Techcon paste dispenser TS-250 / METCAL  DX-250 - Page 1
Forum section: electronics / general

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 23, 2015, 04:55:34 pm
content: Since I find it a hassle to use a syringe to apply solder paste to a PCB and using a stencil is too expensive for my small projects, I wondered if a paste dispenser would be worth it.The Techcon TS-250 is relatively affordable (like 400€ including VAT) and as it's rebadged by Metcal/OKi as DX-250, I guess it can't be so bad. Plus, it can be also used to apply glue which is a nice bonus.Main problem is that I'd need a (silent) compressor which I guess would be in the same price range as the Dispenser (e.g. the Sil Air 20D costs around 380€ including VAT).So does anybody here have some experience with the TS-250 or the DX-250? Is it worth it for the hobbyist or should I better save my money and continue with syringe and toothpicks?

author: neslekkim
author_rank: Super Contributor
timestamp: August 23, 2015, 05:30:40 pm
content: I guess you have read this thread?https://www.eevblog.com/forum/reviews/solder-pasteflux-manual-syringe-applicator/

author: Owen
author_rank: Contributor
timestamp: August 23, 2015, 05:41:20 pm
content: I think it's better to save your money and use a syringe for smaller projects and oshstencils for bigger ones. I've done both plus used an manual pick and place machine as well: Applying it with a syringe is a bit fiddly and i'm not as fast as with a pick and place machine but i'm also not slow as a snail. But you can't beat an stencil even with a manual pick and place machine it's so much more comfortable and it costs almost nothing ($5?). If you still want to buy a dispenser you can take a look at the "Dosiergerät TS9150" from Octamex (round about 300 Euros) plus an airbrush compressor.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 24, 2015, 01:06:40 am
content: Hm, that TS9150 looks like the $80 dispensers from AliExpress. Paying 100€ more for a digital one from a known company doesn't seem completely crazy, does it?Honestly, I'm not a big fan of having to use a compressor. I wonder why there are no stepper based dispensers available. I understand the only one commercially available is the Fishman SmartDispenser which looks very expensive and seems to be not really meant for solder paste.

author: artag
author_rank: Super Contributor
timestamp: August 25, 2015, 02:45:37 pm
content: Medical syringe pumps are motorised applicators. They're expensive new, but you can find them on ebay or at medical auctions.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 25, 2015, 05:11:43 pm
content: Hm, yeah, but I guess they are not really feasible for solder paste or glue application. Firstly, they are meant to be used with a hose. So (nearly?) all of them are large, heavy and bulky and simply can't be used to apply solder paste directly from the syringe. Secondly, I guess they are meant to slowly and steadily apply pressure to the syringe which is quite the opposite of what you want with solder/glue dispensers.Maybe I'm terribly wrong, but sticking a stepper motor to a cartridge holder and using some micro to drive the stepper and implement certain timings for dispensing/retracting solder doesn't sound like rocket science. It's mainly a mechanical/design problem to achieve the needed amount of travel without getting heavy/bulky. Also I guess one problem is that with standard cartridges/barrels, you can't pull back the piston. You'd probably need modified pistons which again means you couldn't use prefilled barrels without fiddling.

author: artag
author_rank: Super Contributor
timestamp: August 28, 2015, 01:46:55 pm
content: They're meant to be used with the syringe in the machine and the output feeding into a drip or canula. The machines themselves are mostly too big to be handheld, though there are some that are small.However, a hose wouldn't be a bad thing. What if you put a syringe filled with water in the machine, then a hose to the point of use. The water would feed into another syringe, back-to-back with the solder paste syringe. This would give a positive coupling between the two (far less elastic than air - that seems like a good thing but maybe not). I don't think the medical syringe pumps to a pullback but as you say, they're only a motor and thread - discard the original electronics and just keep the mechanical parts.My experiments so far along these lines have had a problem with the flow of the paste - it's too stiff. I possibly need to get the right paste before I can go very far.

author: zapta
author_rank: Super Contributor
timestamp: August 28, 2015, 01:58:30 pm
content: Quote from: 0xdeadbeef on August 23, 2015, 04:55:34 pmCan you explain?I am doing small projects with stencils. I buy the paste in 35-50g jars (including the $5 Mechanics from ebay), return the leftovers back the jar, and it last for long time.I am experimenting now with a DIY motorized syringe (see the other thread) and it works very well.BTW, these painting knives are very handy for managing the pastehttp://www.ebay.com/itm/5-pcs-PALETTE-KNIFE-Stainless-Steel-Spatula-Painting-Mixing-Knives-Set-/311339947311?hash=item487d4e952f

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 28, 2015, 05:23:21 pm
content: I meant that paying an extra $16 for a stencil where 10 PCBs only cost me $10 (and I need only two or three at all) is increasing the price per PCB quite dramatically.Anyway, while I still like the idea of a linear stepper for solder paste application, I think I found a better solution for my solder paste problem:http://www.hackeda.com/blog/start-printing-pcb-stencils-for-about-200/The Silhouette Portrait cutting plotter is currently available for ~180€ (even less on eBay) and there seem to be quite a few people using it or its bigger brother for SMS stencil creation.Ordered one yesterday - if it should work as expected, this would be a near perfect solution for my SMD soldering needs.

author: fivefish
author_rank: Frequent Contributor
timestamp: August 28, 2015, 07:36:05 pm
content: I don't know... for me, using air compressor + solder paste dispenser is faster for small jobs.No cleanup or setup needed. Very little wasted solder.And it's right there on my desk if I need a quick spurt, or doing a whole board.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 28, 2015, 10:47:32 pm
content: I see your point and if there wouldn't be other limiting factors, I'd actually like to have a proper solder paste dispenser as well.But for the moment, I don't have much room and don't like to have a loud and/or bulky compressor in my apartment.Besides, the cutting plotter is much cheaper than the solder dispenser alone, not to speak of a silent compressor.E.g. the Techcon TS-250 plus a Sil Air 20D would have cost nearly 800€.Anyway, let's see how this works out.

author: fivefish
author_rank: Frequent Contributor
timestamp: August 29, 2015, 12:50:02 am
content: The 982A unit I'm using is about $99 on eBay incl. shipping... and falling.you can fill up a small tank and hook it up to your dispenser. The compressor is NOT running all the time. When I'm filling up my air tank, it only runs for a couple of minutes.

author: packetbob
author_rank: Contributor
timestamp: August 29, 2015, 01:46:57 am
content: I tested my 983A dispenser with a portable 10 gallon compressed air tank (so no compressor, just the tank) and was able to get a good 1200 shots from a single tank fill...This is more than anyone may want to go in a single sitting...You would need to take the tank to a service station to refill it with air after every 1200 shots but you wouldn't need a compressor or it's noise...YMMV.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 29, 2015, 08:55:41 am
content: Yeah, regarding the dispenser, the problem is that I had to import it from China and while importing small/cheap stuff is not an issue, a package of this size would be stuck in customs for sure.Letting aside the fact that I'd then need to pay 19% VAT plus maybe some other fees, I'd need to waste half a (working) day at the customs office.And about the compressor: agreed that with a larger tank, the compressor doesn't run so often. Then again when you decide early in the morning or late in the evening that you want to solder something and the tank is empty, it's better to have a silent compressor. Besides, a large tank doesn't actually improve the matter of bulkiness.As I said: if one (hopefully not so far) day my place problem is resolved/improved, I will look into this again. Actually, having access to compressed air is useful for other things as well.Yet for the moment, I hope that the cutting plotter will be a viable approach. And if not, at least it didn't waste so much place and money

author: zapta
author_rank: Super Contributor
timestamp: August 30, 2015, 02:24:18 am
content: Please come back here and tell us how well the cutter works for you and how low you can get with pad pitch.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: August 30, 2015, 10:50:12 am
content: Yeah, cutting went pretty goodThe appended pic shows an IC with 1.27mm pitch and two SOT23-5 with 0.95mm pitch (test is 0805 and one 1206). Excuse the bad quality, I was lazy and used my el-cheapo USB microscope.The stencil was cut from Avery 3552 transparencies. I'm somewhat optimistic that also 0.65mm pitch should be possible. At least quite a few people claim that they reached 0.5mm with this approach.Also note that the distance between the pads of the SOT23-5 is only about 0.32mm.It's important to note though there is some trickery involved. The Silhouette Portrait I bought is a cheapish cutting plotter with a drag knife. The Silhouette Studio software that comes with the plotter is nice, but not really meant for cutting SMD pads. Actually it tries to cut polygons in one run, but this ruins the edges of SMD pads.However some clever guy has developed his own Python script to create plotter commands from a gerber file that are optimized for stencil cutting. E.g. the drag knife orientation is set on dummy lines outside the actual stencil and then e.g. all vertical lines are cut and the knife orientation is changed before cutting the horizontal lines. Since all of this is done in several passes, it needs several minutes to cut a small stencil and is rather loud due to lots of movements. Also setting up the script on Windows is a bit of work as it involves several other tools to convert the gerbers via several steps including PDF and some obscure PIC format.Anyway, I think this first trial looks pretty much perfect for my needs and the cutting itself is nearly no work at all. Export the top paste mask to gerber. Start the "Gerber2Graphtec" GUI, create the file and send it to the plotter. The only actual work is to clean the stencil from all these little cutouts.

author: Owen
author_rank: Contributor
timestamp: August 30, 2015, 11:39:12 am
content: Quote from: 0xdeadbeef on August 30, 2015, 10:50:12 amThat's looks good, congratulations. Can you also do 0402 if they are placed close together? BTW is that your normal board size? I would probly solder these kinds of boards still by hand. I'm using solderpaste only for boards with QFN stuff on it or boards with a lot of resistors/capacitors.