Pin Installation Machine

Lancie,

Thank you, that did the trick! Now I find that the last two steps of the program are not working as intended. I will do some further experimenting...

Paul,

I believe that DirectSoft can do what you're talking about, but I'm afraid the hour is much too late with this project for me to learn any new tricks. Thanks for the suggestion, anyway.

Paula

HI,

Could the rung#2 be modified to keep clamp closed until you are sure drill and pin pusher are not moving. Looks like if some one brakes the light curtain or hits the e-stop the clamp will release. If the clamp releases while drill is spinning it could send the part across the room.

My $0.02
BD

bikerdude said:

HI,

Could the rung#2 be modified to keep clamp closed until you are sure drill and pin pusher are not moving. Looks like if some one brakes the light curtain or hits the e-stop the clamp will release. If the clamp releases while drill is spinning it could send the part across the room.

My $0.02
BD

Click to expand...

good point, nothing should move on an e-stop condition.

Tark said:

For your next project you might want to look into using a Drum instruction (EDRUM), they are designed for these types of step sequence applications.

Click to expand...

I agree. A drum is a sequencer, and that's exactly what's needed here.
Paula, I know you said you don't want to "learn new tricks" now, but this is important. Take a look at the manual for the drum instuction. They wrote an entire chapter for it.
You want EDRUM, a drum that will increment on Time or an Event.
A drum is always active, so make step 1 the Idle step. Keep your first rung, and change the output to C0. Use C0 to increment the Drum to step 2.

Take the time to learn it. I promise you'll love it. Much easier to diagnose and edit. If things are happening too fast during debug, you can temporarily set the time base to 1 or 2 seconds to slow things down.

Looks like if some one brakes the light curtain or hits the e-stop the clamp will release. If the clamp releases while drill is spinning it could send the part across the room.

Click to expand...

Good point, Bikerdude, but the drill bit in this case is only .089" diameter -- it doesn't have the strength to throw the part anywhere. It will break first. In addition, the clamp is only of minor importance in the drilling operation, as a cylindrical portion of the fixture engages the I.D. of the the part. I would venture to say that if an E-stop occurred during the drilling operation, the drill would simply back itself out of the hole. At worst, you might wind up with a broken bit, or damaged part.

Thanks, Tark and Keith, for the EDRUM suggestion. I read up a little on it in the manual, and it does seem like it would suit this application well. I'm not really reluctant to learn new methods, it's just that this project is too far along, and there is no time for me to become converscent with these alternate programming methods. If I can get it to work with RLL, that's going to have to be good enough. For this project, at least.

Paula

For Paula

I took a shot at this but not having the machine means its just a guide. I did not incorporate the pin loader part because I was not sure how it was accomplished. If the pin(s) can be detected prior to the loading section then you could run the vibration loader any time. Example: A tube is used to feed pins into loader, use a sensor to maintain X amount of pins in tube.

The first thing I noticed is the ESTOP is using a normally closed contact, its my personal opinion the ESTOP should use a hardwired normally closed contact, therefore the plc should use a normally open contact. The light curtain I also believe should be done the same way i.e. the plc inputs should be looking for power ON condition as an OK. That said the estop and light curtain issues may need to be addressed in more detail.

Attached is a pdf and a zip of what I created for a DL05 which should be easily transfered to any AD plc.

As I stated this is a guide, others are far better at this than I am and can (hopefully will) explain any fallacies with my method.

Technically there are sections I am uncomfortable with but its mainly because I do not have the machine to check what I have done.

Another thought on the pin loader section. If you can detect the pins being loaded then use an up/down counter. Example; count pins being loaded to 20 then stop vibrator. Down count using pin seat or driver to 10 count then start vibrator loader until count is back to 20.

Paula, can you post the program files?

Paula,

This seems to be a streight forward sequence. Hence it could ALL be done with a drum. I understand your in a hurry, but take a few minutes and read up on the DRUM instructions. It might make your life a LOT easer here...

Ron, you are the man! Thanks for taking the time to write that program! It will take me some time to study it and compare it to my version, but I can already see some improvements in your approach.

Addressing some of your other points...

I did not incorporate the pin loader part because I was not sure how it was accomplished.

Click to expand...

The pins will be fed on demand from a vibratory feeder bowl. (I went to pick it up from the vendor this morning to deliver it to the fabricator.) The sequence to feed a pin is quite simple: A solenoid valve is triggered (approx. 1/2 sec. duration) to actuate the escapemant mechanism. This releases a single pin into a chamber. After a short delay (approx 1/2 sec.), another valve opens to blow the pin thru a tube into the driver's nosepiece. LS8(X11) senses when the pin is present in the driver, and shuts the valve off. I am currently attempting to incorporate this operation in a subroutine (per Lancie's suggestion), such that the pin-feed sequence is run whenever the PLC sees that the driver is empty and retracted. Thus, it will only subtract minimal time from the cycle.

...the ESTOP is using a normally closed contact, its my personal opinion the ESTOP should use a hardwired normally closed contact, therefore the plc should use a normally open contact.

Click to expand...

The E-stop button (maintained-type) has both N.O. and N.C. contacts. The N.C. contact ("normal" being when the E-stop button is pulled out) is hardwired to the MCR, which interrupts the feed to the output commons. The N.O. contact is wired to an input, for the purpose of zeroing-out the program when the E-stop is pushed. This is to prevent unanticipated movements when the MCR is reset (with a separate pushbutton).

The light curtain I also believe should be done the same way, i.e. the plc inputs should be looking for power ON condition as an OK.

Click to expand...

The safety light curtain (type 4) may be overkill on this machine, but another customer had ordered one for a machine that never got used, and offered it for a good price. It has a separate relay with two pairs of force-guided contacts, which are hardwired in series with the output commons. It also has an auxiliary output that I've wired to the X13 PLC input, to function like the auxiliary N.O. E-stop contact, namely to zero-out the program whenever the light curtain is breached.

Thanks again for your help, Ron. I will examine your program further.

Paula

Mike,

I'm in the middle of adding a subroutine to the program, so I'll post the program files right after.

I will look closer at the drum sequence possiblity.

Thanks!

Paula

Since you were not worried about issues for the clamp etc I simplified my code, in this version as long as Start Cycle is active it will cycle until Whole cycle has completed. If Start Cycle is deactivated then everything should return to start position. Just in case I did not make it clear on rung 8 the timer will keep on running until Start Cycle is deactivated, this should eliminate issues of it cycling.

With ESTOP I would use the N.C. contact if possible, in other words the actual voltage providing the hardwired circuit. IF using AC for ESTOP and DC inputs then I would use an auxillary contact on the MCR.

I will have to think about the pin loader part. I have noticed there are 2 actions to it, release then blow. Could the release be actuated upon pin present and blow actuated on my stop cycle or pin not present with driver retracted? If that is the case a subroutine may not be necessary. I will think about it some.

Attached is my simplified version in pdf.

This is example 3, since you have a long dwell for pin seat I thought you might could load the pin if a pin is present THEN once pin is seated etc the blow could actuate until pin is detected present. I added it to the stop cycle but it may need to be on its own rung...fast thought.

I noticed I forgot to use the PIN PRESENT sensor in my previous versions and did not like #3 so here is #4.

The pin loader part I still have not fully visualized but if you can control both the load and blow then this should be close. This machine should not need more than 20 rungs of ladder so not sure its worthwhile to tackle drum or stage programming. Since there is what appears to be a 2 second delay for the pin seat then reload could be accomplished at same time as machine run.

I did not get to help much with Learn by Doing so hopefully I got a chance to offer some ideas on this project. Attached is my 5th attempt at providing ideas.