LunaSol 20 PD Modifications

[heckboy]

I just popped the +1/8" button off and put the +1/4" button on. I think I'm finished with the fitting, the +1/4" really feels nice in my hand. Of course walking the dog this evening will tell the tail.

If this fit is right I'll need to decide how I want the final version to look and whether, as McGizmo suggested, I want to design in a lock out feature.

Later,
HB

[manoloco]

A cylindrical spring is fine provided it doesn't bottom out before before you reach your destination. The conical spring can be compressed down to a much lower height as the coils nest within each other. In some cases, you can feel the loops pop over each other and this is cause for some of the clicking or abruptness one can encounter; either manifest as a "bump" or increase in force.

Right, i control this cutting the spring, however on the McE2s i didnt need to, and the spring had quite some lenght, but was thinner, the conical ones can be compressed to a lower height, but its the linearity on force for mode activation what i look after, and i must say after tweaking my McE2S its VERY comfortable, and needs even a tiny bit less force than the one on the L1, i said that the L1 is better to "hold" high, but after re-trying both, its pretty close, and im very happy with both, but i think i would like both switches better, if they could hold high a little better, without affecting the positive feedback.

i dont know how does the spring work in the lunasol, but if its anything like the one on the McE2S, and the PD has less parts, it should yield better results with a less stiff cylindrical one, the only PD light i have is a nitecore EX10 and while its very useful and practical to me, i would love for it to have a 2 stage like the one in the L1. the action is smooth enough on it but one of the things that doesnt help is that the lubricant in there gets the top part kinda stuck to the body and that takes away part of the smoothness, one thing i like about the EX10 PD is that it takes care of what i complain on the L1 and McE2S, the range to mantain or hold the light on momentary is terrific, but it only has 1 stage.

i have another used L1 and another McE2S coming, i couldnt afford to wreck the only L1 tailcap i have, when i get the other i will look into it to see what can be done to improve this.

a 2 stage light is almost unbeatable for practicality, and its GUARANTEED that in a hurry, a moment of stress, or while doing something else, you will not fail to get to the mode you want, its kinda like close to a perfect measure, less (1 stage) and you can only use the light for very limited purposes, (3 and you will be messing with the simplicity too much)

in that sense, i loved when i got the L1, i was about to not buy a surefire for 2 reasons: didnt have money enough at the moment, and was between 2 lights: Novatac and the L1.

The versatility of the Nova and how i could use rechargables won in the end. i am very happy with the way i can interact with the light, but a year later i got an L1 at a good price, and after trying the L1 switch i can say there arent any designs that have beaten it yet for me, only problem though, is that it has too many parts on the switch and that is invitation to failure, i hope it lasts longer than i expect.

sorry for going a bit offtopic but there arent many posts to talk about switch and interface operation, and incidentally i found this one, with HB doing a great investigation and tweaking, with access to great tools and machines to do it, i fell in the temptation.

[js]

Very cool x-ray image, HB! Thanks for posting!

[mudman cj]

Thanks for the spring cutting tip! I have been using my LS20 for over a month now, and while it did get a bit easier, I was actually considering the idea of selling it because the PD action is just too stiff for me. Well, yesterday I cut the top coil off of the spring and it got a bit better, but still not what I wanted, so then I cut a bit more and a bit more and finally got the action just how I want it. And the best part is that for <$1 I can get an exact replacement spring to return to stock if I want. Thanks for making my LS20 the light that I always wanted it to be.

[heckboy]

I just got the new springs in. Wow, with the new spring installed this feels more like what I'm looking for. The actuation force feels much like my L1. Analytically the actuation force is the same:

Light/Low Level Force (lbs)/Hi Level Force (lbs)
L1............... / 1.7 / 3.0
LS20 modified/ 1.6 / 3.2

I've gone from the original spring with a constant k=~10-13 #/in to k = 7.6 #/in. The new spring is also shorter by about .09" which in combination with a lower k has a significant affect on the overall force requirements. The spring I selected is Lee Spring # LB 024A 01 AAA. It is a conical spring like the original in the LS20. I believe given the space constraints inside the battery tube, and the lack of guide rods, that a conical spring is the ideal solution rather than using a cylindrical spring.

Regards,
HB

[Scottiver]

Cool, good job, I may have to order a few of those.

[manoloco]

Those numbers look nice!, how easy is it to maintain the high level?, does any variation in travel affect it, or does it have good range?

The piston drive gives many advantages, i have yet to see any critical weakness (perhaps deformation on the body could affect it, but on a Ti body thats very unlikely), i like how it works on the EX10, its very smooth, and the spring on that piston is very soft, thing is, its only a one stage switch.

doesnt anyone have a spare Lunasol so i can try?

[Scottiver]

I just tried to order a few of these and didn't have any luck. Very difficult to navigate website. When I finally figured out how to get to an order page, it wouldn't put any items in my cart. They also have a $20.00 service charge for orders under 10 springs.

[McGizmo]

...... The spring I selected is Lee Spring # LB 024A 01 AAA. It is a conical spring like the original in the LS20. .......
Regards,
HB

HeckBoy, I figured I would try some of these out myself but on the website going with the part number you have provided, it shows an OD of .208" ? Are you deforming the base to get the spring to remain captive in the piston pocket?

EDIT: Never mind. I looked at the battery springs and in the specs, it shows this spring as having the OD base diameter at .360".

[heckboy]

HeckBoy, I figured I would try some of these out myself but on the website going with the part number you have provided, it shows an OD of .208" ? Are you deforming the base to get the spring to remain captive in the piston pocket?

I just searched that part number and it came up with the wrong part. If you go to this page: http://leespring.com/battSpring_intMount.asp you'll find the parts I ordered. Like Scottiver pointed out the Lee Spring website does suck a bit.

The spring LB 024A 01 AAA is a direct replacement for the spring you used in terms of base diameter (.360") so it fits right into the counter bore in the PD. These are Ni plated as opposed to Ag for your original spring. I think that the plating difference won't be any practical significance.

Regards,
HB

[heckboy]

HeckBoy, I figured I would try some of these out myself but on the website going with the part number you have provided, it shows an OD of .208" ? Are you deforming the base to get the spring to remain captive in the piston pocket?

EDIT: Never mind. I looked at the battery springs and in the specs, it shows this spring as having the OD base diameter at .360".

I ordered five springs. They aren't cheap. I need three, I can send you two of them to play with if you want. Let me know.

Regards,
HB

[Daniel_sk]

I will have a look at the second machine to see if it's outputing any better results.

Here's a quick photoshop, until a better picture can be made .

[heckboy]

Nice photoshop work Daniel_sk.

[RocketTomato]

I just tried to order a few of these and didn't have any luck. Very difficult to navigate website. When I finally figured out how to get to an order page, it wouldn't put any items in my cart. They also have a $20.00 service charge for orders under 10 springs.

Sounds like a perfect group buy opportunity. I'd be willing to organize it if there is enough interest.

The X-Ray image is very interesting. This must be an industrial X-Ray machine? I do not think the X-rays used in medical equipment are high enough energy to penetrate Ti. You can even make out the individuals coils in the cathode wrapping of the battery.

[Scottiver]

Here's a quick photoshop, until a better picture can be made .

Yep, good job. Keissling needs to put this picture in the McGizmo information sticky.

[Dog Chaser]

Sounds like a perfect group buy opportunity. I'd be willing to organize it if there is enough interest.

I'm in for two or three. Sign me up.

[McGizmo]

I ordered five springs. They aren't cheap. I need three, I can send you two of them to play with if you want. Let me know.

Regards,
HB

Thanks HeckBoy but on your recommendation, I already ordered a bunch of these. I too believe that the spring tension can be reduced from where it presently is but I know that at some point, you can have too little return force and the light will not behave properly when it backs off. If the source you have provided us here had been present a few years back when I went the custom route I would have welcomed these as an off the shelf alternative. I too feel that nickle plating is fine for a battery spring and it is by and large the industry standard.

[heckboy]

The X-Ray image is very interesting. This must be an industrial X-Ray machine? I do not think the X-rays used in medical equipment are high enough energy to penetrate Ti. You can even make out the individuals coils in the cathode wrapping of the battery.

Yes, industrial digital x-ray. It sees through everything I've ever put in there. 18 second exposure time FYI.

[heckboy]

Those numbers look nice!, how easy is it to maintain the high level?, does any variation in travel affect it, or does it have good range?

It is very easy to maintain high level, on par with the L1, however, the L1 has just a little bit of travel tolerance at high. LS20 by the very nature of the mechanism (solid metal piston pressing against solid metal contact ring) is pretty much a zero travel tolerance switch on high. At this point I am happy with the actuation force level, travel, smoothness, and button height.

I think I am going to proceed with the design of a lock-out for the button and change the contour of the button to slightly rounded and maybe even put a few LPI of checkering on it.

Regards,
HB

[PoliceScannerMan]

18 second exposure time FYI.

Jeez, really? I X-rayed my buldging Ti PD one time, long story, anywho, those industrial machines must be very low powered. Small mA spots anyways.

[RocketTomato]

Jeez, really? I X-rayed my buldging Ti PD one time, long story, anywho, those industrial machines must be very low powered. Small mA spots anyways.

Sounds interesting, please do tell. What does "small mA spots" mean?

This is probably going too far off-topic but:

High power x-rays can mean two things.

You can have "soft x-rays" which are low energy (i.e. lower frequency X-rays) which are generally used in dental and medical equipment and range from 0.1 to 12 kiloelectronvolts. There are also "hard x-rays" which are higher energy (i.e. higher frequency) and can penetrate items easier and range from 12 keV to 120 keV. Any higher and you get gamma rays.

Then there is total flux, or total x-rays delivered per unit area per unit time. So you can have a soft x-ray source with high flux or a hard x-ray source with low flux. You don't want to get zapped by either.

In short, the x-ray energy determines what can be penetrated and the flux determines how long you need to x-ray something to get the image.

[mudman cj]

Sounds like a perfect group buy opportunity. I'd be willing to organize it if there is enough interest.

I would like one of these springs as well please.

[AndyTiedye]

I'd be interested. These should work on other PDs too, right?

[js]

It's good to know that the Aleph McE2S contact spring sold by the Sandwich Shoppe is the exact replacement spring for the PD.

Personally, I wouldn't change to a lower force spring on my PD lights. I think they are just right. I like the stronger activation and holding force over the force required for the L1. For some reason the design just likes to have a bit more, to my taste.

However, I will say that when I got my Ti-PD-S, the action was a lot less smooth and less appealing than my LS20, and I wasn't sure why. It had a tendency to snap and jump at times during the action, either coming or going. I was about to pull out the spring and cut off the dead loop at the top, just like Don suggested, when I noticed that the battery I pulled out had part of the rearmost shrink wrap burnished off, like it had been tilting to one side when pushed forward, so that the bottom left hit the left side of the piston, and the top right hit the top side of the piston. Then when released, would right itself and go a bit more straight (or vice versa).

Point is, the battery obviously wasn't staying perfectly co-axial. So, because I always wrap my 123's with tape for use in my Arc LSH, I did the same here for my Ti-PD-S, and VOILA!

Perfection.

A very smooth and precise action, just like my LS20. I suspect that I could have achieved the same result by cutting off the top dead loop of the spring, but since I like the force of my light the way it is, this is preferable to me. Two or three wraps of tape is all it takes--and make sure the battery still slides easily in the piston; you don't want to get rid of all the play.

[RocketTomato]

... when I noticed that the battery I pulled out had part of the rearmost shrink wrap burnished off, like it had been tilting to one side when pushed forward, so that the bottom left hit the left side of the piston, and the top right hit the top side of the piston. Then when released, would right itself and go a bit more straight (or vice versa).

Point is, the battery obviously wasn't staying perfectly co-axial. ...

If you look at the X-ray image, you can see that the battery is tilted just as you describe. Actually looking more closely at the image, you can see that the PD itself is very slightly off axis as well, which there is no way to avoid.

[RocketTomato]

Hi everyone,

Here is a link to the group buy feeler.

[maxspeeds]

I'm in for 1, maybe 2.

[manoloco]

It is very easy to maintain high level, on par with the L1, however, the L1 has just a little bit of travel tolerance at high. LS20 by the very nature of the mechanism (solid metal piston pressing against solid metal contact ring) is pretty much a zero travel tolerance switch on high. At this point I am happy with the actuation force level, travel, smoothness, and button height.

I think I am going to proceed with the design of a lock-out for the button and change the contour of the button to slightly rounded and maybe even put a few LPI of checkering on it.

Regards,
HB

on the EX10 the piston has a great "hold range" due to the spring in the head pill working together with the one on the piston, in the L1 maintaining high is not as comfortable as mantaining low, however its security comes from the fact that its at the end of the travel. but its still uncomfortable.

Is the low level on the LS20 like the one i described on the EX10?

[RocketTomato]

I'd be interested. These should work on other PDs too, right?

Yes, I believe all the PDs and the Mc2ES switch all use the same size spring. Don, please correct me if I am wrong.

[McGizmo]

Yes, I believe all the PDs and the Mc2ES switch all use the same size spring. Don, please correct me if I am wrong.

To the best of my knowledge, this is correct. I can't speak for any clones, duplications or replications that may be floating around out there though.