7x42 Ultravid (1 Viewer)

[GrampaTom]

Googled it, Interesting find. Sure its not whole story...

Friction coefficients

Material 1	Material 2	Static dry
Teflon	Steel	0.04
Titanium Alloy	Aluminium Alloy	0.41
Titanium Alloy	Titanium Alloy	0.36
Titanium Alloy	Bronze	0.36

 

[Elpha8888]

Certain market impressions, get started and hang around for a long time. For example galling has been an issue in the past with stainless steel, it was said to be hard to machine, hard on cutters. Given that theres something like 3000 alloys of steel alone, things are not so simple. More recently Titanium, in its earliest uses particularly as consumer product material, say bicycles was thought to have a galling issue. Keeping in mind that the Soviets have used it for submarine hulls, we have to wonder what do we consumers really know about it? Going from one consumer product say flashlights, to another in this case binoculars, from the outside looking in, consumer's point of view, is tricky. I have machined brass, steel, stainless, Titanium, aluminum, plastics. Have heat treated a couple different kinds of steel, and experienced the differences in subsequent machining. As most of these, to include bronze, are currently used in manufacturing, rather widely, they are regularly made to work. Some of those flashlights are gorgeous. So to knives, with lots of Ti in them, often held together with SS screws. I bet I'm not alone spending time with each of these things. It comes down to the specific alloy of the named metal, its hardness (heat treat), the type of cutter, feeds and speeds, CNC vs "manual." Engineers know this.

My question though Trinovid would be this, Why bronze as a gear mated to a titanium shaft? Titanium's benefits are lighter weight than say steel, by almost half. It needs to be said, that shaft is small and makes a very small contribution to total weight. Every little bit helps? Its strength is good. Ti is also highly corrosion resistant so no worries of long term corrosion in something effectively sealed up like a bino. It is reasonably hard as a wear surface, so gear to gear might be OK long term. I dont have that knowledge. Am a wee bit skeptical. But bronze? Its heavier than either steel (arguably a better material for a gear), or Titanium. Using bronze potentially negates the weight benefit of titanium for the shaft. Its softer than both so long term wear and tear, back and forth movement may not be so good. Thinking about how fussy some here are on BF are on focuser feel, maybe this isnt the best long term solution? Ti/Bronze vs SS/SS? And thats just talking about these 3 materials. There are so many more.

Re cost, both raw material and processing costs need to be combined to properly evaluate. It was shocking to learn that Aluminum, in its earliest history was once more expensive than gold.

In the modern world of materials science, Bronze as a gear to mate with a Ti shaft seems.... well sort of like going back to the bronze age. Im open to an explanation of this. I'd really, like to know why this would be the better choice?

I find this interesting as I use high end Abu multiplier fishing reels and often strip them for cleaning etc, their gearing is made up of brass cogs and pinions amongst other materials and those cogs are under extreme pressures, the spools can spin upwards of 30,000 rpm. Brass has stood the test of time, it may be due to lower friction and the way they mate together, the cogs work together extremely well and smoothly.

 

[Trinovid]

Why bronze as a gear mated to a titanium shaft?

I chose bronze as a material long chosen for bearing surfaces to mate with steel. I know that most of the titanium-on-titanium threads that I have had were incredibly gritty, except for the more expensive lights where the focus was on better finish for the mating surfaces, which I suppose Leica would be capable of addressing.

The weight savings of titanium over steel are very minimal, but for whatever reason, Leica decided to go with the backpackers mindset when it came to weight savings and stating the well known advantages of titanium to a group of adults seems a bit unnecessary.

At any rate, despite the cleverness of the bronze age reference, it has nothing to do with utilizing this excellent material in the modern age and is totally out of place in context of this forward thinking and polite conversation.

 

[Trinovid]

Sure its not whole story... Friction coefficients

Material 1	Material 2	Static dry
Teflon	Steel	0.04
Titanium Alloy	Aluminium Alloy	0.41
Titanium Alloy	Titanium Alloy	0.36
Titanium Alloy	Bronze	0.36

No, but you chose to leave the rest of it out in your quest to do...what? Poke holes in someone else's assertion with nothing constructive to add?
It's only the tip of the iceberg; the more important 90% is in the finishing process. Bronze smoothes up far easier and more affordably than titanium.
You could even more constructively have pointed out the excellence of teflon in making of threaded fittings.

 

[GrampaTom]

No, but you chose to leave the rest of it out in your quest to do...what? Poke holes in someone else's assertion with nothing constructive to add?
It's only the tip of the iceberg; the more important 90% is in the finishing process. Bronze smoothes up far easier and more affordably than titanium.
You could even more constructively have pointed out the excellence of teflon in making of threaded fittings.

"No, but you chose to leave the rest of it out in your quest to do...what? Poke holes in someone else's assertion with nothing constructive to add?" Well, no. I assume youre referring to my #121, where I wrote "Googled it, Interesting find. Sure its not whole story..." Note please, I did say its not the whole story. Left something out? Well no again, that was the whole quote I stumbled across. After that I read on some more to other links and realized the whole coefficient of friction subject was at least the basis of a college class lecture or more.

As for, "Nothing constructive to add?" OK, if you say so. Sorry I made you feel that way.

As for "Its only the tip of the iceberg; the more important 90% is in the finishing process." You did read my #120? To quote my 2nd to last sentence in that first paragraph, "It comes down to the specific alloy of the named metal, its hardness (heat treat), the type of cutter, feeds and speeds, CNC vs "manual." I agree coefficient of friction is but one piece of the puzzle. And I agree part finish is important, though doubt its 90% of it. Those other things matter.... a lot. I think that sentence includes with broad brush strokes the potentials. All of the things listed contribute to part finish. All of the things listed contribute to a better part.

I am aware of bronze as a washer to provide lubrication, slickness, between parts that otherwise might drag on each other. These can be simple bronze flat stock or more sophisticated lubricant impregnated bronze things made by Oilite® bushing: sleeve, flange, thrust, bar stock, and plate. As well bearings come in many other forms, Barden, and cartridge sealed, to name two, neither of which seems appropriate inside a binocular. But you were talking about a bronze gear not a bearing I think.

Re, "You could even more constructively have pointed out the excellence of teflon in making of threaded fittings." Well I could have, but I sorta kinda did, no? Here's the last 3 sentences of the second paragraph, "Ti/Bronze vs SS/SS? And thats just talking about these 3 materials. There are so many more." Yes there are many more, to include teflon.

I apologize if my way of asking put you off. It was not my intent. I recognize we come from all over and we're not standing looking at each other so mere words fail short. Having tried to sort this, I still wonder why you proposed a Bronze gear on a Ti shaft?

 

[GrampaTom]

I find this interesting as I use high end Abu multiplier fishing reels and often strip them for cleaning etc, their gearing is made up of brass cogs and pinions amongst other materials and those cogs are under extreme pressures, the spools can spin upwards of 30,000 rpm. Brass has stood the test of time, it may be due to lower friction and the way they mate together, the cogs work together extremely well and smoothly.

Cool. Yes, I guess youre talking the big reels for big fish? 30,000 RPM - Yikes! I would love to know what that drive train is. Looking at things as you clean will reveal part of the tale, is that yellow stuff brass, bronze or some plated other material, hard to know by just lookin. Metallurgy, heat treat, tolerances, balance at those RPMs all have to be a consideration. Bushings, and/or bearings... caged, cartridge sealed? The Bronze washers in a Chris Reeve folder that gets the blade in and out as fast as your fingers can flip, is different than a reel screaming with a big fishing swimming for its life, I'd think. Got pics? Or does Abu describe any of this?

 

[GrampaTom]

I chose bronze as a material long chosen for bearing surfaces to mate with steel. I know that most of the titanium-on-titanium threads that I have had were incredibly gritty, except for the more expensive lights where the focus was on better finish for the mating surfaces, which I suppose Leica would be capable of addressing.

The weight savings of titanium over steel are very minimal, but for whatever reason, Leica decided to go with the backpackers mindset when it came to weight savings and stating the well known advantages of titanium to a group of adults seems a bit unnecessary.

At any rate, despite the cleverness of the bronze age reference, it has nothing to do with utilizing this excellent material in the modern age and is totally out of place in context of this forward thinking and polite conversation.

Ti, part for part, weighs slightly over half the weight of a steel part, approximately 55%. If the whole bino could be Ti, there'd be a nice weight savings. You are right since its a small shaft, the impact on a Bino's total weight is minimal. So why would they do that? Bronze weighs more than Ti or Steel, therefore it would seem using a Bronze gear would offset the weight benefit of a Ti shaft. Curious, no?

A Bronze gear is different from a bearing, its doing a couple more things. Its potential contribution to smoothness, is one thing. I worry about, am asking about, if there's something about softer Bronze rubbing as a gear on potentially harder Ti thats desirable? I would worry about the long term ability to hold tolerances and not become a sloppy feeling focuser down the road. Is/isn't there a better choice? You asked about teflon.. sure would be slippery. What about ceramic or ceramic coated? SS on SS?

I like my Bronze age reference...

 

[Trinovid]

If the whole bino could be Ti, there'd be a nice weight savings. You are right since its a small shaft, the impact on a Bino's total weight is minimal. So why would they do that? Bronze weighs more than Ti or Steel, therefore it would seem using a Bronze gear would offset the weight benefit of a Ti shaft. Curious, no?

If the whole binocular was made out of titanium it would become one of the heaviest binoculars for its size ever made, and the amount of weight that would be affected by the usage of a tiny bit of bronze is far less than that of the titanium shaft, or the whole binocular for that matter, as you've suggested. They made the most noticeable weight savings by swapping out the aluminum for magnesium, but you're worried about bronze threads and upgrading the magnesium body to titanium.

At any rate, my assumption is that they used whatever materials they deemed best for the purposes of building a durable, light and versatile binocular and I'm not really that into second guessing their choices, except when it comes down to their decisions to discontinue the 6x24 and not offer us a Leica version of the 3mm 7x21.

I like my Bronze age reference...

Bronze age was a time when many things were made of bronze by default.
Bronze is very much an alpha metal when used appropriately, so, no, to reference usage of bronze inside of modern mechanical devices is a straw man placed in context of this conversation. Bronze, it would seem in your estimation, was a medieval material, no longer viable and with no redeeming characteristics; a material to be avoided.

Let's go back to talking about the binoculars and less about material choices.

 

[GrampaTom]

Im done

 

[Trinovid]

Disclaimer: not my binoculars.