Page 2 of 2 FirstFirst 12
Results 16 to 30 of 30
  1. #16
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    5,700

    Default

    Good to hear you have good flow.

    Watch out for sucking in stuff.
    As well as mangling stuff that is sucked in it can also mangle/unbalance the impeller and they can be VERY difficult to recover and then run at full speed.

    Unless you have the inlet well out of the way ie above head height I'd be putting a bit of mesh over the inlet.

    I use a 3mm thick x 25mm square SS mesh on my low down extraction inlets.
    Initially I used galv weldmesh but the grit abraded away the galv and then the steel rusted - every time i used it, the rust disappeared but then so did the mesh.
    BSandernew.jpg

  2. #17
    Join Date
    Jul 2006
    Location
    Athelstone, SA 5076
    Posts
    3,916

    Default

    Quote Originally Posted by OxxAndBert View Post
    Hooked up the larger of the 2 fans to a VFD tonight and gave it a run.
    It definitely moves some air at 50Hz. I also found it has a self cleaning function, as it also throws the small gum nuts, leaves and flaking powder coat of the impeller well clear of the outlet!
    At 50Hz it has enough suck on the 200mm inlet that when I placed my open hand about a foot in front it instantly sucked it against the edge of duct before I could react. Lesson learned, and scared the crap out of me.
    30Hz is still moving a fair bit of air - enough to flap the sleeve of my jumper when I put my arm above the outlet.

    Long story short, its got plenty enough suck for welding fume extraction - and will probably do a reasonable job on grinding dust too.

    Steve


    wire mesh over the inlet/s might be warranted...to prevent any large light stuff..like paper, plastic wrapping etc being sucked in and putting wheel out of balance..which could destroy wheel very quickly

  3. #18
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    53
    Posts
    1,033

    Default Welding fume extraction

    Thanks guys - will definitely mesh the inlet. Donít need a ďplease explainĒ over a missing grandkid

    Iíll need to find somewhere to source a 200-150 reducer too.

    Steve

  4. #19
    Join Date
    Jul 2006
    Location
    Athelstone, SA 5076
    Posts
    3,916

    Default

    Quote Originally Posted by OxxAndBert View Post
    Thanks guys - will definitely mesh the inlet. Don’t need a “please explain” over a missing grandkid

    I’ll need to find somewhere to source a 200-150 reducer too.

    Steve
    check out ductwork component suppliers..can get plastic or steel ones..metal dearer

    If steel they make to want you want and should be able to put a flange on one end for easier fastening to side of fan housing...

    Metalflex are in Geelong

  5. #20
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    5,700

    Default

    PVC reducers from 200 to 150 mm are pretty rare but reducers are very easy to make.
    On the input side it doesn't matter if it leaks - all the air is being sucked away.

    One of the nicer materials to make transitions out of is the SS from clothes drier drums.
    Here's a complicated one I made a few years ago.
    https://www.woodworkforums.com/f200/...-issues-204634

  6. #21
    Join Date
    Jul 2006
    Location
    Athelstone, SA 5076
    Posts
    3,916

    Default

    Quote Originally Posted by BobL View Post
    PVC reducers from 200 to 150 mm are pretty rare
    common in the AC industry BobL
    ADA Components 2019-20 (SA) 16.jpg

  7. #22
    Join Date
    Mar 2011
    Location
    Adelaide
    Posts
    384

    Default

    200 and 150 are common sizes in reticulation plumbing, generally for large stormwater applications. PVC reducers to mate them are also available quite readily.

  8. #23
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    5,700

    Default

    Quote Originally Posted by racingtadpole View Post
    200 and 150 are common sizes in reticulation plumbing, generally for large stormwater applications. PVC reducers to mate them are also available quite readily.
    I have installed lots of dust extractor systems for mens sheds using PVC stormwater / DVW pipe and fittings.
    Never seen a 200mm in either.
    Sizes are nominally 150, 225 and 300 mm.

  9. #24
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    8,452

    Default

    Quote Originally Posted by OxxAndBert View Post
    Iíll need to find somewhere to source a 200-150 reducer too.
    Know anyone with a 3d printer?

  10. #25
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    53
    Posts
    1,033

    Default

    Quote Originally Posted by Stustoys View Post
    Know anyone with a 3d printer?
    Now there's an idea....Just happens to be one chugging away in the next room at the moment
    Probably simple enough that I could even manage to draw it up myself too.

    I'll have a ring around and see if I can buy one off the shelf, but if I don't have any luck I'll give printing one a go.

    Steve

  11. #26
    Join Date
    Mar 2011
    Location
    Adelaide
    Posts
    384

    Default

    https://www.pureventilation.com.au/b...c-200mm-150mm/

    At $11ea I reckon Iíd be tempted to forget about the 3D printer

  12. #27
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    5,700

    Default

    Quote Originally Posted by racingtadpole View Post
    https://www.pureventilation.com.au/b...c-200mm-150mm/

    At $11ea I reckon I’d be tempted to forget about the 3D printer
    Thanks for the lead on that website - some interesting products there.

    RE: reducer
    I agree the price is right - the cost of 3D printer filament is something a lot of people forget about.
    Minor point but a tapered reducer would be less resistive to flow.
    According to the Loren Cookbook a stepped reducer of that area ration will reduce flow by the equivalent of adding 10m of ducting.
    Won't make much difference at AC air pressures but for fume ventilation it all adds up.

  13. #28
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    53
    Posts
    1,033

    Default Welding fume extraction

    Thanks for that website. Haven't checked out what their freight is like but the item prices seem pretty reasonable.
    They have this tapered reducer for a few more dollars too https://www.pureventilation.com.au/b...r-200mm-150mm/
    The black plastic reminds me of the cheap toilet plungers, but hey - if it does the job...
    One slight issue is that when I actually measured it, its 225mm. Nothing a bit of duct tape won't sort out.

    Re the 3D printing:
    I had a play yesterday in the background while I was "working" from home. Design was easy in Freecad, just a simple sketch and rotated, but I found actually printing something of that size and small thickness (1.6-3mm range) is a completely different animal to relatively solid items in the 75-100mm cubed range.
    I'd done a few test rings etc to get settings correct for the PETG that I was playing with, but left this one printing when I went to bed.
    I'll have one more crack out of PLA just for the learning experience, but I'm not confident.




    Steve

  14. #29
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    5,700

    Default

    I believe its called "my first blob", yes I've had more than one.

    Mine is too small to do anything useful and I leave it to my son who has several printers and knows how to drive them properly.

  15. #30
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    53
    Posts
    1,033

    Default Welding fume extraction

    Like waiting for a baby to be born, but finally itís here:



    Definitely pushing the build envelope for the printer!

    I wouldnít recommend it for something this size - not worth the time, filament etc if you can easily buy something off the shelf. I did it more from a learning perspective.
    If anyone is interested the filament was Sunlu PLA+

    Steve

Page 2 of 2 FirstFirst 12

Similar Threads

  1. fume extracting mig guns
    By meadow street in forum EBAY, GUMTREE, and other off forum sales sites
    Replies: 1
    Last Post: 9th Sep 2016, 11:33 PM
  2. Fume extraction - is this setup safe?
    By stu50 in forum WELDING
    Replies: 5
    Last Post: 8th Dec 2013, 08:30 PM
  3. Welding bay fume hood
    By BobL in forum METALWORK GENERAL
    Replies: 19
    Last Post: 4th Jun 2012, 11:58 AM

Posting Permissions

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