Customer Review

19 of 25 people found the following review helpful
3.0 out of 5 stars Screw knob came off on first use, March 28, 2009
By 
This review is from: Pedco UltraClamp Assembly for Cameras, Scopes and Binoculars (Sports)
The idea behind this clamp is brilliant. Unfortunately, the design misses on a key point: the knob used to tighten and loosen the clamp may be subjected to a lot of force. I clamped mine down pretty tight on a railing to be sure my camera was secure. When I came back to unclamp it, the knob simply twisted off. Upon closer inspection, the knob has threads in the center that screw onto the same threaded piece that holds the clamping foot pad. With very little force, it simply unscrewed itself since the foot had enough pressure to stay stationary. It took quite a bit of effort to get the the clamp off in the end because the knob would simply not stay on for me to unscrew. Perhaps there was some kind of glue and I just got a bad one. Not sure, but it has definitely rendered it useless for the moment. Perhaps some SuperGlue might work...

It is also worth nothing that this retailer has marked this up over twice what the MSRP is. Check B&H Photo or REI for a more reasonable price.

EDIT: After the discussion with Raleighphile, I'm putting a few stars back. The clamp really is a decent device, but I think the decision of not adding a thread locking agent to nut in the clamp is a potential design flaw. If you're dealing with a surface that is not slick, be sure to pay extra close attention to how hard you tighten it down. If you're cognizant of the limitations (or add threadlock like I did), it really is a decent little gadget to have, but loses two stars for forcing me to do what the manufacturer should have done.
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Comments

Tracked by 1 customer

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Showing 1-10 of 10 posts in this discussion
Initial post: Aug 25, 2010 9:17:13 AM PDT
Raleighphile says:
The clamp load of a 1/4" x 20 threaded fastener is 2000lbs when tightened to between 60-85 INCH/pounds. (that is INCH-pounds not foot-pounds) The average person can get between 10-15 FOOT-pounds of torque through a screwdriver which is about 120-180 inch-pounds. That's 2 times what is necessary and if you have stronger than the average wrist strength no doubt plenty of torque to rip the plastic knob off of the 1/4-20 bolt used in this clamp.

You don't have to tighten it like Magilla the Gorilla until you twist the plastic knob off of the fastener!

...and then blame the clamp when you abused it and torqued it beyond its design parameters.

In reply to an earlier post on Aug 25, 2010 9:52:40 AM PDT
Last edited by the author on Aug 25, 2010 9:53:38 AM PDT
CJS says:
Perhaps you can point out where I said I "abused it and torqued it beyond its design parameters" in my review. Unless, of course, you're reading that into the unscientific phrase "pretty tight," in which case I must assume you clamp yours down so it's loose and potentially not secure?

Since you appear to play an engineer on TV, you surely must have considered all of the following in your obviously-valid critique:
-The friction coefficient of the surface to which the clamp was attached.
-How that friction affects the torque necessary to unscrew the clamp.
-The torque necessary to overcome the static friction of a nut and bolt and compared to the aforementioned torque to unscrew the clamp.
-The orientation of the clamp.
-The distribution of the weight to said clamp.

Need I go on?

Look, it's clear you play an engineer on TV, but if you're one in real life, you apparently missed the lecture on real world application of theoretical formulae. In the future, please don't comment where you have no sense of the facts.

In reply to an earlier post on Aug 25, 2010 10:46:35 AM PDT
Raleighphile says:
It's too bad you are the only person who commented on this clamp here who had such problems.

the clamp was designed to, among other things, clamp onto a glass car window. Is it beyond comprehension that perhaps the force needed to smash said car window would be greater than the plastic knob molded onto the fastener used to tighten up said clamp?

I've used this clamp to secure my camera to the master cylinder casting on my motorcycle handlebar, I've used it to clamp onto the stem of my bicycle, I've used it on a car window, and I've clamped it onto a number of other moving vehicles all without mishap or the camera mount coming loose -even off-road. Of course I still put the lanyard of the camera looped through something like a line lashed to a nearby object just in case the worst would happen. I'm not stupid.

I build things for a living. The next time you are standing below a dropped-ceiling in a commercial building and hear a transformer humming overhead you better hope that the guy who installed its 500-2000lb weight hanging from the building structural steel did more than "play an engineer on TV." That kind of stuff falls on your head and you'll have a headache for a long time :-D

I've installed this camera mount in a number of locations where there was vibration and shaking because it was a moving object and I never had to tighten it so tight that it broke the plastic (!) knob at the end of the fastener.

If you broke the knob when you cranked it down, then you tightened it too tight. I don't think this is rocket science or feel the need to pull out my degree to prove it.

In reply to an earlier post on Aug 25, 2010 11:26:57 AM PDT
CJS says:
No, I didn't crank down. Of course, I also wasn't attaching it to a smooth surface such as glass or polished metal. I'm surprised you don't see the design flaw in an object that is (realistically) going to be used on more than smooth surfaces. The cork pad, after all, is going to do a good job of holding the assembly in such a way that it could separate, especially if you have to tighten it enough to offset an abnormal orientation. It's also worth noting I was just using a P&S here. Not sure if you were, but a Nikon D300 is going to require a bit more "security" than a simple pocket camera.

Of course, it's also entirely possible that mine was just not tight enough to begin with. So I could perhaps substitute "poorly assembled" for "design flaw," but the absence of any type of thread locking agent still has me leaning towards an (easily corrected) weakness in the design. As I (think) I said, I applied threadlock and it works fine now, so maybe your response is an sign for me to give a few stars more than just one. Nevertheless, I can promise you this was not a case of "user error."

In reply to an earlier post on Aug 25, 2010 11:43:16 AM PDT
Raleighphile says:
Well, the knob is an industry-standard plastic threaded part attached with epoxy. This type of arrangement is used in many assemblies and can be ordered from just about any engineering catalog. If your threads in the knob are actually stripped then it shouldn't be hard to source another one at just about any fully-stocked hardware store in the "Jandorff" boxes. If the epoxy has just failed and the plastic female threads are fine then it should be easy to get some 2-part epoxy and put a dab of the mixture in the threads and screw it back on.

It's probably too late to return it to the seller (which is super-easy to do on Amazon) and/or ask for a replacement at this point -but I doubt it would be very hard to fix. The clamp itself is made of aluminum threaded for a 1/4"x20 fastener. Just about any 1/4x20 fastener would work -with the only caveat being getting the rubber stopper end to stay on.

Perhaps if all else fails you could contact Pedco and they could send you a replacement fastener.

Stuff happens, and it is possible that they did not use enough epoxy when assembling the knob or they didn't clean the threads of any oil/grease before assembly. I may have been rash in my initial comment. Either of these things could cause the knob to come unscrewed. I think the producers of this otherwise well-engineered product made in the USA deserve a little chance to make things right before a 1-star review is posted which might dissuade someone from buying an otherwise excellent product.

In reply to an earlier post on Aug 25, 2010 2:02:13 PM PDT
Last edited by the author on Aug 25, 2010 2:03:07 PM PDT
CJS says:
OK, there may be some confusion here. [I had a response, but realize I may be forgetting what actually happened. Let me get home and look it over then respond here as an additional edit]

In reply to an earlier post on Aug 25, 2010 3:55:14 PM PDT
Raleighphile says:
On my clamp there is white epoxy holding the threads on the bolt to the plastic knob. It seems that this epoxy has failed on your unit.

I'd use some 2-part epoxy at a dollar store. Before mixing it and getting ready to apply it use some alcohol (rubbing/isopropyl/denatured -anything like that) to make sure there is no grease or oil on the threads of the metal fastener or the plastic knob. Just about any 2-part epoxy should hold the threads from unscrewing once it sets up. Make sure not to get any epoxy on the threads any further down.

If you want you can simply "pop" off the rubber foot at the other end of the bolt and totally unscrew the assembly off of the clamp so as to be able to work on it easier and not have to worry about getting epoxy all over the rest of the clamp.

This should fix it up like new (better than new in your case). Or just contact Pedco about your problem. They'll probably just send you a brand new knob and threaded fastener assembly.

In reply to an earlier post on Aug 25, 2010 5:47:07 PM PDT
Last edited by the author on Aug 25, 2010 5:54:38 PM PDT
CJS says:
Thanks J. I got home and looked at it and it IS the knob where the failure occurred (I've been thinking it was at the other end). I previously used threadlock to make the repair, but I think you've got a good point about epoxy. I think I may just take it out, break the threadlock, clean and then epoxy it.

Also, upon closer inspection, I see why you thought I torques it too much (it's been a while since this happened). As I spend "new" time with it, I see it was probably just a failure of the epoxy and not a design flaw. I'll revisit my review in the next day or two and edit accordingly.

Thanks for the comments!

In reply to an earlier post on Dec 11, 2010 8:37:18 AM PST
Chicago John says:
This has been an interesting read. I think I'll go ahead and buy one of these. Thanks to both C.Stoneham and J. Moll for the dialectec repartee.

In reply to an earlier post on Oct 24, 2012 3:13:09 PM PDT
Re man "appears to play an engineer on TV"

What does that mean, on what TV? There is a television show about engineers, and he has the role of Casey Jones? Or he made an "appearance" on a documentary program about engineers, and you happened to see it. Can you clarify. You seem very precise otherwise in your descriptions of things.
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