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Sep 18, 2019, 08:47 AM
robinson727
Thread OP
Discussion

Wireless throttle control


Some of you asked me about our wireless throttle set up we are using on the Brodak BiSlob..
Here's a coupla pics.. The only caveat is to use metal gear servo (in case of over run) 2S Lipo only and use only a Clairostat 10K pot on the transmitter side. .. We tried a bunch of others and they were all to "noisy" ..
Our range is about 80 + feet with these modules but your milage may vary.. Thus far? Dead reliable..
Again.. This is a prototype.. Use at your own risk..
The modules are available on eBay .. and I made my own handle.. Note that pic1 is a composite.. The transmitter side uses the pot and the reciever side uses the servo.. The modules can do either, the jumper in the lower RH corner of the pic determines what the modules function is, TX or RX..,
Also notice that the RF boards are not installed on the red PC board.. they just push in and are specific to function, TX or RX..,
Here is the board PN's and yes.. the pic is Chinese but easy enough to figure out..
https://www.ebay.com/itm/113204661435

https://www.ebay.com/itm/MG90S-9g-Mo...72.m2749.l2649

https://www.ebay.com/itm/NEW-Revolec...72.m2749.l2649

Clarostat 928 531-103 10K potentiometer

E Flite 2S 800 mah lipo (transmitter on handle)
EFlite 2S 200mah lipo (aircraft reciever)

I forgot to mention.. There are 3 other slots available for the scale and carrier guys.. Use a trimmer pot and momentary "on"
push button switch or another pot.. Also.. With our lash up turning the pot body on our handle provides throttle trim. and the
trimmer pot on the board provides end point adjustment. (blue square thingy)


More in a bit
Al
Last edited by robinson727; Sep 18, 2019 at 11:45 AM. Reason: clarification and PN's
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Sep 18, 2019, 09:11 AM
Registered User
JMynes's Avatar
Can you provide links to the specific parts? I look at that first picture and have no idea what to search for. The website shown on the circuit board is all Chinese.

Why only a 2S battery? Is there a voltage limit on the electronics? I was planning to use a 4S for flight power, and just plug in the ESC in place of a throttle servo.

As you might guess, when it comes to electronics, I’m a pretty good plumber.
Sep 18, 2019, 09:38 AM
robinson727
Thread OP

Wireless throttle


1) PN's and links are at the bottom.. click yer clicker on the link.. Modules are about 23 bux a pop.. Takes a coupla weeks to get 'em.
2) If the board won't run on 4.8V from your ESC? (rated for 5 - 7.4V DC) Use an adjustable voltage regulator from Hobby King for your electric installation. . If you don't know how to do this get some help... Your LHS maybe. .. or when you get everything, stick it all in a box w/ return postage and send it to me and I'll lash it up for you.. ;-)
3) Use a servo buffer to keep the servo jitters down..
4) Clarostat 10K pot is a must.. Simply the best. Give Jameco or DigiKey a call and they will hook you up.. 3-4 bux.
Last edited by robinson727; Sep 18, 2019 at 11:38 AM. Reason: additional info.
Sep 18, 2019, 04:49 PM
Mike A.
Do you know what frequency these operate on? What if there are two or more transmitters on .. is there an interference issue or do they have some sort of binding to each other?
Sep 18, 2019, 04:50 PM
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coriolan's Avatar
Quote:
Originally Posted by JMynes
Can you provide links to the specific parts? I look at that first picture and have no idea what to search for. The website shown on the circuit board is all Chinese.

Why only a 2S battery? Is there a voltage limit on the electronics? I was planning to use a 4S for flight power, and just plug in the ESC in place of a throttle servo.

As you might guess, when it comes to electronics, I’m a pretty good plumber.
Pretty hard to get info about this product, the company making it is now defunct and the remaining stock is being flogged on ebay:
www.dhmcu.com
https://www.thanksbuyer.com/wireless...-control-34281
The picture show the connections in English, each unit can work as Transmitter or receiver depending on the jumper position.
The price is not bad for a Tx/Rx pair 4 channels unit but there seems to be problems in implementation
Wireless Follow Focus DHmcu from China Dunhuang electronic DH Studio (0 min 46 sec)
Sep 18, 2019, 08:02 PM
Mike A.
Thanks, coriolan. One of your links shows that the RF interface is 2.4 GHz. The reason I asked is that to use an RC system in CL Scale or Navy Carrier - at a contest - it must be 2.4 GHz based. Saves us the hassle of transmitter impounds, and frequency control methods. The video you posted is somewhat confusing - if the servo shown was a standard RC servo, there is no way it could rotate continuously like that. I suspect that with off the shelf servo's, that problem is not possible. Either that or his feedback pot is shot.

The other issue would be if two ( or more) set up as a transmitter would both be controlling any/all receiver units turned on at the same time. All of the sudden, you have the same issue as pre-2.4 Ghz interference problems.
Last edited by mikeainia; Sep 18, 2019 at 08:09 PM.
Sep 18, 2019, 08:17 PM
Mike A.
Quote:
Originally Posted by JMynes
Can you provide links to the specific parts? I look at that first picture and have no idea what to search for. The website shown on the circuit board is all Chinese.

Why only a 2S battery? Is there a voltage limit on the electronics? I was planning to use a 4S for flight power, and just plug in the ESC in place of a throttle servo.

As you might guess, when it comes to electronics, I’m a pretty good plumber.
If you use a 4s for flight power, your ESC will still only put out 5 - 7 volts to power the receiver and servo's. Some have a selectable output, but for a receiver running an ESC with no servo's, it doesn't much matter. The 14.8 volts is ONLY applied to the motor leads.
Sep 18, 2019, 08:19 PM
robinson727
Thread OP

Wireless throttle


1) The servo the guy is using is for robotics, the feed back pot is disabled from the gear box for continuous rotation.. Very handy BTW.. I use one to..
2) I don't know who told you the PCB was out of production.. I just got one... so don't spread BS OK? You don't know what your talking about so keep yer yap shut..
3) Interference? It's amplitude modulation.. And yer gonna fly more than one U/C model at a time? Get real..

Jeeeze.. You guys just look for trouble don't you.. I knew I should have kept my mouth shut.. It was a bad idea to write this up so just delete it all ok?
Vent closed..
AMF
Sep 18, 2019, 09:07 PM
Mike A.
I don't think anyone was knocking your setup - quite the contrary. It's quite a neatly done application. I was interested in it for use in contest setups - so if it's AM, it's not legal for contest applications, because if I'm flying your setup and you turn your transmitter on in the pits, you shoot me down. That's what transmitter impounds prevent. 2.4 GHz radio systems have different encoding schemes and the receiver must be "Bound" to the transmitter - ie: it will ONLY respond to it's own transmitter. So, modern 2.4 GHz systems are safely operated right next to each other without the interference issue.

Another issue would be that I have 6 (or more) carrier models - each with a receiver/servo or receiver/ESC. I only have two transmitters - handles with a pistol-grip car transmitter incorporated. Using these circuits, would I be able to get more than one receiver to respond to each transmitter or would I need to build a handle for EACH model? Since there is no real technical data on any of the sites above, it's impossible to discern. Again, not an issue for the sport modeller unless he wants to fly more than one model with the system, and use only one handle/tranmitter.

OK, that's your point #3. It's ok for sport flying, but not for contests.

Point #2 - I can't read all the chinese characters on coriolan's link, BUT your link to the Ebay site says "Four sold, three available". So maybe there are more available after that, and maybe not. My guess is that if more were available, they would probably say so.

Point #1 - The guy in the video keeps saying the PC Board isn't working, because the servo never stops. My point was that perhaps the PC Board is working, but the servo isn't designed or able to stop. The video isn't really applicable to the situation of a c/l throttle servo.

As far as I am concerned, all the questions asked were valid ones. I certainly didn't mean anything disparaging in my posts, I was just looking for more information.
Sep 18, 2019, 09:26 PM
------
coriolan's Avatar
Quote:
2) I don't know who told you the PCB was out of production.. I just got one... so don't spread BS OK? You don't know what your talking about so keep yer yap shut..
Al
No need to get so "vented" The company who made these closed down in 2018 and what you bought on ebay is just the liquidation of old stock. Lot can be found about the product with a simple search and some ebay vendors have indeed lot of them as well as other products from the same company.
https://www.google.com/search?tbm=is...RGcBLsQ4dUDCAU
Nothing wrong with your build, its only that this source is likely to dry out eventually so not a long term solution as a DIY path!
Quote:
You don't know what your talking about so keep yer yap shut.
This personal attack was uncalled for!
Sep 19, 2019, 07:34 AM
Registered User
JMynes's Avatar
Quote:
Originally Posted by mikeainia
If you use a 4s for flight power, your ESC will still only put out 5 - 7 volts to power the receiver and servo's. Some have a selectable output, but for a receiver running an ESC with no servo's, it doesn't much matter. The 14.8 volts is ONLY applied to the motor leads.
Okay then. As I suspected, the 4s will power the “receiver” through the ESC in the typical manner. I will also need a small battery to provide power to the “transmitter” at the handle, one that delivers 5-7v.

I fly CL at a shared RC field. Sometimes while CL is going on the RC guys are tinkering with their stuff. Was the question of interference definitively addressed? Since I will be only using throttle, it’s not the end of the world if I get hit with interference, but a sudden loss of power in the overhead stuff could be troublesome.
Sep 19, 2019, 08:00 AM
F2D Pilot/Mechanic
Bob Mears's Avatar
http://microflierradio.com/F2DCOMBAT.html This guy can probably build what you need
Sep 19, 2019, 10:19 AM
Mike A.
Quote:
Originally Posted by JMynes
Okay then. As I suspected, the 4s will power the “receiver” through the ESC in the typical manner. I will also need a small battery to provide power to the “transmitter” at the handle, one that delivers 5-7v.

I fly CL at a shared RC field. Sometimes while CL is going on the RC guys are tinkering with their stuff. Was the question of interference definitively addressed? Since I will be only using throttle, it’s not the end of the world if I get hit with interference, but a sudden loss of power in the overhead stuff could be troublesome.
The question of interference has not been answered, due to a lack of information available in the links and references cited so far. No, it would not affect you much if you get hit by an RC system being turned on while you are flying. However, if you shoot down an RC plane I'm sure your welcome at the field would be affected. That is highly unlikely however, due to the aforementioned "Binding" process used by even the cheapest RC transmitter/receiver systems used for RC operations. These little PC boards are likely not capable of outputting anywhere near the signal strength required for much more than the 80' - 100' range that the OP mentions.

Again, my concern is with flying at contests - for example, The Nats, where I am surrounded by other transmitters. The commercially available 2.4 ghz systems are pretty much immune to interference due to their encoding formats and their binding process. That is why the rulebook for control line Scale and Navy Carrier specifies that it be a 2.4 GHz system. The older 72 Mhz systems did not have that immunity. I am not able to discern what the interference rejection or encoding format of these little PC boards is.

So, for isolated sport flying they are a neat solution. It is quicker and easier and cheaper, though, to just form an RC pistol grip transmitter into a control line handle as we have shown several times in this forum. I am still intrigued by this system and will try to find more information on it.
Sep 19, 2019, 03:27 PM
robinson727
Thread OP

Wireless Throttle


We fly BiSlob the same time other folks are flying RC at the park and my Bro fly's it the same time I fly the other wireless rig.. but we tested first and tell everybody whats going on .. Hmmmmm.. No issues?? No hits.. ?? Gee.. Maybe I'm missing something here?? Has Moron #1 experimented with any of this ? No?
But he sez the modules have "Implementation Issues" .. Yeah.. It took me all of 15 min to get the first one together.. ISSUE? Ahhh.. Not..
Transmitter impound? For microwave? AM.. It's how the encoder works.. Everybody else is running freq hopping spread sprectrum.... Your an idiot..

Sorry I got pissed.. Normally I'm a lone wolf and hang out with only a few other modelers .. (or bikers) All I wanted to do was share what we had done when I was asked to but the trolls that don't build, experiment or fly much.. have to demonstrate there expertise.. on the keyboard..
Sorry.. I apologize but I never had any use for "Club Experts" most are zero's..

"Those that can't do.. criticize"
"Those that can't do either ?
Work for the FAA"
Sep 20, 2019, 06:04 AM
Registered User
JMynes's Avatar
Quote:
Originally Posted by robinson727
We fly BiSlob the same time other folks are flying RC at the park and my Bro fly's it the same time I fly the other wireless rig.. but we tested first and tell everybody whats going on .. Hmmmmm.. No issues?? No hits.. ?? Gee.. Maybe I'm missing something here?? Has Moron #1 experimented with any of this ? No?
But he sez the modules have "Implementation Issues" .. Yeah.. It took me all of 15 min to get the first one together.. ISSUE? Ahhh.. Not..
Transmitter impound? For microwave? AM.. It's how the encoder works.. Everybody else is running freq hopping spread sprectrum.... Your an idiot..

Sorry I got pissed.. Normally I'm a lone wolf and hang out with only a few other modelers .. (or bikers) All I wanted to do was share what we had done when I was asked to but the trolls that don't build, experiment or fly much.. have to demonstrate there expertise.. on the keyboard..
Sorry.. I apologize but I never had any use for "Club Experts" most are zero's..

"Those that can't do.. criticize"
"Those that can't do either ?
Work for the FAA"
In the interest of full disclosure, I’m the one who asked you to do a build thread on this system because it looked promising.

Myself and a few others have simply asked questions and made observations hoping to address various concerns. Nobody attacked you or questioned your abilities. Your replies to those inquiries have been pretty much over the top.

Rather than attacking and belittling us for asking questions perhaps you could look at it more like a teaching opportunity.

It’s called “discussion”


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