17mm & 20/26/27mm single-sided DD/FET driver release: A17DD-SO8 / A20DD-SO8 / etc

Do you mean that you don’t find it more convenient or that you haven’t been able to order one?

I only have a stencil for LEDs (TP’s stencil) and I always have a lot of trouble getting the paste to deposit properly. (Either not evenly, not at all, etc.) I don’t use a PCB jig, but I do use extra PCBs to level the stencil. Ordering the stencil is easy, just download the zip of Gerbers from the appropriate OSH Park listing and upload it to OSH Stencils. While the amount of solder paste deposited on any one pad is significantly less important with drivers than with LEDs, I still can’t imagine myself getting results like DBCstm showed.

Also the syringe is pretty easy to use and is flexible. I make a lot of layout changes, both minor and major. That would require a lot of stencils.

As I recall, you can upload the entire zip file and when ordering it will use the proper layers.

https://www.dropbox.com/s/njyq3ncg5zha6fw/17mm_A17DD-SO8_v024.zip?dl=0

And yes, texaspyros stencil for the emitters is immensely helpful, I use them a lot…need to get some new one’s as a matter of fact.

I had ordered 2 of these for the A17DD-S08 and that was good, because it allowed me to cut a left and a right to do the 6 board page. :slight_smile:

Edit: Sorry, I use Kester EP256 in a syringe. I find it has the best flow and is easier to appy. The Mechanic’s in the tub is thick and sticky, very difficult to use with a stencil.

Like your video, DBCstm! I never realized how easy surface mount could be.

For those of you sourcing parts from Digikey… did you know if you prepay your order with a check they will ship for free? I haven’t ordered from them in a while, but this is what the front of my old catalog from 2007 says, “When a check or money order accompanies your order, Digi-Key pays all shipping and insurance (our choice for method of shipping) to all addresses in the USA and Canada, unless such charges exceed 10% on orders of $200 or less, or 5% on orders greater than $200. Digi-Key will notify you prior to shipment if these conditions exist.”

I took advantage of this several times when I was selling a circuit board that I had designed. I never had them not ship due to the 10% or 5% exclusion.

Maybe somebody with a newer catalog can see if the policy is still in place? It was in the fine print under the heading “Ordering Information.”

I thought about taking full on video, but doing it all by myself it was easier to set up the camera and let the Video Library get short video clips at each picture and already have it all tied together. If I had a willing accomplice they could shoot video and do close-ups and such and I could tie all the clips together with Sony’s Vegas Movie Studio.

The actual pictures from the re-flow stage show more clearly the solder liquifying in stages when looked at full size. I didn’t get closer for macro style stuff because I didn’t want my camera part of the re-flow action. :wink:

Still ended up a pretty large video file, and even included the one fuzzy shot that didn’t focus due to the close-up lens. lol

Thanks wight, i understand now when you are developing these drivers using stencils is of less use with all the different revisions.

Dale now you got lots of drivers to last you a while but next time, could you film the process of applying the paste on the stencils and pressing it on the pcb, and the amount paste to apply to the led stencil would be interesting also, before wight just now mentioned it i didn’t know there was some optimum amount for that.

Edit,
I just saw your mention of Kester EP256 i almost missed it, ok you can use paste in a syringe for the stencil work also, i had only heard of the tub before, i guess Kester EP256 it is then everybody is talking so highly of it.

The thickness of the stencil is supposed to determine how much paste is deposited. When you wipe the paste over the stencil excess is taken away with your card/squeejee.

Ok i get it, Nice thats why every of those paste jobs Dale did looked so pristine, i thought it was some special move required :slight_smile:

In trying to do so many at a time I wasn’t completely successful in holding the stencil flat down on the board, a few of those had thicker deposits of solder paste than necessary… one so much so that a resistor floated over and joined it’s neighbor! Other than that though it went pretty well, I’d never attempted that before and think it’s cool to see it happen. :slight_smile:

That was really my point in sharing this, I’m not especially talented…if I can do this most anyone can! Give it a try! The pads are even large enough to do it with a soldering iron, it just doesn’t come out quite as neat. :wink:

Ok, yeah you are right it is probably less complicated than it looks and maybe thats your point :slight_smile: + I just read texaspyro’s post in Any interest in a CREE LED solder paste stencil? when he got the led stencils and that answered many of my questions on the led stencil.

I just want to ask is this driver efficient in low mode, like the LD-1 driver? I like the features of ld-1 driver but it’s very expensive.

Depending on your needs, I’d recommend looking at the A17PZL. It’s simple, well understood, and handsome. :wink: (RMM’s Moonlight Special driver may be easier to build by reflow, but I think that the A17PZL is probably going to be easier to reflow now that I’ve added the scallops around the edge.) The downside is limited current: Without stacking 7135’s you won’t do better than 3.04A. The first driver I linked to, tentatively named A17LDQX, is experimental and should be capable of the same drive currents as the LD1. Unfortunately it is much less compact than the LD1, requiring a two sided board with plenty of components on both sides.

For a better understanding of some different types of drivers we use, please read this thread by lagman: Understanding the difference between Linear, Buck, Boost and Direct Drive drivers.

You mean to tell me that the A17PZL boards that just shipped aren’t coming to me already fully assembled? Crimey! :stuck_out_tongue:

lol yeah yeah yeah, I know. worlds smallest violin…

> haven’t ripped an LED pad off yet

I’ve ripped a ground ring off the outside of a driver, after pressing it into a pill — while fiddling with soldering iron and bits of wire and solder trying to get it to properly ground to the aluminum around it.

To whatever extent vias help — and I’d think having some for little bits of copper wire to go through to engage with the pill — I’d cheer for whoever includes them.

Blame the old eyes and shaky hands, but hey, if a machine were doing the work, it wouldn’t be improving at the same pace. Glad y’all are doing this. Poking along behind trying to pick up some of the skills needed.

BTW, got any tips on how to unsolder a driver from a pill with just a soldering iron and some copper braid? I’ve removed as much solder as I can but the thing is still stuck. I don’t want to apply so much heat that I start melting components off, but it seems that some solder got down between the driver and the pill.

Am I just using the wrong tools, perhaps?

If there’s room in a wire hole to poke through with a tooth pick. Try knifing the remaining solder with an exacto knife. The solder shouldn’t wick to the side of the board so it’s probably just a tight press fit.

What driver/pill? It’s very uncommon (in my personal experience) to see a driver which is soldered to the pill from the inside. This definitely won’t happen just from solder running down the crack between the driver and the pill, it must be done one purpose.

If you can see joints and just can’t get the solder blob to separate (surface tension is keeping it together) then we can do something about that. In that case you can try to use a stainless or graphite implement to separate the liquid solder. An X-ACTO knife is a good tool for this. Solder will not wet to either material.

Good point RBD! In the case of a tight press fit where there is no alternative: comfychair mentioned in another thread that you can solder a wire onto the driver and pull on that. I’ve done it, it works. I’ve pulled quite hard on a driver to get it out that way. It’s scary, you could totally destroy the trace you solder to when pulling like. I tried to choose the largest copper pour available which was also close to the edge (so that I’d get good leverage).

Ideally you’d probably poke the press fit out from the top if possible.

Hmm… I hadn’t thought about cutting through the solder. I’ll see if that works.

This is an AK-47 driver in a UF-602C host, built by RMM. It’s nice, but I wanted to take it apart to reflash it. Remember when he tried to do 16340 EDC lights but the supply of hosts dried up? It’s one of those, after the better hosts were gone.

The driver is press fit into a brass adapter if I’m not mistaken, should be able to get it out if you hold your tongue to the left and squint your right eye while pounding a 1/8” drill bit through the LED wire hole in the shelf.