Dynam RC Flight Simulator USB is cheaply made. Wire in the cable broke internally, rendering the unit dead, and replacement necessary.
Little Weed really wants to learn RC planes. He has been through RC cars but got bored. The challenge of flight has drawn him in. Instead of destroying and losing many planes and lots of cash, it is recommended that we learn on a flight simulator program. To make the interface easier we bought a Dynam RC Flight Simulator USB, a simulated radio, which connects USB to your PC. At $40 I knew it was pretty cheaply made, and I was not surprised when it started glitching. We flew it for a few months before it stopped working, but from the beginning it has issues with reliably connecting to the PC. I knew something was wrong.
When I first bought it, after a day it stopped working, so I opened it up and found one of the wires had broken at a soldering point. A little solder later it was good again. To prevent the wire from pulling out again I used a tie wrap for strain relief to keep the wire tied to a plastic post and therefore minimize unnecessary movement.
After glitching more and eventually going dead I initially thought that a knot in the wire, used to prevent the wire from pulling out of the unit, was the cause of the wire break, so I cut the wire before and after the knot and soldered them together. This did not solve the problem.
The next step was to break open the USB housing. The USB housing also holds a small PCB and some electronics and an LCD, which lights when plugged in. The 3 conductor cable connected to 3 areas of the PCB. This housing is simply pressed fit together, so prying them apart with a flat head screwdriver was pretty easy. Using my multimeter and measuring from the USB to the motherboard connection, it was clear that of the 3 coloured wires, two were cut somewhere in the 4′ length. I would need to replace this wire. This original wire is 1/8″ in diameter. Each individual wire. red blue and black, is 1/32″ in diameter, has insulation and is compromised of 4 strands of copper wire. This wire should have been thicker and should not have broken somewhere in its length.
Dynam RC Flight Simulator USB. The cable connects to 3 conductors. Here is the non-label side with no conductors, shown here for reference. Photo by Don Tai.
On a Sunday the search was on for a 3 conductor wire in my house. The new wire should be 3 conductor, each conductor multi-strand and not solid, and the total diameter should not be too thick as to not fit into the radio shell or be too inflexible to use. Multi-strand wire is necessary because this cable will be repeatedly flexed in use and therefore should be able to take vibration. I could have gone to Home Depot and bought electrical wire, but I found an unused PC power cable, the ones with a rectangular end, that was the right length and diameter. This power cable is 3 conductor, 1/4″ thick and has a plastic wrap and each individual wire also has some plastic protector. Each conductor has about 8 strands of copper, double the original wire.
As the new cable was twice as thick as the old, soldering it to small conductors on the motherboard was an issue, so I used a small piece of the old wire still soldered to the motherboard and made a splice. This part of the old wire, after testing with a multimeter, was still viable. The old wire had conductors coloured red, black and blue. The new cable had conductors coloured black white and green. While we would keep the black the same we would solder the old red to white and old blue to green.
Dynam RC Flight Simulator USB broke: Here the cable connects the USB input to the motherboard. The spacing between connections is quite close so a thicker wire would be harder to solder and prone to shorting to other components. Each conductor is 1/8 in in diameter. Photo by Don Tai
I pried off the plastic input washer that allowed the cable to enter the radio through the antenna opening and hollowed this out with a file in order to accept the wider 1/4″ cable. The fit is tight, which will work as strain relief. The new cable was soldered to the old cable pigtail inline, with heat shrink for each conductor. Heat shrink is better than electrical tape and is probably overkill. I used a multimeter to test conductivity to ensure the new cable, splice and connection to the motherboard were electrically intact.
Dynam RC Flight Simulator USB. The new cable is spliced inline to the old cable, soldered and with heat shrink. Black to black, white to old red, green to old blue. Note the new conductors are twice as thick as the old ones. Photo by Don Tai.
Soldering the new cable to the USB unit was easier. The black conductor had to be longer so I cut back the white and green ones. Heat could be problematic with the PCB so I ensured the soldering tip was clean, hot and tinned. I also tinned the new cable conductors. The white and green conductors were very easy to solder as there was a lot of space available. The old wires went through a hole in the the PCB and were then soldered. Removing them was easy. The black conductor was easy to unsolder. When we first soldered the new black conductor the tab for the USB connection broke off. I had to reheat the black conductor and remove this tab. The black was rerouted to the opposite side and soldered directly to the required USB conductor. All three conductors were electrically tested with a multimeter right back to the motherboard.
Dynam RC Flight Simulator USB. The cable connects to 3 conductors. Note the label ‘fmsusb-2.0’, conductors red (left top), blue (left bottom) and black (far right). The LED is on the left middle of the board, just to the right of the conductors. Photo by Don Tai.
Buttoning up the USB in the plastic housing was easy and uneventful, as it only goes one way. One part of the USB shell is deeper than the other, so the thicker PCB sits into this shell. The two shells press fit together easily but tightly. The cable opening for the shell was exactly 1/4″, good for our new cable.
Before we heated the heat shrink I plugged in the USB to our PC and calibrated and tested the unit. It was all good.
Dynam RC Flight Simulator USB. The completed new cable spliced inline to the old cable and motherboard, soldered and with heat shrink. Photo by Don Tai.
Overall I knew this Dynam unit was cheaply manufactured and would eventually break, and I was not disappointed. Now with a new cable I hope nothing else will break. An electrical cable that breaks inline is inexcusable. They should have used thicker cable and built in strain relief but chose to not do this in order to increase profits. You do get what you pay for, but unfortunately there is now fewer choices for products as low price seems to trump everything.
Improvement: I added a chrome handle to the rear of my unit. I used a simple kitchen drawer pull in chrome, hole to hole, exactly 3.5″, for a perfect fit. The holes were already there but I had to enlarge them.
Dynam RC Flight Simulator USB Settings for FMS 8.0 flight simulator (great learning tool and fun): 4, 2 (inverse), 1, 3
Logitech Rumblepad 2 settings for FMS 8.0: 1, 4, 3, 2