[case]

I have a Pentax-F 1.7X AF adapter in good working condition which I attached to an old slightly damaged K-5 body. I have used the adapter many times on the same body but now it refuses to come offf.
1. The damage to the body has been on the mount with at least 2 of the screws loose or stripped.
2. There is about 1/8 inch movement on the adaper when I I try to remove it..
3. I am willing to sacrifice the K-5 but I would like to try to recover the adapter.
4. I have tried to slip a piece of thin sheet metal in to try to dislodge the lens lock pin and the autofocus pin but no luck there.
5. I cannot see what is causing the adaper to lock on the mont.

Any suggestions on how to proceed

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[mlag]

On my K3 there are 2 lens lock pins... one close to the push button and one between the "two damaged screws" on your picture... in your text you seem to assume there is only one.
Does the unlock button "clicks" ? Maybe wiggle a bit with the lens while unlocking...

[i_trax]

On my K3 there are 2 lens lock pins... one close to the push button and one between the "two damaged screws" on your picture... in your text you seem to assume there is only one.
Does the unlock button "clicks" ? Maybe wiggle a bit with the lens while unlocking...

there is only one locking pin,
the other "thing" is a screw-drive AF spring loaded shaft , can be retracted with AF/MF switch ( next to it ).

[vonBaloney]

Might be AF screw -- set AF switch to MF and see if you can get the screw to retract (give it some hard taps while wiggling the adapter).

[marcusBMG]

I would guess that the locking pin is not being retracted, or retracted sufficiently, by the black button. I assume you've pressed it as hard as you can. It operates on both the pin and the af screw drive, as already mentioned the latter can be retracted anyway by switching the selector to MF.

Pulling tc + mount ring off the camera will cause a bit of damage but not terminal, especially since screws are already missing. The mount ring is just screwed on to the underlying plastic frame with self tapping screws. The issue is once off, it is never fully secure again due to the stripped holes. There is a thread or two about that if you look.
It is possible to loosen the casing, you probably won't be able to remove the front casing past the tc, but this might provide sufficient access to actuate the locking pin with a probe. Have a browse for "dissassemble K5".

[mlag]

there is only one locking pin,
the other "thing" is a screw-drive AF spring loaded shaft , can be retracted with AF/MF switch ( next to it ).

You are right, but both retract with the lens unlock button....albeit the focus one is also affected by the af/mf switch if I read the other posts.

[case]

Thank you for suggestions. I will try to be clear, though perhaps not familiar with some of the names for parts.

mlag/marcusBMG - Yes I am aware that the AF/MF pin and the locking pin are both retracted by pressing the black release button. This button appears to move freely back and forth. It also works as it should when I mount a lens on the teleconverter and can easily detach it.
vonBaloney - my concern now migrates to the AF/MF button. When I mount a manual focus lens on the teleconverter and set to AF, the AF mechanism in the teleconverter does not appear to be working when I try to focus (with AF). I can focus manually and take a proper exposure but there is no hunting or movement of the AF mechanism. I am not shure how this could affectthe rotation and removal of the teleconverter.

Wondering if I should forget about the camera and teleconverter and sell them for parts before I do any more damage? The camera is an extra with some damage so it is expendable but the teleconverter is worthwhile as long as it does not get any damage.

[marcusBMG]

The locking pin on the lens side of the tc is only operated by the black push button on the tc, its not a "through" mechanism, so of course there is no difficulty mounting a lens on it. The push button on the camera operates two spring levers, one moves the locking pin and one the AF pin. It is very possible the operation of the button seems/feels correct but one of these levers is not being actuated fully.

Playing with my 1.7x tc on a K30, it seems to me that the AF pin and the locking pin engage simultaneously pretty exactly. If you have an 1/8" movement then there is something else going on. Perhaps a screw slightly protruding a few thou and catching on a screw recess opposite?

Have you tried carefully using a judicious amount of force?

[case]

MarcusBMG - Thank you for those observations. The thought that perhaps one of those loose screws on the camera mount may be catching above on the TC could be a possibility.
I have been somewhat forceful in my attempts to rotate the TC, but whatever is stopping the rotation appears to be quite solid. If there was a loose screw I beleive I would have deformed it by now. It feels like a solid stop after the 1/8 in movement.

I have always relied on the on-camera locking pin.

I have also put a very small amount of lubricating oil on the camera mount but it still feels like a solid stop.

Your mention of the AF/locking pin leads me to see that if the camera locking pin is not retracting it could catch on the mounting screw hole on the back of the TC at the 8 oclock position. That would account for the 1/8" movement across the diameter of that screw hole. I will try focussing my attention on that position for now.

Thanks again for your help.
John

[Lowell Goudge]

Something to consider here, is that since both the AF screw drive and the lens locking pin are mechanically connected, is that they both have become disengaged from the push button. On the K5, the connection between the physical lens release button and the mechanism is a small pin about 1.5 mm in diameter by about 8-10mm in length. I know because my K5 had the button fall off and this pin was lost. I replaced the pin with a small common nail cut to the correct length, and the button with a plastic cap about the correct size, and then taped over the whole thing with hockey tape (I’m Canadian EH!) the camera has worked successfully like this for about 5 years. On my K10 the spring that is behind the main operating lever does not push the AF drive or the locking pin out to the lens,

But I digress. It is clear that there are common failures that can lead to both the AF drive and the locking pin not working at the same time

If this pin has become dislodged (you indicate the camera is beat up) it may not be activating either the drive release or the locking pin.

I would suggest putting the body in MF ( to retract the AF drive, and then with a thin feeler gauge try to get the gauge between the locking pin and the AF adaptor, and work it off the body

[case]

Thank you Lowell Goudge (from a fellow Canadian). I admire your ingenuity in making practical repairs.

I wondered if the lock/AF mechanisms had somehow been disabled and spent a few hours playing with metal strips and jewellers screwdrivers to try to possibly disloge either of these - to no avail.

I decided to bite the bullet and tear the screws out from the body mount and now I have the same problem but the view is now from the back side of the TC. The problem now is how to get the camera mount dislodged from the TC.

The Locking/AF pins are retracting as they should on the camera body, so the problem was not there.

The only thing I can see now is that one of the three remaining mount screws is catching somewhere on the TC mount.

There is still about 3mm play in the rotation of the camera mount and they are a long way from clearing the mount tabs on the TC.

Now, how to get the lens mount separated from the TC?

[Lowell Goudge]

Look just above the leader line for the “TC MOUNT TAB”. It seems that part of the mount has split and is blocking the bayonet

[case]

Thank you Lowell. I didn't realize till today that the mount on the camera is a custom one called PK+ MM which I put on to adapt to Nikon/Olympus/Yashica/Konica lenses. I have not used it much for those lenses but it has worked fine with any PK/A lens (till now). The tabs are modified to allow it to fit a variety of lenses. It came from Singapore and is no longer in production. (maybe this is why). I cannot see where there is a blockage on the TC tabs to keep it from rotating.free.

[Lowell Goudge]

It appears I misread the shadows into something they were not, but I was curious so I photographed the back of the AFA adaptor I have ( bought new in 1991 when I got my PZ1

I compare this with your shot (oriented roughly the same, ). It might offer some ideas of where it is catching

I wonder what I see at the bottom of the hole at 7:00 the right hole is the screw of the lens mount but what is in the left hole?

[case]

That would be the AF drive for the teleconverter. (at 5 oclock in the photo)