[Darkover]

I always think: there should be a software that if you connect a camera and scan (take a panoramic video) the objectives, you can get the 3-D models automatically.

There are scanner like this. But it is more complicate than you believe.

Your gear is perhaps a standard part. So someone with experience in 3D-software like autocad can draw it in a minute. But a gear should fit very good and perhaps if you print it, it needs to be a little bit smaler or bigger. If you had a 3D-printer in your workshop you would print it three times with different sizes until the tooth fit perfectly.
The next problem. There is a reason why this gear fail so often. I think Pentax calculate something wrong and there is to much pressure in the middle. So perhaps you need the hole a little bit bigger. A very little bit.

Olaf

[grahame]

I contacted a friend in Japan and asked if he could get the gear from the store. Mailing a camera back and forth cost quite a lot. And I know I can fix it if I have the part.
If he can buy one, I will post here to see in case anyone else need it.

[Not a Number]

Any machine shop capable of cutting small gears will cut you one. All you need is the outside diameter, diameter of the opening, thickness and number of teeth. Given those parameters the company in Poland linked above may have them in-stock or will cut them for you.

[dcpropilot]

I purchased the brass spur gear from a place in Europe and replaced it myself. Worked fine! I ordered a few to have on hand, and may have some spares.

[felixkh]

Thank you for the information. Do you know how much did they charge for the repair?

His repair was 30,000 yen, not inclusive of shipping.

[Jyrkira]

Old thread but I think someone could be interested. AF gear went broke from my FA 31 Limited. It's an old made in Japan version.

So I contacted to Kameraservice Kungsör which is Pentax repair for nordic countries. I asked if they can deliver me a new AF gear assembly. They replied quickly that they can order one from Japan. And they did. Today I received the AF gear assembly and installed it to my 31 Ldt.

AF is smoot again and it works flawlessly.

Here are both AF gear assemblies.

[barondla]

Would it be possible to put a drop of glue in the gear's fracture and clamp it together to bond?
Thanks,
barondla

[Jyrkira]

Would it be possible to put a drop of glue in the gear's fracture and clamp it together to bond?
Thanks,
barondla

I think clamping and silver soldering is more durable way to do it. The whole AF gear assembly was not very expensive so I wouldn't bother unless you have all the tools already. Especially when new gear assembly is available.

[zzaletel]

Jyrkira - what did the camera service charge you for the replacement gearset?

[Andrey514]

Old thread but I think someone could be interested. AF gear went broke from my FA 31 Limited. It's an old made in Japan version.

So I contacted to Kameraservice Kungsör which is Pentax repair for nordic countries. I asked if they can deliver me a new AF gear assembly. They replied quickly that they can order one from Japan. And they did. Today I received the AF gear assembly and installed it to my 31 Ldt.

AF is smoot again and it works flawlessly.

Here are both AF gear assemblies.

Please could you explain me in couple words how did you disassembly in order to reach gears?

I just unscrewed the bayonet and saw the pin and the gear. I accidentally pushed it and she fell somewhere inside. After that I was afraid to unscrew because I did not know how. Can you please explain how to get to the mechanism? thanks

[zzaletel]

Please could you explain me in couple words how did you disassembly in order to reach gears?

I just unscrewed the bayonet and saw the pin and the gear. I accidentally pushed it and she fell somewhere inside. After that I was afraid to unscrew because I did not know how. Can you please explain how to get to the mechanism? thanks

Which lense are you taking apart?

FA31 Exploded parts diagram that should help to see how it fits together (password Pentax) http://www.pentax-manuals.com/manuals/service/fa31.pdf
FA77 diagram (same password) http://www.pentax-manuals.com/manuals/service/77mm_parts.pdf
FA43 tear-down photos: vjacesslav: SMC PENTAX FA 43mm 1.9 LIMITED DISASSEMBLE IN 37 PICTURES

Good luck!

[Andrey514]

I have 43mm f1.9

Thank you

[sabarrett]

What were the symptoms of this failure - focus locking up? I have a 77 that I have been delaying fixing. This makes sense, based on what its doing - I can manually rotate the focus a little either way then it stops.

[Andrey514]

What were the symptoms of this failure - focus locking up? I have a 77 that I have been delaying fixing. This makes sense, based on what its doing - I can manually rotate the focus a little either way then it stops.

I disassembled my 43 limited and removed the cracked gear.

Now it works fine in manual mode, but now I am looking for the possibility to reproduce or FIND the gear replacement. For now I ordered some plastic gears, similar to the original size, from aliexpress. Taking into consideration extremely small size of the cracked gear (2mm diameter), it looks impossible to make it with 3d printer. I referred to several machine shops, they are laughing because it is very small and said that the minimum fee to try to make it is 150$ which is too much.

I live in Montreal, Canada, so if you guys have other ideas please let me know.

Otherwise I am using it in manual mode and dont want to get rid of this concrete lens and take a chance buying another one, because it is Extremely sharp and colorful. The question is to find and change this small gear ..

Thanx

[FotoPete]

I have a 43 with a cracked gear as well. Had to ask a tech to remove the cracked gear as it was preventing me from rotating the focus ring in manual.

Let me know how the plastic replacement gears from AliExpress work out. I was told Ricoh didn't have the parts on hand for repair.