robrenz's take on a Vacuum Tweezer design

[robrenz]

Just a quick video on the design of the Vacuum tweezer valve I made about a year ago.

[BravoV]

Damn .. why can I click thumb up more than once at yt ?  .

Thanks and really nice piece of work you've done there.     

PS : Understand that piece of work must the 1st one you made right ? It looks so damn ugly  , better send it to me and make another much more nicer and new one to your self.    ... lol

[robrenz]

Thanks BravoV, I agree its not the prettiest thing I have ever made but in this case it was function over form on the first attempt.

[BravoV]

Yay .. so you agree to "surrender" that "ugly" tweezer to me ? .... j/k ... 

This video is really inspiring, its the idea that I love so much and the perfect (imo) execution & realization of it, definitely many-many thumbs up, keep this kind of videos coming. 

[JuKu]

You Sir, are a genius.

[chickenHeadKnob]

Such a Tease !   You didn't show it in action.  I just wanted to hear the noise it makes when sucking up and releasing. Just once. Its like the best video ever but then no money shot I mean happy ending.

[digsys]

As usual, excellent design / workmanship.

[robrenz]

You Sir, are a genius.

Thanks but I can't take credit, I am just using the gifts that were given to me.

[c4757p]

That is brilliant. I may have to try something like that.

[robrenz]

Thanks all for the generous comments, I am glad to see it may be inspiring some to make some mechanical stuff since that is my purpose in posting these.

[mrflibble]

Very nicely done. I love videos like these!  Always good for some inspiration. 

[nanofrog]

Very nicely done IMHO. 

[ablacon64]

Very nice work! As always! Man, I wish I had the talent and time to build such neat stuff. Let's see it in action!      

[TerraHertz]

Beautifully done! I'm very envious of your mechanical construction skill.
Incidentally, what kind of paint is that? Powdercoat, or just ordinary spray can?

Speaking of pneumatic 'capacitance', it amazes me how crummy all the motor-driven solder suckers I've ever used are. Put the tip on the pin you want to desolder, wait for it to melt, press trigger.... and slooooowly a pump turns on, evacuates the loooong tube, graaaadually begins to pull solder out of the joint... and if that works, you're lucky.

Why don't solder suckers use a large pre-evacuated chamber right behind the nozzle, and a quick-open valve close to the working tip (like yours) to initiate the suck? The objective is obviously to get all the solder out of the hole as fast as possibly, before reduced solder cross section causes big heat sinks (like internal ground planes) to freeze remaining solder. To do that you need to near-instantly expose the molten solder to a full vacuum (30" mercury) with as little impedance to flow as possible. Solder spatter filters should be on the other side of the reservoir, not between the tip and the reservoir. So what if you have to clean solidified solder out now and then.

This is why I prefer the simple mechanical soldapult type suckers - they act fast.

Anyway, the difficult part seems to me to be making a fast-open valve, that still works despite solder dust and spatter. And to get it close to the tip, it will be exposed to heat too.
I think your method would fail in the presence of solder spatters. For one, it's brass, and the solder could stick. Second, it doesn't have the strength to be able to chop off solder spatters that clogged the opening.

I wonder if there are such things as solenoid actuated small PSZ ceramic ball valves, with (say) about 4mm inner diameter?

[SeanB]

Substitute 316 stainless tube and plate for the brass, silver solder it and it will work in liquid solder with no problems.

[Rufus]

Anyway, the difficult part seems to me to be making a fast-open valve, that still works despite solder dust and spatter. And to get it close to the tip, it will be exposed to heat too.

It doesn't need to be that close to the nozzle to be a big improvement. Just behind the solder collection chamber and filter would eliminate the pump start up and about half the volume. You could add a vacuum 'accumulator' after the valve. A pinch valve on the silicone tubing would work there, you could even try it with your fingers.

[TerraHertz]

Anyway, the difficult part seems to me to be making a fast-open valve, that still works despite solder dust and spatter. And to get it close to the tip, it will be exposed to heat too.

It doesn't need to be that close to the nozzle to be a big improvement. Just behind the solder collection chamber and filter would eliminate the pump start up and about half the volume. You could add a vacuum 'accumulator' after the valve. A pinch valve on the silicone tubing would work there, you could even try it with your fingers.

But the point of what I was suggesting, was to use the solder collection chamber as the vacuum accumulator.
So it would be like:

 Tip&heater - valve - chamber - spatter filter------ flexible tube -------- pump and power unit.

The pump would have a vacuum sensor, and just run any time the chamber-tube-pump section wasn't at a good vacuum. So the primary suction is provided by the existing vacuum in the chamber, which could be as large a volume as required, while still being easy to hand hold. There are no moving parts apart from the valve (and pump, but that's an off the shelf item.)

The silicone tube pinch idea is not bad, though still better if electro-mechanical. Certainly wouldn't solder-clog. But I suspect it would deform with age and get slow to open.  Maybe a ceramic version of robrenz's slot valve?
The whole thing needs to be actuated by a small switch in the handle. I don't know about you, but I often end up juggling a soldering iron on one side of a board, the board (being too lazy to clamp it in something) and the sucker on the other side of the board. While doing that sort of stuff I'd just want a small 'go' button under a fingertip.

[robrenz]

Thanks again everyone

what kind of paint is that? Powdercoat, or just ordinary spray can?

It is just rustoleum metallic spray paint. It was the first can I grabbed out of the cabinet.

The silicone pinch valve would be good since its low thermal conductivity would help the solder not solidify in the valve itself like a metallic valve would tend to do. It also would conform to minor solder contamination and still seal reasonably well. But I would think the silicone would have to be fairly thick wall to not stick shut from the vacuum or be molded around a metallic actuation structure that would be able to rapidly and forcibly open the valve to maximum opening. A tri petal heart valve style valve in silicone may also work with mechanical actuation.

The other approach would be to have a metallic or ceramic valve extremely close to the tip and be at the same de-soldering temperature as the tip so the solder cannot solidify in the valve. Then the accumulator chamber directly after the valve with staggered baffles that would force the solder to solidify without seriously restricting the flow. Then a standard element filter at the vacuum pump to protect it. Also use large bore tubing to add to the accumulator volume.

[pickle9000]

Robrenz, is the valve gap adjustable or is it fixed? If adjustable how did you do it?

Nice design, functional is beautiful.

[robrenz]

The gap is fixed. The rear flex tube section was soldered in place to the main spring steel body piece first with proper slot orientation. Then the complete front part with the luer taper and the square block with the slot was clamped to the spring steel body and fiddled with until the valve was super close but did not stick. Then a very careful soldering of the luer taper end only so I didn't remelt the soldered joint of the square block that is soldered over the ovalized tube.  This was thrown together quickly of necessity from what I had on hand so optimum design for manufacture and assembly and asthetics were not a high priority. Lets face it, its ugly.   The only thing that keeps it from looking like a junk yard refugee is the paint