Garden Swing

  1. eSCHEn

    eSCHEn Bit Wrangler Staff Member

    Messages:
    5,906
    Location:
    SW Scotland
    It's a friend's child's birthday coming soon and I'm going to make a swing for him that will live in their garden. It will be a repeat of one I made four years ago that is still standing well. There'll (hopefully) be a few improvements along the way. Rough idea is a metal ridge tube and wooden 'A' frames on each side. The bottom of the frames' legs is braced using another piece of wood. Here's a picture of the previous one I made in all its filthy glory.
    WP_20190417_15_48_42_Pro.jpg WP_20190417_15_49_11_Pro.jpg

    The OH wanted to use that weird basket thing and it rotted out last year. I'll need to make something more robust to replace it but that's another swing for another time ;)


    First step was to acquire some tube for the ridge. As always, I like to over spec to make up for my engineering shortcomings :) Shout went out in the wanted section and @slim_boy_fat sorted me with some old scaffolding tube with a nice thick wall :thumbup:
    WP_20190417_15_58_31_Pro.jpg WP_20190417_15_58_55_Pro.jpg
    Diameter is 48.5mm with a 3.5mm wall. Raw length is 1335mm.

    Now in the first model I used what I had – obtainium. I'd recently done a bit of skip rummaging (with permission) and recovered some bits from office furniture which made up a leg of sorts. I welded two of those end-to-end to get the length I wanted and that formed the internal span. I inset the swinging brackets to match the basket width below and provide clearance.
    WP_20190417_15_49_51_Pro.jpg WP_20190417_15_50_02_Pro.jpg

    One of the improvements I want to make is form a cover over these exposed end grains. Even though they are still completely sound I would still like this new model to have permanent protection.
    WP_20190417_15_50_29_Pro.jpg


    This time I'm fresh outta luck and office furniture so I must fabricate (lol at my bodging being called fabricate) from scratch :welder:


    New post to reset the image limit :)
     
  2. eSCHEn

    eSCHEn Bit Wrangler Staff Member

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    Location:
    SW Scotland
    I've put together some rough CAD in my spare moments (which sadly are not many) and I've had a really kind offer from a forum member for some time on their CNC setup so my plans are geared towards that process.

    The member's stock of mild in 5mm+ (my design request) is 8mm so I guess it'll be… 8mm ;)

    First part is the endplate. There are four of these of the same flattened triangle design. Mounting hardware is all M10 and I try to keep the fitting selection to a minimum to make life easy and sometimes you can save a wee %age on larger quantities :whistle:
    endplate.png

    Dead tree stock is CLS 89mm x 38mm in 2400mm lengths. I use this size as that's what was in the first and it's available locally in straight pieces :thumbup:

    With the main part of the structure sorted and planned out in rough I am moving on to the hangers for the swing. In the first incarnation I knew the use would be light in terms of actual swinging as it was more of a garden seat in operation. This time I'm aware it's going to get a lot rougher usage so I'm going to overdesign the system somewhat but meh, if you can't overengineer a swing then what can you? :D

    Scouting about the 'net there are a few sort of 'systems' in use. Simplest is bare metal to metal and progressing to a sacrificial plastic bearing or even bronze bearings on heavier loads. Poshest of all are the marinized ball-bearing sets with twingingly boaty prices :o

    This time I'm going to make use of the CNC possibilities whilst trying to keep to the KISS philosophy. As my stock will be 8mm then it would be trivial to bore out a place for a simple ball-bearing set to sit inside. Checking the common 6000 series bearings shows that the largest shaft I could accommodate in an 8mm maximum thickness would be 12mm in the 6012 form at 12mm x 28mm x 8mm. I'd again hoped to oversize the shaft to 20mm as that's what seems right to me but checking the calculations shows a 100mm long shaft in 12mm would deflect under 0.5mm for a load that the bearing would max out at in terms of static load. That'll do for me as that's a loading of over 2500N :)

    Well that was my idea until I spoke to @Hood and he pointed out that it would be much easier to machine the acetal hanger in the middle and that's how he does his. Seeing as it eliminates two more bits and he's a smarter-than-your-average-bear sort of fella I figured his idea a lot better :D

    Here's a picture of the CAD for the hanger in exploded view.
    bearing-hanger-60012-cad0.png

    And here it is assembled.
    bearing-hanger-60012-cad1.png

    I did have in mind to do some 3D renderings but I just can't get the tooling to play nice and because I've been so busy it's taken me longer to write up this draft than I wanted and the parts are now made so no point doing a rendering of reality >_<

    This brings us, more or less, up to date. I've got to order the bearings and am thinking some Loctite 243 to stop the endcap bolts coming loose from the repeated motion. The rope will be 20mm synthetic sisal or hemp and I'll splice eyes in both ends and stitch or whip to give me a bit of won't come loose confidence given it'll be rough play :)
     
  3. pedrobedro

    pedrobedro Man at Matalan

    Messages:
    10,445
    Location:
    CX Derbyshire
    This reminded me of something I saw about a tree swing designed by a committee.
     
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  4. gaz1

    gaz1 Forum Supporter

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    westyorkshire
  5. eSCHEn

    eSCHEn Bit Wrangler Staff Member

    Messages:
    5,906
    Location:
    SW Scotland
    Well it's been a while and I thought I should update this thread with progress :)

    The CNC parts that @Hood kindly did for me arrived in my grubby mitts. The mill scale needs removing around the bits I'll be TIGing so I figured it's as easy to do the lot in a batch using citric. 10 minutes at low simmer is just about right.
    post1-1.jpg

    Came out lovely. The eagle-eyed amongst you will see the milled recession in two of the plates, this was just a dashed line on my drawing to remind me of the tube's location and not to foul any spannering with it. Hood very smartly milled into the meat a couple of mm to give me place to centre the tube onto :thumbup:
    post1-2.jpg

    As usual there's no space to work that is flat and out of the elements so it's back in the front room for some TIG action :weld: First get everything lined up and use a wee vice to hold it all up square (ish :D ).
    post1-3.jpg post-1-4.jpg


    All tacked up.
    post1-5.jpg post1-6.jpg


    No putting it off any longer, gotta get them joints fused. In all their scabby glory to behold :D
    post1-7.jpg post1-8.jpg post1-9.jpg post1-10.jpg



    That's what not practising regularly gets you but I'm happy with the fusion, which is the point of the affair I suppose :)
     
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  6. eSCHEn

    eSCHEn Bit Wrangler Staff Member

    Messages:
    5,906
    Location:
    SW Scotland
    Dead tree bits ahead!

    Using the endplates as a template I marked out the drill points for them. The end cuts are to allow the legs to come together when erected. Again the measurement is from the endplates. Haven't shown the drill points for the bottom and cross-craces but it's more of the same. Essential supplies are included in shot :D
    post2-1.jpg


    Rough frame up.
    post2-2.jpg

    Didn't bother with interim photos as, well, they'd be dull. Here's the frame assembled up.
    post2-3.jpg post2-4.jpg post2-5.jpg


    Now the bit I hate most - painting :( However, the OH was feeling guilty about not contributing to this joint gift that I am making so she volunteered to do it and I am not going to say no :D :D :D Helper JRT#3 in shot and she looks lovely with that paint all over her, which it was despite trying to keep her off it lol.
    post2-6.jpg post2-7.jpg

    I never got any shots of the metalwork being painted but I used Jotun 87 as a primer and then went over with some unknown blue that smelt great and a rattle can of red.
     
  7. eSCHEn

    eSCHEn Bit Wrangler Staff Member

    Messages:
    5,906
    Location:
    SW Scotland
    Quite a while went past here as busy lives on all parts got in the way of delivery :( But we finally got a chance to go and visit the wee man this swing is for and get it built up. Good job he's too wee to realise it's three months late on the birthday deadline ;) :whistle:

    Was a lovely trip up through some stunning scenery but most importantly of all though... HE *LOVES* IT :D YAY! Out of all the problems and hazards I'd tried to think of though I hadn't considered the one that happened - greeting when he had to be taken off the swing for dinner :ashamed: He insisted on a go after dinner as well and wasnae happy going to bed either :D I dunno but that's a win sort of isn't it? :)
    post3-1.jpg
    post3-2.jpg


    Properly lovely sunset on the way back. OH couldn't be restrained from taking a shot of her baby :sigh:
    post3-3.jpg post3-4.jpg


    BTW Mam and Dad are smart cookies and manage the wee fella's social presence very well as they know when it's out there then consent is gone forever and that's only for the young fella to decide when he's older. TLDR; no child in pictures just a weld-inspecting dog.
     
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  8. slim_boy_fat

    slim_boy_fat Forum Supporter

    :thumbup:
     
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  9. Hood

    Hood If it walks like a duck....

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    Location:
    Carnoustie, Scotland
    Looks great, thankfully you got it done before his 21st :D

    Oh and the Snack Beard District sign looks good too :D
     
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  10. MCKDAVID Member

    solid looking mate, nice one......:clapping::clapping::clapping:
     
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  11. magnet

    magnet Member

    Messages:
    619
    N E UK
    Epic stuff .........Nice one
     
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  12. barking mat

    barking mat Barking at Pigeons

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    Brittany, The Arz Valley.
    Over engineered, lovely!
     
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  13. barking mat

    barking mat Barking at Pigeons

    Messages:
    3,216
    Location:
    Brittany, The Arz Valley.
    Plank with hole in middle, rope, big knot.

    My style.
     
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