Lifting capacity of a bolt ?
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Does anybody know how much weight I can reasonably expect to lift using a bolt and ratchet(or possibly a longer wrench)?
I think a drawing of what I have in mind will help explain but I'm on a phone atm. I'll draw something up later.
Just wondering if anybody has any hands on experience with something like this. (bolt diameter for X amt of weight, optimum thread pitch, necessary steel quality/hardness, etc)
Thx.
[edit] I'm looking to lift ~1600 lbs with four bolts.
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Jeff
We used to use screw jacks in Log construction for settling adjustment. Mostly we had the specifically engineered, but there are some standard jacks available. http://www.loghelp.com/p-882-the-nortek-leveler.aspx such as this one. They use an Acme thread. This one lifts 20,000 lbs with one jack.Hope it helps.
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Is the load bearing on the threads or the shaft? As in a tensile load or shear load?
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Dale. The problem with screw jacks (or bottle/cylinder jacks etc) Is the clearance. I only have a few inches to work with as far as getting underneath (the yet to be posted drawing with help explain
)
Also, I'm trying to do this lift for the least amt of dough as possible and I don't own any jacks.Rich. The threads hold the weight. The bolts are vertical and the lift is vertical.
And I'm 100% positive that ACME has exactly what I need. Unfortunately, I don't think they have an NYC location.
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Wile E. Coyote swears by the Acme Company
(But I didn't know they made threads.)Edit: Actually you must consider tension, shear and dynamic/cyclic loading.
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There's the info on different load strengths. You can identify different bolt strengths by head markings. No Mark means low carbon etc.
There's also thread fit to consider. I think in the US it's a class 2 fit for bolts with v-thread.
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Hi Jeff,
Is it something like this that you are after?
Theatrical Chandlers have specialist hardware for more limited access lifting applications such as you may be experiencing.
Regards
Sam
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sweet Rich!..
i think that's exactly what i'm looking for.
and yeah Lobster.. kinda sorta like that.. here's a .skp and a jpg.
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Can you weld a threaded bushing in that box iron? It'd beef up the strength and reduce the load on the nut.
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@unknownuser said:
Can you weld a threaded bushing in that box iron? It'd beef up the strength and reduce the load on the nut.
yeah, that's sort of what the .skp meant when i said adding a spacer.. (though i'm thinking about using epoxy to glue it in there instead of welding).. it wouldn't be threaded though -- i was thinking of using a 1/2" spacer if i opt for a 3/8" bolt just to give a little wiggle room.
i'm not really figuring out the chart you linked to.. apparently, a 3/8" bolt will be plenty strong but i just don't know if i'll be able to apply enough torque for the lift.. i'm hoping to use my impact driver to do it which delivers ~1400 in.lbs.
what do you think the torque listings mean on that chart?
[edit] maybe double up the nut in order to spread out the load per nut?
[edit2].. hmm.. ok. i'm seeing the tensile strength section now.. maybe i'll go with some 1/2" grade5 bolts.
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hi Jeff,
We do this type of thing all the time for Special Effects rigs.
my advice is use turn as large a course threaded bolt as you can fit, with a nut welded to the frame.
You can only lift one pitch per revolution, so 25TPI will take 25 turns per inch,
I have welded bicycle sprockets on a four bolt set and ran a single chain around, but it's a bit of a pain to set up.
john
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Oh well never mind,
Not that then but these..... in an ideal world where money is no object.
(If you do go for wiggle room with the bolt you might want to guide the castor beam while it lifts to keep the castors vertical before they get locked off)
The first time i made something like this with swivel castors i welded them too close to the outer frame so they wouldn't flip around....resulted in limited navigation and a rebuild.... the sort of thing you only do once.
Sam
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@unknownuser said:
what do you think the torque listings mean on that chart?
Its the value at which the bolt is considered tight. Where as your 'invention' isn't relying on bolt tightness but drive. That's a different kettle of fish.
I can't view the file as I'm browsing on iPad. But I'm presuming you're raising and lowering this skirt that's 1600lbs? In order to roll this doodad about?
If so the skirt is suspended on the nuts. Tightness or torque isn't necessary but you'll apply torque to raise it. The force acting down on those nuts will mean sweaty Jeff. If you had a threaded spacer/bushing it would mean more mechanical action than brute force. Also a bolt with a double start would reduce the number of rotations needed as John mentioned. And a nice acme or buttress thread would ensure longevity.
I could be looking at this incorrectly
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@unknownuser said:
@unknownuser said:
what do you think the torque listings mean on that chart?
Its the value at which the bolt is considered tight. Where as your 'invention' isn't relying on bolt tightness but drive. That's a different kettle of fish.
I can't view the file as I'm browsing on iPad. But I'm presuming you're raising and lowering this skirt that's 1600lbs? In order to roll this doodad about?
If so the skirt is suspended on the nuts. Tightness or torque isn't necessary but you'll apply torque to raise it. The force acting down on those nuts will mean sweaty Jeff. If you had a threaded spacer/bushing it would mean more mechanical action than brute force. Also a bolt with a double start would reduce the number of rotations needed as John mentioned. And a nice acme or buttress thread would ensure longevity.
I could be looking at this incorrectly
nah.. i think you're seeing it right. (except i don't need longevity.. lift/move/lower/done.
i definitely don't mind getting sweaty though so that's not a problem:D
the problem with some of the welding suggestions etc. are more of a logistical problem.. my welding machine is in storage in long island city (queens) and the lift is in hell's kitchen (west side manhattan).. and i don't own a vehicle..
these people are loaded though so if i said you need suchANDsuch contraption to move this thing then they'd do it.. it's more of a personal challenge of mine to move it for 25 bucks or less
.. well, that and i have a chance to resell some steel and casters that i happen to have which are doing nothing but taking up space and collecting dust.i think i'm good to go.. i'll post a picture of the thing when it's being moved.
it's a pretty cool object (at least to an american? you euros might give it a meh..) -
@unknownuser said:
@unknownuser said:
@unknownuser said:
what do you think the torque listings mean on that chart?
Its the value at which the bolt is considered tight. Where as your 'invention' isn't relying on bolt tightness but drive. That's a different kettle of fish.
I can't view the file as I'm browsing on iPad. But I'm presuming you're raising and lowering this skirt that's 1600lbs? In order to roll this doodad about?
If so the skirt is suspended on the nuts. Tightness or torque isn't necessary but you'll apply torque to raise it. The force acting down on those nuts will mean sweaty Jeff. If you had a threaded spacer/bushing it would mean more mechanical action than brute force. Also a bolt with a double start would reduce the number of rotations needed as John mentioned. And a nice acme or buttress thread would ensure longevity.
I could be looking at this incorrectly
nah.. i think you're seeing it right. (except i don't need longevity.. lift/move/lower/done.
i definitely don't mind getting sweaty though so that's not a problem:D
the problem with some of the welding suggestions etc. are more of a logistical problem.. my welding machine is in storage in long island city (queens) and the lift is in hell's kitchen (west side manhattan).. and i don't own a vehicle..
these people are loaded though so if i said you need suchANDsuch contraption to move this thing then they'd do it.. it's more of a personal challenge of mine to move it for 25 bucks or less
.. well, that and i have a chance to resell some steel and casters that i happen to have which are doing nothing but taking up space and collecting dust.i think i'm good to go.. i'll post a picture of the thing when it's being moved.
it's a pretty cool object (at least to an american? you euros might give it a meh..)Jeff
Make sure you look at what, if any, move obstacles you have to cross. I am sure you have seen the pics of Obama limo getting high centered. When moving equipment we usually worried any ramps, thresholds etc we had to cross to make sure there was clearance in our design and for your case possible over turning -
hey mac, thanks
yeah, i'm ok in that dept.. the floor is level and has 22' ceilings throughout.. at the tightest part of the move (laterally), i'll have 3' clearance on either side.. there's one spot in the concrete that could be a bit of a problem (kinky expansion joint) but i have some 16 gauge sheet stock to lay over it..fwiw, i've moved much(much!) heavier objects before for longer (much longer!) distances but i've had a crew and heavy duty machinery.. my crew doesn't live in nyc and there's no way to get any sort of forklift or crane inside this building..
i'm feeling ok about this safety wise especially because i'm only going up less than an inch.. i guess my main worry is being halfway into the raising or lowering process and have one of the bolts strip out.
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@driven said:
hi Jeff,
We do this type of thing all the time for Special Effects rigs.
my advice is use turn as large a course threaded bolt as you can fit, with a nut welded to the frame.
You can only lift one pitch per revolution, so 25TPI will take 25 turns per inch,
I have welded bicycle sprockets on a four bolt set and ran a single chain around, but it's a bit of a pain to set up.
john
nice.. glad to hear that this isn't such an uncommon thing to do
i'm hoping my impact wrench will take care of most of the turning. if not, i'll have a ratchet with extension arm but i hope it doesn't come down to that.. the rest of the thing extends vertically so it's not like i can just put a socket on there and do 360s with it.. if i have to tighten it manually, i'll be turning the nuts 90º at a time
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@unknownuser said:
it's a pretty cool object (at least to an american? you euros might give it a meh..)
I look forward to it. But I'm more interested in how you get on?
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@unknownuser said:
hey mac, thanks
yeah, i'm ok in that dept.. the floor is level and has 22' ceilings throughout.. at the tightest part of the move (laterally), i'll have 3' clearance on either side.. there's one spot in the concrete that could be a bit of a problem (kinky expansion joint) but i have some 16 gauge sheet stock to lay over it..fwiw, i've moved much(much!) heavier objects before for longer (much longer!) distances but i've had a crew and heavy duty machinery.. my crew doesn't live in nyc and there's no way to get any sort of forklift or crane inside this building..
i'm feeling ok about this safety wise especially because i'm only going up less than an inch.. i guess my main worry is being halfway into the raising or lowering process and have one of the bolts strip out.
Roger sounds like you have the bases covered.
FYI: Don't know the dollar value of the item you are moving nor your liability. For ground handing equipment we usually apply a large safety factor.
Have moved ( technical management resp.)items via Fed X , air ride vans, bought the total first class section seats of United 727 one time so all the electronics could be strapped in the first class seats, over the road coast to coast and even almost filled a C5A with 1 item. All total maybe around 3/4 billion dollars. Move never goes as smooth as I would like( Had a really bad experience with D ring )
Good Luck -
so i ordered some of these today:
hopefully they aren't too coarse.
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