Paul C. Buff, Inc. Technical Forum

as far as I know i have the latest versions of E640 and PLM with speedrings (but not the 8mm PLM).
I have read a few posts here regarding some simple (and not so) mods you folks do.
ie. something about using different screw/bolts with PCB/PLM speedring.
and using a velcro band to help secure PLM shaft at rear of the light unit.
I did not have PLMs at the time so I could not commit the info to memory and it seems the threads are buried deep in the past now.
I rigged an 86 PLM with speed ring and then mounted it to an E640. It didn't fall off but I sure did note signs of loading pressure (no doubt) at the threaded (small) end of the speed ring. there is a lot of torque on the area that the speedring's wing nut threads into the PLM shaft.
I also tried the 86 PLM with E640 (new one) using the 7mm umbrella shaft and the shaft still had a bend from the weight. this is the new E640 that the shaft slides through for extra support.
So...what R you guys/gals doing with your PLMs to make them more user friendly/secure?
BTW new VBML is charging up and I put together the new 51 x-silver PLM for testing fun later.

Not sure what you mean. I have a 86" PLM mounted on my E640 with the Buff Speedring. It is perfectly secure. The PLM is nowhere near heavy enough to effect the speedring bolt or threads... as long as it's tightened. That bolt would take the weight of 100 PLM's without issue.

^ a little over exaggerated on the 100's of plm statement... As long as you have the speedring attached to the plm and that you ensure the screw is tightened with the corresponding "teeth" washers; your einstein should have no problems whatsoever with the plm's weight. I have my shaft for the plm about 4cm above the speedring.

in regards to the umbrella rod with the plm: yes there will be bending but it shouldn't break under normal usage.

Actually, it wasn't an exaggeration. The bolt itself is literally strong enough to hold the weight of 100 PLMs.

Hi,
I've seen much larger(heavier) modifiers, ie 56X80 softboxes, so I do have it in mind that 'some' monoblocks can handle the weight. Also I'm sure PCB thoroughly tested and continually tests products for such things. I'm sure I followed the set up instructions too.
I just did not get a very warm and fuzzy feeling initially as I 'gently' let go of the 86 PLM with speedring attached to the E640 and I watched the whole rig sag in various places under the pressure of the weight. It seemed like the SR wanted to slip off (naturally) and the small point at which the PLM attached to the speed ring showed a certain amount of flex. Yes of course all the sagging does settle, it just gives me queezy feeling watching it all happen.
I imagine, like anything, the more I use the equipment the more confident and less concerned I'll be.

Paul

Of course the actual "bolt" could withstand the pressure but what I was addressing is whether the bolt + speedring support the weight of 100 plms (my silver 86" plm weighs exactly 2lbs 8.8oz) so 40.8oz x 100 = 4080 oz = 255 lbs of weight on the speedring + bolt.