I am attempting to put together a Convoy S2 and the driver has stacked chips on both sides, so I obviously can’t use the driver retaining ring. How do I best fix the driver to the pill? I’ve tried soldering on a pill before, and could not for the life of me get any solder to stick to the pill. I ended up overheating and frying a bunch of chips. I don’t want to do that again. How can I fix the driver to the pill without frying it?
First what wattage is your iron?
If you can get a high power iron 50-80w you can heat the pill up quickly enough to solder to it without burning crap up.
So what I would do is either thin the retaining ring down (dremel and diamond files) to fill the gap, or use a piece of solid core wire cut to fit and shaped to fill that gap. Then you can solder it in place.
Also strip the pill back down, solder the solid wire in on the stove or even with flame, then reassemble and solder the driver to that.
Simplest solution for me has always been A. hot iron (I don’t have an expensive one, I use this one cranked all the way up) and B. LOTS of solder flux. I buy the can of it they sell at radioshack and apply it with a small paintbrush.
I’m kinda surprised — I find stacking 7135’s somewhat trickier than getting the ground ring of drivers soldered to the pill, and yours look great. Well, once I figured out that using what feels like ‘too much’ solder flux makes life a lot easier. I clean up the residue afterwards with isopropyl alcohol and q-tips.
Side notes… these two things also make soldering a lot easier for me - replacement tips for the soldering iron linked above (I use the middle two tips the most - more tip contact = faster heat transfer. solder flows where you want it when ‘destination’ for the solder gets hot enough, so you keep from frying things by getting that one piece hot enough quickly, letting the solder flow where you want it and then pulling the iron off.) and secondly, a sal ammoniac block (it magically keeps my iron’s tips looking almost new. I don’t pretend to understand how it works, but it sure does. It’s amazing. Also good for tinning the tips.)
Thanks for the tips. The soldering iron is 50W, but the tip is really thin. I’ll be looking for a thicker one. I didn’t have any flux available, I’m rather nooby at this so I don’t really know what it is but will be heading down to the electronics store and picking some up (providing it’s called the same in Swedish).
Not my work. The driver is from RMM / Mountain Electronics.
Sorry to jump in here, but I have the same question as Mike C. I was just about to start another thread when I saw his post/thread, so figured it’d be better to do this in one place. I hope that that’s ok?
I guess one thing that would help is pre-tinning the pill (getting some solder to flow/stick to the pill FIRST, before trying to bridge solder to the driver.
Having said that, I have a heck of a time (cannot) get solder to stick to the pill. I have several irons, including an el-cheapo 60 watt one and several fancy ones that claims its a 60W (http://smile.amazon.com/gp/product/B00BSW69LI/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1), and I flux like crazy, but I CANNOT get solder to stick.
I guess the other thing is that in some situations, like Mike C’s, where the pill has threads, and in that case, on the production lights I’ve seen, the manufacturer gets solder only on the top edge of the pill, and NOT the side of the pill, and then bridges to the pill’s battery-side ground ring. That, getting solder only the top edge instead of on the side of the pill, is also another thing I was wondering about. How do they do that?
Gotcha. Here’s what the flux I use looks like (different brand/label, but the container and contents look the same)
There’s a how-to with pictures here somewhere showing
— drilling a small hole in the aluminum pill
— pounding a bit of copper wire into the hole so it fits tight
— soldering to that
Someone will remember where to find that.
You could always pre heat the pill end quick with propane or mapp. I dunno what I’m saying as I’ve never done this specific feat but it sounds doable. Always flux, like grantman has there is good stuff.
Oh wait copper to aluminum. Yeah I have done that quite a bit too. I just realized reading the prev post xd
Use this stuff- RubyFluid Liquid and Paste Flux | Superior Flux & Mfg. Co. The stainless steel flux. It works well to join metals like copper/ss or copper/alum
I do remember that mention, but I think that causes solder on the side of the pill.
In pills that have threads, having the solder on the side of the pill is problematic, as it sometimes prevents the pill from being inserted far enough into the body for the threads to “catch”. In such cases, I use a Dremel to try to grind down the part of the solder that’s attached to the side of the pill, but that doesn’t always work because when I grind the solder down on the side, the solder that is just on the edge is not adhering (it comes off).
Here’s a not-so-good pic of a production pill (from a UF-C108S) where I think that they tried to solder to the edge. If you look closely, they actually weren’t successful soldering to the pill edge, but they it loos like (I haven’t taken the pill apart yet) they actually have a brass ring that they are soldering to. The point is that there isn’t any solder on the SIDE of the pill.
How to do that? That’s the part (plus just getting the solder to flow/stick) that I’m puzzling about…
Can’t tell from the pic… but is the pill aluminum with a brass insert? If so, that would explain it — soldering to aluminum takes a great deal more heat for the solder to stick, so the solder would flow to the brass when it heats up sufficiently but not to the aluminum at all since it wouldn’t be nearly hot enough.
If the whole thing is brass, I assume they held the iron tip where they wanted the solder and when it got there, pulled off before it continued flowing to the outside of the pill. Believe me, I’m still pretty new at all this and have been learning soldering skills as I go to build drivers and lights… but that doesn’t appear to be very difficult - it just takes some practice. And as I said before… a hot iron, plenty of solder flux.
Since it hasn’t yet been mentioned, 60/40 solder (60% tin, 40% lead) will flow more easily than a lead-free solder or a silver-bearing solder. Should go without saying, but don’t breathe the fumes.
In this situation I hammer some used copper braid flat and smooth. Then I cut pieces to bridge the gap in little crescent shapes. Then after pre-tinning the pill and heating it with a a small butane torch I drop in the driver and apply the smashed copper braid in pre cut pieces, holding one corner down with a dental pic that I use for soldering and such. Then add solder until the braid is shiny. That’s what works for me and I like to think the copper helps carry more amps but I don’t really know.
As I said, that pic wasn’t a great example of what I was asking about, and I haven’t taken that pill apart yet, but yes, it LOOKS like there’s a brass ring AND the pill itself is aluminum.
I’m more asking about situations where the pill is aluminum, and there’s no other (like brass ring), so you have to attach/solder the pill battery-side ground ring to the edge of the all-aluminum pill. I think that’s what I (and the OP) would really like to/need to do, which I haven’t had much success with so far.
I’m getting a Weller old-style supposedly 100/140 watt (!!) gun today and will try when I have time with that. If that doesn’t provide enough heat, I don’t know what will :). And yes, 60/40 solder and flux and polish/grind/sand area first for prep.
From your pic, it looks like there’s some space between the driver and the pill, i.e., the driver is smaller diameter than the inner diameter of the pill.
The inside of the pill also looks threaded?
Was there a retaining ring or something that came with the pill, that you had to remove when you removed the original pill?
Ohh…. gotcha. I’m sorry, I must have missed that. In that case you have a few options. From what I’ve read on here, it takes an extraordinary amount of heat to properly solder to aluminum (as in, enough to fry all the electronic components), so you’d have to modify the pill to add brass or copper. If it has threads on the inside and came with a retaining ring (a la Convoy C8) that can’t be screwed in due to stacking 7135’s or whatever, you could cut and fit a ring of solid copper wire into the threads and solder to that. If the retaining ring can screw in at all and just isn’t making contact due to stacked 7135’s or any other reason, you could solder a copper wire ring around the ground ring of the driver to raise that up to make contact with the retaining ring (as mentioned above by CK). If the pill doesn’t have threads/driver retaining ring, you’re stuck drilling a hole in the aluminum and press-fitting some copper in there. Somebody made a thread on that, but I can’t remember who/when/where. If you don’t count the shipping time, this might be a less tedious/time consuming option if there are no threads in the driver cavity: 17mm to 17mm ring. They also sell other various sizes of rings if the pill takes something else besides 17mm. Being brass, you could do a solder bridge to that from the driver’s ground ring just as if the whole pill was brass. If it fits tightly enough, it should work well. If not, I reckon you could cut a small piece of copper braid/solder wick to make it a press-fit.
Pre-tin the pill. Only put flux where you want solder - it will not flow over to where there is no flux. If you slather the poor thing in flux it will, unsurprisingly, end up also slathered in solder.
Also, why is it 'obvious' you can't use the threaded retainer?
Grind out the ID of the pill below the step, if the stacked chips don't clear. Then grind out the ID of the threaded ring so it clears the components on the battery side. Then screw it together.
comfy,
Thanks for that reference. I missed the part in the OP where Mike C said:
If we’re talking about the S2 - there is very little room in there. You could grind the retainer out to fit, I suppose, but I dunno how you’d grip it to get it tight. The S2 pills are brass, so why not just solder to the pill? That’s what I’ve been doing with all the S2, S2+, S3, S4, etc builds I’ve done. Or get strip the 7135’s off of the spring side and stack them on top. Stock 8x 7135 drivers can’t use the (unmodified) retaining ring on those lights even before stacking. But their pills are brass so why bother?
Also, just a minor FYI, but any of those little lights will likely get very hot with 12x 7135’s. I’ve built a handful of 3-up XP-L S3’s and S2+’s for myself and other folks, and I’m fabbing solid copper spacers soldered to the pill and keeping the drivers at 8x 7135’s and still using a 120-second turbo timer to keep them from getting too hot. Using 12x 7135’s will probably be pretty uncomfortable after a minute or two unless you don’t have a good thermal path (in which case the emitter(s) might fry itself/themselves from the heat).
HAH! Some of us (on the east coast) LIKE little handwarmers, esp. with winter coming already :)!!
JUST KIDDING :)!!!
Hahaha - fair enough
I’m on the east coast too, but it’s 75 and sunny here in NC today.
Never said the 3xpl lights stay cool on 3A either 