Posted by ivanc |
Feb 09, 2015 @ 10:20 PM | 3,796 Views
I recently got this 6FN. As it was on the no longer legal 72.240MHz frequency and has a broken throttle trim tab but had otherwise clean good sticks and pots I decided to convert it to DSM2 using a Spektrum DM8 module:
There were several issues using the 6FN as is for a DSM conversion:
1. Futaba uses opposite servo movement to stick deflection compared to Spektrum.
2. Old Futaba transmitters use 1310Ás as center pulse length, Spektrum uses 1500Ás.
3. The "half-shot" chain encoder uses pots which are offset from their center position.
4. Switch operated channel 6 would provide too much throw when re-centered for 1500Ás pulse width.
5. Futaba uses ATER channel sequencing while the module expects AETR which it converts to TAER.
6. Provide positive pulse PPM with open collector output for the DSM2 RF board from a Spektrum DM8 module.
7. Limited space inside the transmitter case for the DSM2 RF boards.
Well, the whole idea behind the conversion is to be able to use the transmitter to fly the BNF aircraft under the Horizon Hobby brands - HobbyZone, ParkZone, Blade and E-flite. To be able to do that I decided to convert the transmitter so it emulates a Spektrum DX5e transmitter while retaining most of the electronics and all control inputs. For that I had to do a couple of substitutions - the DX5e uses a 3-position switch for mode select on channel 3 and the spring loaded 2-position trainer/bind switch for panic/bail-out/SAFE mode on channel 6. To maintain...Continue Reading
Posted by ivanc |
Nov 01, 2014 @ 10:47 PM | 4,202 Views
This was another request from Tim S (Warjet1950). Tim didn't want to use the internal module hack to the Evo so I made an adapter board which plugs into the Evo trainer port and a Spektrum DM8 DSM2 or OrangeRX DSM2/DSMX module plugs into the adapter. This is not limited to the DSM modules - any RF module for Futaba 7U, 8U and 9C will work with this adapter, including the Futaba FASST TM-7 and TM-8, the S-FHSS TM-FH, the OrangeRX 433MHz modules.
The board is similar to the one I make for Futaba but it has the s-video style trainer port connector. Because the SD-10G does not provide enough voltage at the trainer port (only 3.3V) an external battery has to be used to power the module. In this regard the adapter is very similar to the Futaba "Z" style adapter. Binding and using the modules is identical as described in that thread but I'll provide links to those posts further down.
The SD-10G adapter board has a separate servo type connector (Futaba style) used to connect an external battery which powers the module. This battery can be a 2S LiPo or LiFe or even a 5- to 8-cell NiCd or NiMH. The adapter board provides protection from battery reverse polarity.
I can provide the adapter board with or without a 2.4GHz antenna and with or without a 2S LiFe external module battery. The antenna is used with the Spektrum DM8 DSM2 module as the antenna the module comes with is big and bulky and intended to go on top of a Futaba 72MHz transmitter using a plastic post. When using an OrangeRX module the antenna that comes with the module is used so you do not need the...Continue Reading
I received several requests to make a version of the adapter board which converts the signal from the trainer port of Futaba radios to the Spektrum DSM2 module to work with the Futaba "Z" transmitters. These are the 12Z, 14MZ and 18MZ.
The issue with the "non-Z" adapter board and the Futaba 12Z, 14MZ or 18MZ is that the adapter board takes power from the trainer port and sends it to the module. The module has a built-in voltage regulator for 3.3V which in order to work properly needs at least 5.0-5.2V. The trainer port of the "Z" transmitters does not provide battery voltage so an external battery power source is needed.
The "Z" adapter board has a separate servo type connector (Futaba style) used to connect an external battery which powers the module. This battery can be a 2S LiPo or LiFe or even a 5- to 8-cell NiCd or NiMH. The adapter board provides protection from battery reverse polarity.
Testing with a 2S LiFe pack:
I also tested the adapter board and module with a 5-cell NiMH pack and it worked without an issue.
This adapter board works also with all other Futaba transmitters with the micro (square) trainer port like the 4YF, 4YBF, 6EX, 6J, 7C, 8FG, 8J, 9C, 10C, 12FG and 14SG but it still requires the use of the external battery as a power source because it is not connected to the power output of the trainer port - the red wire between the trainer port connector and the adapter board is not connected.
If you decide to use the OrangeRX module you will need to re-flash it using this USB Firmware Update Kit. This allows the module to remap the channel assignment from Futaba's AETR to Spektrum/JR's TAER which is important if you want to fly Spektrum's UMX BNF models and your transmitter does not support channel remapping (4YF, 4YBF, 6EX, 7C, 9C).
What you need to do to use the adapter board with your compatible Futaba radio and the module:
The module I made for the 8FG would not fit properly on the 14SG for two reasons:
1. The 14SG is thicker and the module does not sit flush with the back of the transmitter because the antenna extension of the module case hits the carrying handle.
2. The trainer port on the 14SG is located in the middle of the back of the transmitter and oriented 180░ to the trainer port on the 8FG. Actually the trainer port location and orientation on the 14SG is similar to most other Futaba transmitters while the 8FG trainer port is the oddball one.
This time I decided to do the mod easier - as I could not use the JR module case (which has more space inside) I had two options - stuff everything inside the DM8 module case or make an adapter between the stock module and the trainer port. I went with the adapter. Here's the adapter:
I put heatshrink wrap over the board and heavy duty mounting tape between the board and the Spektrum module.
Posted by ivanc |
Dec 14, 2011 @ 10:42 PM | 34,785 Views
Do not do this mod unless you understand completely what is described below. If you have any questions then you are not qualified to do the mod yourself! For the same reason do not ask me questions regarding the mod as I will not reply.
If you decide to do the mod you are on your own and doing it at your own risk.
I'll start with a picture of the final product:
Check the replies to this thread for the progress on the project.
What is needed:
1. Futaba 8FG. Super or not does not matter.
2. Spektrum DM8 module for a Futaba radio.
3. Futaba trainer cord square-to-square for the square connector. A square-to-round cable can be used too as only one square connector is needed. But if you plan to mod more than one DM8 module the square-to-square trainer cord comes handy.
4. Any NPN transistor capable of at least 20V Vcbo and Vceo and 50mA Ic. I used MPSA06.
5. Resistor anywhere between 10 and 30KOhm. I used 20KOhm.
6. 5-pin gold-plated header. Needed only for the prototype. Afterwards the components will be stuffed inside the module soldered to the board.
7. One 2-position switch (SPST would do just fine). It is used to turn on and off the radio and module while the 8FG internal 2.4GHz RF circuit is not powered to save battery power. The power switch on the radio is left in the off position when used with the DM8 module.
8. Wire 20-22 AWG, preferably 4 different colors.
9. Some heatshrink tubing.
10. A good soldering station and solder. ...Continue Reading
Posted by ivanc |
Sep 10, 2006 @ 11:33 AM | 16,219 Views
S.A.D. stands for Society of Aircraft Demolishers . Each month our club elects a crasher of the month and he is given a S.A.D. patch. I've got 3 - one for my Hobbistar 60, one for the Cap 580 inverted "landing" at WOT and one for a spectacular midair between my Combat SPAD #1 and another Combat SPAD (the other guy won a S.A.D. patch too ).
BTW, these are not all the crashes I've had - the others were not so "spectacular" so I didn't win the Crasher of the Month patch . And I keep crashing...
I just received another patch (#4). For crashing the Cap 580... again.