This is a continuation of my Remote On-Off for a KR Timer thread. That thread had gotten rather long so I decided to start a new thread for the Hubin timer.
In the Remote On-Off for a KR Timer thread there is some discussion about weather or not a remote switch on a frequency other than 2.4 RC is legal for control line. At a contest it may well not be legal. In fact a remote stop function in stunt competition may not be legal at all. However for sport flying I don’t see any problem. The remote Key Fob is FCC legal. The 433 mhz operating frequency will not interfere with any RC or control line activity. So for sport flying and trimming a new ship it will add convenience and safety. Convenience because if trimming a ship you can abort the flight at any time to make adjustments. Safety because if you get sick, dizzy, or the airplane becomes unflyable you can abort the flight. Being able to abort may well save the airplane. This remote switch and a car key fob operate the same. Nobody objects to a car key fob at the flying field so it’s hard to see why he or she would object to a remote ON/OFF key fob. On top of all this it is plug and play. Use it for trim flights. Remove it for the contest flight.
I have never owned a Hubin timer so I ordered a FM-0c REM (with remote switch). I also ordered a one button remote switch from Amazon.
https://www.amazon.com/Wireless-Momentary-Transmitter-Household-Equipment/dp/B08B5W9SM9/ref=sr_1_20?dchild=1&keywords=fushionsea&qid=1595268282&sr=8-20This model remote is a momentary switch that acts the same as the push button switch on the Hubin timer.
I installed the Hubin timer in my 576 E-ringmaster. I set the RPMs to 9K and the flight time to 4 minutes. The delay start time is not adjustable on this model and is preset at 15 seconds. Using this setup I familiarized myself with a Hubin timer. It operates much I expected. When I plug up the battery the ESC emits several beeps letting you know that the ESC is armed. Next I pushed the Start button. After about one second the motor ran at a slow speed for about a second to signal that to Hubin timer has started it’s delay start sequence. Then 15 seconds later the motor came up to speed and ran for the set time. I then experimented to see if the Start button would also act as a Stop button. What I found was that when you press the Start button and the 15 startup delay is in progress pressing the Start button again has no effect on the timer. It marches on, starting the motor after the 15-second delay. However after the motor starts, pressing the Start button does turn the timer off and stops the motor. To summarize the push button does act as a Start/Stop button but the Stop only works after the motor is running.
If you are flying alone 15 seconds does not seem to be enough time to walk to the handle, pick it up and get the safety strap in place. If you do fly alone a remote Start/Stop switch would be a big help.
Attached is a Photo of the my Ringmaster With Hubin remote switch installed.
Next I wired up the remote switch with required connectors. Below is the Remote Start/Stop Switch Wiring Diagram for a HUBIN TIMER. I have flagged the 3 connectors that are soldered to the remote switch. Two of them are standard RC servo connectors, one female and one male. I salvaged them by cutting in half a servo extender lead. The other is a two-pin connector. I bought this one from my LHS. It was a JST power connector by Horizon. Any two-pin connector with a tenth inch spacing will work. I have been dealing with RC for years and have a good supply of servo connectors in my junk box. If you don’t have them on hand you can buy ten of them on eBay for under $10. Order Futaba style to insure the correct lead colors. Also of note is that good soldering skill is required for this project. Also required is shrink tubing.
The two-pin connector is soldered onto the blue and yellow wires of the remote switch. Cover joints with shrink tubing. It doesn’t matter which wire on this connector goes to which wire on the remote switch.
The female connector and the male connector create a jumper system that feeds 5 VDC power from the ESC to the remote switch. Basically the two connectors are wired up with white to white, red to red, and black to black. The red and black lead from the remote switch are soldered in with the red and black leads between the two connectors. Connections are covered with shrink tubing.
The length of all of these wires should be determined by the location of the remote switch on the airplane.
To install the remote timer you plug the connector with 2 wires in place of the start/stop slide switch that came with the HUBIN timer. You then plug the male female jumper between the 3-wire lead from the ESC and the HUBIN timer. Be careful that the polarities of these connectors are correct. In other words the Black wire must pass through the adapter and wind up on the HUBIN timer pin identified on the instruction sheet as black.
The one button momentary remote switch receiver did not come with a case, as did the two-button verity I used on the KR timer. I built a box out of plywood and balsa wood to mount the remote switch. The base was made out of 1/16” plywood with ears extending out each end to allow mounting with two wood screws. The rest is balsa wood. Box is lined with foam rubber and the lid is glued on. A sequence of photos attached in the next posting (More Photos) showing the process.
Attached is a photo of my 576 Ringmaster with the remote switch installed. By the way the remote switch with all its connectors and case weighs .46 oz. However the Hubin switch assembly weighed .22 oz. So the remote switch assembly added a net gain over the old switch of .24 oz. It is located near the CG and should not effect trim.
Final comments: I did the testing on a Hubin model # FM-0c REM. This timer has a remote switch making it easy to set up plug and play. Hubin has several models. Some are programmable and some have the Start switch soldered directly to the PCB. It is reasonable to assume that all of the Hubin models react the same to the push of the Start button and will stop when you hit the button again. So a remote switch should work on all models. However I did say assume…… For the models with the Start button soldered to the PCB it is possible to remove the start button and wire the remote switch in it’s place. This would be easy for me. I have been working on PCBs for 40+ years. If you have not done this before it can be a disaster in a hurry. At a minimum it will void the warrant. So once again, advice is worth what it cost you.
It all works well sitting on my work bench. Soon I will test this setup to see if it works in the air. I will then give a full flight report with pictures.