem if you start out clear. Full width, or even partial width planer shavings are a real pain in the neck if you have a trash bag where it doesn't belong...