Was it me or was it the monolight?

Bought 2 monolights 6 month ago, both of them had the ratchet handle screw worn off (where it lock the tilt angle of the light) so the handle no longer screw onto the bolt anymore, and the light head just drop down dead now, not usable anymore.

Anyone know how long a ratchet handle on the monolight is supposed to last? Are they supposed to last a short time? I am not a full time photographer, so only use it couple of times per week. Don't seem to be able to find replacement easily so had to contact the manufacture.

I have a softbox attached to the front of the monolight, and then the monolight attached to the light stand. Pretty standard stuff I think. Did I do wrong? Softboxes are 36", so not that big.

I am starting to questioning myself, maybe I did something wrong?

Looks like cheap soft metal screw, and maybe insufficient engagement.

Situation is made worse if you tighten the handle TIGHT.

The screw must be long enough to project completely through the nut. Attempting to lock with less than the thickness of the nut places too much force on the few engaging threads, leading to stripping the threads.

Depends where you live.

Replacement screws can be found in many decent hardware stores in the US.

BTW, it is not a ratchet handle. It is simply a handle on a nut, that you rotate around the screw 360 degrees.

A ratchet allows one to crank to tighten in an arc usually smaller than about 120 degrees. Look up "ratchet wrench."

Usually screws last quite a while. - I suppose some last a couple of decades of sane daily use. - No offense meant. Besides my best efforts I am obviously failing to lecture some co-workers what sane means.

Every screw will die at a certain point if too much torque is applied and reaching that point shouldn't take longer than half a minute.

A lot of torque applied via an ill fitting tool is going to kill the head of a screw sooner or later. Plus there are use cases, usually if nut and bolt are made of different materials, when each overtightening and losening costs roughly one turn of the thread length.

Link: http://mdmetric.com/tech/Standard_tightening_torque.pdf

Assuming your carriage bolt is a standard M6, it is meant to be tightened with 5.2Nm (or 7.7Nm according to some German table which I'd trust more), which really isn't much. - Sorry, I am a somewhat practical guy. - I know that 5Nm is the minimum setting for my mid sized 3/8" torsion wrench, but I have no clue how to describe a feeling for it.

I suppose you can find slightly stronger carriage bolts in an (online?) hardware store. OTOH: I'd prefer to increase internal friction of that joint if needed and apply less torque via that fishy plastic lever.

My old Elinchrom heads are tightened via wing nuts that press a flat square against a leather disk in front of a solid 3+x mm piece of metal. - Maybe a bicycle inner tube snippet in your joint could help building up enough friction without overtightening your bolt?

At work we have Chinese Walimex & Jinbei monolights behind softboxes and I did not have any problems with the ratchet handles.

Thanks for the replies, guys.

Gary,

I had thought of the screw not going enough into the nut, it only goes in about 6mm, it could go all the way in about 15mm, I purchased some longer screws yesterday on ebay will see how they work. Btw, I am in Canada, you can't find anything here.

Jochen,

The screw is m8 1.25 thread and 40mm long. Everything here is in imperial measurements and there is only a handful of Metric bolts in Homedepot, and length is either too short or too long. Thanks for the suggestion of adding some friction at the joint. I need to find some thing like a piece of leather or rubber.

I am surprised to see no similar complaint on the INTERNET regarding this, and both of my lights have the same issue.

I've worked with and seen a lot of pro grade gear, and don't recall ever seeing a tightening mechanism stripped. I think this is mainly a case of low grade materials and a not-too-good design.

If I were in your shoes, I'd be looking for a way to modify the mount for less stress on that part. One not so obvious option would be to extend a rod out to the rear of the flash with a counterweight on it (pad or somehow cover the end of the rod so that there is NO POSSIBILITY of someone poking their eye on it). This counterweight has the added benefit that the light stand won't be trying to fall over forward.

I've worked with and seen a lot of pro grade gear, and don't recall ever seeing a tightening mechanism stripped. I think this is mainly a case of low grade materials and a not-too-good design.

 

If I were in your shoes, I'd be looking for a way to modify the mount for less stress on that part. One not so obvious option would be to extend a rod out to the rear of the flash with a counterweight on it (pad or somehow cover the end of the rod so that there is NO POSSIBILITY of someone poking their eye on it). This counterweight has the added benefit that the light stand won't be trying to fall over forward.

Thanks for the advise, Bill. I had thought of that, I had also thought of taking the light off the light stand while I am not using it. Not sure if that's what people do but I just left them on all the time with the softbox attached.

The lights have large handles in the rear end, I am going to attach some weight there to help with the balance.

The lights have large handles in the rear end, I am going to attach some weight there to help with the balance.

Hi, I don't know how mechanically inclined you are, but if the handles are fairly close to the pivot point it could take a lot of weight - several times more than the weight of the soft box. If you could extend a rod for twice this distance then you would only need half the weight, etc.

Using only the handle as attachment point, you might be better off to to attach some bungee cords to pull downwards. For a grip point on the light stand you could probably use an automotive "hose clamp," perhaps holding a piece of stiff wire (from a coat hanger, perhaps) bent into a hook.

I'm sure you'll find some sort of working solution. Fyi, some pro gear uses serrated contact surfaces on mating faces of the pivot mechanism. So the pivot doesn't rely on friction, but rather just holds the serrations in contact. Not something that YOU could easily do, but just an explanation as to why such systems don't have to rely on tight pressure to prevent slipping.

The nut is usually just a friction fit in the plastic handle, and the coach bolt (note the square protrusion under the head) looks pretty standard.

I can't believe suitable replacements can't be found in a stronger material. If you replace both nut and bolt, then whether they're imperial or metric thread is irrelevant as long as the outside dimensions of the nut and the square section of the bolt are similar.

W,

The entire head assembly SHOULD be in BALANCE, or close to it.

The more off-balance the head, the more force is required of the locking mechanism.

So do as Bill said, to balance the head.

Note that the angle of the head, pointed down or level, will affect the balance, because the pivot point is below the head.

Then do as Jochen said to put something into the mechanism to INCREASE the rotational friction, so you do not have to crank down on the nut so tightly. Also clean the friction surfaces of any oil/grease/wax.