Q8 modding

I could design a pcb, but I don’t have a Q8, so don’t have the measurements.

I asked about a switch board on oshpark earlier but got no response. I would definitely be interested too, after so much troubleshooting swapping the leds and resistor i have turned a good part of it into charcoal.

Has anyone measured the size of screw that holds the reflector in?

I’m not touching it “again”, until I have replacement, in hand. And even then maybe only after a rum & coke, or two.

“…turned a good part into charcoal” - lol, perfect description of my soldering skills.

I've used a M4 x 8 mm replacement - worked fine. Think that's the size of the stock screw. Yes, definite replacement candidate. Most are combo phillips/slot but at least 1 Q8 came with phillips only. I noticed pics posted of mangled reflector screws showed the stripped phillips and the slot clearly present, so I dunno why they didn't just use a flat edge screw driver.

Can we get a confirmation the sizes of the screws? Looks like we have 3 sizes… driver (x2) , tail pcb (x4) and reflector (x1).

If I’ve been paying attention the driver screws are M3 x 4mm, tail screws are M2.5 x 6mm and the reflector is M4 x 8mm. Am I remembering it correctly?

Screw Cheat Sheet

NOTE: For 1st Batch Q8’s

Here’s what I have so far, someome double check.

Note: Tom E confirmed

+1 with Etex, just checked. I got a bag of stock screws now.

We need, beyond confirmation of the sizes, confirmation of a source of good metal replacement screws.

I’m afraid I’d end up buying a few hundred of those cheap “put in once and never remove” pot metal screws that are so readily available.

I’m hoping somebody at TF gets the bug to do it right, buys good screws for ongoing production, and offers them to us as replacement kit parts.

I can’t design a board. but there is a basic E-SW board (Tactile switch) on Oshpark already. Its only a SW mount pad but possibly could be redesigned from there.
OD of that board is 12.25mm but the Q8 is closer to 12mm and a press fit. I do not know what the SW size is or what its called. Seems like a common SW and its also used on the L6 as well.

Tact switch (button) board 12.2mm round v2

L6 E-SW board is a possibility with 2 LED pads but it does not have a resistor pad integrated.
MtnE also sells the E-SW board with a switch mounted for $1 and it looks like he used the BLF Helios board from Oshpark.

Guess this as good a place to start collecting info or parts sources. This is what I know so far.

I'm finding stuff from BoltDepot.com works well. Sure has a different finish, not as shiny as the Q8 stock. I dunno enough about this stuff. I do know you can spend a fortune on a couple of screws now-a-days. I also got a M3 screw kit from BG I posted, and they seem very good quality - hexagonal tools need though. Hex or torx really should hold up better, I'd think.

But I really would like brass though, but it's softer, more conductive I believe. Posted earlier these: http://www.ebay.com/itm/M2-M2-5-M3-Brass-Phillips-Pan-Round-Head-Cap-Bolts-Screws. They are phillips for better or worse, not ordered yet, no idea how good they are.

Even if the driverboard screws are M3 x 5 mm I do not think it always is necessary to drill the holes, because my Q8 has the specified lumens output right out of the box. Of course this may vary from item to item. Eventually you can try loosening the screws and screw them right back again while pressing the board with some force to insure minimal gap. My tail PCB screws are M2.5 x 5 mm.

It would be nice if the switchboard holds at least 3 leds. Each with his own resistor. If 4 fit i am happy to get more mixing options. And if someone needs a new switch (because it got damaged or you want to put together new boards) you can get a package of 50 at BG for ~2$.

Drilling the holes is not necessary. You also could use a small roundfile or a reamer. . . just open up the hole 0,5mm so that the screw went throu without gripping the PCB.

Thanks for the screw sizes confirmation. :slight_smile:

Just ordered the brass phillips heads from ebay. Couple a bucks, no biggie. Thanks for the head’s up on em. :wink:

Anybody here work in nuclear power or aerospace, who knows a reliable source of known good metal screws?
I’m tired of the lottery.

A reminder — if you need to shorten a threaded bolt — put a nut onto it first, then file/saw off the excess, then clean up the edge with a file — then remove the nut and that will chase off any extra metal out of the threads and clean them up a bit.

(Noted because I see that eBay seller has no m3 shorter than 6mm, where we want m3x5mm)

I was seeing a near continuous wear pattern on the driver board, but went ahead and bore out the holes. One thing I noticed was the holes in the flashlight body had a mushroom effect at entry. More like a slight raised burr, actually. I used a 7/32 standard drill bit (by hand) to chamfer down that opening slightly. Holes & screws were fairly clean. Tail screws just had a little locktite on ends. Afterwards, I only saw about 10-15 lux difference (approx 100 lumens, calculated). I only have ceiling bounce capability currently.

But the spring bypass was a completely different story, wow! Everyone should try to do that.

this would requite that the resisistors are on the opposite side and 2 LEDs are 0603 if you stick to the same switch size on 5x5mm

you need to order 2OZ boards as they are 0.9mm thick!

I haven’t done a spring bypass on any light yet… and someone reported a 1k lumen increase on the Q8. That seems a lot! Would it mean the springs have a lot of resistance on the Q8? Would other springs be more appropriate…? Just a noob moder question. :slight_smile:

If you are going to buy screws get some taps too. Cleaning the holes of anodize, glue and sand grit helps continuity. Tap will also thread the hole deeper if your screw is too long.

Other than going to a brass screw for better electrical path, the original screws are good enough if they have not been stripped. Mine were OK and I reused them.
Also keep in mind a brass screw is going to be even softer than the originals.
If I desired a “Quality” fastener I certainly would not buy from ebay, Alixp or BG. Places like Fastenal, Mr.Metric, boltdepot sell fasteners that meet industry standards like DIN (something) JIS etc. Go that route and spend the little extra money to do it and you prolly will not find anything under 100pc per size needed. Sell off kits of quality hardware to others. IMO its not worth the time and shipping to do it in order to recoup a $15 order on 300 screws. If you have a Fastenal nearby you can order special (non-stock) fasteners and have them shipped to store for pickup. I have also found Fastenal will sell small quantity of certain items but why buy 5-10 priced each when you can get 100 for the same price.

Aerospace or Military standards grade screws to hold a board in a flashlight? Really? Well you can triple the cost previously.
I already have better quality screws on hand that I could have used but because mine were Re-usable I reused them.