PD - Difficulties

[Freyth]

So I just received my Ti-S27 PD... fantastic light! A little bit small for my hands though. Anyway, I realised that the PD was rather hard to activate. I could only activate the low setting with a considerable push, but to activate the high setting I had to press down hard, real hard and even so, it flickers sometimes.

Is this normal? I don't see the point of the PD if I can't activate the light easily through this mechanism. Any ideas on how to make it easier to activate?

 

[beach honda]

possibly a smaller sized piston o-ring?

-chris

 

[Telkin]

Mine took a bit of working in. At first it was really stiff but after using it for a while the spring seem to be slightly more flexible and it's now at a very good tension so I would say it's normal.

 

[TxTroubleMaker]

I don't think it's the piston o-ring so much as the stiff spring in the piston. I've noticed that the springs in Don's newer lights are pointier and stiffer than the ones that were in the aluminum PD's. My wife's Mule was giving her the same problems that Freyth's S27 PD is having. At the suggestion of another forum member I cut the spring down a bit. Now some of you out there may not be too comfortable with this approach but not only did it soften up the piston action, it made the head easier to operate one handed. The battery is not creating as much resistance on the threads in the head which helped smooth out the action. Take the battery out of your new lights and see how much smoother the twisty action is when there is nothing internally pushing on the head or with the battery in your light pull down on the head while twisting it and feel how much smoother it turns.

If anyone has a better fix, please chime in...

 

[greenstuffs]

I usually cut half coil that should be enough to soften the piston action, if you feel guilty then you can buy springs at the sandwich shoppe.

 

[McGizmo]

What everyone has said. In addition, make sure you have the head twisted down far enough that you don't have to depress the piston any more than necessary. The light will break in for certain and get better and easier to use but it may still require more effort to activate than you would expect or like. :shrug: I have gone back to a larger piston O-ring (#016) and since I had the battery spring pocket deepened in the more recent pistons, I no longer remove the first "dead" coil from the spring as I was doing there for awhile.

 

[jumpstat]

Use it frequently and in time it will be 'normal'.

 

[Freyth]

Thanks for the suggestions! I'm particularly inclined towards cutting the spring by a little - but lack the tools and know-how to do so. I guess I'll continue using the light... every second I look at it, the more fond I am of it. Amazing little bugger this one.


Oh btw, where can I get a C-pack?

 

[beach honda]

tools and know how? all u need is a pair of cutting pliers....

yeah...

-c

 

[Manzerick]

Pliers are for the weak!!!


Go for the dremmel!!! :lolsign:

tools and know how? all u need is a pair of cutting pliers....

yeah...

-c

 

[Freyth]

i tried taking out the piston and i see that it's a one-piece. thought it was separated. I'm afraid if i take the spring out i wont be able to put it back.. so... yeah

 

[Oddjob]

I had no problems taking out the spring in my original PD and putting it back. I took it out of my original PD to stretch it out a wee bit to make it slightly harder to press as I was finding it a bit too soft. My PD-S spring on the other hand is just right. I personally like it a bit on the stiffer side because I use the piston for only a few seconds at a time for a quick look at somethin so it being a little harder to push does not bother me. I would give it time to break in and make sure you lube the piston O-ring.

 

[StrayLight]

I had a very stiff PD and, rather than wait for it to "work" loose, I decided to cut the spring back ever so slightly. Not sure which end others are cutting, but I took off less than 3/4 of a turn at the top (small) end and filed the cut smooth so as not to scratch my AW R123. I chose the top because it is much stiffer, with less travel even under high pressure.

Much improved momentary high and only a light touch for momentary low. I might like an even softer momentary high but not at the expense of low. Kind of a pain getting the spring re-seated.

Completely OT, what on earth is the size of the hex drive of the screws holding the clip? I tried the smallest I have, 1/16" & 1.5mm, which were too small. Next sizes up, 5/64" & 2mm, too big. WTH?

 

[Kiessling]

It is the super secret McGizmo size. Custom made and only available directly from the McGizmo manufacturing plant for $99.99











Just kidding. Of course I don't know the answer, but it is hidden somewhere around these halls. The size, IIRC, is different for the al and ti screws. But of course, I could be wrong.

Welcome to CPF btw!

bernie

 

[StrayLight]

I paged down only enough to see the top of your post... had me going there for a sec.

Mine is Ti, if it turns out there is a difference.

Thanks for the welcome.

 

[Sable]

I have an apparently very old Al-PD (now PD-S thanks to mosport) that is very, very soft in terms of "springiness" on the PD. I like it fine - it's a little lighter than an "old-style" Surefire L1 for the levels.

I also have a Ti-PD-S from...a batch? I dunno which, but it's much stiffer. I have to say that given the choice I like the stiffer one more - it feels like it stays "off" a little more sturdily, even though it's not a difference 'cos the Al one stays off unless I press it? :shrug: Psychological, I guess.

 

[McGizmo]

Straylight,
It should be 1/16" but you need full 1/16" driver. Many of the drivers are undersized a bit. There area couple threads somewhere about drivers. Thorp drivers get my vote.

 

[jumpstat]

I've got both the PD-S HA Nat and Mule Ti, and the best fit is .078" (5/64"), 1/16" may be used but it won't seat properly and may spoil the hex screws.

 

[StrayLight]

Well, neither my 1/16 or 5/64 fit. Surely it's not driver "brand" dependent, but who knows. I don't relish the idea of trying to purchase single hex drivers and hope they fit.

I guess the clip stays.

 

[McGizmo]

Straylight,
If the screws are Ti, they are definitely a full 1/16" in size and not great with most inexpensive wrenches. Lunsford Racing who makes them holds high precision in their dimensions and doesn't apologize for the sloppy standards held elsewhere. At one point, I was going to have custom screws made by them with a larger drive socket size but once I got a hold of a couple precision drivers, including the thorp, I decided to stick with 1/16" so that there would be consistency in the population. I am sorry that this is a problem but it just is what it is.