Convoy L21A 21700 Host - SBT90.2

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ArtieT59
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Convoy L21A 21700 Host - SBT90.2

I am looking for a host for my first “build” (install MCPCB and Driver into a host) and want to do something with an SBT90.2 (Big surprise!). The only SBT90.2 light I have currently is the Lumintop X9l. I wanted the Ft03s or K1, but am interested in doing my own for various reasons.

I am looking for a host that makes the most sense, and really like the look of the L21A. If that is not a good host, I’m open to others. I also favor the M21C look. I am looking while considering these factors:

-I like the 21700 form factor (mostly for size and battery performance/pricing/availability)
-I really like single cell platform (I have never had a need for multiple battery setups as I keep charged replacements on hand and would rather swap out batteries then have multiples in a flashlight at one time)
-I would consider multiple 18650’s if a 2s/2p setup if it is better for the SBT90 in terms of voltage?
-I am not concerned about size (big or small) but really like the size of the ft03 / M21C / 150mm-170mm range Length x 50mm-75mm range head
-I am not concerned about UI, and would actually prefer simplicity such as 10%-40%-100% or 1%-10%-40%-100% and thats it. If I need to have a more elaborate UI to accommodate the optimal driver then that is OK too.
-I am going to need a fabricated / premade driver, and am not sure which one delivers the best amperage (voltage?) for the SBT90, but believe I have read that some convoy’s COULD fit the bill?
-I really prefer a Tail Switch
-I can feel confident I can modify the reflector opening if needed, I have tools.

Is this kind of modification not ideal / realistic at the moment due to the type of driver needed to properly run a sbt90? Meaning, would I need to have extensive knowledge and modify a driver myself for proper performance?

Thank you to all of the fine folks here who spread information generously and freely to the new guys like myself.

**I apologize if this info is in another discussion, This thread started as asking for advice on wether the Convoy L21A is a good host and as I started typing turned into suggestions for the whole build. But my main goal is get experienced people’s thoughts on the L21A as a host, regarding driver size and driver availability as well as reflector dimensions and if they would work properly for the SBT90.

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Yokiamy
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It’s not too difficult, you only need a decent 22mm driver with a good FET.
Mtn sells some 22mm drivers.

Probably you need some adjustments to the reflector, the opening is too small and you need to prevent shorts

ArtieT59
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Yokiamy wrote:
It’s not too difficult, you only need a decent 22mm driver with a good FET.
Mtn sells some 22mm drivers.

Probably you need some adjustments to the reflector, the opening is too small and you need to prevent shorts

Ok, great. Much better then I thought. Prevent shorts … as in – after widening base of the reflector, stop metal on metal contact to the mcpcb? I think ive heard people say use tape? is there a best use type of product to prevent the short?

Thank you!

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Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

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Sirstinky
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You could make it work. Just use a capable driver 22mm and ream out the reflector hole to fit the sbt90.2. I use kapton tape to insulate the reflector to prevent shorts. You need to use a 20mm mcpcb with the L21 I believe.

contactcr
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Get a “centering ring” from whoever you buy the LED from, even if it’s the wrong size you have to open the reflector anyways so you could always shoot for that size if it makes sense.

You will have to bypass the springs or get upgraded high current springs (or both). If you don’t the spring will sag after so many uses on turbo.

ArtieT59
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Sirstinky wrote:
You could make it work. Just use a capable driver 22mm and ream out the reflector hole to fit the sbt90.2. I use kapton tape to insulate the reflector to prevent shorts. You need to use a 20mm mcpcb with the L21 I believe.

Thank you! Sorry late response i have been all over and just came back to this.
Wehn you say capable driver, would mtn be the best route? should i ask simon from convoy? im sorry, this will be my first build..

[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

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ArtieT59
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contactcr wrote:
Get a “centering ring” from whoever you buy the LED from, even if it’s the wrong size you have to open the reflector anyways so you could always shoot for that size if it makes sense.

You will have to bypass the springs or get upgraded high current springs (or both). If you don’t the spring will sag after so many uses on turbo.


Thanks! would the springs that hank sells be ok? https://intl-outdoor.com/catalog/product/view/id/112/s/gold-plated-beryl...

If i got a spring that was of high quality, like if for example Hank’s (if they will work for this), would you still suggest bypassing them anyway? If so, i think ive seen 18 gauge wire suggested, in your opinion would 18 gauge be OK or something else? thank you again!

[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

My Sft40 beamshots / comparison thread: https://budgetlightforum.com/node/78100

contactcr
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Hank’s springs are awesome but they are short and wide base. Doesn’t retrofit to very many lights.

For bypass 18 is too thick imo. I use 20 or 22, allows springs to flex more and it’s not as stiff.

ArtieT59
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contactcr wrote:
Hank’s springs are awesome but they are short and wide base. Doesn’t retrofit to very many lights.

For bypass 18 is too thick imo. I use 20 or 22, allows springs to flex more and it’s not as stiff.


Great info, thank you!

[FLF] Five Light Friday https://budgetlightforum.com/node/78749

Check out some of my new lights (picture heavy) and quick first impressions of them here: https://budgetlightforum.com/node/77180

My Sft40 beamshots / comparison thread: https://budgetlightforum.com/node/78100