|May 28, 2005, 07:08 PM|
Plantraco Tx Throttle Stick Fix !!!!!!!!!
A few people have been complaining about the throttle stick on the new Plantraco HFX900 transmitter. It seems like a nice product, so I thought I would share a method for removing the spring centering and extend the throttle range so the full travel of the stick is used to control the motor from full off to full on.
This will likely void any warranty with Plantraco.
This disables the left/right movement of the left stick.
This disables the easy selection of channel 1 or channel 3 on powerup
Do not attempt this unless you have lots of soldering experience.
Be careful not to burn yourself on the iron or the heated parts.
This will take a couple hours probably.
Soldering iron, desoldering bulb or suction tool.
Solder and flux
Usual hand tools.
1 4.99k ohm (5K) resistor, 603 or 805 size preferable.
1 16.2k ohm resistor, 603 or 805 size preferable.
Remove the AA batteries
Remove the 4 screws on the back of the transmitter
Remove the screws that hold down the large PCB
Desolder the red and black wires that go from the large to small PCB
Locate the throttle gimbal, note has only one trimmer wheel
Remove the stick tip on the throttle gimbal, pull straight off
Remove black paper disk
Turn over the PCB
Locate the 4 large and 6 small solder pads that hold down the gimbal
Add solder and flux to all 10 of the pads
Now carefully desolder each of those pads
If all the solder is not removed, add lots of solder and flux and try again
Wiggle the pins in each hole carefully, you can add heat
If a pin does not come loose, go back add solder, suck solder out…
Then wiggle out the gimbal assembly
Put a mark along one side and bottom to show the alignment of the parts
Locate 4 little metal tabs that are bent over, like on N-20 motor backs
Un-bend these 4 tabs
Remove the grey plastic back panel
Remove the black plastic disk inside the GREY plastic housing
Remove the spring under the black plastic disk
Set aside the removed black plastic disk and spring
Re-assemble the grey housing the metal gimbal assembly
Re-bend the metal tabs holding the parts together
Locate R2 and R3 resistors on the PCB
By adding solder to both ends of the resistor, and moving iron back and forth, slide each resistor off
Put the 4.99K ohm resistor in the R3 place, solder down
Put the 16.2K ohm resistor in the R2 place, solder down
Put the gimbal back in place and solder the 10 pads in the 10 holes
Screw down the PCB
Re-solder the red and black wires
Install the AA batteries and do a functional check
If the system does not appear to work properly, go back and check connections
Then you need to keep the left stick from moving left/right loosely
Solder a bit of brass or copper shim between the gimbal housing and the copper band
Or you can use tape or make a little plate with a slot to only allow the up/down stick movement
Put some tape along the copper band, overlapping so it rubs the stick for friction
Put the paper disc back
Install the stick tip
Screw the case back together
End of procedure
Hope you find this useful, I worked this out with my good friend Chuck Haverlah.
Thanks. –Matt Keennon
|May 28, 2005, 08:20 PM|
Thanks. You and Chuck have done it again. You guys are quite a team. Thanks for sharing. I just added this thread to the "micro thread index."
|May 28, 2005, 10:28 PM|
Joined Sep 2003
Koitchi has a description of how to modify a mechanically similar mini joystick to give non centering throttle and still maintain centering opperation of the left/right pot here :- http://www.oyajin.jp/~toko/pic/0046/index.html
|May 28, 2005, 11:21 PM|
Thousand Oaks, Ca
Joined Jan 2002
Thanks To Matt Keennon
Thanks to Matt Kennon -I just did what he showed me to do to make this change to the throttle stick. He worked out the whole procedure and then shared it with me and guided me thru the steps -step by step -to make this mod.!!!!
It works very well. I love it.
Thanks again to Matt -He is the man !!!
|May 29, 2005, 12:10 AM|
Instead of locking the left stick's left right movement, how about a simple low tech solution? Once the centering spring is removed, a couple of hooks on the face of the transmitter, above and below the stick, with rubber bands to center the rudder but not center the throttle seem doable. That way you still have four functions for the next generation receivers.
|May 29, 2005, 02:32 AM|
Thousand Oaks, Ca
Joined Jan 2002
Just did mech centering change per clipclop link
Thanks clipclop - I had looked for that info but came up short. So using your link as a guide ;I just removed the throttle joystick for the SECOND time in 12 hours and made the centering mode. It works well with the left/right function still centering- BUT- took me several trys to cut the plastic such that the throttle did not try to center from positions close to center AND since the stick travel is slightly shorter with this mode you may or may not need to change thr resistor values Matt and I used. I just moved the trim slightly off center to compenstate for the differance.
Just finished test flying under the street light and it worked very well .
After 50 years of flying without a centering throttle stick ; this now feels GOOD to me.
Now I can select Tx chs at power on by holding the throttle stick to left or center or right.
|May 29, 2005, 03:12 AM|
Don't worry about voiding the warranty - we can fix things for people fairly easily if they mess things up - we can repair any boo boo for our customers.
Having said that, unless your 2 hours of your personal time spent on doing this modification has no value to you, or you actually enjoy hardware hacking, I would like to point out that this modification is not needed - you can buy a Tx from us that has the non-centering throttle stick right now on our website http://www.plantraco.com
Again - We already have throttle sticks that stay where you put them. We went through the effort to make the non-centering throttle stick custom parts a long time ago.
The main reason we did not make 100% of our HFX900 transmitters with the non-centering throttle stick is because I ordered them with springs that felt a bit too stiff (in my opinion anyways). The throttle stick felt like it had a little bit of mushiness to it, and I made the decision to only make about 20% of our production units with the non-centering throttle stick, just in case people did not like the non-centering version "feel". I'll note here that nobody has noticed any problem with the non-centering version! They like the non-centering throttle stick - so I guess it is in the eye of the beholder. Only I notice the mild stiffness and mushiness of the non-centering throttle stick version and I should keep my mouth shut. The more I explain, the more trouble and mis-applied concern it causes here.
We made an adjustment to the spring tension of our custom non-centering gimballed part and future production runs of the HFX900 with non-centering throttle stick have the perfect spring tension that we have improved (at great expense).
I hope readers of my post here will take this information in the right way. I don't mind sharing some information about this issue with the readers here, we value the opinions of the members here. I have had good advice from several veteran members privately, who tell me that if we say too much here we just cause the RC groups readers to make a torrent of potentially misinformative posts. But I always like to set the record straight, as best I can.
Matt, I feel sorry that we have caused you to spend time modifying the throttle stick - I'd rather see another cool airplane from your building board.
Matt, we will send you some of our gear right away to check out - We'll send you 3 pcs of our transmitter - one with current centering stick, one with the current non-centering throttle stick and one with 60% spring strength non-centering throttle stick as well as our new PFM receiver and other goodies (4mm gearbox etc).
|May 29, 2005, 01:00 PM|
I am glad youar responding so quickly to user input. I wish I had known you had a 'standard' configuration available; I would have got one. I will most likely pick up another and save this one for powered gliders - I hat hacking hardware that works!
|May 29, 2005, 03:25 PM|
Thousand Oaks, Ca
Joined Jan 2002
Thanks to Koitchi and Clipclop
Thanks to Clipclop I found Koitcki's method to modify the spring assembly.
It is a little tricky to cut the plastic to the shape required as shown in the diagram that is opened when you click on the highlighted text below the second picture in Koitchi's link.
I found the trick was to check that the throttle stick did not return to center when placed near center position from either side.
Also note that I had to modify the other axis/"bail" in my stick assembly; not the one shown in the link because of the direction the stick is mounted on the PCB.
The finished mod works very well.
Good luck to you who try this.
Thousand Oaks, Ca
|Jun 13, 2005, 02:11 PM|
I am try this mod to turn a 4 axis game pad [ pc ] into a r/c transmitter substitute for FMS .
As I filed down the plastic I came across some embedded metal work and my plastic 'button' has almost come off. Did you find that happened to you ? mine will now stay put at both extremes but in the centre it still springs back to the middle.
Next I think I will remove the plastic and try to fix something in it's place ?
No idea what yet !
|Jun 13, 2005, 02:40 PM|
HFX900 Transmitter can already be connected to the FMS flight simulator. The cable is included with the starter sets, so you can use the same Tx you fly with for the wonderful Freeware FMS R/C flight sim input device.
|Jun 13, 2005, 04:14 PM|
I've been following the Plantraco threads closely of late. I will be ordering one or two systems at the end of the month. But I wanted to say now (and it has been expressed by others here already) that I think it is refreshing, encouraging, brave, and great that Bud and the Plantraco team are so responsive to its customers concerns and for Bud to tell us things just as they are. When was the last time you heard a mfg say "Ah don't worry about the warranty--we didn't design the perfect product, modify it and enjoy!"
Applause for Plantraco.
Las Vegas Realtor
|Sep 02, 2005, 04:12 PM|
Joined Nov 2002
I carried out your throttle stick conversion on the Planraco Tx and it's working allright, only problem is I'm still getting only the half throttle stick travel although I exchanged R2 and R3 with the values you named (16.3/4.99 kOhms). The soldering joints are all good. Any hints what could be wrong?
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