Air diffusers on a 750a

Discussion in 'Direct Drilling Machinery' started by RFR, Oct 13, 2018.

  1. RFR

    RFR Member

    Seems like a few on here fit these air diffuser/brake type gadgets in the seed tube.
    Are they worth while? going to be doing a good refurb on our drill this winter and wonder if fitting them might be a good thing?
  2. Will Blackburn

    I can't see the need in my case.
  3. Tractor Boy

    Tractor Boy Member

    Personally I can’t see the need for them. When I’ve stopped the drill in work to check slot depth etc. I can’t find any seed that’s blown out of the slot with too much air. The seed tab together with the firming wheel seems to ensure that the seed has very little chance in blowing down and bouncing out of the slot.
    I must admit I don’t drill any really light seed such as clover or grass but surely just dial the fan speed down gives the same result.
  4. Fish

    Fish Member

    North yorkshire
    As ^ can't see the point, I have drilled beans to clover, never ever found much on top, just turn the fan speed down.
  5. RFR

    RFR Member

    Cheers Gents. Money saved!
  6. I asked a similar question couple of weeks back and I think people were saying it was possible to block pipes by dropping fan speed too far - I guess there is a point at which there is a balance
    Brisel likes this.
  7. Hasn't anyone read any of my posts ?
    H.Jackson, General-Lee and RFR like this.
  8. Will Blackburn

    I suspect that more air is required for big Aussie seeders. If there isn't trouble with blockage or bounce then surely that is enough?
  9. RFR

    RFR Member

    Yes, and they look a good way to do it if needed. Ours is an old 4m unit with the two piece seed boot. Which means a wider deeper trough for the seed. If we upgrade to the newer one piece seed boot then the same air and seed is going into a narrower therefore smaller opening, so wondered if it made a difference or if you just turn back the wind a bit. Wear on the seed tab will play a big part too I guess.
    Farmer Roy likes this.
  10. Bob lincs

    Bob lincs Member

    On the flat bit
    We use them on all of our drills , I’m not so sure now that they help with the seed placement but they are definitely very handy if you get a blocked coulter as you only get blocked from the coulter to the diffuser not the whole seed pipe .
    Clive and Farmer Roy like this.
  11. If you get a blocked seed boot, they soon let you know with the stream of seed & fert blowing out of the diffuser :)
    Clive likes this.
  12. Simon Chiles

    Simon Chiles DD Moderator

    I can understand that they might be useful on the very wide drills used elsewhere in the world but for the majority of uk seeders that are relatively narrow ( ie all the seed tubes are almost the same length ) then altering the fan speed is a better option.
    Sometimes increasing the fan speed can be useful, for example, when sowing grass I’ve never had a customer willing to pay me twice for drilling although they want to fill between the rows. In this instance I’d keep the fan speed up ( and not use the fan baffle ) so that about 75% of the seed remains in the furrow and the rest is blown over the surface. I know it’s a compromise ( ok a complete bodge ) but it keeps customers happy.
    Of all the 750 users in the uk I know who have fitted air diffusers at least more than halve, possibly 3/4 of them have taken them off after a relatively short time. Of course that may be down to the type of diffuser used and there may be better ones available, however personally I think they’re a waste of money when changing the fan speed can give you the same, or possibly better, results.
  13. Clive

    Clive Staff Member

    I think they are a complete no brainer and would fit them to any drill

    Once you have used them I think most would see the advantage

    Iirc the ones fitted to our drills from Weaving were not much more than £5 each

    They certainly do no harm and fan speed and seed placement and fan speed aside they are worthwhile for blockage spotting alone

    Not sure why anyone would remove a set ? There is no downside other than buying them
    Farmer Roy likes this.
  14. Fish

    Fish Member

    North yorkshire
    The thing about the smaller 750's, the 4/6m machines, is that once the seed leaves the mushroom, it only has a short distance to travel until gravity can take over, unlike wide air bars with multiple mushrooms and long horizontal pipe runs with many possible stall points, where air volume is much more critical.
    That's where air diffusers are a no brainer.
    Clive likes this.
  15. mushroom ? :ROFLMAO:

    distributor heads (y)
  16. Brisel

    Brisel Member

    Your diffuser would slow the speed of the seed as opposed to a Weaving one. Do you get much seed skinning?

    I like excess fan speed as it makes a tidier in/out at the ends of the field.
    Air diffusers seed.jpg
  17. Yeah, that's the aim, slow the seed down so it just drops into the slot without bouncing or being blown out.
    I have used ones similar to the Weaving, but found that they didn't release all the air & some small light seeds escaped out the exhaust.
    I normally like to run my air pressure on the low side ( less wear on hoses / pipes, lower power requirements, less noise etc ) but I also run blockage monitors on all the distributor heads which also let me know when flow starts & stops, makes it easy to judge the in / outs ( manual switch on airseeder )
    Generally, I like the air coming out of the seeder hose to be more of a strong breeze, than something resembling a leaf blower on steroids :)
    But hey, whatever works for you aye

    Pretty much standard here to be using a granular starter fert ( MAP sort of thing ) with the seed & it can be very abrasive, especially on any bends in your main primary ( 75 mm ) hoses, at higher air speeds.
    Seed "skinning" ? The only time I've noticed any seed damage has been with canola seed at silly high pressures.
    Other, "softer" or perhaps vulnerable seeds like sunflowers, cotton or soybeans we wouldn't use an airseeder anyway, but a precision planter with either vacuum or brush meters
    Brisel likes this.

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