Loneoceans GXB172 Driver Group Buy

17mm in S2+
20mm in S21A

I’m just having this nagging feeling that pulling 50w out of a single 18650 might not be the greatest idea.

I dont think many people would be doing this, technically the driver can pull 50W, but with the default settings, max output is 5.5A which means just shy of 20W

Is nothing new, common as apples or donuts. Of course, use a cell with enough power delivery/continuous discharge rating, namely if maxing out the driver's output power. A 30Q cell is just shy of this, although an acceptable or 0K choice in responsible hands. In any case, a high discharge cell is a must (Murata VTC5/VTC5A/VTC5D, Samsung 20S/25R/25S, LG HE2/HG2, Sanyo NSX, Molicel P26A/P42A…).

This is going to be super unpopular, but you really need to build in extra costs for things like lost packages, returns, failed boards, shipping, etc etc etc, and don’t forget your time as well. Just my take. Still in for 4 at 17mm.

In for:
1pcs 17mm
1pcs 20mm

Maybe depending on how much vertical clearance there is in my host, maybe I could swap out default inductor with the largest compatible I can find.

Super excited. I’ve wanted a crazy 1S XHP70.2 since forever!

Yes I agree, Im still trying to work out the final cost, I have to keep the balance of a fair price and not look like im doing it as a means of making profit from an open source design, but at the same time reimburse myself for labour etc.

This is what I intend to build in my convoy with this driver.
Its also a bit tempting for me to make a triple emitter UV light with this driver too.

Big thank you to nzoomed for help make this group order! My gxb172 is running for past year and I am happy with it in my flashlight, always surprise to show friends the brightnest! I do not think I place order since I build some drivers before, but I recommend it for people who want to try gxb172. good luck!

There is nothing wrong in profiting from open source designs. Quite the opposite IMHO, when I open source something I want others to take maximum benefit from it. If it’s financial - that’s great.
Even if profit is not what drives you, bending yourself to balance at the edge of loss it is simply counterproductive. Price it fairly without forgetting about yourself and people should be happy.

Exactly.
Even though the same 100 units would be marginally cheaper for me to do locally (2600 at my shop), I’d still have to charge about 45 to 50 a unit because of the time and labor/testing involved, even if only to have a personal incentive to keep going.

Yes, good point. I think we need to feel out what people are prepared to pay.
As it is, some feel $30 is too much, so would like to keep it at $40 or less.
That is on even par with other drivers I see listed on mountain electronics and sandwich shoppe.

MTNElectronics I’m familiar with, Sandwich? Not at all hehe
Looking over what the GXB can do again, 7.24V@6.5A in 6V mode, 14.7V@2.5A in 12V mode.
That right there is what you get for the price of admission. The MTN Electroic booster can only do 6V and 4.2A at best, barely anything to an XHP70.2
While the end result seems marginal, the amount of parts and engineering involved to get that output AND keep the efficiency above 90% is much more significant. Also, these are premium drivers, likely the best of their class and probably will be for a very long time :wink:

Too bad ya aren’t in the States, we could have probably talked turkey about getting these built locally so ya don’t have to deal with China, Taxes, Import Duties and who know WTF else. Plus, I would be able to have a personal hand in keeping a close eye on the production process.

BTW, RMM was able to sell his BST2 drivers which are quite similar for $25. And make a profit. So maybe he chose cheaper components or maybe he has a cheaper manufacturer.

Quite possibly the former, since I can do it cheaper locally for NZoom than China, but he’s in NZ and I’m in the States. The biggest cost of these drivers, aside from the 4 Layer board itself (can be anywhere from 3 to 5 bucks each), is not the Boost IC or even the Inductor, it is the 1210 Capacitors for the 202 version. Those run an easy 1.1 dollars each and this thing has 4 or more, while the driver IC is 3 and the inductor is another 3.
I’m no engineer, so I could not begin to fathom where to begin to find a substitute for the inductor, but I do have some idea of what could be possible for those caps.

Dropshipping maybe an option. If possible, just have the Chinese factory ship it to people in the list before shipping the rest for yourself to sell at a full price.

That might save a trip of freight and duties resulting in a lower preorder price.

I don’t think it would hurt to get quotes elsewhere but think the cost will be similar.
Some companies don’t charge for small smt components I see.

May pay to do some research on them, they may stick it to ya elsewhere.
Anyhow, my quote is for the 20mm 6V version. Definitely good for those that want to have a pocket missile for those that wanna use a 70.2 with a single cell.

20mm would be great I agree.
Will see what more interest I get.

Richard has just restock 17mm boost drivers

http://www.international.mtnelectronics.com/index.php?route=product/product&path=67_118&product_id=958

But still no real powerfull 4A 12V drivers...

Really looking forward to this GB