A Simple Electrical Powered Vacuum Desolder Suction Pump - Beginner Level

[Mechatrommer]

ok.... took some effort and time here to complete this report... esp the first picture...  but, just for the sake of sharing.
WARNING: this is the simplest circuit around, so for PRO, dont expect to learn anything, but CC are welcomed.
WARNING: its ugly! its gross! so dont expect the luxury of Altium, PCBCart or Polycase etc.

intro:
I've been using Vacuum Desolder Suction Pump (Manual) and try to create the electrical powered version using PIC Microcontroller.
So i got some pictures here, but i think, its better if i start with this one, as majority here expecting and are EE literate people.



How it works?

1) We press the S1 (switch) for the first time, the motor will pull the Suction Pump to energize it (pictures follow)
2) There are S2 and S3 to detect the position of the Pump Handle, which upon closing, the motor stop pulling or releasing (S3, S2)
3) The next S1 press, the motor will release the handle even further, which in effect, pulling a string connected mechanically, to push the blast button on the Desolder Pump (Yellow Button)
4) After the blast, motor will automatically re-energize the pump as in Step (1) and (2) and back to Step (3) again and again.

[Mechatrommer]

Here is the "photoshopped" picture i use to make the PCB, the brown colored are the copper running below, the blue are the components (above), the yellow are the conductor running above.



and here are some of the real deal (plssss, dont laugh):

[Mechatrommer]

and here is the source code
http://www.ximplify.com/members/soasystem/2010593151.c

Hope some beginners will find the info usefull Cheer!

p/s: for the LM317, pic12f509, C945. you can google the net for the datasheet
my favourite http://www.datasheetarchive.com/

[Pyr0Beast]

Seems nice. How is with the performance on such a long tube ?

Might use windshield wiper motor. They are really cheap and pretty strong

[Mechatrommer]

"Might use windshield wiper motor"
thats the motor for "black screen for my previous car rear mirror, i dont know what to call in english, its like a curtain that you can move up or down by the motor to block/allow sun light from coming in. the curtain is like semi transparent. The motor got built in gearing, casing and shaft. so i just use it as it is with no extra effort. Quite strong with its low gearing ratio.

"Seems nice. How is with the performance on such a long tube ?"
really really bad! that i dismiss this project right after i completed the software and fully tested it. The suction performance is really poor. Since from observation, the suction mechanism should be assited by certain level of shock/vibration on to the PCB (just as when we use it manually) maybe to lift a little bit the molten solder up and easily being sucked up. One of main reason i built this stuff, is to remove that vibration, coz i really hate it, its like cracking the component next to it while sucking. it turn out, it is this vibration that help the suction performance. Really Bad Design Criteria! I concluded it as mechanical failure.

But the circuit might be applicable for another usage, i dont know, use your imagination

[Pyr0Beast]

thats the motor for "black screen for my previous car rear mirror, i dont know what to call in english, its like a curtain that you can move up or down by the motor to block/allow sun light from coming in. the curtain is like semi transparent. The motor got built in gearing, casing and shaft. so i just use it as it is with no extra effort. Quite strong with its low gearing ratio.

Sunroof ?

Yes, those are quite strong. Windshield wiper motor is a bit overkill for this actually.

really really bad! that i dismiss this project right after i completed the software and fully tested it. The suction performance is really poor. Since from observation, the suction mechanism should be assited by certain level of shock/vibration on to the PCB (just as when we use it manually) maybe to lift a little bit the molten solder up and easily being sucked up. One of main reason i built this stuff, is to remove that vibration, coz i really hate it, its like cracking the component next to it while sucking. it turn out, it is this vibration that help the suction performance. Really Bad Design Criteria! I concluded it as mechanical failure.

Heh. Too bad for that as I could use something automated.

Hmm. Might be the vibration helping it.
I use the same pump and I hate the kick it gives when you trigger it, it is enough to strip a pad or send the solder flying around. It is better than most other pumps, but not by much.

As far as design goes. Use snubbers across relay terminals and a diode across relay coil to prevent kick-back from it.
Seems most of this stuff is recycled anyway

[Mechatrommer]

"Sunroof?"
no... curtain for rear windshield. at the back.. not at the top.

"Use snubbers across relay terminals and a diode across relay coil to prevent kick-back from it"
thanx. will look into it for the next project in fact somehow, i'm aware of it. i just neglect it, thats why u saw some component are added later after the PCB making (due to noise problem), but since there is no kickback problem, i just leave it as is.

"strip a pad or send the solder flying around"
thats the point. before it fly somewhere else, it will fly directly inside the "sucker"

"Seems most of this stuff is recycled anyway"
u bet it. some... but not "most"... and 100% sure those components will be re-recycle later for the next project

[Pyr0Beast]

From wiki;

A snubber is a device used to suppress ("snub") voltage transients in electrical systems, pressure transients in fluid systems, or excess force or rapid movement in mechanical  systems.

What it does is simply to prevent most of the sparking in relays and wear on contacts. It does not eliminate sparks completely, but reduces them as much as possible.

no... curtain for rear windshield. at the back.. not at the top.

I know what you mean, but I don't know the words for it

[Mechatrommer]

so i guess snubber in electrical system is capacitor? right?

[Pyr0Beast]

Capacitor and resistor in series.

[philbx1]

I was looking at doing something similar myself, although with a different setup which involved
a cheap 12v DC car tyre pump running in reverse (think Supercheap Autos).
So far I have the pump, but haven't pulled it apart to see if I can change the valve setup.
Probably not a great idea, but maybe something else to look at...

[saturation]

Love the look, the effort for trying using a lot of makeshift parts gets 10/10 in my book, very home electronics!  Kudos to your effort.  

A lot depends on the mechanicals and less the electronics: tubing, shape of the orifices etc.,  The handheld vacuum pump demos' that nicely, low potential energy stored in the spring and the volume of the main cylinder, released into a tiny rigid nozzle, creating a very high vacuum for a very short time period.  If you've owned that blue pump for a while you'll note that as it wears out, the orifice size enlarges, and the vacuum drops, its vacuum is better when its smaller.

How did you create the vacuum, by venturi effect?

If you did, the length and rigidity of the tube matters a lot.   You can get a higher suction via venturi effect by using pressurized gas across a T tube, but a lot still depends on the mechanicals and less the electronics, since the primary function is a mechanical effect.  Finding the tube is key. 




May I suggest you buy something like this with a decent suction.  Then modify the nozzle to make it smaller and rigid, it will create a higher suction at the tip, even for elcheapo units.  you can make the nozzle out of a glass funnel, it resists heat, and make a filter screen out of a metal mesh.  You can redesign the electronics controller to adjust the speed if it turns out to be too strong or just because  .



You can get glass funnels in chemistry supplies or online:

[Mechatrommer]

Love the look, the effort for trying using a lot of makeshift parts gets 10/10 in my book, very home electronics!  Kudos to your effort. 

thank you. i dont think i will get any compliment for this. so, i'm quite surprised i just want to share some idea.

A lot depends on the mechanicals and less the electronics: tubing, shape of the orifices etc.,  The handheld vacuum pump demos' that nicely, low potential energy stored in the spring and the volume of the main cylinder, released into a tiny rigid nozzle, creating a very high vacuum for a very short time period.  If you've owned that blue pump for a while you'll note that as it wears out, the orifice size enlarges, and the vacuum drops, its vacuum is better when its smaller.

yes i noticed the tip enlargement due to burnt by solder heat. and agreed that when the tip hole area is smaller it will create higher speed of in rush air to replace in vacum area (hence produce lower pressure, higher suction effect)

How did you create the vacuum, by venturi effect?

Man! u got me here, never heard of the effect's name even tough i'm mechanical, what a shame . (or maybe i already forgotten that, too long that i have abandon the mechy thing) but somehow, i knew the effect very well, coz its related to Bernoulli's Principle. got to googled the wiki a bit to understand the "venturi" effect

Yes, its venturi effect (pressure differential) that sucks the solder. The motor will pull the pump handle, just like when we push it with our hand in handheld mode. And then release of it is by reversing the motor, hence pushing back (spring) the handle to the "rest" position, and then by mechanical mean, push the yellow button (and release the spring energy). This project is nothing more than just replicating our hand action while operating the pump in handheld mode (with no electronic) with just additional tubing and DIY tip with switch.

If you did, the length and rigidity of the tube matters a lot.   You can get a higher suction via venturi effect by using pressurized gas across a T tube, but a lot still depends on the mechanicals and less the electronics, since the primary function is a mechanical effect.  Finding the tube is key. 

Yes, the rigidity of tube is critical. I bought a stiffer tube, but after trying it, i dont think i like it... too stiff. I just use less stiffer (more flexible movement) tube, from observation it should reduce the pressure differential just a little bit.

Analyzing the picture you provided, its something like exhaust system, or "air mixer" or sometype. Quite similar to Bunsen Burner or our "classic" household Butane gas kitchen cooker here in my place, where the Butane Gas and air is mixed through a hole. I think the key point in venturi effect is air velocity, coz that is the relation with pressure (Bernoulli). The stronger the compressor/pump/pressure, the higher the velocity, hence the lower the surrounding air pressure along the high velocity air. the lower the pressure, the higher the suction effect will be (through pressure differential). f(PV)=some constant, P=pressure, V=velocity

May I suggest you buy something like this with a decent suction.  Then modify the nozzle to make it smaller and rigid, it will create a higher suction at the tip, even for elcheapo units.  you can make the nozzle out of a glass funnel, it resists heat, and make a filter screen out of a metal mesh.  You can redesign the electronics controller to adjust the speed if it turns out to be too strong or just because  .

Thanx, will keep the idea in mind. FYI, the nozzle i used is from cut down radio antenna (metal, with varying diameter, the one we can push to become shorter type), i've tried smaller nozzle, but i got annoyed with dried sticky solder around the internal wall of the nozzle, take some effort to take it out. i guess becoz its cylindrical shape, maybe i should get conic shaped nozzle. Yea, u gave me some idea, just thought about it just now thanx. If i found the suitable nozzle tip, maybe i should redo this project

[Mechatrommer]

I was looking at doing something similar myself, although with a different setup which involved
a cheap 12v DC car tyre pump running in reverse (think Supercheap Autos).
So far I have the pump, but haven't pulled it apart to see if I can change the valve setup.
Probably not a great idea, but maybe something else to look at...

what tyre pump are you talking about? coz in my life, i've found 2 type of tyre pump. the "hand or foot push and pull" pump, and another one is a simple 12V motor mechanically connected to a mechanical "compressor like" pump. I tossed the 12V motor with pump away, coz it took too long time to pump the tyre, and usually smoke will come out of it due to its increasing temperature (elcheapo type).

if you are talking about the "hand push pull" pump type, i think this kind of circuit (with adjustment of timing in the software code) will be usable, except i think you are going to need more powerfull motor or lower gear ratio as the "hand" pump is much more difficult/heavy to push.

In Mechanical, the hand push pull tyre pump is using another principle called "Pascal Principle" in hydraulic system. the valve inside is just a one way valve that will let air flow in one direction only (into the tyre) but will be closed if the air is trying to go out. Just like a diode in electronics

[saturation]

Yes, Venturi is just the design, Bernoulli is the physics behind the effect.  If you make the nozzle out of glass, you can see if its blocked, and solder doesn't stick to glass well.  The vacuum pumps are made of plastic, and even if heat resistant as it deforms, it tends to stick solder near the nozzle; luckily the nozzle also get bigger as it wears, so most solder gets through.  To maximize the effect, I always had to clear it with a paper clip.

At point #2, the drop in pressure will create a 'suction' ,h, relative to ambient.

Love the look, the effort for trying using a lot of makeshift parts gets 10/10 in my book, very home electronics!  Kudos to your effort. 

thank you. i dont think i will get any compliment for this. so, i'm quite surprised i just want to share some idea.

A lot depends on the mechanicals and less the electronics: tubing, shape of the orifices etc.,  The handheld vacuum pump demos' that nicely, low potential energy stored in the spring and the volume of the main cylinder, released into a tiny rigid nozzle, creating a very high vacuum for a very short time period.  If you've owned that blue pump for a while you'll note that as it wears out, the orifice size enlarges, and the vacuum drops, its vacuum is better when its smaller.

yes i noticed the tip enlargement due to burnt by solder heat. and agreed that when the tip hole area is smaller it will create higher speed of in rush air to replace in vacum area (hence produce lower pressure, higher suction effect)

How did you create the vacuum, by venturi effect?

Man! u got me here, never heard of the effect's name even tough i'm mechanical, what a shame . (or maybe i already forgotten that, too long that i have abandon the mechy thing) but somehow, i knew the effect very well, coz its related to Bernoulli's Principle. got to googled the wiki a bit to understand the "venturi" effect

Yes, its venturi effect (pressure differential) that sucks the solder. The motor will pull the pump handle, just like when we push it with our hand in handheld mode. And then release of it is by reversing the motor, hence pushing back (spring) the handle to the "rest" position, and then by mechanical mean, push the yellow button (and release the spring energy). This project is nothing more than just replicating our hand action while operating the pump in handheld mode (with no electronic) with just additional tubing and DIY tip with switch.

If you did, the length and rigidity of the tube matters a lot.   You can get a higher suction via venturi effect by using pressurized gas across a T tube, but a lot still depends on the mechanicals and less the electronics, since the primary function is a mechanical effect.  Finding the tube is key. 

Yes, the rigidity of tube is critical. I bought a stiffer tube, but after trying it, i dont think i like it... too stiff. I just use less stiffer (more flexible movement) tube, from observation it should reduce the pressure differential just a little bit.

Analyzing the picture you provided, its something like exhaust system, or "air mixer" or sometype. Quite similar to Bunsen Burner or our "classic" household Butane gas kitchen cooker here in my place, where the Butane Gas and air is mixed through a hole. I think the key point in venturi effect is air velocity, coz that is the relation with pressure (Bernoulli). The stronger the compressor/pump/pressure, the higher the velocity, hence the lower the surrounding air pressure along the high velocity air. the lower the pressure, the higher the suction effect will be (through pressure differential). f(PV)=some constant, P=pressure, V=velocity

May I suggest you buy something like this with a decent suction.  Then modify the nozzle to make it smaller and rigid, it will create a higher suction at the tip, even for elcheapo units.  you can make the nozzle out of a glass funnel, it resists heat, and make a filter screen out of a metal mesh.  You can redesign the electronics controller to adjust the speed if it turns out to be too strong or just because  .

Thanx, will keep the idea in mind. FYI, the nozzle i used is from cut down radio antenna (metal, with varying diameter, the one we can push to become shorter type), i've tried smaller nozzle, but i got annoyed with dried sticky solder around the internal wall of the nozzle, take some effort to take it out. i guess becoz its cylindrical shape, maybe i should get conic shaped nozzle. Yea, u gave me some idea, just thought about it just now thanx. If i found the suitable nozzle tip, maybe i should redo this project

[Mechatrommer]

Yes, Venturi is just the design, Bernoulli is the physics behind the effect.  If you make the nozzle out of glass, you can see if its blocked, and solder doesn't stick to glass well.  The vacuum pumps are made of plastic, and even if heat resistant as it deforms, it tends to stick solder near the nozzle; luckily the nozzle also get bigger as it wears, so most solder gets through.  To maximize the effect, I always had to clear it with a paper clip.

thanx, i'll look into and try to find this conic glass nozzle that will fit in.

[philbx1]

I was talking about the 12v compresser type pump. Also I've noticed as tyre pumps go that this one really does "suck" 

But now after the recent posts re. venturi effect this has me thinking that a crappy little pump like this may just have enough power to blow (thus suck) with minimal smoke from the motor as I'd be running it for only a few seconds.
No micro etc. just a simple momentary (maybe even foot) switch.

Just wondering what you think of that?

I was looking at doing something similar myself, although with a different setup which involved
a cheap 12v DC car tyre pump running in reverse (think Supercheap Autos).
So far I have the pump, but haven't pulled it apart to see if I can change the valve setup.
Probably not a great idea, but maybe something else to look at...

what tyre pump are you talking about? coz in my life, i've found 2 type of tyre pump. the "hand or foot push and pull" pump, and another one is a simple 12V motor mechanically connected to a mechanical "compressor like" pump. I tossed the 12V motor with pump away, coz it took too long time to pump the tyre, and usually smoke will come out of it due to its increasing temperature (elcheapo type).

if you are talking about the "hand push pull" pump type, i think this kind of circuit (with adjustment of timing in the software code) will be usable, except i think you are going to need more powerfull motor or lower gear ratio as the "hand" pump is much more difficult/heavy to push.

In Mechanical, the hand push pull tyre pump is using another principle called "Pascal Principle" in hydraulic system. the valve inside is just a one way valve that will let air flow in one direction only (into the tyre) but will be closed if the air is trying to go out. Just like a diode in electronics

[Mechatrommer]

i think what u need is a more powerful or faster motor. no mcu is needed. there is nothing u can do "electronically" inside the compressor, its all just some mechanical stuffs there. reversing the motor will not do any different, its just the same happening when in forward, ie pumping. if... you talking about:

[saturation]

Yes, a small motor can create a large suction if you make the nozzle correctly, but a bigger one always helps.

Since the handvac was already designed to provide some suction as is, if you reduce the nozzle size, the vacuum will rise.

The switch is mechanical on hand vacs, but if you modify the motor drive to PWM, you can give burst outputs of voltage or simply make an MCU for variable speed, so you have more control over suction, than a simple on/off approach.

Also the handvac is a bit big for desoldering, and the switch is not conveniently placed, so you can have much fun making a mod to a device that, when finished, has a great chance of being practical.

I was talking about the 12v compresser type pump. Also I've noticed as tyre pumps go that this one really does "suck"  

But now after the recent posts re. venturi effect this has me thinking that a crappy little pump like this may just have enough power to blow (thus suck) with minimal smoke from the motor as I'd be running it for only a few seconds.
No micro etc. just a simple momentary (maybe even foot) switch.

Just wondering what you think of that?

[/quote]

i think what u need is a more powerful or faster motor. no mcu is needed. there is nothing u can do "electronically" inside the compressor, its all just some mechanical stuffs there. reversing the motor will not do any different, its just the same happening when in forward, ie pumping. if... you talking about:

[Kiriakos-GR]

Thats my solution ... and even if it is out of production, still works..

[Mechatrommer]

Yes, a small motor can create a large suction if you make the nozzle correctly, but a bigger one always helps.

now i get it, hissyfet is talking of using 12V motorized tyre pump to suck the solder? maybe i misunderstood, sorry. even if we can reverse the pump, i dont think it will be powerful enough to do the suction, i think its becoz in the design of the pump itself.

and saturation is suggesting of using vacum cleaner motor to suck.. hmmm... ok.. thats an idea. but i still think the spring energized suction is more powerful. the sound and speed when the spring is released, is enuf to make me scared.

@Kiriakos-GR: is the gun works satisfactory? any vibration created during the suction? 350degC min adjustable temp? it will burn some of the sensitive chip out! i saw this in ebay, but a little bit pricier for my taste... i think.

[Kiriakos-GR]

@Kiriakos-GR: is the gun works satisfactory? any vibration created during the suction? 350degC min adjustable temp? it will burn some of the sensitive chip out! i saw this in ebay, but a little bit pricier for my taste... i think.

Great tool , made in Japan.  
This tool had helped me lots of times when I had to deal with PCB that has thin copper lines.
This tool its not specialized for SMT work ... so the specs are great,
for the use that it was designed to have.

About " bit pricier " ,  its about comparisons , comparing it with thin air , its expensive .
Same story as with the Fluke 87V .


 

[saturation]

Ah remember too, this is a project, so part of the fun is in making this work, not that you could buy something to solve the problem and be done!

Yes, a small motor can create a large suction if you make the nozzle correctly, but a bigger one always helps.

now i get it, hissyfet is talking of using 12V motorized tyre pump to suck the solder? maybe i misunderstood, sorry. even if we can reverse the pump, i dont think it will be powerful enough to do the suction, i think its becoz in the design of the pump itself.

and saturation is suggesting of using vacum cleaner motor to suck.. hmmm... ok.. thats an idea. but i still think the spring energized suction is more powerful. the sound and speed when the spring is released, is enuf to make me scared.

@Kiriakos-GR: is the gun works satisfactory? any vibration created during the suction? 350degC min adjustable temp? it will burn some of the sensitive chip out! i saw this in ebay, but a little bit pricier for my taste... i think.

[Mechatrommer]

Ah remember too, this is a project, so part of the fun is in making this work, not that you could buy something to solve the problem and be done!

yup! in the middle, many things to learn and experience, but... if i only got the money (budget.. to be accurate), that is a very nice picture there, i can just simply grab that and do another more sophisticated project but for now.... the handheld one is still doing its job

[Kiriakos-GR]

We all use the hand-held pump ,  still there is some times , that the damp ass who designed the PCB ,
to had made very thin the PCB trace ends ,  so small that by heating the component , the trace dies too.

In a such special case, the motorized pump , will act that fast and accurately , that the PCB trace will be saved , for another one or two " part replacements" .

Another special use to justify one motorized pump, are when you deal with round connectors,
with 15 - 20 - 40 pins (telecommunications ).

And one last " Gain " with it , are the Hot air in the reverse mode.
That you can diagnose one part by heating it ...  the reverse of the Freezing spray .