Pick and place Turret lugs into holes on a drilled board

[Doug Hoffman]

In my business, I do custom FR4 Turret boards for my customers
I also have about 50 models of standard turret boards that I sell
Some boards have more than 100 turret lugs in them

My CNC machines drills all the holes in the boards
But then I have to load all the turret lugs into the holes by hand
And then the lugs get swagged/flared into board using a small press

Once I saw a Pick and Place machine I got the idea that it could load the turret lugs into the boards for me

I want to ask the experts here if you think this is feasible - Here are some details
Look at the image below 
-------------------------------------------------------------------------------------------------
The board material is 0.125 inch thick FR4 - glass epoxy board material

The CNC machine drills all the 3/32 inch holes - 0.09375 inches 
So I already have all the drilling G-code that was loaded into the CNC machine.

The turret lugs have a 0.090 inch shaft size that has to go into the 0.09375 inch holes
So there is approx 0.00375 inches of play in the drilled hole (when the drill bits are new)

I will machine a feeder system that delivers the lugs to a fixed location where they can be picked up
The machine only has to pick up this one turret lug style from one location

The machine only has to deal with one part, the turret lugs

The nozzle head does not have to rotate which removes one mechanical process
This makes the nozzle head much simpler

The lugs weight 0.3 grams each, so they are not heavy
I tested picking them up with a small vacuum pump and they can be picked up, no problem
Even though the lugs have a small hole in the center, the vacuum was still able to pick them up and release them

The boards are all the same height which is 3.125 inches tall
The length of the boards can be from 3 inches up to 21 inches long
On my CNC machine, the board material is held in a drilling fixture
The fixture has a Home spot that is set before drilling the boards
All the G-code is referenced from this home location
|
So I would also use a fixture on the pick and place machine with a home location

My question is this:
Do you think it is feasible to design a suction head that can place the lugs into a tiny hole with only about 0.003 inches of play?
I have never seen a pick and place machine load parts into a hole
I don't know if this has been done before?

Here's an image of a partially loaded and swagged turret board
It shows some of the lugs that have already been swagged.

Thanks for any help on this

 

[tony wood]

Hi Doug,

how about something like this.

I am in the process of building this still but it its for placing loose leaded LEDs into a PCB.

Uses Arduino mega and ramps board as in 3D printers uses X Y Z axis and C for board rotation.

It uses a split tube clamp for gripping 3mm LED's and a guide system for aligning the legs (leads) to thread them into holes in the PCB.

These use the servo ports. Also have an inclined vibratory feeder for presenting the LED's for pick up. The vibrator is on the mosfet channel used for the heater on 3d printers.

Runs on basic Marlin programming. The code for this is a basic G code program as it it fairly repetitive.

In your case your would only need the split clamp possibly and that avoids running vacuum possibly.

Haven't had time to think about using Open PNP yet.

.

     

Cheers,

Tony.

[Doug Hoffman]

Thanks Tony

Your pictures are a bit out of focus, but I see what you are doing there

That's in the same neighborhood of what I am trying to do
Except what you are doing seems way more difficult?
The holes in your board and the LED leads are way smaller than what I am trying to do

You are using linear rails which gives great accuracy
That's what I was going to use also

I have built 2 CNC machines and one 3D printer from scratch and so I don't have an issue with the mechanics of the build
I was more interested in how hard it is to place something down into a hole on a board
I am dealing with 0.003 inches of room and was not sure if that would be an issue

This gives me hope :)

If you have some better pictures of your build, I would love to see them

Thanks, Doug

[Doug Hoffman]

Tony,

I am interested in how you are grabbing the LED's

I was wondering if I should with vacuum pickup or a clamp that closes and picks up the turret lugs

It seems like a clamping pickup would be more solid and accurate than vacuum
But I don't know about that?
 

[John]

Are the boards for tube amp's ?

I would try to combine placement and a automated lug press in one machine. Feeder and press is on a fixed position and the board is moved. The required accuracy should be no problem using ball screws for x/y-axis. I think that you do not need the mighty vision system of OpenPnP because lugs are round and holes have enough play.

The big challenge is designing the feeder and automated press.

John

[Doug Hoffman]

Thanks John
Yes, the boards are what guys use to make vintage Guitar tube amp circuits

The lug press would be way more complicated because there are two tools and they have to be in a very rigid are exact alignment position
Plus the down force needed to swage the lugs between the two tools is more than what I need to insert lugs and the machine would have to be built way beefier

I may design a separate swaging machine after I see how well the lug placing machine goes

This also would let me run both machines at the same time.
One machine could be doing a run of boards inserting lugs and one machine could be swaging boards

One issue with moving the board is that I do up to 21 inch long boards and so the machine would have to be really wide in order to move the board max both directions
Maybe a 48 inch long-wide machine would be needed
But moving the board for swaging is how that machine would have to work because the two swaging tools would stay put and be mounting in a very solid way

[Michael Anton]

Couldn't you use the CNC machine that drills the holes to insert the lugs?  You would just need to create some sort of feeder to mount on the machine, and a pickup tool.  Assuming that the CNC machine can supply enough force to insert the lugs.

Have you considered just having bare PCBs made for you in the right shape with the holes already drilled?  FR4 PCBs are pretty inexpensive these days.

[Doug Hoffman]

Can't use the CNC machine
It is set up with a drilling fixture all the time in a dirty dusty machine rioom

They are not PCB's
They are custom turret boards that my customers deign in DIYLC and then have me make them

I am looking for into on grabbing the turret lugs and placing them 

[Doug Hoffman]

No one here picks and places parts that have to go into a drilled hole?

[bert shivaan]

Hi Doug, I would guess most all here are placing surface mount stuff. But I think your needs should be easy to solve maybe.

First the machine part is easy, it is no different than all the rest. the hard part comes with the interface between your lugs and holes. So first question is are either beveled to help start the lug into the hole?

On Sun, Sep 29, 2019 at 3:03 PM Doug Hoffman <hoffm...@comporium.net> wrote:

No one here picks and places parts that have to go into a drilled hole?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/a3e0875e-6298-4e2a-938d-38c7b856f6d2%40googlegroups.com.

[Doug Hoffman]

Thanks for the reply

There is no chamfer on the drilled holes or on the bottom of the lugs that go into the holes

I will be using linear bearing rails on the X any Y movements to get extreme accuracy there

I will design a lug pickup tool that holds it in an exact position
No slop in the lug holder tool
I am leaning towards a clamp type mechanism rather than a vacuum pickup tool

So next I am curious if the camera can locate the exact center of the drilled hole?
I have no experience with the whole camera thing

I am thinking I can get this done, but need more info on the camera system and how accurate it can be?
Thanks for you input on this

On Sunday, September 29, 2019 at 3:58:59 PM UTC-4, cncmachineguy wrote:

Hi Doug, I would guess most all here are placing surface mount stuff. But I think your needs should be easy to solve maybe.

First the machine part is easy, it is no different than all the rest. the hard part comes with the interface between your lugs and holes. So first question is are either beveled to help start the lug into the hole?

On Sun, Sep 29, 2019 at 3:03 PM Doug Hoffman <hoffm...@comporium.net> wrote:

No one here picks and places parts that have to go into a drilled hole?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.

To unsubscribe from this group and stop receiving emails from it, send an email to ope...@googlegroups.com.

[John Plocher]

If you use the same "CAD" between the two machines (drill and place) AND 

if your work holding / reference management is up to it, AND

if the two machines have sufficient precision, AND

the two are both calibrated the same, 

Then you should not need a camera to do the placement positioning :-)

Both machines will interpret the CAD file's "Drill hole for turret at (2.123, 4,567)" by moving to what they think is the same location.

Making sure it actually *is* the same location is the job of work holding and calibration, which may well use a camera for finding edges and fiducial marks;  things should "just work".

One will go to  (2.123, 4,567) and drill a hole, the other will go to  (2.123, 4,567) and stuff a turret.

  -John

[Michael Anton]

Yes, I understand they are turret boards, but you mentioned that the board is FR4 material, which is the same as used for PCBs.  I wasn't suggesting that you replace these with patterned PCBs, just that you could have the base board custom drilled to your specs probably cheaper than buying just the material alone (with increased lead time of course).  You would also get free solder mask, and a legend in the process.  Then install turrets, and you are done.

Sorry I couldn't offer the help you were looking for...

[Doug Hoffman]

Thanks John,

That's what I was thinking at first that I could pick and place without a camera

The two machines would have to be calibrated and the fixtures that hold the boards would have to be aligned exactly
I use precision ball screws and linear rails on the CNC, so it it pretty accurate in it's hole drilling

But Murphy's law is always in effect and things don't always work out the way you plan :)

So if I did want a camera on the Pick and place, can the camera find the exact center of a 0.09375 hole?
I am just not familiar with how the camera systems work and what they can do.

[bert shivaan]

The camera system can for sure find the hole center, and find the center of the lug with an up looking camera.

Having said that, I agree with others that your best bet would be to fashion a tool that could fit on your current CNC. then just place the lugs after you drill the holes. Or maybe it could be on the head such that every time you drill the hole, the lug gets shoved in it. 

If you go the second machine route, the fixturing is not a HUGE deal assuming you use a camera to locate the the board in both X/Y and Theta.

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.

To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/bd742d3d-aac3-4afc-a11d-26076925f03d%40googlegroups.com.

[Doug Hoffman]

The CNC drilling fixture is set up to drill two boards at one time with short carbide bits

Or if I am drilling a one off custom board, just one board is in the drilling fixture

The board material comes to me from my supplier ripped to 3.125 inches
And the board is covered on both sides with a thin peel off tape to protect the finish

The tape is peeled off both sides of the board material when I load the lugs and swage them

So there's no way to go from a drilling operation to a placing lugs operation on the CNC machine

This photo is a bit out of focus, but shows one piece of black board material that just got drilled

To unsubscribe from this group and stop receiving emails from it, send an email to ope...@googlegroups.com.

[tony wood]

Hi Doug,

attached some pictures of the clamp head for picking the LEDs. Essentially half tube jaw inside another half tube, both fixed into corresponding blocks, one fixed the other sliding on it and spring loaded, the servo is used to open the moving half. In my use clearance between LEDs is minimal. When I get back to the project I will probably try a vacuum pick up with a tube outer to locate on the ball ends of the LEDs.

I have built quite a few custom insertion "stations" or tools when I was tool making and they always have some interesting issues.

Several points to consider-

Number of units produced versus cost of equipment can govern how to approach this type of thing.

Can you drill location holes in your boards other than for lugs i.e. screw holes maybe to be used for location? Can you derive a set of hole patterns for various boards?

In your application a vee shaped type of clamp is preferable as it centers round pins better, allows for more positive location than a round split clamp.

Use of pneumatic cylinders is easier and more adjustable than fixed mechanical systems. (also can be used for swaging lugs into boards)

For something like this would consider a head fixture with a vertical travel only,or fixed and the board moves up and down as in something similar to 3D printer,  lugs are fed in when head is up via suitable feed system the lug is clamped, then inserted into board and swaged from underneath.

Just some ideas....

   

Cheers,

Tony.

On Sunday, September 29, 2019 at 6:34:22 AM UTC+13, Doug Hoffman wrote:

[Doug Hoffman]

That's cool, Thanks Tony

I am still sorting out mt clamping method
A tiny stepper motor and a V clamp pickup is the direction I am leaning presently

[Doug Hoffman]

I think what I am going to do for now is to create and test a Lug pickup tool using my 3D printer
Since I already have that unit sitting here and I don't use it that often, it's a perfect test unit.

I have 4 x Nema 17 motors and Bi-Polar stepper driver boards on the printer
I can unplug one motor and use the stepper driver for testing a lug pickup tool

I run my CNC machine and 3D printer using Mach3 
I am already familiar with Mach3 and so I may just stick with that for my pick and place machine

I ordered a small Nema 11 motor that I can use to create some sort of lug pickup tool
No sense in going any further until I work out how to pickup and place those Turret lugs :)