 |
| It's a lot of wire regardless of what choices made with component selection with tandem aircraft having just half the space to place that stuff in |
Overview
Wiring, according to "Kitplanes" wiring has finished many a builder off. Having reached that stage of this project, this builder has come close many times. This blog will cover some of the good, most of the stupid that the builder created to reach the point where connections to the Circuit Breaker Panel could be manufactured.
Comments
Estimated runs determined and installed, this was covered in very early blogs and at this end, I would do the same. It went wrong with the final mix of wires, this was a function of the "guesstimate" of the requirements for the central cores but did not allow for the inter-connections. This was due to a complete lack of any detailed design of the wiring, especially areas like the flap drive, controller, radios and stick.
The factory used a Flybox controller, and all those connections are completed at the RS232 port located at the rear of the instrument.
My choice of a separate module was a function of the panel being space poor and/or just the builder stuffing in stuff, and that has ramifications most that do not appear to later.
One choice that did work was the use of coloured wire. Still, it did create an issue in that many time the correct gauge was not on the shelf and supply was weeks away, white wire is readily available, and if doing it again, I would examine the use of 18/20 gauge white and a felt tip Sharpie pen to add a coloured stripe.
This was used when exchanging 16 gauge for two 18 gauge for the flap power, white as active and a black stripe was added to indicate earth by running the wire thru the tip of the pen. Black, black/white would be used for earth solely with red used for all actives.
The builder would try to use 18 gauge [10 amps] and 20 gauge [5 amps] and forget wire smaller than 22 gauge except for specialized installations, and larger sizes would use red/black and red/white striped to indicate an active and earth.
A series of terminal strips were used to allowing wire from various equipment to be connected to their relevant power supply being either a circuit breaker of gang strip for active/earth. This enables the looms to behind the panel to be linked with the looms from the airframe at any point of assembly.
The T shaped mount that the factory developed is a good idea as it allows a reasonable amount of area to mount the necessary hardware. On this install, the terminal strips were mounted vertically on 12 od x 20 mm high nylon spacers. These spacers are really good at creating more space by freeing up the deck of the main spine.
The negative is weight as the builder is sure that there are a few kilos of unneeded wire, terminals, brackets, and crimps. The cleanest method is to directly go-between the hardware and instruments, but diagnostics can be more challenging to undertake.
One of the few good ideas was looming the cables in the PPS sleeve, while a little time consuming it created a series of defined cables to connect to the various points on the aircraft and for 95% of the time they just drop in.
Finally, they just look right and to burn this much effort, aka time, there must be something at the end as a justification.
Even though the panel is analog, all the instruments use a DB port of 9 or 15 pins allowing ease of connection and facilitating panel removal.
Flying Legend has created as much maintenance access at the rear of the panel that would be practical and being able to put a panel of the bench in under 15 minutes just makes it all better.
To do this, every connection has to be a plug and preferably a DB - Why? - I have the tools. All the interconnections are then installed into the terminals strips creating ease of reorganization when required.
Another error was to use solder DB in the junction they made the work in the stick junction box a neverending nightmare. The use of the crimp pin type was considered but rejected initially because of the cost of the crimping tool, no change out of $US400.
In the end, desperate people will try anything, and the pin crimper appears to work well for 20/22 guage in the crimps, but everyone has to be checked as about 10% fail. The real benefit is being able to swap pins to fix those stupid errors, this was covered in a Facebook post.
Can a builder justify the cost of the correct crimper that a choice but so far so good?
All wires entering screw terminal block were fitted with pin sleeve that is crimped onto the end of the wire. The purpose is to protect the wire from the cutting action of the screw crimp.
Initially, I used solder plugs because they were available BUT wasted a bucket of time in just trying to sort out the interconnections. In the end, the junction box for all the switches on the stock was removed then a terminal strip added. The plugs used on the external connections changed to the pin type, again for ease of attachment and correction.
Would I use a junction box again, not if I could come up with a better idea, but at the time it seemed like a good idea?
The terminal strips were mounted vertically to increase the available space, initially, these were fitted directly to the central member, but it was found that mounting these on 20 mm long nylon spacers allows the wires to be installed freely at the base.
This frees the top enabling installation of the jumpers, which in turn allowed the looms to be tied to them with cable ties. The excess wire could be tucked under or run between rows freely.
A number of connectors were used in the assembly to allow various areas to be connected/ typically the wings to the fuselage, and circuit breaker panel to the main panel. For the smaller connections, Molex 2/3/4 pin were selected for their size and availability.
Most connections internally in the aircraft were AMP connectors to connect the circuit breaker panel and the wings with the Seal-All connectors.
These were used in external areas like the wheel wells and for the rudder tail light.
Comments
Where was the most significant error and loss of time - well, several places stand out?
1 - Continuity, this is the biggest issue for this builder, while basic schematics existed; they were necessary, and to create the physical world, it was at best "stick and cane design." Simply put, it means you know where you have to go, but as you are half-blind, you are going to trip up on every logistical on the way, with the lost time not worth talking about.
"The more paper, the better - a wiring diagram would be a lifesaver."
2 - Wire tracing, while the coloured wire was used it in places, became disjointed, defeating the purpose and in an area like the joystick/junction box created a total black hole for time with red to green, etc. Another area was the interface between the intercom, radio, and mike switches, just too many wire colours on the same circuit, creating a complex matrix even to record on the schematics.
"Keep the colour consistent as possible even if you have to ditch the wire supplied with the switches to colours at your disposal."
3- Labeling, here, the numbering system works well but was not used from the start, and when used, it may have been a little thin. Doing it again, I would be more verbose mainly were a lot of circuits mix. In the case of the stick, an "ELEV UP" at the plugs would have saved a lot of time. This does not replace the id numbers but should be at the start and end of every wire as far as practical.
"Start with a labeler from day one - these can be changed later, but anything that removes the guesswork with saving 10 x the time taken to install it."
The wiring exposed every personal fault I possess, and being raw at this type of work, the builder had no tools to stop time evaporating.
Put simply, I stuffed up and paid in time in hundreds of hours and frustration. The only key is to plan and to steal ideas. This was the one reason the wiring diagrams attached to this site will be updated as soon as practical to "As-built" in the hope that one or two may be of value to at least one person.
Define "as-built": Fewer stuff-ups
Wiring, according to "Kitplanes" wiring has finished many a builder off. Having reached that stage of this project, this builder has come close many times. This blog will cover some of the good, most of the stupid that the builder created to reach the point where connections to the Circuit Breaker Panel could be manufactured.
Comments
Estimated runs determined and installed, this was covered in very early blogs and at this end, I would do the same. It went wrong with the final mix of wires, this was a function of the "guesstimate" of the requirements for the central cores but did not allow for the inter-connections. This was due to a complete lack of any detailed design of the wiring, especially areas like the flap drive, controller, radios and stick.
The factory used a Flybox controller, and all those connections are completed at the RS232 port located at the rear of the instrument.
My choice of a separate module was a function of the panel being space poor and/or just the builder stuffing in stuff, and that has ramifications most that do not appear to later.
One choice that did work was the use of coloured wire. Still, it did create an issue in that many time the correct gauge was not on the shelf and supply was weeks away, white wire is readily available, and if doing it again, I would examine the use of 18/20 gauge white and a felt tip Sharpie pen to add a coloured stripe.
This was used when exchanging 16 gauge for two 18 gauge for the flap power, white as active and a black stripe was added to indicate earth by running the wire thru the tip of the pen. Black, black/white would be used for earth solely with red used for all actives.
The builder would try to use 18 gauge [10 amps] and 20 gauge [5 amps] and forget wire smaller than 22 gauge except for specialized installations, and larger sizes would use red/black and red/white striped to indicate an active and earth.
A series of terminal strips were used to allowing wire from various equipment to be connected to their relevant power supply being either a circuit breaker of gang strip for active/earth. This enables the looms to behind the panel to be linked with the looms from the airframe at any point of assembly.
The T shaped mount that the factory developed is a good idea as it allows a reasonable amount of area to mount the necessary hardware. On this install, the terminal strips were mounted vertically on 12 od x 20 mm high nylon spacers. These spacers are really good at creating more space by freeing up the deck of the main spine.
The negative is weight as the builder is sure that there are a few kilos of unneeded wire, terminals, brackets, and crimps. The cleanest method is to directly go-between the hardware and instruments, but diagnostics can be more challenging to undertake.
One of the few good ideas was looming the cables in the PPS sleeve, while a little time consuming it created a series of defined cables to connect to the various points on the aircraft and for 95% of the time they just drop in.Finally, they just look right and to burn this much effort, aka time, there must be something at the end as a justification.
Even though the panel is analog, all the instruments use a DB port of 9 or 15 pins allowing ease of connection and facilitating panel removal. Flying Legend has created as much maintenance access at the rear of the panel that would be practical and being able to put a panel of the bench in under 15 minutes just makes it all better.
To do this, every connection has to be a plug and preferably a DB - Why? - I have the tools. All the interconnections are then installed into the terminals strips creating ease of reorganization when required.
Another error was to use solder DB in the junction they made the work in the stick junction box a neverending nightmare. The use of the crimp pin type was considered but rejected initially because of the cost of the crimping tool, no change out of $US400.
In the end, desperate people will try anything, and the pin crimper appears to work well for 20/22 guage in the crimps, but everyone has to be checked as about 10% fail. The real benefit is being able to swap pins to fix those stupid errors, this was covered in a Facebook post.
Can a builder justify the cost of the correct crimper that a choice but so far so good?
All wires entering screw terminal block were fitted with pin sleeve that is crimped onto the end of the wire. The purpose is to protect the wire from the cutting action of the screw crimp. |
| This crimper is used with the sleeve crimps but has seen duty with the DB pin crimps shown above |
 |
| Adding the wiring to a DB15, four systems meet at this plug - this interaction has been the single biggest issue for the builder. |
Initially, I used solder plugs because they were available BUT wasted a bucket of time in just trying to sort out the interconnections. In the end, the junction box for all the switches on the stock was removed then a terminal strip added. The plugs used on the external connections changed to the pin type, again for ease of attachment and correction.
 |
| Checking the junction box for all the control sticks The addition of controls to the rear seat created more work than the simple "yes" agreeing do it took. |
 |
| Interconnections in the junction box |
Would I use a junction box again, not if I could come up with a better idea, but at the time it seemed like a good idea?
The terminal strips were mounted vertically to increase the available space, initially, these were fitted directly to the central member, but it was found that mounting these on 20 mm long nylon spacers allows the wires to be installed freely at the base.
This frees the top enabling installation of the jumpers, which in turn allowed the looms to be tied to them with cable ties. The excess wire could be tucked under or run between rows freely.
A number of connectors were used in the assembly to allow various areas to be connected/ typically the wings to the fuselage, and circuit breaker panel to the main panel. For the smaller connections, Molex 2/3/4 pin were selected for their size and availability.
Most connections internally in the aircraft were AMP connectors to connect the circuit breaker panel and the wings with the Seal-All connectors. These were used in external areas like the wheel wells and for the rudder tail light.
Comments
Where was the most significant error and loss of time - well, several places stand out?
1 - Continuity, this is the biggest issue for this builder, while basic schematics existed; they were necessary, and to create the physical world, it was at best "stick and cane design." Simply put, it means you know where you have to go, but as you are half-blind, you are going to trip up on every logistical on the way, with the lost time not worth talking about.
"The more paper, the better - a wiring diagram would be a lifesaver."
2 - Wire tracing, while the coloured wire was used it in places, became disjointed, defeating the purpose and in an area like the joystick/junction box created a total black hole for time with red to green, etc. Another area was the interface between the intercom, radio, and mike switches, just too many wire colours on the same circuit, creating a complex matrix even to record on the schematics.
"Keep the colour consistent as possible even if you have to ditch the wire supplied with the switches to colours at your disposal."
3- Labeling, here, the numbering system works well but was not used from the start, and when used, it may have been a little thin. Doing it again, I would be more verbose mainly were a lot of circuits mix. In the case of the stick, an "ELEV UP" at the plugs would have saved a lot of time. This does not replace the id numbers but should be at the start and end of every wire as far as practical.
"Start with a labeler from day one - these can be changed later, but anything that removes the guesswork with saving 10 x the time taken to install it."
The wiring exposed every personal fault I possess, and being raw at this type of work, the builder had no tools to stop time evaporating.
Put simply, I stuffed up and paid in time in hundreds of hours and frustration. The only key is to plan and to steal ideas. This was the one reason the wiring diagrams attached to this site will be updated as soon as practical to "As-built" in the hope that one or two may be of value to at least one person.
Define "as-built": Fewer stuff-ups
