Trying to fix some ultrafire 502b's

I have a couple ultrafire 502b’s that quit working. When I pulled them apart the little circuit boards that control the LED were poorly soldered or connection was broken entirely. Unfortunately I didn’t find this forum until after I already ordered parts. I purchased these drop in’s from ebay. If they are as advertised will they be an upgrade? I know none of these lights have the output that is advertised but when working correctly they are a nice light for cheap.

http://www.ebay.com/itm/221471859674

Can you post any pics of the original drivers(circuit boards)?
Hard to tell if it’s an upgrade since it doesn’t specify the drive current.

I cant get a pic clear enough to read the writing but here is what I got.

Can’t tell w/o details whether this is an “upgrade”, but you will likely be well pleased with the drop-ins you bought, IFF you like a stink-load of light (no, not actually “1800 lumens”!!) and no stupid blinkies.

Make sure you wrap the new drop-ins with Aluminum foil when you install them, enough to assure a tight fit, so the heat will be transferred most expeditiously to your hands.

With a single mode, you may find a Momentary-ON switch more useful.

Consider (as many of us did) using the old drop-ins for upgrading/modding… Your wallet, lighter and thinner in no time at all, will be glad you did!

Welcome to the nut house!

Dim

With a single mode drop in a forward clicky is the way to go. Since I’m sensing you may not be confortable with your soldering skills, you may want to check these switches: http://intl-outdoor.com/components-switches-c-57_116.html Beware that the forward clickies tend to be quite a bit “taller” and the reverse clicky so you may need to do something with the boot.

If you haven’t already purchased you may want to look into this: http://www.ebay.com/itm/331287848181?\_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I have one purchased from that link and it came as a nice, almost neutral tint and can be had for less than $6 to the door (they accepted a $5.80 offer from me a while back). I’d GUESS the lumen rating is off by about a factor of 3 (600 lumen).

Thanks for the info and tip on the foil… I have never soldered something this small. Ill have to find the smallest tips for my ultratorch before I try. I have an ultrafire 501 b mounted on my AR 15. When I fire it the light changes modes. If this drop in doesnt fix that Ill blame it on the recoil and look to change the switch. (I dislike the pressure switches) I need a lot of light. Im blind as a bat in teh dark and need to occasionally whack a predator on my little farm after

The dropin you’ve ordered is listed as single mode. If it starts changing modes…. heh!


That’s funny, right there!

What’s happening is the battery is staying still as recoil moves the rest of the system in space around it. It pulls away from the switch end & Bob’s yer Uncle. Or if you have a Nanjg-105c or similar with a very stout, short driver (i.e. B+) spring, from the driver end.

First off, the new single-mode drop-ins won’t stop the Root Cause, but they at least won’t change modes. So you’ll have that going for you.

To stop it from blinking off, get a second spring for the tailcap. Just insert it inside the existing one & you can solder it if you want. Ditto for the driver-end spring, although it’s probably already pretty stout — start with the tailcap.

If it helps any, it wouldn’t matter if you had the remote switches (I prefer them personally, but YBTJ) since they also have the single, thin springs at B-.

Bottom line, you need significantly stronger springs, probably in both ends, but the single mode drop-in will at least not change modes on you.

(Don’t forget the rules. It’s almost impossible to be sure of what’s beyond your target at night…)

Thanks Dimbo. That is what i assumed was going on but I figured a single mode wont help. Im sure you can imagine how hard it is to hit a coyote that is killing your chickens when the damn light switches to strobe.

I can imagine it might look a lot like this:

…when it should look like a fine, pink mist.

Tactically, it would seem to me that the ones you don’t get to hit would learn to duck when the light goes on. That’s why I chose the wired pressure switch for the 501b I mounted on my 10-22… It’s single-mode, of course, although I doubt .22lr recoil is an issue. Maybe I’m working too hard.

Also, I was thinking that maybe you could work out a different position to minimize movement in recoil, such as prone (especially with a bipod), or rested on a door frame or porch column (whatever you have) … maybe? IMO the recoil battering by the battery may be the reason your drivers broke in the first place…

Also, not trying to “upsell” you, but my friends who live further out than I do like the “big head” C8 bodies for rifle lights. They still fit the same rings as the 50x bodies but give a lot more range, assuming you can find room for that fat head. Single mode C8s are getting easier to find, but you can build a nice one on a budget by getting one with an old LED, then getting a single-mode XM-L dropin. (Bonus: That replacement pill is “Warm White” which should give you better color rendition than the stock “cool” white)

I’m looking for better springs, so this is a lot of synchronicity all at once.

DJozz just published a wonderful test of the electrical characteristics of a random selection of springs. He also looked at their mechanical properties briefly.

I found the post to be Quite Useful and hope you will too.

Bottom line, when you find a strong spring, solder in some de-soldering wick to carry the current, and you and I will be on the same page on this. As for me, I’m hunting that “Good Spring”…

So I received the two drop ins I listed from Ebay. They are single mode. But they are slightly dimmer than the current light. I expected them to be overrated but i was hoping they would be brighter.
I also ordered one of the drop ins labrat listed. if it ever gets here ill see if it is any brighter.

When i get some time Im going to change the springs and test fire the rifle and light.

Remember recoil will push the battery towards the head of the light (initially). You can try using a 6 or 7mm tall (2-3 mm shorter than your spring) cardboard or plastic (any non conductive materials) doughnut. This will allow the positive spring to connect but not let the battery come off the tailcap spring.

Ideally you want to have this on both tail and head springs. Immobilized battery won’t smash your driver, battery and won’t change modes. Sort of like potting your battery tube temporarily.

Did that make sense.

I hope you get them working. I’ll see if I can rig something up quickly and show you.

Makes perfect sense. Just need to find time to tinker. I was just very disappointing to see these drop ins were dimmer than my light is currently.

Ok so my idea isn’t really a quick one.

Get a thick straw, your battery tube and some silicone rtv. Coat the straw and the inside of your tube with some lube. Try to keep the straw in the middle and use the rtv to create a slug. You can make it as long as you want and cut it to size after. You should also be able to widen it to allow the base of the spring to fit inside.

This will give you all the recoil protection you need.

Obviously rtv takes a while to cure but this is the idea.

Straw and 501b tube. I’m not familiar with the 502b

Rtv. Make sure you use lots of rtv and lube the inside of your tube well. Probably need some force to get it out. Once out just shape it how you need.

I didn’t use lube so I’ll just let that dry in there and see how it works. I didn’t use a lot of rtv either. Just a quick toss up to show.

What exactly were you trying to do there?

Making a recoil buffer. It’ll stop the battery from moving and impacting the driver.

Well not actually making it, just showing an idea of how to make one. Should keep constant spring connections without damaging the battery or driver.

I suppose you could use some small rubber bushings and shape them. A lot less mess. This was just a top of the head idea. It will work though.

http://www.ebay.com/itm/331287848181?\_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

This drop in that was suggested came today. I ha dto cut apop can and make a shim but I out it in a romisen light for a drastic improvement. brighter drop in than teh other ones i listed for the ultrafires.