Kowa 883 - best arca swiss plate? (1 Viewer)

[Hans Weigum]

Moin!

That's an interesting page, but it hardly talks about the topic of antirotation at all, other than accepting rubber padding as functional antirotation device. In fact, your comment below the page is the most specific thing on antirotation over there!

Regards,

Henning

Hallo Henning

You are right, that in the detailed text I quoted, the problem of antirotation gets hardly covered. I was mentioning it all the same, as it gives the most detailed design information I could find so far, helping better to understand this design and find its several flaws. In my comment only the simplest to explain gets listed.
The original Arca-Swiss plate design, based on friction only, despite not being outstanding might have been sufficient for the original purpose intended: Arca-type-cameras mostly used indoors. The problems probably only started later, when this device, better suitable designs lacking, got used differently with equipment creating higher forces of inertia specially when used under outdoors conditions. Trying to save a design based on friction fit only, adding form fit ("formschlüssig") features later (and so making friction fit completely redundant) is contradictory at least to my understanding.

An example of successful rotation prevention by friction only and according to much more demanding standards:

EP0779795B1 - Device for externally securing fractures - Google Patents

PCT No. PCT/CH95/00189 Sec. 371 Date May 19, 1997 Sec. 102(e) Date May 19, 1997 PCT Filed Sep. 4, 1995 PCT Pub. No. WO96/07362 PCT Pub. Date Mar. 14, 1996A device for securing fractures, the device having at least one traction/compression rod, a plurality of bone screws and clamps wherein the...

patents.google.com

Best regards

Hans

 

[Hans Weigum]

No, I don't think it proves that at all. From what I've seen, it reflects the fact that most users of Arca-type plates are not using plates with anti-rotation features. The vast majority of plates do not incorporate such features, so they work no better in that regard than any other crappy quick-release system. Plates from Really Right Stuff, Kirk, Acratech, and others that offer custom-fit or generic plates with lips are extremely successful. Plates with pins are a misdirect and fairly useless since most lenses, cameras etc don't have a receptacle, and even when they do the pin is usually too small to fit snugly. Consequently, plates from RRS and Kirk don't use pins. Although the mass market is dominated by crappy products, these better designs from RRS, Kirk, and others are what I see in use by professionals and educated enthusiasts, esp. outdoor photographers. For studio use, perhaps anti-rotation features are not so important, but they are critical for anyone who keeps their gear mounted on a tripod and regularly turns it sideways etc during carry. I've been using these plates with my gear for decades without issues, e.g. some of the custom plates from RRS that I use with my macro rigs or long lenses were first attached decades ago and haven't been reset/removed/tightened since!

--AP

Hallo Alex

I fully understand, that you cannot accept my statements. Main purpose of this forum seems to be talking about, not to solve problems. Problems solved would eliminate all need for further discussions.

Not to spoil the ongoing discussion is one of the reasons not to disclose my solution of a better functioning modification of the Arca-Swiss design using friction fit only.

Best regards

Hans

 

[Hauksen]

The original Arca-Swiss plate design, based on friction only, despite not being outstanding might have been sufficient for the original purpose intended: Arca-type-cameras mostly used indoors. The problems probably only started later, when this device, better suitable designs lacking, got used differently with equipment creating higher forces of inertia specially when used under outdoors conditions. Trying to save a design based on friction fit only, adding form fit ("formschlüssig") features later (and so making friction fit completely redundant) is contradictory at least to my understanding.

An example of successful rotation prevention by friction only and according to much more demanding standards:

EP0779795B1 - Device for externally securing fractures - Google Patents

PCT No. PCT/CH95/00189 Sec. 371 Date May 19, 1997 Sec. 102(e) Date May 19, 1997 PCT Filed Sep. 4, 1995 PCT Pub. No. WO96/07362 PCT Pub. Date Mar. 14, 1996A device for securing fractures, the device having at least one traction/compression rod, a plurality of bone screws and clamps wherein the...

patents.google.com

Hi Hans,

Vielen Dank! If friction fit is good enough to entrust it with life and limb as per your patent, it's probably good enough in a birding context too

I'll have to admit that my preference of form fitting devices comes from experience with consumer-grade equipment, where whenever a mechanical connection given problems, it seems to be a friction fit.

Maybe it's also because as an amateur designer of 3D-printed stuff, I usually don't have that much control over the material pairings and thus over the friction coefficients, being limited by what my printer can handle on one side, and what the device I'm trying to improve is made of on the other side.

I fully agree that the Arca Swiss plate was not designed with birders in mind, and in it's "native" form is not fully up to birders' requirements.

Regards,

Henning

 

[Alexis Powell]

Hallo Alex

I fully understand, that you cannot accept my statements. Main purpose of this forum seems to be talking about, not to solve problems. Problems solved would eliminate all need for further discussions.

Not to spoil the ongoing discussion is one of the reasons not to disclose my solution of a better functioning modification of the Arca-Swiss design using friction fit only.

Best regards

Hans

I'm not against discussion, even for its own sake. However, before diving in to such, I feel it is important to let readers of this thread know that if they are looking for an immediate solution to the problem of eliminating rotation of tripod-mounted equipment that they already own, that a solution already exists. It is available now and it works with birding/photography/etc equipment that generally relies on a single 1/4 or 3/8 inch bolt for attachment. Perhaps in the future, other and better solutions will exist. In the mean time, I am glad that companies like Really Right Stuff and Kirk exist (in fact, solving the rotation problem was the whole point of RRS at its inception) and that products are available to use with my equipment, both new and old. Their solutions are expensive (though cheaper clones or similar products may now be found from other companies), but they do work very well and are often very elegant (often made to avoid interference with operation) and very versatile modules of a larger system for those who own a lot of equipment or use it for different tasks. I struggled with these issues and wasted plenty of money on a lot of crap QR plates and other pieces from Bogen/Manfrotto, Velbon, Slik, Gitzo, and others for years. Now I don't struggle and I don't waste time and money. I just convert everything to use with anti-rotation plates from RRS, Kirk, Desmond etc. Peace of mind.

--AP

 

[Tringa45]

Not to say I wouldn't prefer a purpose-designed scope-tripod interface that does away with the need for an extra plate entirely. Seems like an easy way to reduce weight and complexity.

Yes, why not? But then the scope manufacturers would have to place the foot directly under the centre of gravity. Most of them don't seem to be aware of this requirement and there are some pretty catastrophic offenders.

John

PS:- The 883 with TE-11WZ is OK in this respect, but I suspect that is more coincidence than design.

 

[rpg51]

Yes, why not? But then the scope manufacturers would have to place the foot directly under the centre of gravity. Most of them don't seem to be aware of this requirement and there are some pretty catastrophic offenders. ...

Of course, people will always be experimenting and doing things that change the center of gravity anyway. Digital cameras attached to eye piece, iphones, different camera bodies attached to long lens etc.

I'm still experimenting - more later - but my first impressions using the simple and inexpensive stuff that AP recommended above is that when rotation is the problem, rubber pads are BAD. Metal to metal (at least aluminum) is GOOD. Reminds me of aluminum studded fishing wader boots. They stick to river ledge and boulders very solidly. I would never dive into the deep end with mechanical engineers. But, I will observe how the things they design perform in my applications. The plates AP references, aluminum and lipped, seem to work well in my application. At least that is my preliminary observation.

Also, in the interests of full disclosure - I own (and maintain) Japanese vehicles. Just sayin'.

 

[Hans Weigum]

I'm not against discussion, even for its own sake. However, before diving in to such, I feel it is important to let readers of this thread know that if they are looking for an immediate solution to the problem of eliminating rotation of tripod-mounted equipment that they already own, that a solution already exists. It is available now and it works with birding/photography/etc equipment that generally relies on a single 1/4 or 3/8 inch bolt for attachment. Perhaps in the future, other and better solutions will exist. In the mean time, I am glad that companies like Really Right Stuff and Kirk exist (in fact, solving the rotation problem was the whole point of RRS at its inception) and that products are available to use with my equipment, both new and old. Their solutions are expensive (though cheaper clones or similar products may now be found from other companies), but they do work very well and are often very elegant (often made to avoid interference with operation) and very versatile modules of a larger system for those who own a lot of equipment or use it for different tasks. I struggled with these issues and wasted plenty of money on a lot of crap QR plates and other pieces from Bogen/Manfrotto, Velbon, Slik, Gitzo, and others for years. Now I don't struggle and I don't waste time and money. I just convert everything to use with anti-rotation plates from RRS, Kirk, Desmond etc. Peace of mind.

--AP

Dear Alex

I understand, that you consider it as your noble mission to warn a general public from substandard (Arca-Swiss-type) products, based on your extensive market research and testing. An effort you took, because, your enthousiasm showing, you firmly believe in this type of product. Which I don't.

In contrast my approach to the identical problem was much more egocentric. Dismissing available Arca-Swiss-type products as sub-my-standard all together, I invested instead my effort in creating something superior for my own use only, at least so far. By the way, as a citizen of that country myself, I consider the use of „Swiss“in the designation for a product of doubtful reputation as similar to „Swiss“ in connection with banking.

To profit from all your accumulated experience, I would appreciate that you explain to me, and that is an honest, not an ironical question, by what specific characteristics you (and/or your favorite supplyers) define the claimed better"quality" for this type of product. Is it to get the obviously inherent design flaws reduced by specific features added, and/or are with this concept manufacturing tolerances required, tighter than usually applied?

Best regards
Hans

 

[Alexis Powell]

Dear Alex

I understand, that you consider it as your noble mission to warn a general public from substandard (Arca-Swiss-type) products, based on your extensive market research and testing. An effort you took, because, your enthousiasm showing, you firmly believe in this type of product. Which I don't.

In contrast my approach to the identical problem was much more egocentric. Dismissing available Arca-Swiss-type products as sub-my-standard all together, I invested instead my effort in creating something superior for my own use only, at least so far. By the way, as a citizen of that country myself, I consider the use of „Swiss“in the designation for a product of doubtful reputation as similar to „Swiss“ in connection with banking.

To profit from all your accumulated experience, I would appreciate that you explain to me, and that is an honest, not an ironical question, by what specific characteristics you (and/or your favorite supplyers) define the claimed better"quality" for this type of product. Is it to get the obviously inherent design flaws reduced by specific features added, and/or are with this concept manufacturing tolerances required, tighter than usually applied?

Best regards
Hans

Dear Hans,

I hope I understand what you are asking. For the record, I made no reference to "Swiss" design or to "quality" in my previous replies. In fact, I am not a fan of actual Arca-Swiss brand plates. The ones I like happen to be from American and Chinese manufacturers. I will also note that it is not so much that I "believe" in these products, but that after many headaches trying stuff that didn't work, I found my way to them, spent the extra money they cost, and found that they made my troubles go away. They have proven themselves to me in use, empirically.

If if you are asking what I think makes my favorite Arca-type plates (e.g. those from Really Right Stuff) better than others, I would say it is mostly a matter of their designs--custom shapes to fit items (and, if possible, not get in the way of ports etc, which is especially important for complex designs like L-plates for cameras) or more general designs with lips--which aim to prevent rotation of the plate once it is installed. It is also the case that products from RRS and Kirk are made from materials that more robust than some of their competition, which, in combination with their design, can make their plates and related products more rigid and secure. RRS also uses better mounting hardware that withstands higher shear forces or engages more threads or is more precise in matching standards, thus leading to a more perfect, tight, free-from-play fit, than is achieved by some other products that I have tried. For example, I much prefer this bushing from RRS

Reducer Bushing: Converts 1/4"-20 to 3/8"-16

DetailsStainless reducer bushing, converts from 1/4"-20 to 3/8"-16.

www.reallyrightstuff.com

as compared to what is more widely available, like this

Amazon.com : Standard 1/4"-20 Female to 3/8"-16 Male Screw Adapter Reducer Bushing Converter for DSLR Camera Camcorder Tripod Monopod Ball Head Ballhead Video Light Stand (4 Pieces) : Electronics

Amazon.com : Standard 1/4"-20 Female to 3/8"-16 Male Screw Adapter Reducer Bushing Converter for DSLR Camera Camcorder Tripod Monopod Ball Head Ballhead Video Light Stand (4 Pieces) : Electronics

www.amazon.com

Hope this answers your question.

--AP

 

[Tringa45]

Dear Hans,

I hope I understand what you are asking. For the record, I made no reference to "Swiss" design or to "quality" in my previous replies. In fact, I am not a fan of actual Arca-Swiss brand plates. The ones I like happen to be from American and Chinese manufacturers. I will also note that it is not so much that I "believe" in these products, but that after many headaches trying stuff that didn't work, I found my way to them, spent the extra money they cost, and found that they made my troubles go away. They have proven themselves to me in use, empirically.

If if you are asking what I think makes my favorite Arca-type plates (e.g. those from Really Right Stuff) better than others, I would say it is mostly a matter of their designs--custom shapes to fit items (and, if possible, not get in the way of ports etc, which is especially important for complex designs like L-plates for cameras) or more general designs with lips--which aim to prevent rotation of the plate once it is installed. It is also the case that products from RRS and Kirk are made from materials that more robust than some of their competition, which, in combination with their design, can make their plates and related products more rigid and secure. RRS also uses better mounting hardware that withstands higher shear forces or engages more threads or is more precise in matching standards, thus leading to a more perfect, tight, free-from-play fit, than is achieved by some other products that I have tried. For example, I much prefer this bushing from RRS

Reducer Bushing: Converts 1/4"-20 to 3/8"-16

DetailsStainless reducer bushing, converts from 1/4"-20 to 3/8"-16.

www.reallyrightstuff.com

as compared to what is more widely available, like this

Amazon.com : Standard 1/4"-20 Female to 3/8"-16 Male Screw Adapter Reducer Bushing Converter for DSLR Camera Camcorder Tripod Monopod Ball Head Ballhead Video Light Stand (4 Pieces) : Electronics

Amazon.com : Standard 1/4"-20 Female to 3/8"-16 Male Screw Adapter Reducer Bushing Converter for DSLR Camera Camcorder Tripod Monopod Ball Head Ballhead Video Light Stand (4 Pieces) : Electronics

www.amazon.com

Hope this answers your question.

--AP

Alexis,

I very nearly liked one of your previous posts because I agree that Arca-Swiss is an available sytem that works. However, your mention of "boutique European brands" (who could you mean by that?) and the assertion that an anti-rotation lip is superior deterred me .
The latter may certainly have advantages for cameras without a pin socket, but for a scope is in no way superior to a pin of the right diameter. Without either even the inadequate three or four thread turns of a loosened screw would not result in equipment loss. Perhaps both sytems are better regarded as a positioning aid.

As regards materials, there is no difference in rigidity of the same design made of different aluminium alloys. All aluminium alloys have approximately the same modulus of elasticity. The alloy with the higher yield strength will experience a plastic deformation at a higher load, but we are not hanging tons on a QR plate! I fell for this myth years ago when I had a commuter bike frame made of Nivarox steel. 25CrMo4 (4130) would have done the job just as well for a lower outlay.

Bolts and anti-rotation pins should not experience shear loads if sufficient torque is applied. All loads are carried by the friction of the metal interfaces just like that between a car wheel and its hub.

Lastly, that RRS adapter looks better than most, but why use an adapter if you can use a 3/8"x16 screw?

Regards,
John

 

[Hauksen]

Hi John,

Bolts and anti-rotation pins should not experience shear loads if sufficient torque is applied. All loads are carried by the friction of the metal interfaces just like that between a car wheel and its hub.

Hm, what's the purpose of the anti-rotation pin, then? The car hub isn't held by a single central screw, so I'm not sure what to do with the analogy.

Regards,

Henning

 

[Hans Weigum]

Dear Hans,

I hope I understand what you are asking. For the record, I made no reference to "Swiss" design or to "quality" in my previous replies. In fact, I am not a fan of actual Arca-Swiss brand plates. The ones I like happen to be from American and Chinese manufacturers. I will also note that it is not so much that I "believe" in these products, but that after many headaches trying stuff that didn't work, I found my way to them, spent the extra money they cost, and found that they made my troubles go away. They have proven themselves to me in use, empirically.

If if you are asking what I think makes my favorite Arca-type plates (e.g. those from Really Right Stuff) better than others, I would say it is mostly a matter of their designs--custom shapes to fit items (and, if possible, not get in the way of ports etc, which is especially important for complex designs like L-plates for cameras) or more general designs with lips--which aim to prevent rotation of the plate once it is installed. It is also the case that products from RRS and Kirk are made from materials that more robust than some of their competition, which, in combination with their design, can make their plates and related products more rigid and secure. RRS also uses better mounting hardware that withstands higher shear forces or engages more threads or is more precise in matching standards, thus leading to a more perfect, tight, free-from-play fit, than is achieved by some other products that I have tried. For example, I much prefer this bushing from RRS

Reducer Bushing: Converts 1/4"-20 to 3/8"-16

DetailsStainless reducer bushing, converts from 1/4"-20 to 3/8"-16.

www.reallyrightstuff.com

as compared to what is more widely available, like this

Amazon.com : Standard 1/4"-20 Female to 3/8"-16 Male Screw Adapter Reducer Bushing Converter for DSLR Camera Camcorder Tripod Monopod Ball Head Ballhead Video Light Stand (4 Pieces) : Electronics

Amazon.com : Standard 1/4"-20 Female to 3/8"-16 Male Screw Adapter Reducer Bushing Converter for DSLR Camera Camcorder Tripod Monopod Ball Head Ballhead Video Light Stand (4 Pieces) : Electronics

www.amazon.com

Hope this answers your question.

--AP

Dear Alex

I see much clearer now, in how far our points of view differ: You seem to agree, that the design common to all Arca-Swiss-type plates might not be ideal. But as no better one seems to be generally available, you reached to a selection of brands you feel, that they had made the best out of it.

In an engineering way of thinking, however, it is not a very fortunate approach to save a misled design by having to use better materials and processing than otherwise necessary.

Not closely related, but good examples of extremely proven sound designs:

SA3 coupler - Wikipedia

Kalashnikov rifle - Wikipedia

en.wikipedia.org

Not just a coincidence, that both originate from Russia, with its tradition of often crude looking, but efficient designs.

This coupler consists mainly out of castings, thrown together after hardly any machining. Functioning long time and reliably despite, or may be because of considerable play between components. Absolute compatibility to ever changing opposite parts being a top requirement!


Arca-Swiss-type plates are comparable in relation to shape, size and extent of processing with:

[Hot Item] Xc Medico Orthopedic Spinal Implant Self-Locking Anterior Cervical Plate

But they are completely overpriced, considering these surgical plates being made out of titanium and having to correspond to quite different requirements! Not just a damaged scope, but permanent loss of motion might be consequence in case of failure.

Best regards

Hans​

 

[Tringa45]

Hi John,



Hm, what's the purpose of the anti-rotation pin, then? The car hub isn't held by a single central screw, so I'm not sure what to do with the analogy.

Regards,

Henning

Hi Henning,

As I mentioned above, I think the anti-rotation pin can be viewed as a positioning aid to assure parallel alignement of scope and plate. Admittedly, it would prevent rotation of the scope with a loosened screw, but if the latter were adequately tightened there would be no shear load on the pin.

Many sports cars in the 1960s had knock-on wheels with a central nut, but I think there was a splined connection, so that doesn't count. However Formula 1 wheels are retained by a central captive nut. The teams are secretive about their solutions but I think any positive tangential location would hinder sub 3 second wheel changes.

On a small car an M12 wheel nut or bolt tightened to 140 Nm would produce a load of 65,000 N or 26 tons for 4 nuts or bolts. No transmission or braking torque could overcome the enormous friction between steel or aluminium wheel and cast iron hub and there would be no shear loads on bolts or studs, merely tension, as on the 1/4" or 3/8" screw of a QR plate.

Regards,
John

 

[Hauksen]

Hi John,

As I mentioned above, I think the anti-rotation pin can be viewed as a positioning aid to assure parallel alignement of scope and plate.

I see. My impression is that the tolerances are not tight enough to keep the alignment truly parallel as required for a reflector sight (mounted to the plate) to stay on center. I would have preferred to have conical surfaces on that pin and the recess in the plate to eliminate any play.

With regard to friction locking ... maybe it would work, if I could find the correct screwdrivers to actually apply some meaningful torque while tightening. Do you happen to know if there's a standard for 1/4" slotted-head screws? The ones I have seem to be just a bit too small for a 2 mm x 12 mm screwdriver bit.

Regards,

Henning

 

[GeorgeL]

Not Kowa, but on my Pentax I use both 1/4” and 3/8” screws to attach the plate. Scope’s base has two separate mounting holes, maybe 3/4” apart, and I take advantage of both to secure my ArcaSwiss plate

 

[Alexis Powell]

Alexis,

I very nearly liked one of your previous posts because I agree that Arca-Swiss is an available sytem that works. However, your mention of "boutique European brands" (who could you mean by that?) and the assertion that an anti-rotation lip is superior deterred me .
The latter may certainly have advantages for cameras without a pin socket, but for a scope is in no way superior to a pin of the right diameter. Without either even the inadequate three or four thread turns of a loosened screw would not result in equipment loss. Perhaps both sytems are better regarded as a positioning aid.

As regards materials, there is no difference in rigidity of the same design made of different aluminium alloys. All aluminium alloys have approximately the same modulus of elasticity. The alloy with the higher yield strength will experience a plastic deformation at a higher load, but we are not hanging tons on a QR plate! I fell for this myth years ago when I had a commuter bike frame made of Nivarox steel. 25CrMo4 (4130) would have done the job just as well for a lower outlay.

Bolts and anti-rotation pins should not experience shear loads if sufficient torque is applied. All loads are carried by the friction of the metal interfaces just like that between a car wheel and its hub.

Lastly, that RRS adapter looks better than most, but why use an adapter if you can use a 3/8"x16 screw?

Regards,
John

John,

Thanks for setting me straight--I'm not schooled in engineering so I fear I used some technical terms incorrectly or too loosely.

As for boutique European brands, that was a lazy way of referring to some of the brands that I tried a long time ago that didn't seem so good but that I can't remember for sure. Otherwise, I wouldn't hesitate to name names. Arca-Swiss was among them, maybe Novoflex too, but I'm not absolutely certain.

My preference for lips over pins is based on the fact that (1) most scopes don't have pin sockets, (2) some scopes with pin sockets don't have them in the right location, or else the plate doesn't have the pin in the right place for the scope foot, (3) many pins are too narrow and so do not prevent a bit of wiggle and thus loosening over time, (4) many plates from Manfrotto and Gitzo have spring-loaded pins that are somewhat loose in their housing so have lateral play and thus do not prevent a bit of wiggle and thus plate loosening over time. Sure, a good plate with a good pin can work well. I just haven't met many that do, and generally they are combined with a rubberized surface which, again, allows for a bit of wiggle and thus loosening over time. I guess this brings up a point. For me, a good plate not only prevents rotation, it also doesn't loosen over time. I have never had a plate from RRS or Kirk become loose. Ever. And I've been using them for 20+ years. On a related topic, I've also never had a screw-action QR clamp from any manufacturer (RRS, Kirk, Gitzo, Neewer...) loosen or lose its grip on the plate, so I have no interest in the various "safety retention" pins and releases that some systems offer. If possible, I remove them for convenience.

As for better materials of mounting rigs, I wasn't thinking so much in terms of different aluminium alloys in plates and more about RRS's near exclusive use of machined metal parts for brackets and such, so that all joints and fittings are metal to metal, never metal to plastic or rubbery material, as some others do (e.g. the irritating macro rail system I got from Bogen/Manfrotto many years ago).

On the material or precision of bolts etc, I guess I shouldn't have used the word shear. What I was thinking about is that I have have never had issues with the material quality of RRS fasteners, whereas with other brands, I have sometimes found the following: (1) soft metal that allows the head of the bolt to twist off--admittedly, probably when over-torqued, but still..., (2) soft metal or poor precision or shallow depth of socket sizing in the heads of bolts such that the screwdriver slots or hex key socket is a slightly imperfect fit and thus distorts and become damaged over time, (3) the threads of bolts or thread adapters being ever so slightly undersized such that they thread into sockets but still have a bit of lateral play in them and aren't really tight until they are screwed in very firmly. Such fittings seem vulnerable to breaking free and loosening when subjected to shocks or vibrations.

I use 3/8" bolts and screws when I can, but some tripod bodies and other mounting hardware come with fixed (nonreplaceable) 1/4" threaded parts for attaching tripod heads etc, hence my use of the adapters here and there. They seem to cut some vibration or flex that can occur when, e.g. a head is threaded onto the mounting bolt of a tripod or clamp stud using an adapter that only encloses 2.5 or 3 threads worth of length of the bolt, as is the case with many cheap adapters.

Sorry for being so obsessive about this. Although I figured out what actually works a long time ago, it was a long time in coming, so I never take my solid tripod and other brackets etc for granted. I always appreciate how well they work and I never forget how much trouble I used to have. It's such a blessing to have solutions that do the job so well that persistent problems are laid to rest entirely.

--AP

 

[Alexis Powell]

...With regard to friction locking ... maybe it would work, if I could find the correct screwdrivers to actually apply some meaningful torque while tightening. Do you happen to know if there's a standard for 1/4" slotted-head screws? The ones I have seem to be just a bit too small for a 2 mm x 12 mm screwdriver bit...

This is the reason that Really Right Stuff never uses slotted screws. Everything is tightened with hex keys, which allows for plenty of torque. In fact, one must be careful not to over tighten. I usually use a torque wrench when working on my bicycle, but not with my photo/birding gear.

Really Right Stuff - Camera

Discover RRS's world-class camera gear. Crafted for quality and performance, our tripods, heads, and supports empower photographers to capture perfect shots.

www.reallyrightstuff.com

--AP

 

[Alexis Powell]

Dear Alex

I see much clearer now, in how far our points of view differ: You seem to agree, that the design common to all Arca-Swiss-type plates might not be ideal. But as no better one seems to be generally available, you reached to a selection of brands you feel, that they had made the best out of it.

In an engineering way of thinking, however, it is not a very fortunate approach to save a misled design by having to use better materials and processing than otherwise necessary.

Not closely related, but good examples of extremely proven sound designs:

SA3 coupler - Wikipedia

Kalashnikov rifle - Wikipedia

en.wikipedia.org

Not just a coincidence, that both originate from Russia, with its tradition of often crude looking, but efficient designs.

This coupler consists mainly out of castings, thrown together after hardly any machining. Functioning long time and reliably despite, or may be because of considerable play between components. Absolute compatibility to ever changing opposite parts being a top requirement!


Arca-Swiss-type plates are comparable in relation to shape, size and extent of processing with:

[Hot Item] Xc Medico Orthopedic Spinal Implant Self-Locking Anterior Cervical Plate

But they are completely overpriced, considering these surgical plates being made out of titanium and having to correspond to quite different requirements! Not just a damaged scope, but permanent loss of motion might be consequence in case of failure.

Best regards

Hans​

Hans,

I don't disagree w/your points. I was just concerned to point out to anyone who having problems with their mounting equipment and who wants to get back to birding, photography, etc that solutions that work without troubles exist.

You've highlighted some awesomely simple, inexpensive, crude, robust designs that do their jobs reliably. As you say, the Russians are famous for such. Quite admirable.

As for pricing of Arca-type plates, yes, those from RRS, Kirk, and Acratech are expensive, but the cost is not about materials, it is because these are small businesses that sell only these products. They have to make a living. So we pay for the design. Chinese companies clone these designs and sell some near-equivalent products for much much less. I try to support the designers, who continue to innovate with new products, by buying their plates instead of the clones.

--AP

 

[Hans Weigum]

This is the reason that Really Right Stuff never uses slotted screws. Everything is tightened with hex keys, which allows for plenty of torque. In fact, one must be careful not to over tighten. I usually use a torque wrench when working on my bicycle, but not with my photo/birding gear.



--AP

Why not use ISO 10664 hexalobular internal, better known under a registered name Torx. This drive system is definitively superior to in-hex, not only torque-wise. The quite relevant problem of over tightening should not get solved by a substandard drive system. Over tightening is not only a problem of bolts, but at least as much of the socket of the device connected with. Less with telescopes, more with cameras, with their thinner walled bottoms.

Hans

 

[Hans Weigum]

John,

Thanks for setting me straight--I'm not schooled in engineering so I fear I used some technical terms incorrectly or too loosely.

As for boutique European brands, that was a lazy way of referring to some of the brands that I tried a long time ago that didn't seem so good but that I can't remember for sure. Otherwise, I wouldn't hesitate to name names. Arca-Swiss was among them, maybe Novoflex too, but I'm not absolutely certain.

My preference for lips over pins is based on the fact that (1) most scopes don't have pin sockets, (2) some scopes with pin sockets don't have them in the right location, or else the plate doesn't have the pin in the right place for the scope foot, (3) many pins are too narrow and so do not prevent a bit of wiggle and thus loosening over time, (4) many plates from Manfrotto and Gitzo have spring-loaded pins that are somewhat loose in their housing so have lateral play and thus do not prevent a bit of wiggle and thus plate loosening over time. Sure, a good plate with a good pin can work well. I just haven't met many that do, and generally they are combined with a rubberized surface which, again, allows for a bit of wiggle and thus loosening over time. I guess this brings up a point. For me, a good plate not only prevents rotation, it also doesn't loosen over time. I have never had a plate from RRS or Kirk become loose. Ever. And I've been using them for 20+ years. On a related topic, I've also never had a screw-action QR clamp from any manufacturer (RRS, Kirk, Gitzo, Neewer...) loosen or lose its grip on the plate, so I have no interest in the various "safety retention" pins and releases that some systems offer. If possible, I remove them for convenience.

As for better materials of mounting rigs, I wasn't thinking so much in terms of different aluminium alloys in plates and more about RRS's near exclusive use of machined metal parts for brackets and such, so that all joints and fittings are metal to metal, never metal to plastic or rubbery material, as some others do (e.g. the irritating macro rail system I got from Bogen/Manfrotto many years ago).

On the material or precision of bolts etc, I guess I shouldn't have used the word shear. What I was thinking about is that I have have never had issues with the material quality of RRS fasteners, whereas with other brands, I have sometimes found the following: (1) soft metal that allows the head of the bolt to twist off--admittedly, probably when over-torqued, but still..., (2) soft metal or poor precision or shallow depth of socket sizing in the heads of bolts such that the screwdriver slots or hex key socket is a slightly imperfect fit and thus distorts and become damaged over time, (3) the threads of bolts or thread adapters being ever so slightly undersized such that they thread into sockets but still have a bit of lateral play in them and aren't really tight until they are screwed in very firmly. Such fittings seem vulnerable to breaking free and loosening when subjected to shocks or vibrations.

I use 3/8" bolts and screws when I can, but some tripod bodies and other mounting hardware come with fixed (nonreplaceable) 1/4" threaded parts for attaching tripod heads etc, hence my use of the adapters here and there. They seem to cut some vibration or flex that can occur when, e.g. a head is threaded onto the mounting bolt of a tripod or clamp stud using an adapter that only encloses 2.5 or 3 threads worth of length of the bolt, as is the case with many cheap adapters.

Sorry for being so obsessive about this. Although I figured out what actually works a long time ago, it was a long time in coming, so I never take my solid tripod and other brackets etc for granted. I always appreciate how well they work and I never forget how much trouble I used to have. It's such a blessing to have solutions that do the job so well that persistent problems are laid to rest entirely.

--AP

Finally the first time, to my knowledge in this forum, the debate over quick-change-plate-technology is nearing a level of professional knowledge with the introduction of terms as shear and others more, that a real gain of comprehension, overtaking even that of manufacturers, leading to real product improvement now seems possible.

Hans

 

[Alexis Powell]

Why not use ISO 10664 hexalobular internal, better known under a registered name Torx. This drive system is definitively superior to in-hex, not only torque-wise. The quite relevant problem of over tightening should not get solved by a substandard drive system. Over tightening is not only a problem of bolts, but at least as much of the socket of the device connected with. Less with telescopes, more with cameras, with their thinner walled bottoms.

Hans

I would guess the reason to be because hex works fine and is more widely available. Changing standards would irritate existing customers as they would have to fumble between two keys until they took time and trouble to retrofit everything to no practical gain. -- AP