I am working on a project that we were hoping to tighten parts in the machine by use of a pulse gun (Fancy torque setting air impact driver)
Has anyone done this or have a better way to tighten bolts to a specified torque with a robot? We are running a torque setting of 80ft lbs currently and are concerned of switching to hydraulic workholding due to the fact this is in a HMC with pallet changer and we are very green on the hydro side of the world
Pulse gun as EOAT
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Rico Traversa -
January 24, 2019 at 3:44 PM -
Thread is marked as Resolved.
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I have used ABB robots to both tighten and loosen bolts. I cannot help you yet because I don't fully understand what you are asking.
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I agree, a bit more info would be helpful here. I have set up two different torqing applications using electric Atlas-Copco drivers. The drivers were around $60k for a pair and were tightening fasteners to 60 lb-ft or so. These applications needed very complicated torque profiles and these drivers may very well be overkill for your application.
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We are in a HMC and we are doing a very basic job. Its a 1.5 dia round 8 inches long and we drill a .858 dia hole thru the middle.
Our current fixturing is basically a V block with a 5/8 bolt thru it to sandwich the part into the solid V on the table. My Fanuc integrater has been no help saying yes or no can the robot hold a pulse tool to torque the bolts, he recommeded making using hydraulic pistons to pull the clamp instead but thats alot more money to remake all fixtures and buy the piston and pumps needed.
Currently we hand load this job and we are putting a robot on the job to gain back 3 employees to run other jobs -
A pneumatic driver is an option providing the robot is able to handle the forces from the driver and get the socket onto the nut or bolt head. I think one concern is how will you confirm the piece is clamped correctly? If a part isn't clamped properly, things will get pretty ugly as I'm sure you know. A disadvantage of pneumatic drivers is no feedback as to success of the process. Perhaps there is a manufacturer that now offers feedback??? Another disadvantage I have come across with pneumatic drivers is it is very tough to rotate the socket a quarter turn or so to get it to engage the bolt or nut. Electric drivers can easily be programmed to do so in forward or reverse.
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OK, next question, very important. What model robot do you have or are considering for this application? Also, it looks like parallel pairs so you could maybe cut your time in half if you put two drivers at the correct spacing. Some compliance like spring loaded spindles and sockets that can wobble a little to find their way onto the bolt head.
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We haven't decided on a model of robot yet but maybe a m20 series, most likely going to do a force sensor on it and maybe a big lead
to help get the socket on the bolt. Time isn't an issue as the cycle is 35 min so plenty of time to load and tighten.
Do you have a recommendation on a robot model? Our rep isn't very helpful and likes to oversize everything to make sure it works. -
Do you have a copy of the Payload Checker Spreadsheet? Someone on the forum shared a copy not long ago. How big is the driver? How much does it weigh?
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I do not have a copy of that, and the gun only weighs around 5.5 lbs