Fixture for work piece while tightening bolt which requires high torque 1

[CAT4WAR2]

How to hold the work piece with radius at the outer side while tightening a bolt (into the work piece) which requires 1300 N.m torque.

My questions is; is there any readily available fixture for this?

Thank you very much

 

[desertfox]

Ask yourself from the information you've provided how anyone can possibly help you.

 

[byrdj]

1) shop table with a couple chain falls strapping the piece down
2) skid steer with a 4 way bucket
3) depends on where and what is avalaible

instead of torque, can you measure and tighten using elongation
are you turning a bolt or nut, if nut you could use rotation to achieve desired elongation

 

[ornerynorsk]

Your wording suggests that you are trying to hold a round part securely for assembly. Research the following:
Band clamp
strap wrench
lateral clamps
machinable jaw vise or chuck
eccentric edge clamps

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[rb1957]

are you installing only one bolt through this piece ? ie, can't you install the other fasteners before you tighten up the first ?

are you really installing a piece that has no designed loadpath for installation torque ? sounds like a pretty crap design (if it is). i'm visualising a piece with a flat face and only one fastener through it ... no anti-rotation design features, no washers, no ...

another day in paradise, or is paradise one day closer ?

 

[JStephen]

Possibly an impact-wrench type set-up, where the resisting torque comes mainly from the inertia of the larger piece. I'm not sure if it's feasible to measure torque accurately in that case.

Had to look it up- 1300 N-m = 959 ft-lbs.

Long ago, I remember the "nut" on the end of a hydraulic cylinder had notches in it, and a chisel and hammer in those notches would turn the nut. I don't think that required anything to hold the cylinder in place.

 

[rb1957]

"a chisel and a hammer" ? really ?? was that under "how to blunten a chisel quickly ?"

another day in paradise, or is paradise one day closer ?

 

[Signious]

JStephen:

I have seen nuts like those before on hydraulic cylinders - they are meant to be used with something like a collet wrench so you don't have to worry about the wrench slipping off.

Using a chisel & hammer does work, but would wear down the bolt waaaaaay before it reached design life

 

[UnusedHandle]

Look up RAD gun. They have a mounting fixture that you can attach to something that will allow someone to hold onto it. It your piece is on a work table you could tap the table for the torque resistance.

 

[byrdj]

a battery pack RAD gun looks like it would be great to have. However, after I finally found a price, $7,000 USD I doubt If I get one

 

[JStephen]

If you'll notice, I didn't say the chisel-and-hammer method was the proper way to do that job, just that I had seen it done (and that I don't think it required anchoring the cylinder, which was the point I was intending to make). This was on track-hoe cyclinders. Just checking here, it looks like cold chisels for that will run $10-$30 or so, pretty much nothing compared to the cost of the cylinder, so dulling a chisel is about zero concern. Tearing up the gland nut is a bigger concern.

Curious thing- there at that same shop, they had a 60" pipe wrench. Which is an uncommonly large and heavy and unwieldy size of pipe wrench. But the curious thing is that it was BENT. They had bought it specifically to try to use on those cylinder glands, and had pushed it with the bucket of another trackhoe and bent the wrench sideways a little.

Googling around a bit, I find this contraption, not sure just exactly how it is used:

http://www.ms-d.com/nutBuster.html

And I find a couple of rigs specifically set up to do shop work on hydraulic cylinders, and I assume they can undo that gland nut:

http://www.maruma.jp/pdt_hc_ss.html

http://www.tuxco.com/products/hydraulic-cylinder-service-equipment.asp

"can generate up to 30,000 lb-ft of torque to loosen threaded glands...then provides 5,000 lb-ft of torque at 8 rpm to quickly remove the loosened gland"
That's impressive when 8 rpm is considered "quickly" removing a nut!

I find hand tools for glands like that, but they seem to be very light weight relative to the items they attach to, and I think would have been fairly useless for the cylinders in question:

http://www.epsstore.com/index.php/cas1456.html

 

[gruntguru]

Flogging spanner?

Engineering is the art of creating things you need, from things you can get.

 

[kingnero]

weld the part to a large enough table, then apply the torque

 

[rb1957]

this sounds like me trying to open a bottle of wine after the cork has busted ...

two options ...
1) invent a subspace dampening field, or
2) get a proper design ... show us a pic and why sensible solutions are not an option.

another day in paradise, or is paradise one day closer ?

 

[KYSlowhand]

CAT4WAR2 This sounds like a test maybe Gov.gom work; like torquing a tank turret? Hope you have completed the task but, for instance to secure a 10K metal coils for transport in a wooden floor box-trailer we set blocks nailed into the floor- as another poster said inertia might be enough. An adequately large machining table like a boring mill- w/ slots for strap clamps might work. Perhaps setting on the ground or in sand? Selah

 

[gruntguru]

Essentially you need to be able to attach a lever to the workpiece, arranged in such a way that the line of the force you intend to apply to the wrench will pass through the lever. You will then be able to apply an equal and opposite force to the lever.

Nett torque on the workpiece = 0.
Nett force on the workpiece = 0.
Result = workpiece does not move.

If the wrench is long enough say 2.5m, the bolt can be tightened by hand(s)- one on the wrench, one on the reaction lever and pull them together with a force of 520N. If the wrench is not long enough, you can winch the two towards each other with a ratchet winch or similar.

Engineering is the art of creating things you need, from things you can get.

 

[Tmoose]

OP said " a bolt." Is it in the center of the assumed round workpiece?

 

[gruntguru]

It doesn't matter much. Clearly the workpiece is difficult to restrain. If it is cylindrical with no fixing points it might be necessary to fabricate a band to clamp around it.

Engineering is the art of creating things you need, from things you can get.

 

[tbuelna]

There wasn't much description of how difficult it might be to restrain the "radiused edge" workpiece when applying 1300 N-m to the bolt. The most obvious method that comes to mind is to add some wrenching feature to the workpiece that can be used to apply a counter-torque when the bolt in tightened.