| Author |
Message |
    
Steve_roberts
Tinkerer
Username: Steve_roberts
Post Number: 36
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 03, 2009 - 03:11 am: | 
|
Hi,
I've just bought a Petri Color 35 that (amongst other problems) has a very stiff focussing wheel to rack the lens in and out. Can anyone advise what lubricant, if any, should be applied to the helical thread of the focussing mechanism? On an SLR I'd use LM grease, but the helix is a very fine multi-start and I have a feeling that grease would actually give more drag rather than less. Equally, I'm not comfortable about oil, as who's to say where it will go. Secondly, the focussing seems to lack the infinity click stop. Any info on where the mechanism for this is to be found would be much appreciated. The symptoms of both the above faults seem to indicate congealed lubrication.
Thanks in anticipation,
Steve |
Reiner
Tinkerer
Username: Reiner
Post Number: 79
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 03, 2009 - 01:31 pm: |
|
In cases like yours I successfully used synthetic engine oil or nyoil. But my current favorit is teflon oil from the bycicle shop. The teflon oil is quite thin. I loosenes the congealated grease. It dries out quickly but leaves teflon particels as some kind of dry lubricant.
I practiced that since several years. So far I never had a problem with oil which spreads to everywhere. I use the oil carefully in few amounts, move the focus, let is sit for some days and redo it if neccessary. I have specially cured 2 Petri Color 35 in this way.
For very fine threads I made bad experiences with grease. Once I took a whole focussing thread apart, cleaned it completely, re-lubed it with silicone grease and reassemled and it was nearly as stiff as before. |
Steve_roberts
Tinkerer
Username: Steve_roberts
Post Number: 37
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 04, 2009 - 03:51 am: |
|
Thanks Reiner. That seems like very good advice. The Petri has many moving parts for which the lubricant chosen needs a little thought. The infinity click was very obvious once I dissolved the old grease that was stopping it from dropping into the slot on the ring.
Thanks again,
Steve |
|
