| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 919.1 | Sermos connectors | K::FISHER | Stop and Smell the Balsa! | Tue Nov 21 1989 15:48 | 18 |
| Sermos connectors:
I have several and so far have had 3 intermittent connections with them.
The last one is still in the plane on the side for charging. I have to
wiggle and fuss with it to have it take a charge. Yet they seem
to get a lot of high praise in the hobby press.
Bottom line is I don't like the, don't trust them and want to switch to
some other type of connector. Should be able to handle 20+ Amps
(Astro Cobalt), reliable, and reasonably light. The connectors that
came on the Astro motor seem good - anybody know what they are called?
Anybody want to suggest a good 2 pin connector?
Bye --+--
Kay R. Fisher |
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| 919.2 | Sermos woes | K::FISHER | Stop and Smell the Balsa! | Wed Nov 22 1989 09:12 | 46 |
| > Concerning Sermos conn. I've always had excellent results, would'nt
> consider anything else. Do your own soldering, tin the conn. & wire
> beforehand. Make sure the curved portion of the contact is snapped
> down firmly in the slot at the mouth of the plastic housing. Use
> at least a 50 watt iron. Can't go wrong.
There is no slot at the mouth of the plastic housing. It is a square hole
with a little metal ledge. The connector is over and pushed up against the
metal ridge. As you know they push in very hard and I have done several
and they all look alike so I assume this must be correct.
I fluxed both ends and used a Weller Gun. After, I end up with an open circuit
(until I wiggle the connectors).
Problem seems to be in the specifications for the clearance between the
contacts.
Inside the connectors when you plug them together they look like this!
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-------------------\___/
/---\___________________
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======================================================
If you pull them apart a bit then the center humps contact and it works!
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/---\___________________
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=================================================
At best I got a hold of a bunch of "out of spec" Sermos connectors.
You could argue that I used too much heat and the metal deformed?
Out of 6 or 8 pairs I have had 3 bad sets so far. The one haunting
me now is semi-permanently mounted in the plane. When I extract it
I would like to never see another Sermos connector.
Bye --+--
Kay R. Fisher |
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| 919.3 | Proper Mating Rituals | ELMAGO::TTOMBAUGH | | Wed Nov 22 1989 09:56 | 13 |
| Kay, you're description of the Sermos conn. is accurate. My written
description didn't agree with my mental image. At any rate, the
curved contact end should snap audibly over the end of the flat
blade below it when you push the contact in, and should remain over
the end of the blade at all times. If you have any back and forth
play with the two conn. shoved together then something is wrong.
Is the wiring insulation binding up inside the housing, or is the
wire inserted at a slight angle into the rear of the contact?
Both of these conditions will put pressure on the contacts and prevent
proper mating. Good luck.
Terry
|
| 919.4 | Connectors measured | DAVE::MITTON | MS-DOS: 50M sold, 15M per year | Fri Jul 20 1990 01:04 | 21 |
| There's an interesting article in the June 90 "Model Builder" page 16,
on connectors. Interesting from the standpoint of actually measuring
the effectiveness of various connectors using a 12v battery to an
electric motor. Their findings:
Item mv drop milliohms
Sermos 2.9 0.28
Homemade 3.1 0.30
spade lug 4.2 0.41
Mod. Tamiya 4.5 0.43
Adams 4.7 0.45
train 5.3 0.51 (this sounds like a Marklin)
bullet 6.0 0.58
Tamiya 25.7 2.48
Deans 2-pin 10.7 1.03
RC Prep 12.2 1.18
19cm SR #16 30.5 4.72 mohm/ft
The article will be continued. Conclusions so far, crimp connectors
are 100x worse than soldered. Stock connectors can be modified and
improved. Bare copper will corrode.
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