[uttam.hathi]

An attempt to present dissassembly of Pentax DA* 16-50/2.8
flickr album
pentax DA 16-50/2.8 disassembly | Flickr

[BigMackCam]

Fascinating and terrifying in equal measure

[HarisF1]

Good job, I also disassembled mine because of a dead SDM. I'll be doing it again soon because it was an excellent experience. I didn't break too much of it!

I took some images and maybe they can be of use too.

One question though, when you remove the 4 screws that hold the main lens body in place (in your images), where do the bronze and steel shims go? I stacked one on top of the other when reassembling and it seems to work fine.

[chaxdaman]

Should be tagged as NSFL - Not Safe For Lenses

[uttam.hathi]

@HarisF1 no shims in my lens, i brought dead lens from a forum member, tried conversion of sdm to screw did not work as the upload did not happen using k7 How to deactivate SDM and allow for screw drive autofocus with DA* 16-50mm f/2.8 - Le site des amateurs de PENTAX

need a new motor lets see.
but as to shims if they were present its just a reversal process.

[HarisF1]

Ah I see.. As I was pulling the focusing unit away from the optics/helicoids the shims popped out and I couldn't see where they came from.

I'm now looking for a cheap Pentax DSLR to convert my 16-50 to screwdrive.

Your conversion might have failed as the little contact strip is broken between the lens circuit and the focusing circuit.

[uttam.hathi]

@chaxdaman : of its not safe, but if u need to open a lens material needs to be made available like thinkpads [ ThinkWiki ] thats what makes thinkpad really great. To me if a company makes available their service manual then that company has nothing to hide, ofcourse they would make a lot more money as unnecessary opening would result in more servicing.

---------- Post added 09-11-2016 at 09:14 PM ----------

you would need one which does not have firmware upgrade, my k7 has firmware upgrade did not upload.

---------- Post added 09-11-2016 at 09:15 PM ----------

Ah I see.. As I was pulling the focusing unit away from the optics/helicoids the shims popped out and I couldn't see where they came from.

I'm now looking for a cheap Pentax DSLR to convert my 16-50 to screwdrive.

Your conversion might have failed as the little contact strip is broken between the lens circuit and the focusing circuit.

any pics

[HarisF1]

This image shows the shims in the background. There are four of them. Two are bronze, two are steel or something else. They fit between the optics (as shown) and the focusing body, and are held by the screws. I really should have taken better shots.

[uttam.hathi]

u have a real tough call, but since the came, understanding they were there main helicoid body, just a guess, they were below above the holes at the bottom of the pics, confirm the didtance by placing the shim there in the dismantled state. if correct

[uttam.hathi]

if correct then align the helical body and the casing and then try fitting them from top by pushing them in.

---------- Post added 09-11-2016 at 09:57 PM ----------

or hold it upside down and try managing, looks very difficult.

[uttam.hathi]

but are u sure it was not below this four screw and the casing

---------- Post added 09-11-2016 at 10:03 PM ----------

next time use a voigtlander to click pics,

[HarisF1]

The second pic shows the focusing unit. This sits on top of the shims, and requires 4 screws to fix it in place.

[HarisF1]

New development - I tore the motor strip just like OP did... While trying to massage it. Ohhhhhhhhhhhhh well. Time to get it converted to screwdrive now. Does anyone know a contact that can do it in the UK?

Cheers

[uttam.hathi]

Do it yourself its not difficult at all,
install notepad++, though notepad will work.

find the modset for ur pentax model,
get into debug mode .
download the coding of the lens which u read thru ur dslr.
modify the code
upload the code to ur lens thru ur dslr.

modset
https://www.pentaxforums.com/forums/6-pentax-dslr-discussion/274316-pentax-hack-modset.html

changing the lens code
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/208353-how-...-2-8-a-45.html.

an youtube demo.

You Tube

You Tube

five minute job.

[HarisF1]

I understand that it's really easy but the process doesn't work on the K-3. I'm trying to find a cheap K10d for doing conversions only (and maybe a bit of cheap photography on the side) but they're still quite expensive (around £80 for the cheapest, most are £100+).