HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jun 23, 2013, 02:42 PM
Registered User
United States, CA, Livermore
Joined Jan 2012
929 Posts
Quote:
Originally Posted by mrforsyth View Post
If you plan to 'test' the Chemtronics material by dispensing a blob and then jamming meter leads into said blob in an attempt to measure resistance, expect this material to 'fail' as well, unless it has ridiculously high solids content (which is doubtful). Note however, that this does not for a second mean that the material is non-conductive, as has been clearly pointed out above. It merely means that the test methodology is flawed.
I have used the Chemtronics silver loaded epoxy and it is conductive without compression. Never used the grease so maybe it conducts without compression and maybe not. I guess we'll find out soon. Generally what you guys are saying about needing compression is true. The density of particles is often not enough to conduct in a blob.
rhodesengr is offline Find More Posts by rhodesengr
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 23, 2013, 03:32 PM
Registered User
So. Cal.
Joined Oct 2004
8,165 Posts
I work with several different conductive epoxies but the only one that I have ever used that is conductive without compression is Eccobond 56C, which is highly filled with silver particles. Will have to get my guys to order some of the Chemtronics material and perform some lab testing to see how it compares to 56C.

None of the conductive greases that I have ever used had the level of metallic fill required to show conduction without compression. I would expect that such a high fill level would be a detriment to their lubricity. e.g. - It would resemble wet sand.....

Edit: After reviewing the datasheet for CW7100, it shows volume resistivity of <.01 ohm-cm so it appears as though it has very high silver content and may conduct without compression. If so, I personally would be very wary of using it on my flight connectors.
mrforsyth is online now Find More Posts by mrforsyth
RCG Plus Member
Last edited by mrforsyth; Jun 23, 2013 at 03:48 PM.
Reply With Quote
Old Jun 23, 2013, 04:08 PM
Ultra Violet
Electromagnetic's Avatar
Joined Feb 2013
2,818 Posts
Quote:
Originally Posted by mrforsyth View Post
I work with several different conductive epoxies but the only one that I have ever used that is conductive without compression is Eccobond 56C, which is highly filled with silver particles. Will have to get my guys to order some of the Chemtronics material and perform some lab testing to see how it compares to 56C.

None of the conductive greases that I have ever used had the level of metallic fill required to show conduction without compression. I would expect that such a high fill level would be a detriment to their lubricity. e.g. - It would resemble wet sand.....

Edit: After reviewing the datasheet for CW7100, it shows volume resistivity of <.01 ohm-cm so it appears as though it has very high silver content and may conduct without compression. If so, I personally would be very wary of using it on my flight connectors.
Your link locked up my PC 2 times, strange. I hope it does conduct well, that is the whole point, after all silver is the best conductor. If there is a good balance of conductivity and lubrication I will be all set.
Electromagnetic is online now Find More Posts by Electromagnetic
Reply With Quote
Old Jun 23, 2013, 04:13 PM
Registered User
So. Cal.
Joined Oct 2004
8,165 Posts
I'm sure it'll work just fine. Just be sure to use it very sparingly as those pesky silver particles could wreak havoc if they decided to migrate to an unintended location (bridge between contacts, etc.).

Sorry about the lockup. The link goes straight to the .pdf datasheet on Chemtronics' website.
mrforsyth is online now Find More Posts by mrforsyth
RCG Plus Member
Reply With Quote
Old Jun 23, 2013, 04:26 PM
Ultra Violet
Electromagnetic's Avatar
Joined Feb 2013
2,818 Posts
Quote:
Originally Posted by mrforsyth View Post
I'm sure it'll work just fine. Just be sure to use it very sparingly as those pesky silver particles could wreak havoc if they decided to migrate to an unintended location (bridge between contacts, etc.).

Sorry about the lockup. The link goes straight to the .pdf datasheet on Chemtronics' website.
At least the silver will be trapped in grease, unlike graphite powder which can get all over the place.
Electromagnetic is online now Find More Posts by Electromagnetic
Reply With Quote
Old Jun 23, 2013, 04:32 PM
Registered User
So. Cal.
Joined Oct 2004
8,165 Posts
Graphite bonds to the surfaces and stays put. Never had an issue in 30 years. Additionally, conductivity is much lower than silver so shorting is a zero concern. Myself and many others successfully use graphite powder and spray on challenging connectors.

My chosen flight connectors are Anderson Powerpoles so engagement / disengagement do not need additional crutches.
mrforsyth is online now Find More Posts by mrforsyth
RCG Plus Member
Reply With Quote
Old Jun 23, 2013, 04:34 PM
Ultra Violet
Electromagnetic's Avatar
Joined Feb 2013
2,818 Posts
Quote:
Originally Posted by mrforsyth View Post
Graphite bonds to the surfaces and stays put. Never had an issue in 30 years. Additionally, conductivity is much lower than silver so shorting is a zero concern. Myself and many others successfully use graphite powder and spray on challenging connectors.

My chosen flight connectors are Anderson Powerpoles so engagement / disengagement do not need additional crutches.
The only connectors I have used are the EC3's by default.
Electromagnetic is online now Find More Posts by Electromagnetic
Reply With Quote
Old Jun 23, 2013, 05:27 PM
Registered User
Joined Feb 2008
2,750 Posts
I've used graphite for 5 years on EC3s and EC5s. Probably somewhere around 10-15K flights.
Dave H. is online now Find More Posts by Dave H.
Reply With Quote
Old Jun 25, 2013, 05:58 PM
Ultra Violet
Electromagnetic's Avatar
Joined Feb 2013
2,818 Posts
The silver grease arrived. It comes in a little syringe with an extension tip. The tip fits inside the EC3 female perfectly. I put a little in and worked it around. The connector slid right on easily. Taking it apart is easier but because of the compressive nature of the brass it still has some resistance. I measured resistance through the extension tip. The resistance jumped from 35 to 90 ohms and settled around 60. So it has about 50 Ohms per inch at a diameter of about 16 gauge wire. This has been a success. Keeping shorts from happening are fairly easy, just wipe off any residue.
Electromagnetic is online now Find More Posts by Electromagnetic
Reply With Quote
Old Jun 26, 2013, 12:15 PM
Too much is just not enough...
Woody_99's Avatar
Joined Jan 2009
1,057 Posts
I've found that some EC3's can be tight when new, but eventually will loosen up.

Problem is more the plastic mating much more than the bullet inside.
Some paraboards must have different batches of connectors and are really tight and hard to install and even worse to remove.
What works for me is to spray a little bit of silicone on a cotton tip applicator. Brush that around on the outside of the plastic male connector.
Insert and remove a few times in the paraboard so a bit is on that side too.

No need to worry about the conductive surfaces. Leave that alone, just put a bit on the plastic and you should find the connection MUCH easier to install and remove.

Another point, if the above doesn't help, the bullets in the connector may not be straight. That again would put extra resistance on the plastic mating area.

If you have any separate bullets, not in the housing, test to see how hard they are to separate. It won't be nearly as difficult without the added friction of the plastic.

Keep in mind too that these are friction fit connections, and too loose will not be a good thing.
Woody_99 is offline Find More Posts by Woody_99
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold EC3 Connectors BWEC10 Aircraft - Electric - Batteries & Chargers (FS/W) 2 May 13, 2013 05:35 PM
Found EC3 Connectors Raydee Aircraft - Electric - Batteries & Chargers (FS/W) 4 Apr 07, 2013 11:27 AM
For Sale EC3 paraboard and a few EC3 connectors itsmillertime Aircraft - Electric - Batteries & Chargers (FS/W) 2 Feb 04, 2013 11:30 PM
Sold NIP E-Flite EC3 Connectors gabrielisrael Aircraft - Electric - Batteries & Chargers (FS/W) 2 Jan 13, 2013 11:16 AM