How's the working mechanism of the sucker or pump suction in Hakko desoldering gun or other product alike?

 

How's the working mechanism of the sucker or pump suction in Hakko desoldering gun or other product alike?

Suction...

It gets hot and sucks. Not sure what answer you're expecting, but that's all it does.

 

How's the working mechanism of the sucker or pump suction in Hakko desoldering gun or other product alike?

It's usually a small vacuum pump. Doesn't take much vacuum to do desoldering.

 

It's usually a small vacuum pump. Doesn't take much vacuum to do desoldering.

Ok, your interpretation of "mechanism" made more sense than mine. I thought he was asking about "principle of operation."

 

The mechanism is an O-Ring sealed single stroke vacuum pump that is powered by a spring. There is a mechanical hand operated release on the latch that holds it in the cocked position. TRiggering it causes the spring to rapidly withdraw the piston, creating the vacuum. The exact nature of the latch varies with model.

 

The mechanism is an O-Ring sealed single stroke vacuum pump that is powered by a spring. There is a mechanical hand operated release on the latch that holds it in the cocked position. TRiggering it causes the spring to rapidly withdraw the piston, creating the vacuum. The exact nature of the latch varies with model.

I think he is talking about the gun which has a hollow core soldering tip:

 

The mechanism is an O-Ring sealed single stroke vacuum pump that is powered by a spring. There is a mechanical hand operated release on the latch that holds it in the cocked position. TRiggering it causes the spring to rapidly withdraw the piston, creating the vacuum. The exact nature of the latch varies with model.

I don't think that most Hakko desoldering guns use a manually operated spring vacuum pump, but rather an electrical vacuum pump in the hand piece or in the base station.

They also strike me as being very overpriced. I notice that they sell the classic hand desoldering pump for $18.97 when you can buy a set of five of them on Amazon for $9.

 

I used a powered, vacuum desoldering station years ago and it's principle was to heat the junction with a hollow tube head, like a soldering iron, then the operator would step on a floor switch which would activate the vacuum pump. That would rapidly draw the molten solder melted by the head into the hot iron and then gravity would drop the heavy solder into a fabric lined glass jar (small, like 1.5" in diameter and 1" tall) hanging at a right angle to the iron. The insulated grip for the operator was after that as was the power cord. So it looked much like a regular soldering iron with the exception of the glass. With the glass vessel it was easy to see whether or not it needed to be emptied.

 

...it's principle was...

Glad to see I'm not the only one who saw "mechanism" and thought "principle of operation" rather than "physical apparatus."

 

@strantor: I'm happy to be your 2nd.

But I was just rambling as remembering that apparatus was a treat. That was back in the '80's and I had eye hand coordination difficulties with it, but it was cool.

 

They also strike me as being very overpriced. I notice that they sell the classic hand desoldering pump for $18.97 when you can buy a set of five of them on Amazon for $9.

Whether is it overpriced depends on your requirements. We use the Hakkos in an undergrad electronics lab and they worked for years, easily, with only a little instruction.

On the other hand, even the high quality Edson SOLDAVAC piston pumps didn’t hold up. The mechanism was generally OK but the PTFE tips (not particularly cheap) while intended to be consumable, didn’t last in the lab. They were mangled and generally a mess.

Also, the skill level needed to operate that sort of tool meant it ranged from frustrating to useless for almost all the undergrads. The Hakko, on the other hand, just worked. It was easy and aside from needing to be cleaned regularly, it was pretty much problem free.

Even in an environment where there are careful, responsible, skilled operators the speed difference between the piston pump and the Hakko could easily justify the expense.

 

I had been aware of the existence of assorted powered vacuum desoldering devices, and I think I can recall actually seeing one in operation years ago. But my familiarity is only with the hand operated devices. Certainly the melted plastic tips are always a challenge to adequate performance, and the very limited volume of suction is always not quite enough to do the job correctly.
So the requirements for the optimum de-soldering system are: #1. Adequate thermal mass at the melting location to hold the solder melted until it is removed, #2. An adequate air flow to sweep the molten solder away, #3. Heating tip material able to last long enough to complete the task of solder removal while maintaining it's shape. Reasonable temperature control is also important, but not at the show-stopping level of importance.
Adequate air flow mandates either a high capacity vacuum pump and a high-flow suction hose, OR a vacuum pump with a reservoir, high flow solenoid valve, and a high-flow suction hose. Either will require a control button on the soldering implement or a foot operated switch.
Thus a really useful de-soldering system does consist of a few items that will not be cheap.

 

I've always used either solder wick or the old-fashioned hand-operated spring & piston pump. The one I have I bought at Radio Shack about thirty years ago and I still have the original tip. I don't know what it's made of, seems like nylon, but I'm not at all certain. It shows almost no signs of melting. I almost always get complete removal of solder from normal connections. The only time that I have issues is when trying to remove solder from significantly larger items that have been soldered, but those usually have sufficient thermal mass that I can operate the pump multiple times to suck it off. I typically use solder wick on fine-pitch components (which, for me, tend to also be high pin count items) because the reach of the solder pump is so short that it takes too long to work my way around the part and solder wick works particularly well (for me) in those situations.

 

I've always used either solder wick or the old-fashioned hand-operated spring & piston pump. The one I have I bought at Radio Shack about thirty years ago and I still have the original tip. I don't know what it's made of, seems like nylon, but I'm not at all certain. It shows almost no signs of melting.

Yes, the tips can last a long time—but they can also be destroyed by an unskilled operator. It also requires some skill to get the tip in a position where it will effectively suck up the molten solder. This is part of the reason for the destroyed tips, the unskilled operator thinks shoving the tip up to the iron is the answer.