Ground block on firewall

[tonyjohnson]

I am planning my electrical system. I plan to use the ground block sold by B&C Specialties. I would be interested in the opinions of those of you who are using them, and those of you who chose not to.

One of the things I need to determine is what size blocks I should use. A person at B&C indicated that many builders do not put a block on the forward side of the firewall, and ground the items on the engine to the engine block. A 24 or 48 connector block on the rear of the firewall should be used.

Any comments or opinions?

[dan]

I used B&C's 24/48 ground block and I'm happy with the design and that sort of thing. I used something like 30 tabs on the cockpit side, but I didn't use a single tab on the engine side. I had nothing that needed to be grounded firewall forward other than the engine itself. All of my transducers and what not fed back in behind the firewall to the engine monitor. My ignition system is mounted behind the firewall, etc.

So I have a 24-tab grounding block sitting there on my firewall not being used. That said, I do use it when timing my mag, or whenever I need to clip to ground. It's convenient in that regard, if not a complete waste.

While I could easily get away with just the 48-tab block on the cockpit side, I'd still need to have the brass bolt protruding from the front of the firewall where the short battery ground wire attaches. I don't regret having the extra 24-tab block sitting there unused. You never know...someday maybe it will be used.

Just my personal experience, fwiw.

)_( Dan
RV-7 N714D
http://www.rvproject.com

[sf3543]

The grounding strips that B&C sells are a nice idea but the price set me back a bit.
You can get fast on adapters from Steinair for 25 cents each. Each lets you attach two fast adapters. You can rivet these to an aluminum strip and screw/bolt it to any metal surface in your plane to make a ground block. I made several by riveting 6 or 8 in a row together on a strip. I also used a couple of singles by themselves by just screwing them down.
This is a whole lot cheaper than B&C's solution.

[Davepar]

Sounds like you're talking about these:



SteinAir also sells these strips for $1 each that have 10 fast-on terminals:



I bought a few of them and plan on using #6 screws to attach them directly to the firewall.

Dave

[szicree]

I've got no great advice on the ground block thing, but as somebody also at the electrical stage I can whole-heartedly recommend a software called ExpressSch. It's available for free at http://www.expresspcb.com

This thing allows you to design and print your wiring diagram and comes out real nice. When you need to make changes, it's all just cut and paste. There is a bit of a learning curve to climb, but it's worth it. I can't imagine doing without it.

Steve Zicree
RV4

[Davepar]

I've seen a few people suggest that program. It looks pretty cool. Has anybody made a library of symbols for common aircraft items, like contactors, fuses, lights, etc.?

So far I've just been scribbling on paper, but I'd like to transfer everything to CAD eventually.

[tonyjohnson]

I have downloaded the ExpressSch program. I became a bit frustrated with it because I could not find the symbols that I needed to design my electrical system. I know that you can custom make them, but it takes a lot of time. If anyone has a library of the symbols that we RV folks need, I would very much appreciate having them. Then the challange will be in how to import them into the program. I'll cross that bridge later.

Thanks to all who have posted so far in response to my inquiry. The information has been very valuable. I plan now to buy the parts from Stein and make my own ground block.

I am also intrested in knowing what tools I need to install my electrical system...crimpers etc. Any suggestions would be appreciated. If any of you have completed your wiring and would like to sell your tools, let me know.