BlackRapid

gman

gman

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Graham
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I've been looking at the BlackRapid straps and a few of the alternatives and I came across one called a CarrySafe, but it was the mounting plate that caught my interest.

I'm wondering if the ones which screw straight into the tripod mount are perhaps putting an awful lot of local stress on that point on the camera, whereas the ones which use the plates are spreading the load more?

Saw some video where a guy pulled a car using a BlackRapid (I think) so I don't doubt it's a strong point, but what about ongoing stress?
 
I wouldn't worry at all. The only way there would be enough weight on it to be worried would be if you had a really massive lens attached.... But then you should be attaching to the lens not the camera anyway, so not a concern then either.

However, if you are really that concerned you could just get this....

http://www.blackrapid.com/product/hardware/fr-t1/
 
Cheers for the link. Isn't this still the same principle as the normal one being it's just a screw holding things together or is there a secondary support that I can't see?
 
Graham, I agree with you. From an engineering perspective I think those systems that use a plate should be more robust than those that transfer the load/stress straight through from the strap to the tripod mount.

I'm currently experimenting with a few different ideas, because it seems to me most of the current designs are uderspecced and overpriced and I think I can make something stronger, with more (ie, some) redundancy, for less than £10.
 
What exactly do you mean by the plate? If the plate just attaches to the tripod mount then it won't do much for reducing stress, only perhaps "bending".
 
I'm not an engineer but I'm thinking that when it comes to sideways stress if it's just the screw going in then the stress will be very local within the thread and the immediate surrounding parts. If using a plate, because it's a rigid item then it will help take some of the stress away from the thread and screw?
 
Possibly, but I would think that it doesn't really suffer much sideways stress in this case. Imagine the forces that go through it when on a car rig, they can handle a lot.
 
But don't the car rigs use plates? I'm just thinking that this thing bouncing about as you walk about can't be great for it?
 
Yeah yeah they do, but I mean, compared to those forces, I wouldn't worry about walking around.

My advice would be not to worry about fatigue. Unless you're planning on hanging a 5kg lens off a plastic body, and even then you'd probably be fine.

You're worrying too much....
 
Please excuse the rough and very un-technical diagram, but this is what makes sense in my head - approximately.

All input most welcome!


Looking behind the camera....


stress.jpg
 
I see what you mean, but I don't think it would be quite like that.

stress.jpg


Red represents stress. A gradient shows where it is countering the "bending". As in, it gets more the further away from the centre it is.

In the second one I have assumed that the thread will counter the sideways force because the rubber coating on the pad will have more sideways "give" than the metal thread would.

But yes, the plate would indeed reduce the stress levels.
 
Whom, you seem to know what you're talking about. What do you think about those systems that attach the carabiner to the end of the plate rather than directly to the screw?

My veiw is that they are preferable since flex in the plate will lessen any tug on the strap being transmitted straight to the thread of the screw.

Alternatively the plate could act as a lever.
 
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Like the "Q Strap"? I just ordered one haha

lplate3.png


I think the levering effect will be significant, but in the case of the "Q strap" one at least it extends beyond the mounting point, acting a little like the example on the right above.

I expect the mount is designed with a huge safety factor. Imagine how tight people must do up the threads?!
 
Ah, that plate above I saw in a video review and it shows a considerable benefit to having the strap at the side rather than more centred is that the camera sits better on your hip.

I'm going to need to look into all this me thinks..
 
gman said:
Ah, that plate above I saw in a video review and it shows a considerable benefit to having the strap at the side rather than more centred is that the camera sits better on your hip.

I'm going to need to look into all this me thinks..
Click to expand...

I wouldn't worry about stresses too much unless you're hanging a 500mm from a 1000D.....

Like I said before, imagine the stresses going through the camera in a car mount. Regardless of having a plate or not, going over a bump is going to put the whole thread in tension.
 
I just wish there was a second backup, even if it were a thin wire running to one of the original strap mounts or something.
 
gman said:
I just wish there was a second backup, even if it were a thin wire running to one of the original strap mounts or something.
Click to expand...

Use one of these?

Metal_Tip_Shoelace.jpg
 
I've got some of this on the way...

I did think about using a P&S camera wrist strap as those things seem damn tough. Another abundant option is a Nintendo Wii remote strap - they're given some abuse.
 
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whom said:
Sure that's long enough?
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Hehehe. I've already mentioned redundancy!

It looks like useful stuff to have around hence the bulk purchase.

I'm planning on splicing 3 strands into a short length to go through the camera's neck strap attachment and a quick link.

Once I've got everything delivered, cut, stitched, spliced and fitted, I'll post some pictures...

...And then someone can point out my fatal design flaw.
 
Garnett said:
Hehehe. I've already mentioned redundancy!

It looks like useful stuff to have around hence the bulk purchase.

I'm planning on splicing 3 strands into a short length to go through the camera's neck strap attachment and a quick link.

Once I've got everything delivered, cut, stitched, spliced and fitted, I'll post some pictures...

...And then someone can point out my fatal design flaw.
Click to expand...

I look forward to seeing it (y)

Remember how useful a lick of flame is at cleaning up any cut ends.
 
Ah yes. Several inches of blackened nylon fabric currently forming a prototype can give testament to my willingness if not my aptitude for that technique.
 
Garnett said:
Ah yes. Several inches of blackened nylon fabric currently forming a prototype can give testament to my willingness if not my aptitude for that technique.
Click to expand...

He buys 300m, useful stuff to have around he says, I'll probably burn it all he means.
 
I've basically done the same thing using some paracord - attached it to the strap point on the base of the grip, and then attach the other end to either high up on the camera strap or a belt using a carabiner. Just made sure that I had enough length to raise the camera comfortably, without too much that it would smash to the ground! Tried it originally connected to the strap next to the original carabiner, however found that they tended to snag a bit, so preferred moving the attachment elsewhere.

I decided to do this after I noticed the screw coming out the tripod ring of my 70-200 (this was using the Black Rapid Manfrotto adapter), despite me having used what I thought was enough force to tighten it, as well as some threadlock stuff! To be fair, after I tightened it up, I have not had the same problem since, but the thought of £5k worth of gear hitting the ground inspired me to come up with an additional tether....
 
A guy mentioned in a video review that wetting the nut before threading it can help because the water evaporates and helps secure it? Is this right?
 
gman said:
A guy mentioned in a video review that wetting the nut before threading it can help because the water evaporates and helps secure it? Is this right?
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Errr..... I have never heard of this....

Water doesn't actually lubricate like oil. Under pressure it just displaces whereas oil becomes more viscous.

I suspect a drop of loctite would be 10000X more effective.
 
Here's the link, it's at about 1.20. My first impression is perhaps not to believe him but then he says "they tell you" as if it's in the BlackRapid manual or something?
 
Yeah, not sure about the water trick. Not heard of it myself.

Edr, I've managed to squeeze some obligatory paracord into my prototype but it's cored and not for taking any load.
 
This is seriously not an issue. Maybe if you buy a cheap after-market part to screw into the camera it might be, but if you use original RS products you will be fine unless you are carrying a 1200 f/5.6 or a Sigma 200-500 f/2.8..... And even with those you will probably be fine if you attach the RS to the lens and not the camera.
 
gman said:
Cheers for the link. Isn't this still the same principle as the normal one being it's just a screw holding things together or is there a secondary support that I can't see?
Click to expand...

It is still just a screw... Not sure what other support you could conceivably have. But the principles discussed further down the thread for spreading stress would still apply to this base plate.
 
I looked into the water thing some more and I believe it's because it temp. lubricates the bolt allowing you to tighten it a little further and then it drys making it uber secure. Probably more effective when using rubber washers.

Some interesting comments here and a little worrying that Nikon don't recommend putting stress on the tripod plate area of the camera. I'd be using it on the lens collar anyway but still worth looking at all the options.
 
gman said:
Here's the link, it's at about 1.20. My first impression is perhaps not to believe him but then he says "they tell you" as if it's in the BlackRapid manual or something?
Click to expand...

Unless it causes the two surfaces to rust together then I would ignore that advice.... I reckon he made it up as an excuse to make out with it. I heard he likes a rapid screw.
 
arentol said:
It is still just a screw... Not sure what other support you could conceivably have. But the principles discussed further down the thread for spreading stress would still apply to this base plate.
Click to expand...

If the screw fails (unscrews) I was thinking that perhaps a thin but strong cable/wire as a last resort, just something to give you enough time to grab the camera?
 
http://forums.dpreview.com/forums/read.asp?forum=1021&message=39507561

One last tip is to follow BR's tip, and moisten both sides of the rubber washer before tightening the connector down. This lubricates it temporarily and lets it go on tighter. When I do this on my gear, it ends up so secure that I have to use a screwdriver or my Leatherman for leverage to loosen it.

Not sure how much BR know about this stuff.
 
Ah, well this is different to wetting the thread. I made the mistake of thinking it was meant to be the metal you made wet. It makes sense in the case of the rubber pad. The surface area is large, the pressure low and the coefficient of friction is also large.
 
Be brave Gman. Go buy a Q Strap and a shoelace.

Or wait till mine arrives tomorrow or Wednesday and I'll use one of my last few days as an engineering student to analyse it :LOL:
 
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