Stiff focus ring on a Chinar 135mm 2.8

awscreo · 12-08-2018, 09:31 PM

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So was passing by a vintage lens store today, and saw a bargain bin outside (everything $10), had to look through it. Saw this lens, in very good condition cosmetically, very clean glass, looks great, definitely K-mount. Got home, mounted fine on K-1. Took it apart to see what's what, cleaned some of the dust out, and tried to apply some new grease on the helicoid (cleaned off as much as I could the old stuff that was on it). Still quite stiff. Was wondering if anyone has any advice on how to deal with it. Has anyone taken one apart? It's a non auto lens, fully manual, and optical formula seems pretty simple. Should I just take it apart completely? The helicoid is almost fully exposed, just need to take the focus ring and extend the barrel to full length (that's how I cleaned the old grease off). Can i maybe just put few drops of WD-40 on the helicoid and move it around? would that losen up the old grease further?

Thanks

This is the closes I could find to what I have, I couldn't find one exactly like mine - http://allphotolenses.com/lenses/item/c_696.html

**Derek** · 12-08-2018, 09:59 PM

Originally posted by awscreo

So was passing by a vintage lens store today, and saw a bargain bin outside (everything $10), had to look through it. Saw this lens, in very good condition cosmetically, very clean glass, looks great, definitely K-mount. Got home, mounted fine on K-1. Took it apart to see what's what, cleaned some of the dust out, and tried to apply some new grease on the helicoid (cleaned off as much as I could the old stuff that was on it). Still quite stiff. Was wondering if anyone has any advice on how to deal with it. Has anyone taken one apart? It's a non auto lens, fully manual, and optical formula seems pretty simple. Should I just take it apart completely? The helicoid is almost fully exposed, just need to take the focus ring and extend the barrel to full length (that's how I cleaned the old grease off). Can i maybe just put few drops of WD-40 on the helicoid and move it around? would that losen up the old grease further?

Thanks

This is the closes I could find to what I have, I couldn't find one exactly like mine - The Chinar chinon 135 mm f/ 2.8 Lens. Specs. MTF Charts. User Reviews.

I would avoid WD-40. It's great for rusted parts but it's way overused for other applications. It would probably attract a lot of dust in the long term.

You'd need to remove the old grease and replace it. A detergent perhaps?

Good luck with it!

**marcusBMG** · 12-09-2018, 07:30 AM

You need to properly clean the helicoid - use eg coleman fuel to take off the greas, then eg acetone or other good solvent that will take off any varnish like residue. Then your new grease needs to be suitably light, otherwise your helicoid will indeed be stiff. I use a light white lithium grease from an online marine supplies. It was cheap! Works v well, not sure if its going to have the appropriate longevity.
A couple of times I've had a lens with a stiff helicoid due to a knock causing a small dent/distortion of the focus ring.

WD40 etc is a no no for lenses. Will inevitably creep where you don't want it - on the optics.

awscreo · 12-09-2018, 11:06 AM

Thanks! Thankfully I haven't applied wd 40 yet. I'll try to disassemble the lens tomorrow. I have a nice silicone based grease that worked really well with my helios, should be fine with this one I think

---------- Post added 12-09-18 at 11:06 AM ----------

I read denatured alcohol is a good solution to remove grease as well, would you guys agree?

Not a Number · 12-09-2018, 05:13 PM

I use this stuff for re-greasing my lenses. It's made for helicoids. Synthetic, lithium and PTFE, good temperature range, non-creeping etc. Read about it's virtues in the listing. Available on Amazon too.

HELIMAX-XP Camera Telescope Optical Instrument Focusing Helicoid Grease w/ PTFE 36663592378 | eBay

You're going to have to clean off all the old grease first. White gasoline, lighter fluid even soap and water for solvents. A stiff toothbrush to get the clay out of grooves.

You don't want to use any lubricant that has a noticeable odor - the outgassing will film the optical elements.

12-08-2018, 09:31 PM	#1
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722	Stiff focus ring on a Chinar 135mm 2.8 Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. So was passing by a vintage lens store today, and saw a bargain bin outside (everything $10), had to look through it. Saw this lens, in very good condition cosmetically, very clean glass, looks great, definitely K-mount. Got home, mounted fine on K-1. Took it apart to see what's what, cleaned some of the dust out, and tried to apply some new grease on the helicoid (cleaned off as much as I could the old stuff that was on it). Still quite stiff. Was wondering if anyone has any advice on how to deal with it. Has anyone taken one apart? It's a non auto lens, fully manual, and optical formula seems pretty simple. Should I just take it apart completely? The helicoid is almost fully exposed, just need to take the focus ring and extend the barrel to full length (that's how I cleaned the old grease off). Can i maybe just put few drops of WD-40 on the helicoid and move it around? would that losen up the old grease further? Thanks This is the closes I could find to what I have, I couldn't find one exactly like mine - http://allphotolenses.com/lenses/item/c_696.html

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12-08-2018, 09:59 PM	#2
Derek Site Supporter Join Date: Jun 2008 Location: Terrace, BC, Canada Photos: Albums Posts: 122	Originally posted by awscreo So was passing by a vintage lens store today, and saw a bargain bin outside (everything $10), had to look through it. Saw this lens, in very good condition cosmetically, very clean glass, looks great, definitely K-mount. Got home, mounted fine on K-1. Took it apart to see what's what, cleaned some of the dust out, and tried to apply some new grease on the helicoid (cleaned off as much as I could the old stuff that was on it). Still quite stiff. Was wondering if anyone has any advice on how to deal with it. Has anyone taken one apart? It's a non auto lens, fully manual, and optical formula seems pretty simple. Should I just take it apart completely? The helicoid is almost fully exposed, just need to take the focus ring and extend the barrel to full length (that's how I cleaned the old grease off). Can i maybe just put few drops of WD-40 on the helicoid and move it around? would that losen up the old grease further? Thanks This is the closes I could find to what I have, I couldn't find one exactly like mine - The Chinar chinon 135 mm f/ 2.8 Lens. Specs. MTF Charts. User Reviews. I would avoid WD-40. It's great for rusted parts but it's way overused for other applications. It would probably attract a lot of dust in the long term. You'd need to remove the old grease and replace it. A detergent perhaps? Good luck with it!

12-09-2018, 07:30 AM	#3
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,870	You need to properly clean the helicoid - use eg coleman fuel to take off the greas, then eg acetone or other good solvent that will take off any varnish like residue. Then your new grease needs to be suitably light, otherwise your helicoid will indeed be stiff. I use a light white lithium grease from an online marine supplies. It was cheap! Works v well, not sure if its going to have the appropriate longevity. A couple of times I've had a lens with a stiff helicoid due to a knock causing a small dent/distortion of the focus ring. WD40 etc is a no no for lenses. Will inevitably creep where you don't want it - on the optics.

12-09-2018, 11:06 AM	#4
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722 Original Poster	Thanks! Thankfully I haven't applied wd 40 yet. I'll try to disassemble the lens tomorrow. I have a nice silicone based grease that worked really well with my helios, should be fine with this one I think ---------- Post added 12-09-18 at 11:06 AM ---------- I read denatured alcohol is a good solution to remove grease as well, would you guys agree?

12-09-2018, 05:13 PM	#5
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	I use this stuff for re-greasing my lenses. It's made for helicoids. Synthetic, lithium and PTFE, good temperature range, non-creeping etc. Read about it's virtues in the listing. Available on Amazon too. HELIMAX-XP Camera Telescope Optical Instrument Focusing Helicoid Grease w/ PTFE 36663592378 \| eBay You're going to have to clean off all the old grease first. White gasoline, lighter fluid even soap and water for solvents. A stiff toothbrush to get the clay out of grooves. You don't want to use any lubricant that has a noticeable odor - the outgassing will film the optical elements.