Sofirn SP31T thrower

Hi all

I’ve just ordered a Sofirn SP31T as the basis of compact thrower for use when dog walking and wildlife spotting.

I’ve already got a Convoy C8 running a FET driver, but I wanted something that throws further and also has a side switch.

The way I intend to use the light dictates the way I’ll end up modding it, so I thought I’d throw this out to the forum for advice/ideas.

My initial thoughts are that the tailswitch will be there purely as a lock out. On/Off will be controlled by the side switch and it will only power up the emitter while you’re pressing the side switch.

I only expect the light to be turned on for a few seconds (10 secs max.) at a time so the current to the emitter can be at the upper limit.

So, what emitter would people recommend and what would the max current be? I’m very new to modding so any advice is appreciated.

Could I run without a driver, straight off the battery?

Thanks in advance

This light is similarly sized to a C8 (very similar head diameter) so it won’t necessarily throw any further. What emitter do you have in your C8? XPL HI?

You can make this light throw a bit further if you use a smaller LED with higher luminance, but your beam size would be smaller.

My C8 is running an XPL-HI. I like it a lot, but I find it a bit slow when I want a quick powerful beam of light to enable me to spot my dog.

Hopefully the SP31T will be able to run higher current.

What do you mean by slow? You can get a bit more power by going with a lower Vf emitter like a sliced SST40.

Do you think you want more beam intensity or beam width or both?

This is the light you’re talking about:

You can’t expect readers to keep up with the Sofirn catalogue.

You like the C8.
Go for a C8+, and upgrade if necessary.

Nicely balanced torch to carry that one
and well upgradable to more beam plus…

C8+ is not a C8 though…

But he wants a side switch and more throw/more power.

Since he has already bought the sofirn, there are a few options.

  1. Go with a dedomed XPG2 or even white flat to get more throw but a more narrow beam.
  2. Sliced SST40 or dedomed XPL V6 to get similar beam size as XPL HI but with a bit more power/intensity.
  3. Go with a XHP35 or XHP50 and boost driver. This might get you a larger beam and more output, but the beam intensity will go down since the available boost drivers are not very powerful.
  4. Go with 2x18350 and sliced XHP70.2. This will get you a lot of power and decent throw.

If the OP wants more power and throw there are better lights than the sofirn to get it, but since he already bought it, I think the above options are what he has.

This light uses a buck driver, which is not such a good idea with an XP-L HI or XP-G2 because they have high Vf.
The “White Flat” would work very well i.m.o. Low Vf and very tiny die.

Yep.

And since it’s a regulated buck driver, that means not only will the LED run in a good and efficient zone, but it will stay at max brightness for a long time.

It will also give you a ton more throw.

The buck driver most likely is not powerful enough to drive any of these emitters optimally, so it will have to go in any case.

If C8 reaches high output too slowly, change mode group and/or use mode memory?

I can go from off to turbo in under a second on my Atrolux in 4 mode without memory…

By ‘slow’ I mean it takes too long to scroll through the modes to get to full power.

What I’m after is instant full power as soon as I hit the button. I don’t really want multi modes on this particular torch.

I’m sure my C8 could be made to throw a bit further, but it’ll never have the side switch that I want.

I don’t want a tiny spot of light either. I’m happy with the XPL-HI, but need a bit more range.

This light hasn’t cost a lot, so if the consensus is that it’s not right for the job, then I’m open to suggestions, but I want something that fits in a jacket pocket.

You should just be able to set mode memory on to achieve that. What version of the C8 do you have?

I’ve fitted a A17DD fet driver to my C8. Can’t remember what the tail amperage is though without checking.

For speed I prefer a side switch to a tail switch

I certainly wouldn’t try to dissuade you from buying/modding another light (I think that’s like… illegal here?) but in the meantime you can use this to set up the mode memory on your C8 and IDK if you’re on 4-mode or 7-mode but changing that will make mode switching way faster too.

3 or 4 mode driver, mode order high to low no memory

you always come on at turbo, just to lower output need to cycle

I got Bistro HD OTSM drivers for most lights including the C8

Yes, I can change the UI so that the C8 goes straight to turbo, but that won’t increase throw or make it any easier to handle/switch on.

I need a bit more throw than I’m getting with the C8. My L6 throws further.

Thinking of a SST-40 driven to the max.

Yes, although it depends on what you consider optimal.
Don’t know if the stock driver is moddable to do 4 Amperes or 4.5 Amperes.
I mean, you can put another sense resistor on top of the stock one, but the coil may get too hot…

SST-40 wont beat XPL HI for throw in a C8 unless its dedomed. Youre gonna get more backscatter/glare unless ypur C8 is already cool white too.

D1S, GT Mini or Oslon emitter in C8 are the only real choices for more throw from the same size light.