Page 1 of 2 12 LastLast
Results 1 to 15 of 18

Thread: Dust collection hood that fits? What cyclone separator to get?

  1. #1

    Dust collection hood that fits? What cyclone separator to get?

    I got my planer wired and working and now need to better setup my dust collection.

    The planer came with that massive hood. I added the reducers and try and use a harbor freight ď2hpĒ setup but the chips donít make it. Most collect around the sides.

    Iím getting a 2hp 220v grizzly dust collection motor and plan to mount it on the wall with a cyclone under neath. No brands have been picked. The super dust deputy xl looks nice.

    My questions: does anyone make or have ideas on a dust hood thatís half as tall? Canít seem to find anything.

    What cyclone should I use? Iím a one man shop and current setup has worked pretty well.


    Last edited by Lee Schierer; 04-19-2019 at 2:10 PM. Reason: fixed the title

  2. #2
    In the corner where the wood is, I was thinking about something like this.



  3. #3
    That is a large duct to be reduced down like you have it. Your air velocity in the tapered portion may not be high enough to move planer chips with a fan that moves only 1550 cfm.
    Lee Schierer
    USNA- '71
    Captain USN(Ret)

    My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Please Contribute

  4. #4
    Join Date
    Apr 2013
    Location
    Okotoks AB
    Posts
    972
    2 HP is smallish. As Lee said, you need enough velocity & I bet you'd need at least a 6" duct for that planer. If the 2 HP was right close the planer & you used duct rather than all that flex to connect it, you might be alright.

  5. #5
    I doubt changing from one 2hp DC to another 2hp DC is going to make much of a difference. Any claimed better performance from the Grizzly will be reduced by the extra drag of the cyclone. Keep in mind the CFM claims by DC sellers are approximately half in the real world. I can't tell from the picture how big the planer is but it looks like it is 20" to 24". If that is the case you are likely going to need at least a 3hp as a minimum preferably 5hp pulling through a 6" duct.

    I have to ask about the coil of flex hose in front of the bagger in the second picture. You are not trying to pull the planer chips through it are you? Flex hose has close to 3 times the drag of smooth pipe so that pile of hose could be equal to pulling the dust from the neighbour on the other side of the road. 4" hose only moves half to a third what a 6" hose can flow providing the DC is big enough.

  6. #6
    I assumed that large hood funneled down like I've down isn't ideal. I was thinking about capping it off and drilling a 4" hole but then didn't want to wreck that hood.

    I am using that flex hose and it works great for my table saw, 5hp sawstop, and 8" grizzly jointer. I'm just a hobbyist and unhook each tool for use. I'm in a towhnouse and not gonna here long so plumbing pvc didn't seem appropriate. Plus with the role up door, it's pretty hard to figure out how to run pipe and still be able to roll up the door.

    Planer is a 16" by the way. I was thinking about making a hood out of sheet metal with a 4" opening.

  7. #7
    Join Date
    Feb 2011
    Location
    Central WI
    Posts
    5,183
    Patrick, I answered over at owwm but a 4" port on that machine won't work well even with a larger diameter impeller. I tried it with an Oliver 399 and the long stringy shavings plugged up the port with a 5 hp Oneida blower. The hood is fine with a 15" impeller but those old planers have a poor design for DC so you need to be able to pull in the 1200 cfm range through a 6" port to effectively deal with the collection. Find a used bagger or cyclone - 3hp 14" impeller minimum and 5 hp 15" as ideal. Dave

  8. #8
    Quote Originally Posted by David Kumm View Post
    Patrick, I answered over at owwm but a 4" port on that machine won't work well even with a larger diameter impeller. I tried it with an Oliver 399 and the long stringy shavings plugged up the port with a 5 hp Oneida blower. The hood is fine with a 15" impeller but those old planers have a poor design for DC so you need to be able to pull in the 1200 cfm range through a 6" port to effectively deal with the collection. Find a used bagger or cyclone - 3hp 14" impeller minimum and 5 hp 15" as ideal. Dave
    I pretty much agree with Dave here.

    At one point in time, I too had a 1.5 hp 13" 2 3/4" tall blower. I retooled and rebuilt. With my 5 hp I do believe I'm pulling 1200 CFM through four-inch duct.

    Old machines, Need a lot of CFM.

    I've been playing with DC from my old tablesaw. At 1200 CFM there still seems to be some lingering dust below my blade. Next step for me is going to 5 inch instead of 4 inch. but... This really chokes my expectations for having 3 inch above the blade. I only have a 6 inch main trunk.

  9. #9
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    48,540
    I agree with the others...this particular machine needs a substantially larger source of air flow in order to properly collect from it. "Big iron" like that is typically connected to an industrial system that moves enough air to practically consume whole two-by-fours.

    ----
    Matt, it would be really hard for you to pull 1200 CFM through a 4" duct as that much air will not physically fit in it. The practical limit for 4" at normal velocities is about 400-500 CFM max. 6" will typically get you to 800-1000 CFM, give or take, at the same velocities. Some DC systems now have the ability to manipulate velocity a little to provide more optimal performance, but there are still no substantial gains for a given duct size. The area of the duct work absolutely matters relative to how much air it can physically accommodate at any one time. It's important to look at actual fan curves for a given system to understand how it might perform as the stated CFM in a machines's specifications is often "free air" and/or contrived for marketing purposes.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  10. I agree with the above and would add, if you take the hood off that planer and sent one board through it the chips are going to come straight off the back. The hood design should be straight out the back to use the directional discharge to your advantage..
    You also need at least 6" from the planer to the barrel.. anything less isn't going to work..
    As for the corners of the plenum, think of air like water.. your planer doesn't throw 1200cfm of air so where does that come from...
    I would make a new plenum and have a 1/2" hole in the corners to allow air to enter the plenum and supply that 1200cfm to the blower. You might have to make them even bigger.. This generates a stream of free flowing air to grab the wood chips coming off the planer and enter the air stream..
    Metal 6" from the hood to the cyclone.... a 24"-30" cyclone to handle the amount of chips coming off that planer..
    In making your hood.. plan a piece of 24" wide wood and watch the discharge, preferably from above.. the natural jet of chips will tell the pattern of the plenum.. by adding the artifical air stream to the plenum right next to where the plenum attaches to the planer, you have chip collection at the source.. Each to their own.... Best of Luck.. Denis

  11. #11
    Join Date
    Feb 2011
    Location
    Central WI
    Posts
    5,183
    I'm not sure you would need additional holes in the plenum. Those old planers allow so much air, it works better to put some flex strips over the outlet so the board passes through them but they shut down air intake from the backside which allows more from the inlet side. Cyclones designed for 1200-2000 cfm will be in the 18-20" diameter range. Larger cyclones need a lot of height and a long cone so you need 12' ceilings and more cfm if you go that route.

    Matt has a special impeller he made that pulls cfm at higher pressure than most. My system will pull over 12000 fpm velocity so I can get 1000 cfm through a 4" port. That is measured with an anemometer so I assume the reading is a little high but no curved blade impeller less than 17+" will deliver near those numbers through 4". You want a 6" port in the 16" planer. My newer 20" SAC needs much less cfm than my old planers of similar size. Dave

  12. #12
    Quote Originally Posted by Jim Becker View Post
    Matt, it would be really hard for you to pull 1200 CFM through a 4" duct as that much air will not physically fit in it. The practical limit for 4" at normal velocities is about 400-500 CFM max. 6" will typically get you to 800-1000 CFM, give or take, at the same velocities. Some DC systems now have the ability to manipulate velocity a little to provide more optimal performance, but there are still no substantial gains for a given duct size. The area of the duct work absolutely matters relative to how much air it can physically accommodate at any one time. It's important to look at actual fan curves for a given system to understand how it might perform as the stated CFM in a machines's specifications is often "free air" and/or contrived for marketing purposes.
    Maybe I am off a little bit. I have a 6 inch main spiral duct branching off to a 5 inch blast gate. I have a 5 inch flex hose that clamps the OD of 4 inch PVC 90į elbow. The inside of that elbow I believe is only 4 inches. It steps up from that elbow into the bucket and into an 8 foot long X 10 1/2 inch ID Sono Tube. So it is restricted to 4 inches just before the machine. Watch the video and tell me what you think.

    https://www.youtube.com/watch?v=SB9Bt23iYBY

  13. #13
    Matt here is a link to a paper that talks about the correction factors that have to be considered when using a fan type anemometer you showed in your video. They also mention that the readings should be taken in the test duct 7.5 diameters from the opening or a change in the pipe to get acceptable readings. You'll need to cut a port in the middle of the Sonotube to do that. The fan anemometers are accurate measuring in the middle of a large opening like a doorway but when the opening gets smaller the instrument reads higher. So your readings are about 20% high, possibly higher. So 1200cfm corrects to 960cfm. I have no doubt your cyclone probably pulls as much as possible through a 4" duct because your fan is so efficient, I don't think it is as much as you believe. Your 5hp impeller on a bad day will outperform the OP's 2hp by a lot. Even if he uses smooth pipes and waxes them he won't be able to keep the chips clear from that planer as long as it is through 4". Even a 6" pipe may not keep up with the 2hp DC pulling on it. As I pointed out the long hose he uses, while convenient, is killing his suction.

    https://www.cdc.gov/niosh/mining/use...dfs/ri9061.pdf

  14. #14
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    48,540
    In addition to Peter's comments, there's also a small "venturi effect" where the diameter knocks down right at the end. You need to measure the actual duct work farther in as Peter mentions for greatest accuracy. But you do have a substantial cyclone system and it's going to pull a lot better, even in "less than ideal duct work situations" than the typical small 2hp mass market dust collector.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  15. #15
    How would this setup do instead of the wall mounting idea? Assuming I use 6" hose or pipe now which I plan to. This would be a much faster setup. Just a matter of swapping in my grizzly 2hp motor and adding a dust deputy/cyclone.

    What cyclone would be best? There's the Super DD XL 6", rated 3hp-5hp and the plastic or metal 5" rated up to 3hp.



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •