T mount concerns

Davros (Lauren) · #1 03-10-2009, 01:34 PM

Just bought a T mount the other day and it fits the Nikon well but when attached to the scope the camera can easily undo and spin off the bayonet mount and hit the deck. I assume this is not regular? Anyone had similar problems or thought of a solution.

Merlin66 (Ken) · #2 03-10-2009, 03:13 PM

Assuming the problem isn't the internal thread portion of the adaptor but just coming unscrewed from the male thread on the scope attachment...
Unfortunately this IS a common occurance!!
If the camera is out of balance in the anti-clock direction it can easily unscrew from the thread!!
I had a similar experience with a spectroscope! It just turned on the thread and fell, clipped my knee and bounced of the observing table.....
Took me a week, and a few $$$$ to re-build!
I now use an additional "safety strap" all the time. This joins the spectroscope to a piggyback adaptor on the top of the scope.

mill (Martin) · #3 03-10-2009, 03:31 PM

I have superglued the inside of the "T" ring because sometimes the small screws that hold the threaded ring in the "T" ring come loose and the camera will fall out, now it wont happen in a million years

And i will make a steel wire going from the camera to the scope, this way the camera will only fall the distance the cable is long.

Davros (Lauren) · #4 03-10-2009, 04:15 PM

It is the bayonet end that has the problem. It is quite loose until it sort of clicks in to full lock. the problem seems to be that the uneven weight of the camera makes it pull back out of full lock and then easily spin off.

mill (Martin) · #5 03-10-2009, 04:42 PM

Mick that is not normal.
It can have a little of slack to the left and right but never backwards.
It is better to take it back from where you bought it and get another one that fits properly.

Moon (James) · #6 03-10-2009, 04:45 PM

On my D50, the camera body has a small pin that sticks out 1.36mm. It's spring loaded, so when the lens (or t-adaptor) clicks into position it stays there. I've never had the problem you describe, but there is some play which I don't like. I have looked everywhere and I can' find a better t-adaptor. I can't find anything that is as good as a genuine Nikon lens.

Merlin66 (Ken) · #7 03-10-2009, 04:50 PM

Don't know about the Nikon, but on most bayonet adaptors there's a couple of small copper(?) springs inside the mechanism to reduce the play/ slop but still allow the thing to rotate into place.
These can become loose; just needs a slight "tweek" with a small instrument screwdriver to lift the small spring tabs a smidgin more to bring back the "resistance"

leon · #8 03-10-2009, 08:40 PM

Hmmm, that sounds very odd to me, and it should not happen, IMHO.

Leon

Moon (James) · #9 03-10-2009, 08:48 PM

Quote:

Hmmm, that sounds very odd to me, and it should not happen, IMHO.

I agree. Can you make a YouTube video to show us how much movement there is?

Davros (Lauren) · #10 04-10-2009, 05:41 AM

Quote:

Originally Posted by Moon

I agree. Can you make a YouTube video to show us how much movement there is?

Wouldnt have a clue how, i will fiddle with the pins though and see if tis makes a difference. If not i will go back to the shop. Hes a nice bloke and i dont think he would have a problem.

Davros (Lauren) · #11 06-10-2009, 12:05 AM

Problem solved, thanks guys. It just needed a poofteenth of alloy removed which was stopping the locking pin engaging.

All good now.