Digest for sci.electronics.repair@googlegroups.com - 8 updates in 2 topics

Three Jeeps <jjhudak4@gmail.com>: Jan 25 09:15AM -0800

> Anyone having an issue with Fluke cases getting brittle? I have a 177 that had the battery cover crack in the screw boss area, and the other side won't hold a screw as the inside post is cracked. The plastic is brittle and reminds me of the aging of plastic in 1990s plastic television cabinets. My 85s never did this and I have a very old 77 that is still in perfect shape although it doesn't get a of use. The 177 is my daily meter and yes, it's fallen a few times.
 
 
Sorry to hear.
I have 3 fluke multimeters: a 77(30 yo?), 179 (6-7 yo?), and 289 (~2 yo). None of them have the issues you describe. The 179 is my daily driver most of the time.
Surprising that the aging plastic issue would crop up on a Fluke.
For the inside post repair, you may want to consider, if there is enough space, to slide over a plastic sleeve filled with epoxy to reinforce it? Then use a slightly oversized screw?
Heat-shrink sleeve over post perhaps?
good luck
J
"ohg...@gmail.com" <ohger1s@gmail.com>: Jan 25 01:54PM -0800

On Tuesday, January 25, 2022 at 12:15:06 PM UTC-5, Three Jeeps wrote:
> Heat-shrink sleeve over post perhaps?
> good luck
> J
 
I'm sure I could kluge up a fix (or just retire the meter - it's close to 10 years IIRC), but I was more curious if anyone else had seen this (yet?) The brittle plastic syndrome was bizarre and I'm wondering if I'm an early victim of this on Fluke meters. Years ago, I remember two guys bringing in a 32" Sony flat CRT TV for repair and heard the telltale snapping as they muscled the beast in the door. It literally came apart in their hands and the CRT fell out the front as they put it down.
Phil Allison <pallison49@gmail.com>: Jan 25 01:56PM -0800

ohg...@gmail.com wrote:
====================
> Anyone having an issue with Fluke cases getting brittle?
 
** Yep.
 
>I have a 177 that had the battery cover crack in the screw boss area,
>and the other side won't hold a screw as the inside post is cracked.
 
** All the posts for the back screws on my 70 series 2 have failed.
Plus the "clicker" on the ranges switch broke about 10 year back.
 
Bought the meter in about '95 - it failed completely 2 years ago.
Not a common problem with other DMMs I own,
 
 
..... Phil
Jeff Liebermann <jeffl@cruzio.com>: Jan 25 02:39PM -0800

On Tue, 25 Jan 2022 08:29:42 -0800 (PST), "ohg...@gmail.com"
 
>Anyone having an issue with Fluke cases getting brittle? I have a 177 that had the battery cover crack in the screw boss area, and the other side won't hold a screw as the inside post is cracked. The plastic is brittle and reminds me of the aging of plastic in 1990s plastic television cabinets. My 85s never did this and I have a very old 77 that is still in perfect shape although it doesn't get a of use. The 177 is my daily meter and yes, it's fallen a few times.
 
Any sources of ozone nearby, such as electric motors? A friend, who
owned a machine shop, used to have the same problem with meters after
a few years. However, we're not sure if it's the ozone or the machine
oil in the air that's causing the plastic to become brittle. I also
created some cracking in one of my Fluke meters when I repeatedly used
alcohol to clean the case.
 
This might be of interest:
<https://www.eevblog.com/forum/testgear/fluke-quality/>
Note the photo of the replacement metal hex standoffs for the broken
plastic.
 
At some point in the past, it became necessary to put additives in the
plastic to make it fire retardant. My guess(tm) is that this has
something to do with the crumbling plastic. Look on the inside of the
case for the acronym that indicates the type of plastic used in your
177.
<https://www.bpf.co.uk/plastipedia/abbreviations/Default.aspx>
 
--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
Jeff Liebermann <jeffl@cruzio.com>: Jan 25 02:47PM -0800

On Tue, 25 Jan 2022 08:29:42 -0800 (PST), "ohg...@gmail.com"
 
>Anyone having an issue with Fluke cases getting brittle? I have a 177 that had the battery cover crack in the screw boss area, and the other side won't hold a screw as the inside post is cracked. The plastic is brittle and reminds me of the aging of plastic in 1990s plastic television cabinets. My 85s never did this and I have a very old 77 that is still in perfect shape although it doesn't get a of use. The 177 is my daily meter and yes, it's fallen a few times.
 
This might be of interest:
"Problem plastics, types of deterioration & where you find it"
<https://mmics.files.wordpress.com/2008/04/problem-plastics-check-list.pdf>
 
--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
"ohg...@gmail.com" <ohger1s@gmail.com>: Jan 26 06:44AM -0800

On Tuesday, January 25, 2022 at 5:39:58 PM UTC-5, Jeff Liebermann wrote:
> <ohg...@gmail.com> wrote:
 
> >Anyone having an issue with Fluke cases getting brittle? I have a 177 that had the battery cover crack in the screw boss area, and the other side won't hold a screw as the inside post is cracked. The plastic is brittle and reminds me of the aging of plastic in 1990s plastic television cabinets. My 85s never did this and I have a very old 77 that is still in perfect shape although it doesn't get a of use. The 177 is my daily meter and yes, it's fallen a few times.
 
> Any sources of ozone nearby, such as electric motors?
 
Nothing out of the ordinary certainly. My older meters have been used in the same environment and never had this issue. I just checked my 40 year old Beckman HD100 that I keep at home. I pulled the back cover to replace the battery last night (overdue) and flexed the inside plastic parts of the case. Shows no sign of brittleness even when tested with a pocket knife.
 

 
> At some point in the past, it became necessary to put additives in the
> plastic to make it fire retardant. My guess(tm) is that this has
> something to do with the crumbling plastic.
 
 
That makes sense. Unfortunately. Another case of creating far more problems than it solves.
 
 
"Peter W." <peterwieck33@gmail.com>: Jan 26 06:59AM -0800

Generally, my approach to cracked cases of this nature is to clean thoroughly, add a generous bead of JB-Weld, right up to and including filling the screw holes, allowing it to cure, then drilling out the holes as needed Haven't lost a patient yet. It may not be the prettiest of cures, but it has the overwhelming virtue of working well.
 
Peter Wieck
Melrose Park, PA
Chris Jones <lugnut808@spam.yahoo.com>: Jan 26 09:37PM +1100

On 24/01/2022 04:01, -faver- wrote:
> needed, but not quite.  Assuming this crystal would even work, would a
> series trimmer cap allow me to adjust to the proper frequency?
 
> Thank you.
 
Bearing in mind that the thing cost you $1, you could try scraping away
at the glass around what is left of the crystal pin, to expose as much
metal as you can on the wire, and then joining on a fine strand of wire
with silver conductive paint (for example the type used to repair car
window de-misters). Once you have a good electrical connection, you can
cover the joint with 2-part epoxy (araldite etc.) to make it robust.
 
It is also possible to remove crystals from their metal can, it may
still work if you are careful and there will be much more wire to make
contact to inside the can.
 
If you think the thing is worth much more than $1, you can either order
a custom crystal or use a PLL frequency sythesiser chip like the ones
from Silabs that radio amateurs often use as a local oscillator - they
are very simple to use and can produce whatever frequency you need. The
frequency can be programmed with some arduino-type processor etc.
You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page.
To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.

No Response to "Digest for sci.electronics.repair@googlegroups.com - 8 updates in 2 topics"

Post a Comment