Page 1 of 15 12311 ... LastLast
Results 1 to 10 of 142

Thread: Norman's Jib Crane adventure

  1. #1
    Join Date
    Apr 2012
    Location
    Sydney
    Posts
    498

    Default Norman's Jib Crane adventure

    If all goes to schedule then by end of the week, on the slab in the first image, there will be an erected shed.

    Who would have thought that such a simple thing could take so long in the planning and execution. It has been 2.5 years near enough; I engaged the certifier to work thru and attain the DA in November 2014.

    Anyways a "shed in the flesh" is close; time to get real with what happens on the inside. Not all the space can go to my toys as the business will need some ... but I do plan to get a fair share.



    I expect pretty quick I will shuffle all the big kit in and commence the game of tetris to find best slots for stuff.

    High on my agenda is a Jib Crane. My thinking is that the Jib Crane would be best positioned at the intersection between the bays ... pretty much at the stool that is pointed to by the arrow in the first picture.

    The shed is 8 meters wide x 12 meters long spread over 3 bays; so a Jib Crane with span of 4 meters does cover near two thirds of the area.

    Plan is the base of the Mast will be bolted to the floor and the top of Mast to the roof joist that divides two bays. In this design the whole mast swivels.

    My understanding is that the swivelling mast design also places the least stress on the building structure. Regardless, I am going to limit myself to 200kg max ... and could even go for less. The loads will essentially be chucks, dividing heads, milling vices and the like. Most of those are less than 30kg.



    A straight Boom will sweep most of the area but will miss access to the shed corners by 1.5 meters; hence am open to considering the Hinged Boom style.



    Hinged Boom Jib Cranes seem not to utilize the running gantry of other styles; instead have a fixed mounting point for the load at the end of the mechanism. This does mean that the load is effectively always at the end of the Boom; plus there are now twisting forces on the Boom.



    Comments and guidance welcome.

    Have not yet gotten a clear picture of the sizes of the materials required. Do have a couple of lengths of 150mm x 165mm W flange beam;
    think that is the correct term as it has little flare where the plates join; they have 7mm plate thickness top and bottom and 10mm width in the joining plate.

    Was thinking a deep groove roller bearing (say 40mm inside diameter) for the top of mast and a tapered roller bearing from 4WD (also about 40mm inside diameter) for the bottom of mast. That said, most of the commercial designs seem to use bronze bushes with a bronze thrust plate at the base. My concern with the taper roller at the base is that the Mast may "climb" up and out of the cup; I could put a longer shaft in to "catch" this should it occur; but if it is a risk then maybe the parallel shaft to bronze bearing is the better way to go.

    Norman

  2. #2
    Join Date
    Jan 2010
    Location
    Kansas City area
    Posts
    4,967

    Default

    I would build the straight boom, put the mill in a corner, the lathe along the wall where the boom comes tangent, and storage on wheels in the other corners. Then you can roll out the lathe chucks, rotary table, ect. to where the crane can pick them up and the machines will be in the reach of the crane.

  3. #3
    Join Date
    Apr 2012
    Location
    Sydney
    Posts
    498

    Default

    The straight boom approach is certainly simpler.

    As I push on with it all I am comming to the realisation that not all the width (and height for that matter) is available for a fixed length straight boom to rotate within.

    The framing and cleats that join them need to be taken into account. The image below shows cleats on the edges that are angled across the C150 members; those MIGHT be only for the end rafters. The inner rafter cleats at the sides MIGHT have a "knee cleat" that sits fully within the C150's ... the doco is not clear on this, but if so, that would assist some for a fixed swing.

    If there is not at least 2.5 meters under the jib there is need to start placing kit and storage away from the swing.

    Here are some heights of the taller stuff.
    2.5 meters for Bridgeport Interact 4 mill
    2.2 meters for Konkia FV1 mill
    2.0 meters for most cabinets; though I do have some that are higher

    Shed is 3 meters high at the eve. Deduct 150mm for the beam; possibly another 90mm for the battens that sit under the roofing iron; then around 165mm for the Jib Boom height; allow say 45mm for clearance above the boom and 50mm below and our 3.0 meters is reduced by 500mm ... dang close.

    The hinged version may alleviate some of that height and depth stress. The main boom can sit above the 3 meter line (as it is in the pitch of the roof) and the hinge can "step around" the low hanging shed rafter when need be.



    Am seeing that there are cheap enough (like $8 each) 40mm thrust washers inclusive of what I presume are hardened running washers. A SKF 40mm deep groove bearing can be had for around $20 each. This is looking more like the solution for the Mast.

    Norman

  4. #4
    Join Date
    Oct 2002
    Location
    Bremerton Washington
    Posts
    5,643

    Default

    That swiveling extension is gonna play hell with the jib boom. I beams don't resist torsion very well. Besides, 100 Kg? Well within dragging range.

    How are you going to resist overturning moments on the mast? Is the shed structure stout enough? Corner to corner wire vangs? Struts?

    Have you considered a bridge crane? Wall to wall to door reach and no mast to clutter the center. Maybe raise the walls o allow 4 meters under the hook?

    100 Kg seems hardly worth it. I suggest at least a tonne.
    Last edited by Forrest Addy; 04-17-2017 at 11:56 AM.

  5. #5
    Join Date
    Jan 2010
    Location
    Kansas City area
    Posts
    4,967

    Default

    Now would be the time to spec higher sidewalls if at all possible. Remember, a chainfall or any type of hoist has considerable height before you can attach anything. I would want 4 meter sidewalls at the least. My shop ceiling is 10 ft. and I'm always wishing it was more like 15 feet.

  6. #6

    Default

    Quote Originally Posted by Forrest Addy View Post
    That swiveling extension is gonna play hell with the jib boom. I beams don't resist tension very well. Besides, 100 Kg? Well within dragging range.
    Do you mean torsion here, as in a twisting moment on the I-beam?
    .
    "I am often asked how radio works. Well, you see, wire telegraphy is like a very long cat. You yank his tail in New York and he meows in Los Angeles. Do you understand this? Now, radio is exactly the same, except that there is no cat." : Albert Einstein

  7. #7
    Join Date
    Oct 2002
    Location
    Bremerton Washington
    Posts
    5,643

    Default

    Quote Originally Posted by TGTool View Post
    Do you mean torsion here, as in a twisting moment on the I-beam?


    Yep. Dumb me. Always typos.

    Fixed it. Thanks.

  8. #8
    Join Date
    Apr 2017
    Location
    Kelowna BC
    Posts
    358

    Default

    What if you had a section of smaller beam that bolted on top of the 6 inch, then you could use it in the corners with an electric winch or ratchet winch to lift say 120 lbs, then pull it back to end of 6 inch beam, and hook to your main trolley. Might be easier than a folding end.

  9. #9
    Join Date
    Sep 2015
    Location
    NW Illinois
    Posts
    332

    Default

    The jib you sketched has a reach equal to the column height. The horizontal force it transmitted to the building structure at the top will be roughly equal to load plus weight of the hoist. Make sure your structure can handle that load.

  10. #10
    Join Date
    Apr 2012
    Location
    Sydney
    Posts
    498

    Default

    Quote Originally Posted by Forrest Addy View Post
    Have you considered a bridge crane? Wall to wall to door reach and no mast to clutter the center.
    I certainly did consider the bridge crane approach. Nearly purchased a second hand one that was just perfect for the task. It went for a song. The sad fact is that there is not room under the beams to hang such a thing. By the time it is put in place you would near need to duck every time you walked anywhere.

    Quote Originally Posted by Forrest Addy View Post
    Maybe raise the walls o allow 4 meters under the hook?
    Quote Originally Posted by Toolguy View Post
    I would want 4 meter sidewalls at the least. My shop ceiling is 10 ft. and I'm always wishing it was more like 15 feet.
    I hear you loud and clear on the height restriction. However this is a residential zone; I think I did well to get the DA approved for what I have. The DA approves a workshed. The only restriction is noise. The council sent me a letter approving the DA that also said they are "going to monitor the noise". I think the council would have preferred the application to have been objected to by those entitled to object.

    Quote Originally Posted by Illinoyance View Post
    The jib you sketched has a reach equal to the column height. The horizontal force it transmitted to the building structure at the top will be roughly equal to load plus weight of the hoist.
    I am not sure I agree with this statement; would certainly like to know more. Let's say the boom is 35kg per meter; hence 5 meters = 175kg is total boom weight; call it 200kg with the girder trolley and chain hoist.

    I have it that the weight of the boom is shared equally with the mast (direct load to the floor at that end) and then equally (the other 50% of the boom weight) is load at the end of the boom. Now that 100kg is hanging free; hence is supported by push (at mast base) and pull at mast top. Subject to your agreement on this, I have it, that due to the boom being a fixture to the mast, that the push and pull forces are equally loaded to the mast such that the pull (the only one that is difficult to address structurally) is 50kg.

    I have toyed in my head with the option of adding a counterweight boom to the mast. My thoughts were to add enough weight (say) 1.5 meters out from the mast to make the push negative by around 20kg when the boom is unloaded.

    Quote Originally Posted by 754 View Post
    What if you had a section of smaller beam that bolted on top of the 6 inch, then you could use it in the corners with an electric winch or ratchet winch to lift say 120 lbs, then pull it back to end of 6 inch beam, and hook to your main trolley. Might be easier than a folding end.
    It is enticing ... but I eventually resisted this approach. Ideally the workflow is best if the load does not need to be placed (on floor) and picked up again when transitioning to the extension. I tried to get a design that allowed the girder trolley to somehow run onto an extension; but could not get there without hinges, clips and other uglyness that would still operate well from ground level.

    Quote Originally Posted by Forrest Addy View Post
    That swivelling extension is gonna play hell with the jib boom. I beams don't resist torsion very well.
    I agree that use of an I beam for an articulated boom will not fly. All the commercial examples use RHS box section. Am leaning towards the first stage of the boom being 150mmx150mmx6mm (26.8kg/mtr) and the secondary 100x100x5mm (14.7kg/mtr). Both to be close to 3 meters long. The secondary needs to be slightly shorter than the primary so that it can swivel inside and still pass the mast.

    Norman

Posting Permissions

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