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foreign gauge / estensimetry

  • Thread starter Thread starter Fulvio Romano
  • Start date Start date
If you put a pattern, we can help you. from what you tell me I imagined an anthropomorphic robot that must give load/unload of the piece on a lathe or an automatic milling machine.

I schematized the clamp as in the pdf attached. I practically have two independent jaws controlled each by its hydraulic cylinder for positioning. Moreover each jaw has an additional degree of freedom that is rotation around the pin, where on one of the two centers it is possible to mount a torsion load cell.

high pattern can be to mount the jaws on two small sleds and on a mount a compression load cell (see second pdf). It's the mechanically simplest solution than the twist.
 

Attachments

Fulvio Romano said:
on paper, maybe... I have a few millimeter race of a cilidro d30

I can't discriminate against the fact that I reached the end of the race instead of grasping the piece.
Click to expand...
I can contact you with a Tuscan company that produces custom strain gauges.
 
Fulvio Romano said:
I can't.
the cylinder is made ad hoc. Why? I don't know, hands of the mechanic:redface:

apart from the jokes, it is a jewel of mechanics, but unfortunately it has some special choices that prevent me from using the standard sensory.
Click to expand...
you can't mount a lvdt inside The cylinder?
the mts does the temposonic with race even 25mm
so knowing the stroke and pressure you are (almost) sure you have taken the piece or not
 
If you have space and possibility to act between the manipulator's arm and the clamp you might think of fixing the clamp so that it can spring a few millimeters and make him do some sort of "crying test".
- grab the piece
- back with the robot
- if the clamp springs you're in hold otherwise not.

there is however the risk of ruining the piece in case of "partial socket" but depends much on how rigid the spring is
 
excuse the oct (maybe the moderator moves the discussion elsewhere) but we have to put strain gauges on a stern straight.
problems are as follows:
- are installed today that the ship is in the basin but will be used in 30 days. the thirty days are therefore of stay in water.
- when the test is carried out, the same will be invested by the accelerated flow of the propeller.
is anyone aware of a type of strain gauge suitable for use in sea water?
Is there a solution for fixing the same ones that can last in water for the above time?
thank you all for the answers.
 
exatem said:
excuse the oct (maybe the moderator moves the discussion elsewhere) but we have to put strain gauges on a stern straight.
problems are as follows:
- are installed today that the ship is in the basin but will be used in 30 days. the thirty days are therefore of stay in water.
- when the test is carried out, the same will be invested by the accelerated flow of the propeller.
is anyone aware of a type of strain gauge suitable for use in sea water?
Is there a solution for fixing the same ones that can last in water for the above time?
thank you all for the answers.
Click to expand...
Can't you put on a hat with an inspection box to keep them dry?
 
Fulvio Romano said:
Can't you put on a hat with an inspection box to keep them dry?
Click to expand...
no, they are a temporary installation on the stern straight realized "piece" and must be removed at the required time. you can not create specials like hats or tanks because the ship leaves and does not fall into the basin until next year.
 
I add some info to better focus the problem.
Following a malfunction of a rudder we need to detect experimentally:
1) the couple agent on the rudder machine;
2) the arrows of inflection of the rudder straight.

for the first point, we can apply strain gauges to the steering machine biellas in axial direction, in order to measure the agents forces on them, then to obtain the agent pair on the machine, knowing the arm of the steering handles. we can also make a verification of this pair, through a second measure carried out with strain gauge applied to the axis of the rudder in a tangential direction (i.e. according to the verse of the torsion). to carry out these 2 measures should be no problem, because we are dry, so we can use strain gauges and we can also place them with the floating ship.

for the second point, the work is complicated, in fact we must find strain gauges able to operate in sea water, to be fixed in addition to glues that can resist the action of the water during the virata. It is also necessary to consider that the strain gauges on the straight should be placed now with the ship in the basin, and must stand in the water for a waiting time of 35-45 days, before the ship goes out in navigation to make the test.
 
As for my problem, I solved with a camet and an ultrasonic baumer sensor. outside your fingers, and we hope you don't take a fight...
 
exatem said:
for the second point, the work is complicated, in fact we must find strain gauges able to operate in sea water, to be fixed in addition to glues that can resist the action of the water during the virata. It is also necessary to consider that the strain gauges on the straight should be placed now with the ship in the basin, and must stand in the water for a waiting time of 35-45 days, before the ship goes out in navigation to make the test.
Click to expand...
I think you should ask maxopus for contact with that company that he said produces custom strain gauges. the sensor of a strain gauge should be easily applicable and then the epoxy resin drowning. becomes part of the rudder itself and the sea water makes him a moustache.
 
PaoloColombani said:
I think you should ask maxopus for contact with that company that he said produces custom strain gauges. the sensor of a strain gauge should be easily applicable and then the epoxy resin drowning. becomes part of the rudder itself and the sea water makes him a moustache.
Click to expand...
then "very" it with a layer of resin to be removed at the next stop.
but should the extensometer be of a particular type? (waiting the max intervention).
 
You could use fiber optics instead of strain gauges.
have no problem with exposure to atmospheric agents or working underwater.
I know that they have been used for similar applications, if you are interested I can give you a reference in with a private message.
 
Onda said:
You could use fiber optics instead of strain gauges.
have no problem with exposure to atmospheric agents or working underwater.
I know that they have been used for similar applications, if you are interested I can give you a reference in with a private message.
Click to expand...
I did not say that the affixing of strain gauges and their use does not do so to us, but an office to us outside but somehow connected to which for reasons "institutional" we must address, that to our request has emphasized these observations.
for this reason it is a land outside me and I was trying to figure out if there is a viable solution. I don't know if the use of different means from strain gauges is possible for them (instrumentation available).
However if you can send me a reference I thank you in advance.
 
I'm not a field expert, so I don't know if the company solutions I know can be suitable for purpose.
know that they build wire strain gauges, electrical, vibrating rope and tape.
 
maxopus said:
I'm not a field expert, so I don't know if the company solutions I know can be suitable for purpose.
know that they build wire strain gauges, electrical, vibrating rope and tape.
Click to expand...
hello max, you who now know my "reality", what would you do?
 
exatem said:
hello max, you who now know my "reality", what would you do?
Click to expand...
I can get in touch with you.
They're serious people, and if they don't do it for them, they tell you, and if they're part of their knowledge, they'll pass the names of companies that can help you.
 
maxopus said:
I can get in touch with you.
They're serious people, and if they don't do it for them, they tell you, and if they're part of their knowledge, they'll pass the names of companies that can help you.
Click to expand...
Okay, so in the morning, if we hear each other.
Hello and thank you.
 

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