Hey guys , I am thinking of making a automated different sized bolt separator with controls using a PLC.

I have though of 2 ways to do it .

1st way : throw a whole bucket of random different kind of bolts in a v shaped tank and using openings and closing at the bottom of the tank I can automatically sort out the different sized bolts ? on the theory that smaller sized bolts will drop to the bottom of the tank when there is vibration .

2nd way : putting it on a conveyor and using 2 distance sensor ,I can measure the length of the hexagonal head of the bolt and different ones goes in to different boxes . I am using distance sensors because I cannot find a sensor which tells me the length of some thing on a conveyor .

If anyone has any suggestions please do advice .

Thank You .

 

How many different bolt sizes are there and what are their dimensions?

 

I am thinking of all kinds of bolt size.

Maybe i should use a vision system .

 

Hey guys , I am thinking of making a automated different sized bolt separator with controls using a PLC.

I have though of 2 ways to do it .

1st way : throw a whole bucket of random different kind of bolts in a v shaped tank and using openings and closing at the bottom of the tank I can automatically sort out the different sized bolts ? on the theory that smaller sized bolts will drop to the bottom of the tank when there is vibration .

2nd way : putting it on a conveyor and using 2 distance sensor ,I can measure the length of the hexagonal head of the bolt and different ones goes in to different boxes . I am using distance sensors because I cannot find a sensor which tells me the length of some thing on a conveyor .

If anyone has any suggestions please do advice .

Thank You .

I would make a system that sorts by weight.

 

I would make a system that sorts by weight.

Not possible . What if there is dirt on the bolt ?

It will change the weight of it .

 

Not possible . What if there is dirt on the bolt ?

It will change the weight of it .

How will you account for dirt on a bolt if you are using a vision system?

 

Best system for dirty/rusty bolts - pour them all in a bucket, take the mixed mess to a scrap yard. Then buy the size bolts you need.

 

You will have to deal with too many variables, dia, length, head size, head type.
Max.

 

I am thinking of all kinds of bolt size.

Maybe i should use a vision system .

If you don't know how many different bolt sizes there will be how do you know how many bins you will need to contain the sorted bolts? You could have 100s of different bolts.

The machine would have to measure the first bolt, assign it to a bin and remember which size of bolt it assigned to that bin (so that it can add all further bolts of the same size to the same bin); it would have to do this for all bolts. If you don't know the sizes of the bolts, how can you define the resolution of the detection system?

Perhaps you could take an iterative approach and just filter out one type of bolt on each pass.

How would you deal with different threads or thread lengths or heads or material?

Or, are you just hoping to sort them into a few groups of similar sized bolts?

 

If you don't know how many different bolt sizes there will be how do you know how many bins you will need to contain the sorted bolts? You could have 100s of different bolts.

The machine would have to measure the first bolt, assign it to a bin and remember which size of bolt it assigned to that bin (so that it can add all further bolts of the same size to the same bin); it would have to do this for all bolts. If you don't know the sizes of the bolts, how can you define the resolution of the detection system?

Perhaps you could take an iterative approach and just filter out one type of bolt on each pass.

How would you deal with different threads or thread lengths or heads or material?

Or, are you just hoping to sort them into a few groups of similar sized bolts?

I would just want them to be sorted out with different size thats all .

I know its almost impossible to sort them with threads and thread length .

I was thinking something like this .

1) Because all different sized of bolts have different head sizes.

2) thus the vision will then see the head size and measure it.

3) also the vision will see the type of head , hexagonal or rounded .

4) through this the system will know where to place the bolts .

I can take all the measurement of the bolt's head size that I want to sort (which is only about 15 different types) and program it into the vision system.

Is there a problem with the above steps ?

 

Is there a problem with the above steps ?

Their actual position at the moment of being evaluated which, I suspect, could be any. Not good..

 

Because all different sized of bolts have different head sizes.

I wouldn't bet on it. Bolts with a specific thread diameter may be available with a choice of head shapes and sizes.
Personally, I'd use a conveyor system passing the bolts singly through an alignment arrangement then over slots of varying width to separate them on the basis of either head size or length as a first step.

 

Not possible . What if there is dirt on the bolt ?

It will change the weight of it .

I wouldn't bet on it. Bolts with a specific thread diameter may be available with a choice of head shapes and sizes.

And varying amounts of dirt.

 

"1) Because all different sized of bolts have different head sizes."

Bolts of differing sizes often have identical heads.

 

You could pay a human to do it. I know that idea is "so 20 years ago" and all, but for some applications, the rational human cranial processor and articulating 5-finger kinetic grasping system just can't be beat.

A human could even sort by bolt grade, material, thread pitch, rusty/not, imperial/metric, fully threaded/not, pan head/hex cap internal/external, thread condition, etc.

 

so many questions..
Why? is the first one..
Volume?
I can't imagine why someone would need to sort a random box of dirty bolts over and over and over again that they could justify automation/vision/plc,etc...
Then if you aren't worried about thread pitches,etc... are you really doing any good by sorting them?

But the typical way a random sorting system might be constructed now is with a "flexible feeder", vision system, robotic arm.. (NOT cheap at all)
something like this... http://www.graco.com/us/en/products/contractor/g-flex-1500.html

With 100% "random" your choices are really limited.. Now if you are going for a smaller range of fasteners then there are many other options..

 

Bolts - steel, brass (maybe bronze). Dirt - grease, oil, fluff, etc.

There is a significant difference in density of the bolt and the dirt so I would still think weight is a good option as long as you sort by length as well. What ever you do I suspect you will need some way of orienting the bolts, once oriented getting length and weight should not be too hard.

Assuming the length of the smallest bolt is significantly longer than the head of the biggest then a rotating cylinder with slots big enough to accept the biggest bolt at the bottom of a hopper may work. As the cylinder rotates a bolt drops into a slot and then is tipped out in a known orientation.

Although bolts are pretty cheap and such a machine plus your time is not so as has been pointed out above, scrap the bolts and buy what you need,

 

You could pay a human to do it. I know that idea is "so 20 years ago" and all, but for some applications, the rational human cranial processor and articulating 5-finger kinetic grasping system just can't be beat.

A human could even sort by bolt grade, material, thread pitch, rusty/not, imperial/metric, fully threaded/not, pan head/hex cap internal/external, thread condition, etc.

Have you seen people selecting fruit - quality wise - prior packaging? They work incredibly fast and do it very well.

Even myself, with all the resistors in a small tray (they go there after testing whatever in a breadboard). Once in a while, in 30 minutes, I have them are in they respective slots in a big box.