The There Are No Stupid Questions Thread

It doesn’t have to be strictly silicone, but you should avoid using motor oil, petroleum jelly, or lithium grease.

Here’s a useful page over on CPF that identifies excellent, very good, fair, and poor choices in lubes for flashlights: LINK.

I bought a small 1oz tube of Nyogel about 10 years ago. I’ve not even gone through half of it. Great stuff. I also have “Magic Lube II” which is actually a silicone lubricant. You’re not supposed to use silicone grease on silicone o-rings. The black ones tend to be rubber, while the clear/white ones tend to be silicone. I’ve used that lubricant and had no problems.

It should be possible but with 3A it will not be as bright as with 5A. The NM1 has a 3030 footprint so it will not be a direct swap with the LH351D which is 3535. I don’t know if a 16mm MCPCB fits the WK30 or if it uses a custom MCPCB.

Thanks, I won’t go ahead of this. I might just slice the dome.

I would like to drill a 1/4” hole on the Sofirn SP36.
Can someone link me the tool that will create the threads? It’s so shallow I don’t want to buy the wrong ones.

I don’t see how to do that without punching through the light. Just buy a 1/4”x25 hex nut and epoxy it onto the light, I would say.

I have one question for veteran Flashoholics: When is the best annual sale of flashlights?

Could it be on 1 October, the Chinese National Day, since most sellers (including Banggood and Ali Express) are Chinese, or during the Black Friday (26 November), or during the year-end holidays, from Christmas until New Year Day?

I am asking because I am saving all I can to buy a few “big ones” during the biggest sale.

For AliExpress and some other Chinese web shops, it's Single's Day, or 11/11.

Thanks Raccoon City. Noted. Will keep any eye on the 11/11 Sale. :innocent:



Where on the light are you wanting to drill? (and why...?)

The tool you want is called a tap and there are lots of different kinds of them (thread sizes and types, a few other things). You need a) to have enough metal to cut threads into, which is hard on most flashlight bodies other than around the meat of the head usually), and b) to know what size tap/thread you are using and to pick the correct size drill based on that tap size (very important!). Don't drill a hole and then hope the tap works because that's backwards. :)




That's really weird...I can't tell what the differences are, if any. Sofirn often does multiple listings for models that appear to be the same but usually it's a different emitter or temperature...something clear in the description or options. That last link says 6500K down in the text description (below all the extra marketing photos as you scroll down the page) but that's not the temp option up above. I'd message them first to be sure you're ordering what you want - they usually reply very quickly even on weekends. I see one of those listings added the link to the anduril repository, which everyone is supposed to do if they are selling items using the firmware...the other two mention it but don't have the link. But they all look the same to me otherwise.

The last site I think is a retailer, not Sofirn's actual site....I think? There were/are two "sofirn" sites and one was official while the other was a retailer with great prices but I can't recall who was who. It's legit, though.

If you want, it may be worth getting their added battery since they're cheap and fairly decent...as long as there are no Canada issues in the post. The charger is a little cheapie with no fancy smarts inside, but it works well enough.


Add them to Aliexpress cart. The prices changes all the time. Remember to check the App for 10% off coupons as well in the listing.

I definitely got deals randomly.

Starts from 3:15 https://youtu.be/QOMDt66k2ic
More than one person has success with it.

I found this too https://ymwtapsusa.com/download/tapping-tips/USA%20070%20Tapping%20tripod%20mounting%20screw.pdf

Thanks

Great light. My favorite Sofirn, and non-work EDC.

Have used SC31PRO on board charging twice, including charging an 18350 with the short tube (although I wouldn’t do it w/18350 on a regular basis). Charging 18650 terminated at 4.18, 18350 terminated at 4.19. Safe and good to go for on board IMO.
I have a couple of the peripheral Sofirn chargers. Only used one once on a 30T for my C8G. Green light at 4.17 from my Fluke 115.
As with any charger, I wouldn’t walk away and leave it unsupervised. I keep it in my travel bag with a standard wall wart. You should be fine with it.

^ Make sure your wall wart supports 3A and above and can handle over 10w. I discovered some of mine, borrowed from cellphone accessories, are pitifully weak for doing any robust charging. I picked up a couple of intelligent higher capacity A/C charging adapters for USB-A and USB-C from Amazon when MyVipon linked some terrific deals. They work really well and have retractable socket prongs.

D’oh…I forgot what light that was and was thinking about a normal single cell tube. Yeah, looks like plenty of meat there but this will still require some care with measuring, placement, and the actual drilling and tapping. That’s really interesting about the “special” tripod threads. I’ve always assumed they were normal 1/4-20 and for the most part they are. I only have a few items here with tripod threads/sockets (mini and micro tripods, pair of binos, and two cameras) but I did a quick check with all of them. With the exception of one camera that has a nylon socket that is slightly damaged, a standard UNC 1/4-20 fits just fine. On the binos I was able to thread it in over an inch and it felt good. Nut seemed to fit fine on the tripods. One camera had a fairly loose fit on the bolt…makes me wonder if some makers bother to use the special thread and some just use the normal one. But I think for the light you can use a standard tap and be ok.

First question…do you have a drill press or access to one? I think this is kind of important here because there is limited room for error on this job (and it’s always nicer to do accurate work when you can). If not, the below still applies but you’ll have to be extra careful to stay plumb/square and steady in all operations.

So you need a way to accurately measure the thickness of the body tube, a way to accurately lay out a point down the tube that will rest more or less in the exact center of the thickest part of the tube (a normal carpenter’s combination square would be ok for this, or a cheapie sliding depth/angle gauge), a vise to securely position and hold the tube for drilling and tapping, the tap and a tap wrench to hold/drive it. Drilling an accurate depth is important here of course, and you want to go as deep as you can for the most thread engagement while still accounting for the “wasted” depth from the drill point and also leaving enough metal at the bottom to preserve integrity if the tripod screw is overtightened or something. On a drill press you can set a depth stop easily…in a hand drill you’ll have to be careful and maybe use a flag/wrap of tape on the bit since I don’t think you can find clamp-on stops for the size of bit you’ll need.

This is a relatively “large” thread and it’ll be a shallow hole, so some of the risks of not being plumb/square are lessened but it’s still very important to be plumb/square any time you are making threads. You don’t want your tripod to be cockeyed but there’s also the issue of having the hole angle matching the angle that the tap is driven into it - when they are misaligned you end up with ugly rough threads, sometimes torn metal, and this is also the #1 reason that people break taps no matter what quality they are (well, this and not using the correct drill size, both). So…highly highly recommend a drill press here, and taking care when mounting the body into the vise to get that aligned properly as best you can. If the body is tilted a tad, that’s not the worst…more important to have the drill and tap aligned together, which is easy in a drill press vs. by hand.

The “correct” standard drill bit for a 1/4-20 hole is a wire gauge #7 (that’s 0.201”). According to that .pdf on the tripod-special, they call for a 5.19mm, which is spot on with a #6 bit, a touch larger at 0.204”. Splitting the difference is a 13/64” drill bit at 0.203”. If you’re not tooled up and already have the latter, I think that’d be fine. Considering the runout and inaccuracy of hand drilling and the possibility of having that actual tripod thread (and aluminum), I’d probably opt for the usual #7 but the fractional size should be ok. Only talking a couple thousandths’ difference here but that actually does matter sometimes in metal work…and again, this application isnt’ leaving a lot of room for error and extra material/strength.

There are lots of styles of taps (lots). What you normally see in stores is called a “plug” tap…the end of it is slightly tapered and/or pointed so that it enters more easily into the drilled hole. There are also “tapered” (aka “starting”) taps which have a longer taper and narrower end….this is to help reduce errors in getting started plumb/square, but those will be much too long for this shallow hole we’re drilling. Actually the standard plug tap may also be too long and might hit bottom before getting more than a full thread or two cut. This brings us to “bottoming” taps, which is what I think I’d recommend for you here. Those still have a slight taper at the tip but are much more blunt, allowing it to go deeper into a blind/flat bottom hole for maximum thread engagement. The disadvantage of those is that it’s very easy by hand to get started crooked. If you can’t use a tap guide or put the tap holder/wrench in a drill press for accuracy, then sometimes you can use the corner of a small piece of wood board or cube and try to stay aligned right on that corner as you go (works for drilling, too).

I’ll link to some taps on Amazon US….surely something similar on the Canada offerings. Most hardware stores won’t carry bottoming taps but sometimes a good auto parts store will, if you don’t have any other tool or industrial supply houses around. Worst case I suppose you could grind down a plug tap if you have the means and an clean it up afterwards. Most hand taps are a straight flute design, which is fine. Spiral taps are all the rage these days, and if you get one of those - because this is a blind hole - you want to be sure the spiral flutes are the same direction as a drill bit where they pull the chips up out of the hole rather than pushing them forward ahead of the tap (this is ok/better sometimes for a through-hole but not what we want here). These links are for high-speed-steel taps…generally higher quality, even the cheap ones, than the normal “high carbon steel” taps and dies. The high-carbon are really more for rethreading and repairing than cutting new threads…they can work for cutting albeit with sloppier threads usually, and they are often cheaper, but I haven’t seen bottom taps in those. The cheaper China high speed steel is pretty decent for most work and not much more expensive…kind of a crap shoot in quality but workable.

For this, you don’t really need to use cutting oil but it never hurts. Use a good quality sharp drill bit, though. And use a good sharp center punch to mark the point once you locate it - don’t rely on split-point “no walking” bit designs for this, even though those are generally great. The center punch mark will ensure the bit starts where it should and this is important here. If you want to use cutting oil then a little kerosene or even crisco/lard is actually great for aluminum, so no need to purchase a bottle of fluid if you don’t want to. No need to bother with any other lube really (motor oil, household lubes, etc, etc) since they don’t do much of benefit and this is soft aluminum, brief operations, shallow hole….dry is ok.

The quality on these vary but I’ve gotten several…fairly decent. This is a set of three, one each of the different styles. Left to right: taper, plug, bottoming. Amazon.com

Same thing, bottoming only: Amazon.com

Cheaper basic spiral tap style…not sure I’d want this for this job, but it would work: Amazon.com

For wrenches, there are lots of choices at lots of price points and generally the cheapies are fine. The t-handle type are a little harder to start/keep straight unless you can chuck them in a drill press (or use a spring loaded “tap follower” in the chuck which will center itself in the divot or on the point of the heel of the tap…usually around $10 give or take) in conjunction with your vise. The straight-handle give you more leverage and can be easier to control. Just a couple quick examples that aren’t the cheapest.

https://www.amazon.com/Bosch-BTH1412-4-1-T-Handle-Wrench/dp/B07GRP817W/ (for 1/4 to 1/2 taps…that is to fit the size of the milled square flats on the tap…not actual opening size on the tool)
Amazon.com (for very small taps and up to 1/4”….not sure if either of these have the divot on the end for a follower…also not sure which would be best for whatever size the flats on a China tap might end up being…it varies…less leverage here but also less height)
Amazon.com (these from Park bicycle tool company are actually pretty nice and not expensive…a cut above most of what’s out there…this is the smaller of the two they have. made in Taiwan from actual steel instead of zinc casting)

There are some special sockets made to hold taps for use with a ratchet, and sometimes people try to use a 12-point socket on a tap the same way, but I wouldn’t recommend doing this on this job. Does make it nicer for things like automotive work where you’re repairing rather than cutting new threads, and for reaching down to difficult places or in tight corners, but sort of like the t-handle tap wrenches, using a ratchet with only one lever arm makes it super easy to get tilted and end up with terrible or cockeyed threads/broken taps when cutting new threads.

Lot of words, sorry. Figured it might be helpful since it sounds like you may be new to the tools and concept. It’s not hard to do, just a learning curve to do it right, and it can be done pretty cheaply really unless you need all the tools, vice, etc. :slight_smile:

I love their green…nice shade. I have several C8Fs now and just got the green one not long ago because…had to have it and had been denying myself the purchase. lol. Didn’t notice that the 18650 was the cable only…but yeah, the onboard charging seems to be just fine with most lights and I’ve not heard anything negative about it with Sofirn specifically. Seems kinda normal for many to slightly (very slightly) undercharge the cell but it’s fine. After reading some comments here I tested mine and some actually go to 4.2v and some cut out a bit earlier as mentioned. Of no consequence, though. The little single-cell usb charger with the C8F and others…about the most basic charger out there but they work fine. I don’t think I’ve ever heard of anything bad with those. I feel comfortable enough about them that I’ve gifted them along with lights and cells to friends that were lithium-noobs so that they would be all set and not have to buy those. The charging rate on it is pretty low, so it just takes longer to charge up a higher capacity cell like the 21700 compared to what you might do with a dedicated fancier charger.

I really like the C8F with the Samsung LH351D emitters but they don’t offer the green host with those, only the XPL. Still a good emitter and a great light…I really like the ramping and simplified firmware compared to Anduril and such, but there are a couple features that would be nice to add. I also like the dual switch setup. I often leave it on turbo (with the side switch) and then turn the light off at the tail switch….then I can instantly blast turbo with the tail and ramp down as needed. That’s the opposite of what I like/do with smaller utility lights, but I really like it on the C8F. They have two different 21700 cells…the original 4000mAh and a newer 5000mAh. All of mine have come with the 4000 and it’s a decent cell. I have some better Samsung cells and I can’t say that I really notice any difference in the brightness or run time between those and the Sofirn cells. The cell may arrive with some marks or minor dings on the negative end…nothing to worry about. For whatever reason, three of my four were like that…pretty sure they were brand new but it made me wonder at first. They’ve been a-ok.

I will give it another read when the tools arrives. Thanks for the long write up. It deserves its own thread.

Considering safety, you should be nearby so as to monitor the cells as they charge. A slow charger might take several hours. No one really wants to sit there for that long and monitor charging cells. I watch YouTube videos while they charge and my cell’s usually only take 1 to 1.5 hours (26650 and 21700). A strong USB based charger might make the difference from taking 8 hours to charge a battery to only 3 hours. So at least give those little USB chargers the power they need.

Charging slowly does reduce degradation, but for most people it’s not an issue. If you charge a particular cell everyday it will reduce capacity quicker, but most folks don’t charge that often. I charge once a week and I use a fast charger. I don’t really care if it degrades faster. It should still last several years. By then newer, better cells might have came out and I’d want to replace my older ones anyway. So don’t covet a battery as being precious. They are a disposable commodity. One accidental discharge too low and they are junk anyway.

It definitely helps to have a good charger. I switched to the Miboxer C4-12 when it came out. It can do a wide range of charging levels up to 3A x 4. It’s great for charging bigger, high drain cells quickly. Theres lots of other good chargers out there as well. I’d at least get one that’s 4 slots and can do 2A x 4.

You can find the safe charging levels of a particular battery by looking up its data sheet. For instance, a Samsung 30Q has a nominal charge rate of 1.5A (180 minutes) and a max charge rate of 4A (70 minutes). A good charger can give you the flexibility to charge at whatever rate you want. I would normally charge a 30Q at 2A, but if I’m in a hurry I can go 3A. No big deal. My high drain 26650 cells I always do at 3A otherwise it takes forever. They can easily handle that. Certain high capacity or older chemistry cells tend to have a lower max charge rate. Like the old Sanyo/Panasonic NCR18650B has a max charge rate of only 1.6A. I don’t even bother buying older cells. I stick to newer chemistries and not so high capacity. Those tend to have higher charge rates.

Here is the link to HKJ battery and charger tests. Lots of good info there.
https://lygte-info.dk/info/indexBatteriesAndChargers%20UK.html

Also online battery data sheets.

No risk, just slower (and less taxing for the battery).

Unless it has been upgraded at some point, or replaced by a newer model, that single-slot Sofirn/Thorfire charger they bundle with their kits only has a 5W (1A) input, and 750mA output.

It’s not demanding, and plugging it into a higher output adapter will not make any difference.

I have a Nitecore charger (UM2) and when I had a weak USB A/C adapter powering it, the UI didn’t behave properly… So, problems like that can happen. UM2 charger input 5V/2A 9V/2A, 18W (MAX). Anyway, always good to have a power adapter with surplus capability in case of future needs.