RC throttle interface build tutorial........

[AussieJester]

Haha yup, sort of the same boat, cept i'm a angle grinder/Welder type I must admit I enjoy a good hammering though

KiM

[adrian_sm]

I have done this mod with hall throttles too, worked a treat. Only issue was if the throttle was disconnected, current leakage would slowly cause the throttle to creep up. Not an issue if it is hardwired in, but definitely an issue if you have a connector that could come loose.

any ideas what would cause it? Didn't just stop either, it went pop Blew a cap on the tester...was Astro servo tester to, not one of the hk cheapies.

KiM

P.s smoked the hvbec to! Also still have that if pics help?

If it was blowing things up it sounds like it may have been wired up wrong. Those pics might help.

- Adrian

[jawshnitzel]

well, i ordered the new parts, and decided to leave it for a while..... then cleaning my shop up i came across the unassembled servo tester and put it back together... then embarassingly noticed i hadnt cut the tail off the jumper wire from under the board and it was JUST long enough to short to the case... ha ha ha... embarassing....

soooooo, i just tried it again, and it seems my throttle is working now. running the signal wire through about .4v - 4.6v... or thereabouts...

buuuuuuut, now my motor just jumps WILDLY back and forth when i touch the throttle. just like it did when i attempted to try the "auto" setting on the servo tester. jumped wild.

i havnt changed ANY wiring since it all worked on my porch, same motor leads still soldered to the CC160 leads.

closer... ha ha ha.... im going to do some more research on the matter. just thought id touch base on my progress.

shnitz

[hotschott]

Up!

I need your help because I want to use a servo tester with a hall effect thumb throttle on my new project.

The thumb throttle I bought has a led battery gauge, so is it possible to make this gauge work while using a servo tester?

This is the throttle: http://www.alibaba.com/product-gs/24146 ... kable.html

Sorry for my bad english

[Dauntless]

So this is one of favorite threads up here, for all the work being done and for the technical extremes of Sir Jeremy's exotic work and Hillhater keeping it simple. So I'm assuming this is the Magura Twistgrip in question. http://holmeshobbies.com/product.php?productid=280 And this is as cheap as I know a Hall Effect Throttle to come. http://holmeshobbies.com/product.php?pr ... =32&page=1

Here's where I figure I can put this to work. The motor and controller, with shipping, I think was just over $30. And just powerful enough for the 7 year old nephews' bike. Gotta build a little more powerful one for the Dad, at least a 24 v.

http://www.leaderhobby.com/product.asp?ID=9394001224131 Yep, 12v.

http://www.leaderhobby.com/product.asp?ID=9394001070004 I'm thinking you have to overkill with the controller size or it'll kill you.

eBay has the cheap servo tester, $2.93 with free shipping. http://www.ebay.com/itm/3-CH-4-8-6V-Mul ... 46022f4348 (Item number: 300684362568 if the link doesn't work.)

They're in another state, they gotta find their own bikes, but I pointed them in the direction of one of these for $50 on Craiglist. Great dirtbike, eh? Maybe they can find one for the not so tall Dad.


Less than $200 to build a dirtbike with a fairly light drive. Let's see you do that with a brushed motor. (Seriously. put it up there and I'll look.)

[Hillhater]

I think you may be more than a little disappointed with the performance of that 35mm motor on an Ebike.
Even on 12 v , its 1250kV will need an enormous reduction to get it to a useable rpm, and that reduction will consume most of its available power. Not to mention hooking up a drive to its 4mm shaft !
Go with a low kV 63 mm motor at least.
And good luck with those cheap aero ESC's !!

[Dauntless]

Oops. I think you missed where I said it's for a 7 year old. Disappointing performance is good for the moment. We can upgrade a few years from now. Or maybe his sister gets big enough to ride and he gets something else. I'm thinking 6364 lined up for his Dad. Yeah, I'd like a bigger shaft, but a small enough motor for a little kid means small everything. But it's an outrunner so there's screw holes on the revolving housing.

Ah, 1933. A time when a kid that age could have a motorcycle that went 40mph, even before the feet reached the shifter or the foot brake. As the article says, 'Keen Thrills.'

[Hillhater]

I just dont see that motor even moving the bike ......even with no rider. !
Why not just use a proven low kV, motor and restrict the power ?
That way you avoid the rpm reduction problem and get a durable motor.

[Dauntless]

I just dont see that motor even moving the bike ......even with no rider. !
Why not just use a proven low kV, motor and restrict the power ?
That way you avoid the rpm reduction problem and get a durable motor.

Well, I'm easily convinced. How do you restrict the power without creating a heating problem in the motor? And I read so much about the controller fried when it output less than the motor wanted to draw.

[Hillhater]

Most modern RC ESC's & Ebike controllers have programmable current limits .

[roblenderman]

Small issue I cannot figure out. I have the turnigy ST and I jumpered the signal pin on the input(throttle side) to the input on the ST POT(lead opposite the LED's when looking from top). This essentially means the throttle controls the speed but I can control the top speed via the ST pot since it is second in line after the throttle. This is a new build so I want to be able to control the top end if needed. You do have to clip the lead from the board to the POT so that the normal + voltage is not the input but rather the voltage from the throttle is the input. The issue is that if I turn the ST POT all the way up the motor spins at a very slow speed even though the throttle is not touched. The only way to get it to stop is to turn the ST POT down about 1/4. Then the throttle works fine BUT the measured watts on the motor at max with no load is 43 watts vs 53 watts when I just use the ST alone and jumper the throttle side + with the signal line as though it were full throttle and no resistence beign added. So why would the throttle being in place cause a slow turn on the motor of a few hundred RPM?

At first we thought the throttle was just not providing a low enough voltage to the ESC to stop the motor but it output roughly 0.93 volts at idle and the ST POT when used along outputs 0.89 which seems to be so close that it would not make a difference? Any idea how to stop the low end spin and still keep the high end speed? Obviously I could just turn down the max but who wants to do that?

Rob

[adrian_sm]

Sounds to me like you need to teach your ESC the throttle range.

Usually this is done by holding the throttle @ 100%, then powering up your ESC. It should make a few beeps, then turn the throttle down to 0%, more beeps. Now the throttle range should be set.

Hope it is just that.

Good luck, Adrian.

[mrderekcu]

Don't mean to post my problem multiple times, but this is the most relevant thread to my issues.

I bought this servo tester
http://www.hobbyking.com/hobbyking/stor ... duct=11780

Did the mod with the hall throttle, but it's actually backwards. Pulses seem to go from 2.0ms to 1.5ms. I put a servo on and forward with the hall throttle is actually backwards with a regular servo tester

I got a universal hall throttle from tnc scooters. I'm assuming I just need to go find a different servo tester? Only reason why I bought this different one was due to stock.

[roblenderman]

You nailed it. I put the St between the throttle so I could control the toop and and in testing I was starting everything with it turned all the way down. That threw off the range. If you just start with it turned all the way up or where ever you want to set the max it all works fine.

Rob

[roblenderman]

Ramping question now with this setup.

I have everything working perfectly but the startup is brutal with the 6s and 6374 on an 11T to 90T setup. I am able to slowly turn the throttle and get going almsot every time but I have to be careful. I built the throttle ramp found here http://www.instructables.com/id/The-New ... ignalling/

In sumulation it works perfectly but in real life it does not work. With the 100K the thrittle never works. With a 50K the throttl ramps but the max watts unloaded is 12 watts and normally it is 50 watts. The output throttle voltage is 4.7V but after it goes through this ramp circuit it is barely 1V with the 50K resistor and more like 0.5V with the 100K. Any ideas why this circuit would not work? I can always keep ging down on the resistor but the advice on the post and the simulations say that is not the right thing to do.

Rob

[adrian_sm]

I don't know about that circuit, but I do now one of these works well. It will allow you to adjust the ramp up, and ramp down. Just place it between your servo tester and ESC.
http://www.hobbyking.com/hobbyking/stor ... oduct=8863

[roblenderman]

Already orderd that just in case. Turns out the load is higher than expected and I need to drop the resistor to a much smaller number. I will test it today. Total cost to build is $0 if you have the parts and $1 if you don't.

Rob

[roblenderman]

So I got the turnigy ramping circuit. Seems to work with no load on the motor just fine but when I stand on the scooter and try to go it stutters. It starts to ramp and then seems to shut off for 1/2 second and then starts to ramp again for 1/2 second. Does this over and over until I release the throttle. System works fine without the circuit and have been riding for a month. I have to control the ramp manually but everything works. Even slightly turning the throttle with this circuit causes the stutter. Any ideas?

Rob

[adrian_sm]

Don't know never seen that happen, and I don't use them anymore so not sure if I can help.

It sounds a bit like the motor is loosing sync, which can happen when you accelerate too hard. If you think that might be true, then adjust the ramp up speed to slow things down. Also check that the throttle limits are still correct on your ESC, you know how you teach the ESC what max and min throttle is.Not sure if this will cause issues, but always good to get it done properly.

[roblenderman]

Not 100% sure how to set the throttle limits. I did try slowing it down but it didn't help. What is strange is that without the circuit things are fine. In fact it accelerates so quickly I will fall off the back if I stand up straight and don't hold on. It seems to only happen with the circuit and when weight is on it other than the scooter weight itself.

Rob

[adrian_sm]

Not 100% sure how to set the throttle limits.

Easy. Check the manual for your ESC but usually you just...... Hold the throttle at 100%, turn on the ESC, it should beep, then turn the throttle to 0%, more beeps. Done.

[renaatdb]

Hello,
I have servotester.
http://www.hobbyking.com/hobbyking/stor ... rvo_Tester
Also Hall sensor
I did the following
1) remove the potentiometer.
2) insert a jumper lead from the input signal pin to the potentiometer socket centre pin location.
3) reassemble and plug in your throttle.
But it did not work for me.
Testing the hall sensor give me 0,7 - 4 V
What else I can do?

Tanks

[garp]

This is great! Thank's all. Speaking as a newbie, this was one of the things I puzzled over.

[AussieJester]

Hello,
I have servotester.
http://www.hobbyking.com/hobbyking/stor ... rvo_Tester
Also Hall sensor
I did the following
1) remove the potentiometer.
2) insert a jumper lead from the input signal pin to the potentiometer socket centre pin location.
3) reassemble and plug in your throttle.
But it did not work for me.
Testing the hall sensor give me 0,7 - 4 V
What else I can do?

Tanks

I could be wrong often am, but i never had any luck connecting a hall sensore effect throttle to
a servo tester, actually when Hyena was over he tried and blew up a servo tester Dunno if it can be done?
I have always used Magura (pot) throttles...

KiM

[gwhy!]

Hello,
I have servotester.
http://www.hobbyking.com/hobbyking/stor ... rvo_Tester
Also Hall sensor
I did the following
1) remove the potentiometer.
2) insert a jumper lead from the input signal pin to the potentiometer socket centre pin location.
3) reassemble and plug in your throttle.
But it did not work for me.
Testing the hall sensor give me 0,7 - 4 V
What else I can do?

Tanks

I could be wrong often am, but i never had any luck connecting a hall sensore effect throttle to
a servo tester, actually when Hyena was over he tried and blew up a servo tester Dunno if it can be done?
I have always used Magura (pot) throttles...

KiM

It really depends on the servo testers design, you will need to test by looking at the pot in the servo tester to see if both ends of the pot are connected to the rest of the circuit first, then with a voltmeter mesure the voltage across the pot if it dont read a steady 5v then its not doing to work

edit: if only 2 connections from pot to servo tester then will only work with a pot throt, if 3 connections from pot to servo tester and there is 5v across the pot then a hall throt should work.