Source of dispensing solderpaste?

Started by SteveW, May 23, 2014, 02:54:13 PM

Previous topic - Next topic

SteveW

Actually, how about a standard HSS twist drill for the auger? Available in lots of sizes, made to decent accuracy, cheap...

Mike

Another thought I had from the DIY angle is that if the main issue with compressed-air systems is the springiness of the air, maybe a hydraulic system (maybe water rather than oil) might be an option, perhaps driven by a peristaltic pump.

SteveW

I was thinking just yesterday - could you do something like an inkjet printer, and have a reservoir of paste that you thwack with a solenoid to shock some paste out of the needle? Knowing my luck, paste does humorously non-Newtonian things under a shock load, and seizes solid...
Push paste into the reservoir by air from a syringe, same as usual.

Gopher

I think I got the impression from a manufacturers video that they used an archimedian screw to deliver a constant flow of paste to some kind of actuator that then spat it out as dots. Essemtec offer a range of options to bolt on their pick and place machines including time/pressure, screw and piezo. The quickest option they call jet which does use air but the mechanical voodoo is not apparent.

Mike

Just found this video of Mydata's MY500 paste jet printer - apparently it uses special paste:
http://www.youtube.com/watch?v=cC41j-LJZm4
They claim up to 500 dots/second
Just struck me that the piston reminds me of the old dot-matrix print heads - I wonder.....
Also Essemtec have this, which think is based on a piezo actuator. Aparently way cheaper than Mydata, and uses standard fine-pitch paste
http://www.youtube.com/watch?v=SZ-Kq2Gkm5Y

Mike

Just found this Mydata patent that shows an auger surrounded by a stack of o-rings, to stop the solder particles getting squashed
https://www.google.co.uk/patents/US6450416?dq=mydata+paste&hl=en&sa=X&ei=RMMdVaOiJ4LZauSFgIgO&ved=0CDUQ6AEwAw


SteveW

Yeah, that's about what Dima charge. It's why I live in fear of my pump failing...

That said, disposable heads are only £24 each (in 10-off)
http://www.adhesivedispensing.net/DMP6R_10_Feed_paths_p/dmp6r-10.htm
with an interesting pic of the auger.

Mike

Interesting - pity they're only available in tens though.
Looks like  these wouldn't be too hard to use as the basis of a DIY system. 

Gopher

So all the money goes on a motor, controller and a pretty housing? Madness, I was expecting way more engineering than those pictures suggest.

SteveW

Quote from: Mike on May 16, 2015, 11:51:44 AM
Interesting - pity they're only available in tens though.
Looks like  these wouldn't be too hard to use as the basis of a DIY system. 

Singles here...
http://www.dosieren.de/en/products/cat/ersatzspindeln.html

Mike

This guy seems to have got good results using that replacement auger unit
https://youtu.be/PeYb3snGrU8

SteveW

Straight flux is a lot* easier than solder paste, though - there's none of the pain as the flux is squeezed out leaving a pellet of compressed solder balls.

I've started looking at 3D printer nozzles instead of dispensing needles. Still metal, and nicely controlled tapers. They also let me stop messing about with the spacer foot and shims, and just file or mill the standoff into the nozzle.
This sort of thing
http://www.aliexpress.com/item/10pcs-lot-3D-Printer-Nozzle-Mixed-Sizes-0-2mm-0-3mm-0-4mm-0-5mm-Print/32246531754.html
Next step is to try to use a (decent) twist drill as the pump - I've got the makings but not the time yet.

* orders of magnitude. Flux is what I use to purge mine when it's being a dick (more truthfully, when I don't have the  temperature high and equalised, but even then, some days, it just won't run right for long. Coming back the next day fixes it, no amount of messing about changing things does).



dirk1980

Hello.
I just bought a DOTMASTER SMDU-5000.
Unfortunately, the serial cable is not included.

A standard cable seem not to work, does anyone have the exact assignment  DB9 (PC) -> DB25 (device)?

Regards, Dirk

SteveW

Hi, did you get this sorted?
Been hellish busy here, but grabbed these photos.

I've also come up with a crude but reliable heater method that doesn't need the whole room heated to 35 degrees, and comes up faster. I was planning all sorts of stuff with resistors screed to the dispense block, nice PID control, but -

A car headlight bulb mounted next to the home position, run from a bench PSU. Heats the black anodised block and paste syringe nicely.
Sigh. It's so crappy, but so effective.