Building a Dynon Avionics Harness | CH-750SD Update (Ep79) 

A few thoughts about crimping D-Sub pins: 1. There's a knurled collar on the back side of the crimping tool that adjusts a depth stop. That stop should be adjusted to that the pin/socket that you're crimping is flush with the flat face of the tool. That puts the crimp indents in the correct place on the outside of the wire cavity. 2. The wire insulation should be stripped just enough so that when the wire is inserted into the pin/socket, the wire bottoms out before the insulation touches the pin/socket. If the insulation touches, you can't be sure that the wire is bottomed out. 3. There's a tiny witness hole in the wire cavity of each pin/socket. After crimping, you should verify visually that the wire is visible in the witness hole. This confirms that the wire was inserted deep enough to be properly crimped (assuming that the tool is properly adjusted).

The right connectors make all the difference in doing the job right and making it look like a professional job. I really enjoyed watching you demonstrate how this is done.

Hi Mark. Not a licensed pilot or a builder. Been around aviation most of my life. I've flown quite a bit and have a quite varied range of experiences. I got tied up with raising a family and simply couldn't afford the lessons. Figured I'd get to it when I retired. I was badly injured in a car wreck and developed COPD. Retired early but am unable to build now. I'm fine with flying as long as I don't have to walk too far. I always wanted to build and the advent of ELSA created a lot of great kits. I just can't hold up to build so I got creative and put my mechanical skills to use. I installed a rear end in my recliner and started watching others build. I get some sense of satisfaction from watching others build and the Zenith is my favorite. Chris got his kit just right. I am very much like you but just the opposite. My workbenches and shop spaces were always messy and cluttered but I could tell you where anything and everything was. I absolutely hated for anyone to move something. But I created many beautiful pieces of furniture, rebuilt motors that are still running great, and built many beautiful houses that I can go see today with curved staricases and detailed ornate trim. I look forward to each and every one of your videos and enjoy watching your mind at work. Looking forward to you completing your Super Duty and flying it. P.S. I like Mike Patey and Jimmy's Wofld too. Ever checked out Farmfox?

I thought I was going senile, putting something "away" in a "safe place". Only to hunt for hours weeks later, because I can't remember where that "safe place" was. Thanks for putting that concern of my mental state to rest, as I now realize I'm not alone in that mental conundrum. Cheers from Winnipeg.

Hey Mark!....you are more than welcome to some of my surplus OCD! I can tell you exactly which building, tool chest and drawer that my 1950s bent Craftsman screwdriver is in, and probably which direction it's pointed! I'm serious, it's a sickness! Anyway..love the flap switch idea. Thanks for the update and tips!

Quick thought on the flap switch; With longer screws for the face plate, you could make a small bracket/cage on each side that would prevent the switch from rotating too far

I fall victim to "I don't know where away is" as well. I invested in a cheap label maker to help me identify what I put in bins, cabinets, etc. It has saved me so much time, absolutely invaluable. For the DB25 connector, and all d-subs for that matter, I have found it beneficial to install all pins in the connector, regardless of connection. This helps prevent bending over a single pin when servicing. They are also easy to remove, so you can't put them away if you need them again, they will be right where you need them.

Nice to see (electrical) life in the airframe. Looking good.

Looks really nice. I too have fallen victim to cleaning up and losing things. Can't wait to go flying together.

Here is a quick story about pin connectors that happened on a Lockheed JetStar in 1967 . The engines were battery start . Pulled the plane out of the hangar on a cold Cleveland winter day . Hit start switch and nothing . Tried another engine and nothing. Pushed it back in the hangar to troubleshoot. Tried it in the WARM hangar and they would spin. Took it back outside and tried again - no spin. Found that the expansion and contraction of a pin connector was just enough to create the problem.

I love your methodical. It’s just good stuff

Maybe you could model that flap switch in CAD including a little hinge that keeps the lever in the same orientation. It looks quite simple geometrically. Then have it printed professionally by one of those online printing services like Shapeways. Looks like an hour or two modeling work and then maybe $30 to print.

The green-and-white was included in the connector kit because that's the proper tool for the contact gauge. Installing the pins are easy and can usually be done by hand, but you'll need the tool to extract them. Don't force the extractor and you'll get a lot of use out of that plastic tool. I think your flap switch is defective. Have you contacted the vendor?

Good catch on the ground wire. I missed it also.

Mark, if you bend {2 } 90 deg tabs and install them under the flap screws, (one on each side of the toggle) it will help to keep the toggle from rotating. I am talking half moons on either side.

You're CruZin' (see what I did there?) through that SD pretty quickly! Any chance of an S-21 build next?? 😉😆

Build a little guide on both sides of the flap switch

Have you thought about a service loop in the air lines to the AHRS? Up and down keeps any moisture that may accumulate in the line from reaching the AHRS units.

Hey dude. You probably have a video where you already answerd this question. What did you use for the instrument and switch labels? I am just about to start a build of a Bristell NG5 Speed Wing in the UK and your videos are really, really useful. Many thanks.

Next to your radio, I noticed a square piece of plastic with a zip tie on it. I am finding myself using these throughout my plane as well. In back of my mind, I am wondering about then longevity of the adhesive on these guys? When able, I have been placing a rivet in the center of these, but a lot of areas I cannot.

Great video thanks. Did you create a list of the current draw of each Dynon device you could share. I’m in the planning stage of my Dynon panel. I’ve got starter switch problems also, all fitted and wired but now the key won’t come out!! 👍

You can make two little guide bars to keep it from spinning maybe?

Is the electronic box of AHRS the probable failure mode or the tube pluging, icing. Is the marginal cost of a tube small compared the the electronics? Just wondering why nobody has redundant tubes?

Did you do the ground calibration for the ADAHRS? I think that needs to be completed first if you haven’t already. I never thought I’d tackle the wiring but after a lot of time reading and studying I’m going to go for it. I figured every wire out for my Dynon build and for a Garmin build. Dynon seems to have a easier system to understand. Now the engine company is going to take all the money I will save thanks to insane price increases. Thanks for the videos!

I am just starting planning of my panel. This is a super video Mark. What kind of device provides the "wig wag" signal to the lights? Where to find? I also routinely lose things because I forget where I put them. Its always an "obvious" place once I find them.

Are you gonna be down in Boerne,Tx for the zenith workshop ?

Do you have to build the wiring harness for most experimental? Or does it depend on Engine and Avionics choices?

Regarding that flap switch: Have you considered that Anti-Rotation Washer for Toggle Switch from SteinAir?

i have one of those away safe places that I don't know where it is

Mark, i found the flap switch, but i couldn't find the momentary down, off, on switch. Could ylu tell us where you found it, and a part number if possible? thank you, Thom Zenith 750

Stupid question: For the GPS 175 does it just need to hookup to the ARINC 429 and then it uses the Dynon GPS antenna or do you need a Garmin or 2nd antenna for the Garmin Nav?

The fact that your trim tab switch rotates shouldn’t be a problem unless it rotates 180 degrees.

Insertion and removal tool for you D sub. Please don't use capton wiring, teflon does not have the problems with wire fire travel. Capton uses Mylar covering.

You got the tool backwards. White side is removal, colored side is installation. That’s why the white side is wider, to push the internal locking tabs out of the way and allow the wire to be extracted from the connector. You can get away using it backwards, but the proper way is to use the white side for removing pins. Any AMM or general practices guide will tell you to use the white side to remove and the colored side to install. Just fyi.