Ultra Post Slip
Posted 29 November 2005 - 10:26 AM
I'm finding that I can no longer clamp my monitor arm securely enough around the Ultra's sled post. When doing radical dutching etc. the monitor wants to rotate around the post. I can't work out what's changed as it never used to be a problem. I've taken the thing apart and made sure both sides of the clamping mechanism are secure and the plastic ring is OK but it seems the only way to stop it from slipping is to clamp it shut and then tighten those two grub screws up another 1/2 turn, making it a non-tools-free-solution!
Any pearls of wisdom gratefully received.
Posted 30 November 2005 - 05:04 AM
Thanks for your input but yes the clamps are adjusted OK and it seems that the only way I can get the monitor to stay put is to tighten those two grub screws still further once the clamp is shut.
Posted 30 November 2005 - 07:07 AM
I know it may sound obvious but maybe there is a little contamination with grease or something slippery on the post. Have you tried cleaning the post area and inside the clamp ?
I have found a little lubrication helps on the shoulder of the clasp, where the grub screws bite, makes it easier to close tighter without over stressing the locking mechanism.
Posted 30 November 2005 - 07:51 AM
A common cause for this is when the little catch that the lever engages with works loose. It is fixed by 2 screws from the inside of the clamp ring so means that you have to take the clamp off the post to fix it. Symptoms are that the clamp won't lock and that it sort of squidges into place instead of clicking to lock.
No prob to adjust it here if you need it, if you do it yourself don't forget to loosen the two adjuster screws before reassembly to avoid cracking the ring itself.
All, be VERY careful with the adjuster screws - they have course threads and should only be tightened a tiny bit at a time. Again the result of over enthusiasm is to crack the ring where the lever pivots.
As an aside a little lube on the lever pivot pin does not go amiss, we have seen several rings cracked where the pivot pin has seized and strong hands have forced the lever open so causing the damage.
Posted 30 November 2005 - 05:19 PM
I did think about the grease contamination possibility and cleaned the surfaces pretty well but the problem was still there. Also I made sure that those two screws which can work loose were nice and tight........but still no joy! Maybe I will drop the sled off with you Robin so that you guys can have a go. I love taking things apart and having a go myself but this has got me stumped!
Posted 14 January 2006 - 08:34 PM
ill try and see if i can make the tiny adjustments on the clamp but in the meantime would llike to see how this event turned out...
Posted 17 January 2006 - 08:07 AM
Posted 18 January 2006 - 09:29 AM
I was wondering if this is the same problem we had in Stockholm - 2005 Workshop - with 2 Ultra type sleds. Jerry Holway fixed one of the slippery gimbals, the other was beyond reach. As I remember the solution included a very thin piece of papertape applied to make the clamp diameter a fraction smaller...
Sorry I didn't see this thread earlier.
I think Robin's suggestions are the first things to do, and one should do all of them.
All of the post clamps are accessible on the Ultra without any real disassembly; remove batts, camera, monitor to make it easier, and lay the sled on a table or floor. Pull the posts beyond the "red line" revealing the internal cables, and the two little screws Robin mentions. You may have to rotate or remove the plastic liner to get at the two little screws.
Tighten the screws hard, reassemble as per Robin's instructions, and test.
If this in inadequate, i.e.,you've run out of room on the external adjustment, then as a last resort, add a very thin sheet of material on the exterior of the plastic. I used an adhesive backed label or name tag for this purpose, about .002 inches thick, carefully trimmed to the width of the plastic. This shim brings the exterior adjustments back into the middle of their range. AGAIN, follow Robin's instructions and loosen the adjustment screws before you make the first attempt to clamp the post, and tighten very slowly and carefully.
BTW, Tiffen has completely re-designed post, gimbal and monitor clamps in production on the Clipper Two, which fix this problem and are really slick to use. Positive locking and un-locking, easy user adjustment of tension, no chance of lever catching on anything.
Posted 19 January 2006 - 11:55 AM
Sorry I couldn't reply earlier....computer problems! And I thought Macs never went wrong!
Your problem seems more drastic than mine and as such I'm sure it'll be solved by following Robin's advice.
In the meantime, Jerry, I like the tape idea and I think I'll give that a go and see how it feels.