FA*85 1.4 Auto Focus Sound on K-1: Is this normal?

**Kerrowdown** · 11-23-2017, 04:03 PM

Originally posted by dcpropilot

It sounds like to me, time to get her older cousin, my “Sweetheart” (Pentax-A* 85mm F1.4), it's beautifully smooth and quite... unless of course I make a noise.

Medex · 11-23-2017, 10:31 PM

Originally posted by Kerrowdown

It sounds like to me, time to get her older cousin, my “Sweetheart” (Pentax-A* 85mm F1.4), it's beautifully smooth and quite... unless of course I make a noise.

Sweetheart is really fantastic

**Kerrowdown** · 11-26-2017, 10:33 AM

Originally posted by Medex

Sweetheart is really fantastic

Aye... she has her moments.

HarisF1 · 11-27-2017, 12:28 PM - **3 Likes**

Hi guys, I completed my repair of the FA*85 a few minutes ago and wanted to document the process for anyone willing to do the same.

Here's a link to the album of images, as requested.

I bought a replacement gear from the link previously provided (actually have two spares now) and it arrived pretty quickly (PL to UK delivery). The tools required are: JIS Screwdrivers, New gears, Pliers, Sellotape, Flathead screwdriver ~2.5mm and (optionally) magnets.

Simple method, also use my images for a bit more detail:

1) Disassemble lens mount by removing 5 screws - be very careful to use JIS drivers only. Also take care with the pins. These can be taped so they won't fall off too easily.
2) Remove aperture ring (careful with the ball bearing).
3) Use pliers to pull out screwdrive shaft. The gear should remain in the assembly. This can be removed.
4) Take new gear and compare dimensions. This new gear is thicker and can be sanded.
5) Use force to push the shaft into new gear, away from the lens.
6) Place gear in the correct place in the assembly, then place the shaft over it and use force to put into position.
7) Re-assemble aperture ring (remember the ball bearing, this bit is the only annoying part).
8) Re-assemble the mount.

Hope these instructions help.

Haris

Last edited by HarisF1; 11-27-2017 at 01:58 PM.

Medex · 11-27-2017, 02:35 PM

Originally posted by HarisF1

Hi guys, I completed my repair of the FA*85 a few minutes ago and wanted to document the process for anyone willing to do the same.

Here's a link to the album of images, as requested.

I bought a replacement gear from the link previously provided (actually have two spares now) and it arrived pretty quickly (PL to UK delivery). The tools required are: JIS Screwdrivers, New gears, Pliers, Sellotape, Flathead screwdriver ~2.5mm and (optionally) magnets.

Simple method, also use my images for a bit more detail:

1) Disassemble lens mount by removing 5 screws - be very careful to use JIS drivers only. Also take care with the pins. These can be taped so they won't fall off too easily.
2) Remove aperture ring (careful with the ball bearing).
3) Use pliers to pull out screwdrive shaft. The gear should remain in the assembly. This can be removed.
4) Take new gear and compare dimensions. This new gear is thicker and can be sanded.
5) Use force to push the shaft into new gear, away from the lens.
6) Place gear in the correct place in the assembly, then place the shaft over it and use force to put into position.
7) Re-assemble aperture ring (remember the ball bearing, this bit is the only annoying part).
8) Re-assemble the mount.

Hope these instructions help.

Haris

Congratulations

krazykat · 11-27-2017, 03:52 PM

Originally posted by HarisF1

Hi guys, I completed my repair of the FA*85 a few minutes ago and wanted to document the process for anyone willing to do the same.

Here's a link to the album of images, as requested.

I bought a replacement gear from the link previously provided (actually have two spares now) and it arrived pretty quickly (PL to UK delivery). The tools required are: JIS Screwdrivers, New gears, Pliers, Sellotape, Flathead screwdriver ~2.5mm and (optionally) magnets.

Simple method, also use my images for a bit more detail:

1) Disassemble lens mount by removing 5 screws - be very careful to use JIS drivers only. Also take care with the pins. These can be taped so they won't fall off too easily.
2) Remove aperture ring (careful with the ball bearing).
3) Use pliers to pull out screwdrive shaft. The gear should remain in the assembly. This can be removed.
4) Take new gear and compare dimensions. This new gear is thicker and can be sanded.
5) Use force to push the shaft into new gear, away from the lens.
6) Place gear in the correct place in the assembly, then place the shaft over it and use force to put into position.
7) Re-assemble aperture ring (remember the ball bearing, this bit is the only annoying part).
8) Re-assemble the mount.

Hope these instructions help.

Haris

Great guide, I feel confident to do it myself now!

By the way, was there any threadlock on your lens mount screws? I haven't done mine yet but I've been 'practicing' on a couple of junk F series lenses and both of them had threadlock.

HarisF1 · 11-28-2017, 12:00 AM

Originally posted by krazykat

Great guide, I feel confident to do it myself now!

By the way, was there any threadlock on your lens mount screws? I haven't done mine yet but I've been 'practicing' on a couple of junk F series lenses and both of them had threadlock.

There usually will be. It takes a JIS driver and a good fit in order to get break the threadlocker seal. Your other lenses will be good practice.

HarisF1 · 11-28-2017, 10:17 AM

Even better

Thanks DCShooter!

krazykat · 11-28-2017, 03:22 PM

Originally posted by dcshooter

A drop of acetone or MEK on a Cotton swab will make life a lot easier and decrease the risk of stripping screws or breaking your driver tip.

Thanks for chiming in dcshooter.

Without wanting to derail the thread, I've read 3 (seemingly) feasible methods of helping the removal of thread-locked screws:

1. Acetone applied via tweezers, using the surface tension to hold the drop until application;
2. The "rubber band trick" - placing a wide rubber band between the screw head and the screwdriver to increase grip & reduce the chance of stripping the head; and
3. Applying a hot soldering iron to the head of the screw to cause an expansion of the screw.

Looks like acetone might be the most effective.

11-27-2017, 12:28 PM - 3 Likes	#34
HarisF1 Veteran Member Join Date: Apr 2016 Posts: 543	*FA85 repair - replacement of broken gear** Hi guys, I completed my repair of the FA85 a few minutes ago and wanted to document the process for anyone willing to do the same. Here's a link to the album of images, as requested. I bought a replacement gear from the link previously provided (actually have two spares now) and it arrived pretty quickly (PL to UK delivery). The tools required are: JIS Screwdrivers, New gears, Pliers, Sellotape, Flathead screwdriver ~2.5mm and (optionally) magnets. Simple method, also use my images for a bit more detail: 1) Disassemble lens mount by removing 5 screws - be very careful to use JIS drivers only. Also take care with the pins. These can be taped so they won't fall off too easily. 2) Remove aperture ring (careful with the ball bearing). 3) Use pliers to pull out screwdrive shaft. The gear should remain in the assembly. This can be removed. 4) Take new gear and compare dimensions. This new gear is thicker and can be sanded. 5) Use force to push the shaft into new gear, away from the lens. 6) Place gear in the correct place in the assembly, then place the shaft over it and use force to put into position. 7) Re-assemble aperture ring (remember the ball bearing, this bit is the only annoying part). 8) Re-assemble the mount. Hope these instructions help. Haris Last edited by HarisF1; 11-27-2017 at 01:58 PM.*

11-27-2017, 03:52 PM	#36
krazykat Veteran Member Join Date: Aug 2010 Posts: 546	Originally posted by HarisF1 Hi guys, I completed my repair of the FA85 a few minutes ago and wanted to document the process for anyone willing to do the same. Here's a link to the album of images, as requested. I bought a replacement gear from the link previously provided (actually have two spares now) and it arrived pretty quickly (PL to UK delivery). The tools required are: JIS Screwdrivers, New gears, Pliers, Sellotape, Flathead screwdriver ~2.5mm and (optionally) magnets. Simple method, also use my images for a bit more detail: 1) Disassemble lens mount by removing 5 screws - be very careful to use JIS drivers only. Also take care with the pins. These can be taped so they won't fall off too easily. 2) Remove aperture ring (careful with the ball bearing). 3) Use pliers to pull out screwdrive shaft. The gear should remain in the assembly. This can be removed. 4) Take new gear and compare dimensions. This new gear is thicker and can be sanded. 5) Use force to push the shaft into new gear, away from the lens. 6) Place gear in the correct place in the assembly, then place the shaft over it and use force to put into position. 7) Re-assemble aperture ring (remember the ball bearing, this bit is the only annoying part). 8) Re-assemble the mount. Hope these instructions help. Haris Great guide, I feel confident to do it myself now! By the way, was there any threadlock on your lens mount screws? I haven't done mine yet but I've been 'practicing' on a couple of junk F series lenses and both of them had threadlock. Last edited by krazykat; 11-27-2017 at 03:58 PM.*

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Is this sound normal?	eliphas	Pentax K-1 & K-1 II	8	08-17-2016 01:01 PM
For Sale - Sold: Pentax fa85, a85, fa43, fa31, fa200, fa28-70	chirocanonpan	Sold Items	35	03-15-2013 11:25 PM
K-x making sound in longer exposure. Is it normal???	gut1kor	Troubleshooting and Beginner Help	2	07-17-2010 09:37 AM
Is it normal for K-X to make a gearing sound when shaken?	hockmasm	Pentax DSLR Discussion	8	04-30-2010 09:54 AM
For Sale - Sold: Pentax FA* 200 macro, FA* 85, FA* 24, FA 31 LTD, FA 77 LTD, A 50/1.2, VL 125 M	aegisphan	Sold Items	86	09-03-2009 02:37 PM

11-23-2017, 04:03 PM	#31
Kerrowdown PEG Moderator Join Date: Aug 2008 Location: Highlands of Scotland... "Hold Infinity in the palm of your hand" - William Blake Photos: Gallery Posts: 57,821	Originally posted by dcpropilot FA85 1.4 Auto Focus Sound on K-1: Is this normal? It sounds like to me, time to get her older cousin, my “Sweetheart” (Pentax-A 85mm F1.4), it's beautifully smooth and quite... unless of course I make a noise.

11-23-2017, 10:31 PM	#32
Medex Pentaxian Join Date: May 2013 Location: Vilnius Posts: 1,020	Originally posted by Kerrowdown It sounds like to me, time to get her older cousin, my “Sweetheart” (Pentax-A* 85mm F1.4), it's beautifully smooth and quite... unless of course I make a noise. Sweetheart is really fantastic

11-26-2017, 10:33 AM	#33
Kerrowdown PEG Moderator Join Date: Aug 2008 Location: Highlands of Scotland... "Hold Infinity in the palm of your hand" - William Blake Photos: Gallery Posts: 57,821	Originally posted by Medex Sweetheart is really fantastic Aye... she has her moments.

11-27-2017, 02:35 PM	#35
Medex Pentaxian Join Date: May 2013 Location: Vilnius Posts: 1,020	Originally posted by HarisF1 Hi guys, I completed my repair of the FA*85 a few minutes ago and wanted to document the process for anyone willing to do the same. Here's a link to the album of images, as requested. I bought a replacement gear from the link previously provided (actually have two spares now) and it arrived pretty quickly (PL to UK delivery). The tools required are: JIS Screwdrivers, New gears, Pliers, Sellotape, Flathead screwdriver ~2.5mm and (optionally) magnets. Simple method, also use my images for a bit more detail: 1) Disassemble lens mount by removing 5 screws - be very careful to use JIS drivers only. Also take care with the pins. These can be taped so they won't fall off too easily. 2) Remove aperture ring (careful with the ball bearing). 3) Use pliers to pull out screwdrive shaft. The gear should remain in the assembly. This can be removed. 4) Take new gear and compare dimensions. This new gear is thicker and can be sanded. 5) Use force to push the shaft into new gear, away from the lens. 6) Place gear in the correct place in the assembly, then place the shaft over it and use force to put into position. 7) Re-assemble aperture ring (remember the ball bearing, this bit is the only annoying part). 8) Re-assemble the mount. Hope these instructions help. Haris Congratulations

11-28-2017, 12:00 AM	#37
HarisF1 Veteran Member Join Date: Apr 2016 Posts: 543	Originally posted by krazykat Great guide, I feel confident to do it myself now! By the way, was there any threadlock on your lens mount screws? I haven't done mine yet but I've been 'practicing' on a couple of junk F series lenses and both of them had threadlock. There usually will be. It takes a JIS driver and a good fit in order to get break the threadlocker seal. Your other lenses will be good practice.

11-28-2017, 10:17 AM	#38
HarisF1 Veteran Member Join Date: Apr 2016 Posts: 543	Even better Thanks DCShooter!

11-28-2017, 03:22 PM	#39
krazykat Veteran Member Join Date: Aug 2010 Posts: 546	Originally posted by dcshooter A drop of acetone or MEK on a Cotton swab will make life a lot easier and decrease the risk of stripping screws or breaking your driver tip. Thanks for chiming in dcshooter. Without wanting to derail the thread, I've read 3 (seemingly) feasible methods of helping the removal of thread-locked screws: 1. Acetone applied via tweezers, using the surface tension to hold the drop until application; 2. The "rubber band trick" - placing a wide rubber band between the screw head and the screwdriver to increase grip & reduce the chance of stripping the head; and 3. Applying a hot soldering iron to the head of the screw to cause an expansion of the screw. Looks like acetone might be the most effective.