PAM cyclops

[sssurfer]

Ok guys, let's go on?

I was saying that SF11 seems no problem about color, transparency, clearness, reflections, and so.

But the lens I tried, at magnification max, showed a twisted date window.

I think this is not due to SF11.

And that test was quite unreliable, as the only case I had at hand to try was from a low-cost 028 rep, whose bezel is about 4 mm high (instead of the usual 2.5-3 mm).

Still, that sounds like a warning to me, so I would highly prefer that we could try a prototype lens before placing the big order. Perhaps it could be possible with SF11. Archibald?

If that is not possible, still I vote for SF11, expecially because its (very) lower cost is leaving us less exposed in case something goes wrong.

Edited March 18, 2006 by sssurfer

[Faber]

yes...dont make us curious

[rbj69]

hey sssurfer, is there a place i can get one to test for us ? if u want send me the one u have and i will put it on mine i have ready for testing and post my results if u want me to lmk ok

[sssurfer]

Sorry Faber, thanks for your interest, but right now that was just a call to arms for the people who were involved in the project on the 'old' RWG: archibald, kruzer00, finepics, rbj, ...and me, obviously

We hope we'll have some good news for the board soon.

[sssurfer]

RBJ, that lens is 2.5 mm thick, so you will have to grind 1.2 mm off from it. But as you already grinded and polished the previous glass lens, you should be skilled in the matter.

Your best option is to get it directly from Edmund Optics America, where it is cheaper than in EU and you will not pay scandalous expedition fees as I did from UK (you figure, more than $62 from lens + shipping + taxes!).

There in USA it is $22.5 + shipping.

At that cost it's not worth that I send you mine: on what I paid for it, I simply can't think of getting the risk that it get lost in transit... And I still want to play with it a little, as well as to try grinding and polishing on it.

Here is the link:

http://www.edmundoptics.com/onlinecatalog/...?productID=1747

and the lens is:

LENS PCX 6 x 6 UNCTD TS

Stock Number NT45-077

Edited February 17, 2007 by sssurfer

[rbj69]

is it thinner than the ones from the other place u got the 6X6 from ?

[sssurfer]

It is thinner than one of them, and thicker than the other one. But main differences are:

1) quality: this is impeccable

2) expecially, its useful thickness is much lower than in the other two lenses, while its unuseful thickness (edge thickness) is higher. So, you have to grind more thickness out from it, but when you will be done, then you will have full 2x magnification.

3) And you have 0.2 mm tolerance in your grind work -- quite high, compared with that of all other lenses we tried.

Here I copy-and-paste what I said about this lens in our 'old' thread:

Numbers already done: that 6x6 lens is already perfect as it is, it will give 2x magnification whatever ET we are going to leave on it.

And if we are able to grind out all its ET, then we are going to get 2x magnification with a cyclops less than 1.1 mm thick -- i.e. a cyclops that will surely fit on any reps.

And I also wish to stress that, differently from glass, on these lenses we don't need such a high precision in our grinding work. Considering a cyclops 1.3 mm thick (as we did so far), we have a 0.22 mm tolerance. In other words, we are only required to be able to grind out the edge down to CT = 1.3 mm. If we want to go even lower, we are allowed to, but not obliged to. Should we go lower by mistake, no problem as long as we don't go below CT = 1.08 mm.

Briefly:

grind it how much you like, until it is between 1.1 and 1.3 mm thick. Then polish.

Edited March 18, 2006 by sssurfer

[Watchmeister]

You lost me. Are we talking flint glass or sapphire?

[sssurfer]

Hi kruzer, welcome!

Flint glass exactly like the last proposal that archibald received -- but actually that lens that I got from Edmund's some days ago. Same as lenses proposed to archibald, just with a thicker edge.

[Watchmeister]

So we are over the extreme temperature issue? I can't remember whether the issue was degradation of the lense, risk that it falls off the crystal. or glue used. Are there any refractory issues with the two different materials (sapphire and flint glass)? I know these are cheaper but I ask because for those without skills (me and others who ultimately will buy) we have to factor in the cost of shipping and work if there is an issue. So lower chance of failure is worth something.

[panerailord]

hello where is finepics?

[archibald]

hello where is finepics?

Probably caught up in all the drama, like me. OK, here's an update. I spoke w/ the sapphire people, and according to them they said "pretty close" because the salesman has to run the specs one more time by the engineering department to get the absolute lowest price. I pretended that the world would come to an end if I didn't have these lenses soon, so he promised to tell me on Monday their absolute lowest drop dead price. I sent an email to the SF11 people asking for a prototype--In case they say no, and we end up going w/ them, I wanted them to be sure they could do the edge thickness below .5, since they'd be the only ones so far who could do it--i sent them a large version of the following schematic so there would be no confusion.

Edited March 18, 2006 by archibald

[Finepics]

Hello boys - I'm here. Damn - feel like a noob!! Can we not carry over our scores!! Let me do some reading here and see where we are. Actually just picked up my Anchor lenses (only just arrived!!!) and had to pay 10 quid import duty - on top of the exhorbitant postal fees. Still gives me something to play with while we sort this out.

[Finepics]

So we are over the extreme temperature issue? I can't remember whether the issue was degradation of the lense, risk that it falls off the crystal. or glue used. Are there any refractory issues with the two different materials (sapphire and flint glass)? I know these are cheaper but I ask because for those without skills (me and others who ultimately will buy) we have to factor in the cost of shipping and work if there is an issue. So lower chance of failure is worth something.

Hey Kruzer - the problem with this was due to different Cof E (Coefficient of Expansion). If two materials are bonder together that have a different composition they will expand and contract at different rates with different temperatures, which might be enough to pop the cyclops off in extreme temps. Most of us would not wear our reps in a hot bath but if they were left in sunlight that could be enough.

[Matte]

Hello finepics!

I wrote a pm on the old rwg about pam cyclops and other upgrades (relume, fix recessed pin), please check mail

Thanks

[Finepics]

Got ya - will go check it out.

[rbj69]

It is thinner than one of them, and thicker than the other one. But main differences are:

1) quality: this is impeccable

2) expecially, its useful thickness is much lower than in the other two lenses, while its unuseful thickness (edge thickness) is higher. So, you have to grind more thickness out from it, but when you will be done, then you will have full 2x magnification.

3) And you have 0.2 mm tolerance in your grind work -- quite high, compared with that of all other lenses we tried.

Here I copy-and-paste what I said about this lens in our 'old' thread:

Numbers already done: that 6x6 lens is already perfect as it is, it will give 2x magnification whatever ET we are going to leave on it.

And if we are able to grind out all its ET, then we are going to get 2x magnification with a cyclops less than 1.1 mm thick -- i.e. a cyclops that will surely fit on any reps.

And I also wish to stress that, differently from glass, on these lenses we don't need such a high precision in our grinding work. Considering a cyclops 1.3 mm thick (as we did so far), we have a 0.22 mm tolerance. In other words, we are only required to be able to grind out the edge down to CT = 1.3 mm. If we want to go even lower, we are allowed to, but not obliged to. Should we go lower by mistake, no problem as long as we don't go below CT = 1.08 mm.

Briefly:

grind it how much you like, until it is between 1.1 and 1.3 mm thick. Then polish.

i just ordered one, now i await , also i will have u a price of those sapphires soon ok , i also will have my 2892 datewheel back at the end of the week from screenprinting , my guy just copied my genuine datewheel so it will be exact basically, im also using a fade resistant vinyl cover to see if it will be a good thing for the do it yourselfers , i have started on the new exact crowns , waiting on a knurling tool to cut the teeth in correctly on the crown , have a great weekend joe

also just a note the reason i wanted the datewheel done so quickly is now so i can try with new cyclops to see what it will exactly look like , i found it really hard to do a accurate comparison with the bad datefont on my watches

[Finepics]

Guys, I'm wondering if we have our calculations right. Look at this photo.

This is my 063 crystal with original cyclops on left (obviously). New Anchor cyclops on Right. I know the anchor cyclops is miles too thick but it's just to illlustrate my concern. Now look at this photo and see the problem - it's [censored]!!

If we dont have some sort of ET we will end up with this look as the light is refracted from the edges to form this halo reflection. We might need to concentrate more on Radius of curves etc. I wonder if original PAMs are like the rep version. The companies that make these crystals must do them similar to the gens as this is their business and I would have thought use standard techniques even if different dimensions. Comments please.

[sssurfer]

finepics, please have a look at my old post about anchor lenses on old RWG. I thought that halo was due to poorly polished edges -- but it could also be due to something else. Do you think it is due to lacking of edge thickness? It could be due be to that very domed shape.

But, expecially:

I grinded the Edmund's lens to about 1.4 mm. Edge chipped a bit while polishing. No problem (apart from $$$), as I just wanted to test the overall magnification of this lens.

Results: higher magnification than expected. Too high. It seems that RBJ was right when he was wondering about excessive magnification.

I thought a lot about it, and the only reason that I can identify is that the distance between the datewheel and the crystal is higher than we believed. Actually, that was the most critical datum to us -- and a one that we always lacked of.

It seems that adding the facts that the datewheel is a little below the dial, and that the crystal has an o-ring that keeps it a little above what we judged by measuring the bezels, we have some fractions of mm more than expected between the datewheel and the crystal.

And to an extreme lens like the one we designed, some fractions of mm is A LOT of space.

RBJ, try to cancel your order with Edmund's. I already did the test.

In conclusion:

It seems than we can achieve better results with a longer focal length. I.e., with a less thick lens. Not so flat as the one from Anchor that RBJ already tested, but flatter than what we thought so far.

This should also make it easier for the companies to manufacture it.

I have to perform some new calculations, but weekend is family time. I hope to have some news for tomorrow.

Edited March 18, 2006 by sssurfer

[Finepics]

Also the lens needs to have a fairly shallow Radius of Curve to avoid circular distortion of the numbers. I now think that the rep cyclops is probably the right design just slightly bigger in the gen with altered dimensions and sapphire.

Another thing is the rep cyclops is only mineral glass, no popping off with them so the CofE might not matter now. I wonder if we should just copy the rep cyclops in either sapphire or flint. We can slightly increase the radius of curve to give a bigger mag as we have a little room to do that (the rep cyclops is 1mm with an ET of .50mm) and leave the rest the same. The increase in dia will effectivley increase the size of the radius of curve which might be all we need. Also we might be able to get much more accurate tolerances on this as there is no knife edge to maintain.

[Watchmeister]

Great work by all. Joe, I am sure having the proper font on the date wheel will make it more apparent what the right answer is. It appears that the laws of refraction are not serving our purpose (or we can't measure) Am I correct in assuming that we may have to get made exactly what we want as there is too much variance in the stock items?

[archibald]

Great work by all. Joe, I am sure having the proper font on the date wheel will make it more apparent what the right answer is. It appears that the laws of refraction are not serving our purpose (or we can't measure) Am I correct in assuming that we may have to get made exactly what we want as there is too much variance in the stock items?

The stock items are already more expensive when you factor in the cost of milling, shipping, etc --the only benefit would be a couple weeks at best, depending on the work load of whomever you hire to mill them.

That's great news about Joe's wheel--if it turns out that it works good enough with glass I have a quote for custom 1.3 CT glass for $7 ea.

[Watchmeister]

Get outta here!

[sssurfer]

finepics, keeping same dimensions as in reps but using sapphire or SF11 will just add about +0.15x to rep magnification -- i.e., from 1.2x to 1.35x. Too low, IMO.

My new recommendation:

Sapphire or SF11

Diameter = 6 mm

ROC = 6.2 mm

ET = 0.4 mm

CT = 1.17 mm

FL = 8.0 mm

Tolerance unchanged (= 0.06 mm on ROC and CT).

Those values theorically stand for 1.8x magnification on a date window 3.5 mm away (1.6 at 3mm), and for a lens sensibly flatter -- in its convex portion, not its ET -- than our previous one, without a knife edge. Sort of tradeoff between all our thoughts.

Surely, a prototype would stay highly recommended.

Glass is out on any calculations.

Edited March 19, 2006 by sssurfer

[archibald]

Get outta here!

honest to god...actually it was the first quote I got before it became apparent that glass would do 1.6 at best. Personally, I don't believe that glass will work, but I've been keeping an open mind since the only one of us who has actually held a gen in his hand side by side w/ a new cyclops equipped rep maintains that w/ the new wheel glass will work, and since we have never officially documented that OEM Pannies have a 2.0 mag.

Believe me, I'd love Joe to be right 'causeif he is we do our mods for less than ten bucks, but I still believe there's only about a 5% chance he is and that we'll be shelling out the comparative big bucks.

Edited March 19, 2006 by archibald