Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Loose focus on [old] sci-fi 445nm 1W

clansley

clansley

0
Joined
Sep 20, 2014
Messages
295
Points
28
Having just obtained my highest power laser to date (1W), I was a bit worried by a loose focus adapter as it can easily move from a non-reflective surface to a reflective one without moving the host! :eek:

From searching the forums I gather I should use 'Teflon tape' on the threads. Looking at Thread seal tape - Wikipedia, the free encyclopedia it seems there is some confusion over the term 'Teflon tape' - so I just wanted to be doubly sure that using PTFE tape (the tape plumbers use) is the right thing to do.
 
Last edited:





Livinloud

Livinloud

0
Joined
Feb 21, 2013
Messages
5,013
Points
0
Re: Loose focus on sci-fi 445nm 1W

Yes the white tape normally found in a blue and white holder at any plumbing store, home depot, wal mart or even dollar store. Just make sure its not folded around by the lens or the beam will melt it
 
clansley

clansley

0
Joined
Sep 20, 2014
Messages
295
Points
28
Re: Loose focus on sci-fi 445nm 1W

Livinloud said:
Yes the white tape normally found in a blue and white holder at any plumbing store, home depot, wal mart or even dollar store. Just make sure its not folded around by the lens or the beam will melt it
Click to expand...

Cheers mate!

Update: tape now added and it's now perfect!
 
Last edited:
Livinloud

Livinloud

0
Joined
Feb 21, 2013
Messages
5,013
Points
0
Re: Loose focus on sci-fi 445nm 1W

I use it on all my lens, gets rid of that little wobble and helps keep the lens from adjusting itself :beer:
 
DTR

DTR

0
Joined
Jun 24, 2010
Messages
5,684
Points
113
Re: Loose focus on sci-fi 445nm 1W

Yep it will work good but suggest you only put it on the top 1/3 of the threads so that it just starts to thread into the module when you are near focus. If it is lower than that over time bits can fray and work their way down into the module. If any gets on the diode window it can damage the diode.:beer:
 
clansley

clansley

0
Joined
Sep 20, 2014
Messages
295
Points
28
Re: Loose focus on sci-fi 445nm 1W

DTR said:
Yep it will work good but suggest you only put it on the top 1/3 of the threads so that it just starts to thread into the module when you are near focus. If it is lower than that over time bits can fray and work their way down into the module. If any gets on the diode window it can damage the diode.:beer:
Click to expand...

The trouble is it wouldn't help me if I only put it on the top 1/3; Infinite focus is when I have it unscrewed by 4mm and it's very loose (the whole thread is only 8mm long). But I guess your message is to keep as much of the bottom clear as possible.
 
Last edited:
BowtieGuy

BowtieGuy

0
LPF Site Supporter
Joined
Oct 14, 2012
Messages
6,090
Points
113
Re: Loose focus on sci-fi 445nm 1W

Are you using any kind of spring (internal/external) to help keep pressure on the lens barrel? Not sure if you're using one of the standard focusing adapters, or one of the custom ones which are much larger, and heavier.
I've heard of some people having to use a heavier spring when a large custom focus adapter is used.
 
Last edited:
3Pig

3Pig

0
Joined
Oct 26, 2013
Messages
242
Points
0
Re: Loose focus on sci-fi 445nm 1W

I've got an external spring on my 445, it sure makes focusing easier but I still get the same wiggle. Go for the plumbers tape :)
 
clansley

clansley

0
Joined
Sep 20, 2014
Messages
295
Points
28
Re: Loose focus on sci-fi 445nm 1W

BowtieGuy said:
Are you using any kind of spring (internal/external) to help keep pressure on the lens barrel?
Click to expand...

It has a large focus adapter.
There is a 14mm long (weak) spring behind the focusing barrel.
 
Last edited:
DTR

DTR

0
Joined
Jun 24, 2010
Messages
5,684
Points
113
Re: Loose focus on sci-fi 445nm 1W

clansley said:
The trouble is it wouldn't help me if I only put it on the top 1/3; Infinite focus is when I have it unscrewed by 4mm and it's very loose (the whole thread is only 8mm long). But I guess your message is to keep as much of the bottom clear as possible.
Click to expand...

Yep.:beer:
 
Thejoker301

Thejoker301

0
Joined
Mar 30, 2012
Messages
1,321
Points
0
Re: Loose focus on sci-fi 445nm 1W

Hi ,

I send it with springs I get from DTR. They usually work just fine.

But if you really want to get a more stable adapter just get an external spring. Or put Teflon like DTR advised.

Enjoy your laser , and if you need anything else let me know. Next time , you can just email me first :) I usually reply quickly to emails.

:beer:
 
clansley

clansley

0
Joined
Sep 20, 2014
Messages
295
Points
28
Re: Loose focus on sci-fi 445nm 1W

Thejoker301 said:
Hi ,

I send it with springs I get from DTR. They usually work just fine.

But if you really want to get a more stable adapter just get an external spring. Or put Teflon like DTR advised.

Enjoy your laser , and if you need anything else let me know. Next time , you can just email me first :) I usually reply quickly to emails.

:beer:
Click to expand...

Hi!

I would have emailed you if I had got it from you new, but as I got it second hand from "SN P", and it clearly didn't bother him so I thought I must be fussy and it might be wrong to contact you.

I will use teflon tape for now, but will also see if I can source an external spring and see how that goes too. :beer:

[Added "old" to original post, although I have no idea how old it is!]
 
Last edited:
10fenny

10fenny

0
Joined
Sep 10, 2014
Messages
1,054
Points
83
just make sure its not the liquid teflon tape. I have some at work for automotive and its pretty nasty stuff to be putting anywhere near a laser. You might hafta re-apply it every now and then too. teflon tape is made as pipe thread sealant so it not going to take being screwed in and out all the time.
I just had to do this to one of my lasers last week, for it was too easy to be bumped out of focus.
 
Last edited:
You must log in or register to reply here.




Top