Sofirn SP40 kit: 18350 tube won’t accept tailcap

Yea,

I am working with Aliexpress, they replaced the light once for a $1 like I said but it still has the same problem, I have now asked them to just send my something a different light that uses an 18350. see what happens

Received a new email from Sofirn: “Ok, I will ship the tube from China, tracking number is #########”. Fantastic error resolution from Sofirn. I’ll be tracking of course, probably will be a few weeks. Fingers crossed it’ll be the correct tube. Thanks to Sofirn.

Looks like there’s at least one batch of bad 18350 tubes.

Those threads would be screwcut for sure, so somebody at the factory simply typed in the wrong pitch for the thread when progamming a CNC lathe. You’d think someone would test at least one of the threads on each batch somewhere down the production line…

Hopefully they’ve identified the bad batch(es) and replaced them with the correct fitting tubes BEFORE sending anymore replacements.

2 things to check.

“Sawtooth” the threads together to see if they’re the same pitch. Ie, rest one tube on the side of the other so the threads overlap, and hold it to the light. If the same pitch, you’ll see no light, but if they’re off a bit, they won’t mesh together very well.

Then just hold the threads to the light and see if one’s triangular and the other’s square or trapezoidal.

Yessir, did both things. They seemed identical - same square cut, same thread count, even the pitch. Something is different though, right? As an aside, for these inspections the diffuser mounted on my MT07 mini makes for a perfect backlight. Also the RRT01 Raptor with its infinitely adjusting rotary switch trumps even a ramping light for this close work. It’s really satisfying to put your fidget gadgets to good use! Back to the tube - after closer inspection - I have discerned a difference. The tip of the thread ridges on the 18350 tube are definitely WIDER than those on the 18650 tube. This must be indicative of a small difference in thread count? Pitch? Coarse vs fine? Wish I could send pics. Posting pics on Wiki forums are a snap. Why not here?

I was about to order a SP40, guess I will hold off for the problem to be fixed before ordering, how much time do you think it will take to clear out the problem batches?

Nice sherlocking! My thinking exactly.

I had measured mine on an optical comparator for them. One set was the thread body was thicker and the root diameter of the thread was also too big. Like the lathe did not make a final pass on the threading cut of the tube, or the tailcap has tighter threads than the main body/head part.

They asked me for pictures and a video again a 2nd time, but I don’t have time for that right now, I think I see too where aliexpress offered me a replacement for $1……It made me complete the first transaction and then the 2nd one is only $1.00. If I open a dispute they would just refund me a $1.00 and be done.

I really really like my IF22A and I hope they can figure out a resolution for this. I do not need another 18650 right angle lamp. I need an 18350 one, that is what I have paid for. I hope they can deliver. Would restore my faith in them. I bet I could sell at least 10 IF22A’s but I have mentioned to people that I have an issue with another one of their lights and they aren’t super eager to fix the issue.

This forum doesn’t host the images itself so you have to link and/or embed from a different host that you upload to. It’s not hard really. In the composition box just click on the mountainscape/sunset image button thing (“insert image”) and you can put the host link there. There are other options if you want….actually Raccoon City created a whole thread about how to post images here if you want to look that up - has several methods that people use.

Imgur has been about 95% totally broken for me for months now but there are two other places that seem to have no problem at all. I use this one…free, no account necessary unless you want to make one, and seems secure enough although I’d never host something with PI info on any of them.

I’d like to see some good closeups, too, if you can manage it. Curious.

Correllux, understood, I’d be curious too. Thanks for the link. Everything is better with pictures, especially visual descriptions like this thread. Arghh!

TEST

Correllux, with that site it’s stupid easy. Thanks! Tube comparison pics to follow.

It’s easy to see the difference under magnification. 18350 short tube on the right.

The result being only about a 3/4 turn. Darn.

Hmm, looks like the threads on the right are the way they should be (symmetric) but the “right” threads on the left are asymmetric.

Possible to drag a grinding wheel (dremel-type) through the grooves to shave them down, but that’d be tedious. And no more ano so no more lockout, if that’s important.

I agree. I’m thinking one day I might be able to use this ‘wrong’ short tube elsewhere. Maybe with some modifications as you said. That particular thread pattern must be used somewhere in Sofirns line-up….cap-wise.

Oof…there’s a problem. lol. Hopefully they get you sorted with the new tube on the way. Little hard to say for sure but if I’m seeing what I think I’m seeing I wouldn’t bother attempting to alter the shape of either threading to try and get them to work. Sofirn is usually really good about fixing things and making it right, even if there’s some delay or trying to work around communication/language issues. Their reps (on aliexpress anyway) sometimes seem not to be very tech savvy or fully knowledgeable about the particulars of the lights, too, but they should make it right in the end. Glad you got the photo posting sorted!

Alright, so the short tubes’ a bust for now. Well we can still make fun with the 18650’s. I have to say I absolutely love the two-tone mash treatment, do it wherever possible and have never gone back.

One more.

From your picture of the tubes side by side; the left is a trapezoidal thread and the right is a square thread. The trap isn’t up to specs (it’s overcut: ie, the flanges aren’t equal to the groove).

I’ve taken the liberty of making a copy. Classic example of thread forms.