issues with servo tester

[Sam-Q]

hi guys I have been trying to use a servo tester with an auto and manual mode and when I try and use it it seems to make the motor act different than how it would with the wireless controller.

I have the servo tester going into a motor speed controller and a high current outrigger brushless.

When I use it it seems to only use part of the travel to do the same thing. Anyone ever use these things properly?

[Gunner]

Home made or purchased? Not very familiar with them though. Whats it for, and what is this wireless controller?

[Sam-Q]

I have bought a new Hobbyking in house model which I have not tried but the previous one was an ebay job.

When I say wireless controller its what you put in the car/plane/thingy that you plug your servos into, oh yeah they call them a received whoops.

These things are intended for replacing the receiver and replicating their function without the remote control bit. This is so I can use brushless engines made for planes on other things, it just so happens that these engines are independantly unbeatable in price, power, weight and size.

[Gunner]

http://www.modelflight.com.au/rc_model_electronics/jr_propo_matchmaker.htm

like this sorta thing, or something else?

I'm not very good with electric stuff, so i am a bit lost at what you are trying to do.

[Sam-Q]

could be, have a look at this one though

http://cgi.ebay.com.au/RC-Plane-Helicopter-CCPM-Servo-ESC-Consistency-Tester_W0QQitemZ290327253135QQcmdZViewItemQQptZAU_ Toys_Hobbies_Radio_Controlled_Vehicles?hash=item43 98da508f


this is the one I am using right now

[Sam-Q]

no sorry I am using this one right now:

http://cgi.ebay.com.au/E-Sky-RC-EK2-0907-Servo-Tester-for-Radio-Controlled-Toy_W0QQitemZ260571497717QQcmdZViewItemQQptZUK_Toy sGames_RadioControlled_JN?hash=item3cab4584f5

[Dool]

Late Reply.

Could be relating to where the power (current) is coming from. Does the ESC for the brusless motor have a uBEC? are you ading power through the battery connection on the tester?

May have to disengage the uBEC on the ESC.

OR try setting the tester to -100% travel, as most ESC require 'arming' at the lowest possible throttle position, to avoid hard (hi powered) starts.

Phil.

[Hyperslide]

I may be a bit simple but I don't understand what you are trying to do. Servo testers are for diagnosing if you have a dud servo or if the problem is elsewhere (receiver/speed controller/transmitter).

A dumb question but I will ask anyway - You are using a brushless speed controller (ESC) with your brushless motor aren't you? Are you using Li-Po batteries and what voltage are you running at?

Servo's usually run at 6 Volt and sometimes servo testers sometimes reduce this voltage further.

Without fully understanding what you are doing I cannot offer more help.

[Dool]

at a guess, i think sam is trying to use the tester to control the ESC, inturn to control the brushless motor.

If he is using the ECS's uBEC, voltage should not be a problem, but i am unsure if a servo tester can work like this.

if he is running a seperate batt pack, then the he may need to disable the BEC (disengage or cut the red wire).

also, as it seems to work (but not fully or correctly), it maybe that the ESC is not arming properly.. (set tester to -100% travel)

[Hyperslide]

One would think it would be a lot easier if he used a transmitter and receiver to do that. What is the benefit of using a tester in this situation?

Ok, lets forget about the ESC for a moment, what will he use to control the steering (rudder/aileron etc).

I'm still struggling to understand why he is doing all this in the first place when systems that are already tried and true are avaliable very cheaply.

[Dool]

knowing sam, it prolly isnt for flying!

[Sam-Q]

thanks for the replies guys and sorry for taking so long myself.

ok the way I had it hooked up initialy was using my remote controller unit which sent signal to a receiver powered by the usual 4 x AA batt, which then had a normal servo on one channel for testing and the cheapo brushless ESC on the other channel. When I ran it like this the servo moved as per usual and the brushless ESC also was linear and predictable. I had a 14.8V LiPo plugged directly into the brushless controller and I am unaware of it having its own battery eliminator.

I then unplugged everything and plugged it directly into the twin channel servo tester. In theory it should act exactly the same way as the receiver did with the same sort of control Vs servo movement. I used the same battery pack which I admit is pissweak and all. I have a new Turnigy servo tester that I will try to see if acts any different. I do now have a battery elimintator that will alow me to use the main battery back to power my servo tester and hence my brushless controller. This will let me take the battery pack out of the equasion and rule out that it's causing the issue. I am posting on here to see if anyone has specificly dealt with servo testers and maybe give some feedback on their quirks, I will make my own if I have to.

Hyperslide : Dool is right, I care very little for remote controlled vehicles however the off the shelf parts for them are increadibly useful, versatile and very affordable. Because they will all be hard wired I have no need for remote control, using servo testers is an old trick for running brushless controllers & motors with the minimum of parts. All of these involve using outrunner brushless motors on things. I have a few things I plan to use these parts for, one of them is converting a 240V grinder to work off a 14.8V 5A/h LiPo pack which is also powering my drill right now. Using this motor (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=7069) gives me almost the identical power and RPM as my Hitachi 240V grinder for a very minimal price. This will be tottaly superior to any of the units that can be bought and for a very small price seeing I will just swap batteries from my drill. I also want it for my trike (http://s-86.com/s-trike4.html) and possibly even for my 20V's water pump.

Hey you guys should see what powering a normal Nicad drill off a Lipo does, biggest kick in the balls ever!

[Hyperslide]

Ahhh, now I see. My mind was stuck in RC-application mode, not tinkering and testing mode :) . So your after something to control the variable speed of the cordless/grinder.

I have used servo testers a few times (in RC applications) but have found them to be inconsistent and not much use.

I hear you on the Li-Po swap for cordless drills. Heaps more grunt and a lot lighter to boot.

We are currently Radio Controlling a ride on Mower using a wiper motor for steering and we may convert it from a petrol engine to a brushless setup, and also a Self-Propelled push mower with articulating front wheels for steering as my kids are too young to mow the lawns yet...

[Dool]

Sam, deid you try starting at -100% travel?

possibly wrong, but it may be the ESC trying to 'arm' correctly.

Phil

[Sam-Q]

Hyperslide: thats pretty much the answer I was looking for, perhaps I need to make my own servo tester? your projects sound awesome, any pics? I like the LiPos because how simple they are to use, the bulk power capacity, price and less important for me the weight. I could before stop my Ryobi drill with my thumb and index finger in second gear, I tried the stunt with the new battery and I literally burnt part of my hand, which was awesome- well the non painfull part of it it. I currently am putting together what I need to use an 18.5V pack to run my leaf blower, whipper snipper, portable grinders, dewalt 3 speed drill and a dewalt 1/2" impact gun. I use a 14.8V for my Ryobi drill and I plan to use a combination of either one of these for my trike. It's probably not the best idea that I put the 5A/h in my back pocket to power my leaf blower but it's working for me for now till I build a battery enclousure on a tool belt.

Dool: I will give it a go soon when I have a moment, thanks for the tip

[Hyperslide]

Not much to take photos of right now. The ride-on is still getting stripped down, (tbh I would prefer to get the self-propelled (SP) mower working first, it is the harder of the two to do), and we are currently working on a skid-steer setup on the driven wheels of the SP mower to be able to steer. Impossible to do with the standard chain-driven solid axle so it looks like the best setup will be with an electric motor driving each rear wheel. Front wheels will be shopping trolley-like for tight turning and I would really like to be able to control the ride height remotely as well although this is a-whole-nother engineering exercise in itself.

I will keep you informed.