HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 10, 2011, 02:05 PM
f5b-uk
Mike Seale's Avatar
United Kingdom, Dorset
Joined May 2002
3,063 Posts
Discussion
Throttle ramps - traction control for F5B

A year ago we were all switching the throttle on instantly but then it all changed and now everyone is using or experimenting with throttle ramps. Some are using a slow setting on their fancy transmitters. Others have even fancier ESCs that can do it and today I read in the RW4 thread that some receivers can be programmed to do it. So I've checked my gear and find that I can do two of the three options. I don't have a fancy ESC, but I can set a slow function in my transmitter (profi4000) as well as being able to set a curve and a slow function in the receiver (Jeti Duplex). So I'm wondering which is the best way to go or does it really make no difference? I'm tempted to programme the receiver because the programming with the Jeti box seems a little easier than profi4000 programming.

What are your thoughts?

Mike
Mike Seale is offline Find More Posts by Mike Seale
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 10, 2011, 03:08 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,105 Posts
Mike, i have been thinking about what is best also. Unfortionately i don't have the option to do anything on the RX and i don't know enough about programming option on Jeti RX but it sounds to me like it's better to split the work if possible.

I would put a small slow in the RX that gives a smooth enough start so that the drive system is always safe. No more broken props and gearboxes. This should be something in the order of 0,3-0,5 seconds.

Then anything after that, i would do on the TX so you can change it mid flight when you feel it is needed. Like switching between distance task and duration.

Makes sense?
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Jan 10, 2011, 03:55 PM
Registered User
Mark Haigh's Avatar
Barnsley, Great Britain (UK)
Joined Dec 2000
656 Posts
Quote:
Originally Posted by jjmouris View Post
Mike, i have been thinking about what is best also. Unfortionately i don't have the option to do anything on the RX and i don't know enough about programming option on Jeti RX but it sounds to me like it's better to split the work if possible.

I would put a small slow in the RX that gives a smooth enough start so that the drive system is always safe. No more broken props and gearboxes. This should be something in the order of 0,3-0,5 seconds.

Then anything after that, i would do on the TX so you can change it mid flight when you feel it is needed. Like switching between distance task and duration.

Makes sense?
On my Futaba Z9 I can set a ramp, but it also ramps down, so not turning off the motor instantly, but creating a 'brake'. With the Futaba 10C I dont know if this different. If I cant achieve what I want - ramp up, and no ramp down with the Tx, I am thinking about knocking up a ramp device from a PIC micro that sits between the ESC and Rx.

Are you creating an asymetric ramp in your Tx Joe?

Mark.
Mark Haigh is offline Find More Posts by Mark Haigh
Reply With Quote
Old Jan 10, 2011, 04:15 PM
Registered User
Joined Oct 2010
119 Posts
Quote:
Originally Posted by jjmouris View Post

I would put a small slow in the RX that gives a smooth enough start so that the drive system is always safe.

hy joe,

i have got the weatronic system, and my knowledge till now was that you have to prog everything with the weatronic TX modul by using the gigacontrol software (beside the programming of the transmitter)...i guess on the RX of weatronic you can only install new software versions...thatīs what i was also wondering about your post in the RW4 thread about the programming of the weatronic RX

maybe you are right and i am not on the actual state of play, i donīt know?

until now i am not using ramps, because it is not really clear to me how to create such a ramp... in the gigacontrol menu i have got for every function a diagramm with a linear curve where i can move the curve to make it in some areas flatter or steeper.

is a ramp we are talking about now a curve which is in the beginning flatter and becomes than steeper...you know what i mean?...if not i can make a print screen of a curve in the gigacontrol menu and post it here.


thx., thomas
blumebernburg is offline Find More Posts by blumebernburg
Last edited by blumebernburg; Jan 10, 2011 at 04:21 PM.
Reply With Quote
Old Jan 10, 2011, 04:19 PM
f5b-uk
Mike Seale's Avatar
United Kingdom, Dorset
Joined May 2002
3,063 Posts
I hadn't thought about the ramp down issue. I'm guessing that any transmitter or receiver based ramp is going to follow the curve at whatever speed you've set on the way up and the way back down again. Or will it? Whether it does or not, a slow 'off' at the transmitter is going to create problems at base A entry every now and then.
Mike Seale is offline Find More Posts by Mike Seale
Reply With Quote
Old Jan 10, 2011, 04:26 PM
Registered User
Joined Oct 2010
119 Posts
you mean if you creat a ramp with a softer start of the motor you will also get a softer brake?


thomas
blumebernburg is offline Find More Posts by blumebernburg
Reply With Quote
Old Jan 10, 2011, 04:43 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,105 Posts
Mark, yes you only want a delay / ramp switching the drive on, when going off you want nothing what so ever.

This is something i think a T10C can't do, this is one of the reasons why Roy bought the 12FG i believe.

I think building a little unit to go between RX and ESC is a very good option. You could even feed in a second channel to change the ramp for distance and duration. There might be a market for such a device!!!

Thomas, there is more information on the german forum i believe. I think they use a throttle curve function to give the ramp a different shape then just plain linear and then use a delay on the TX still.
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Jan 10, 2011, 04:49 PM
Tragic case
davidleitch's Avatar
Sydney Australia
Joined Feb 2002
5,866 Posts
On the Futaba 12Z there are separate ramp up and ramp down menus and the ramp can be controlled in two stages. I haven't used the MPX 4000 for a few years but my recollection is it was a very flexible tx and I vaguely recollect being able to set separate up and down servo speeds.

My own results with ramping have been dissappointing.
davidleitch is offline Find More Posts by davidleitch
Reply With Quote
Old Jan 10, 2011, 04:55 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,105 Posts
Here is a picture of my ramp as it was on the last competition of 2010.

You can see the blue line goes up in two different speeds to shape my ramp, then reaches full power. When motor goes off it goes almost instantly, there is only 1 servo pulse between 100% and 0% throttle.

I use the first speed to smooth the startup so that the prop does not break. Then the second speed i use to remove the stalled prop noises.

Joe
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Jan 10, 2011, 04:55 PM
Tragic case
davidleitch's Avatar
Sydney Australia
Joined Feb 2002
5,866 Posts
How much extra motor run time does ramping provide?
davidleitch is offline Find More Posts by davidleitch
Reply With Quote
Old Jan 10, 2011, 05:03 PM
sloping addict
Protocooler's Avatar
France
Joined Feb 2003
1,536 Posts
Thomas: Yes, but maybe not on all transmitters.
On MPX 3030, the SLOW feature is set by servo (in 0.2 seconds steps), thus there is no reason it would not work both ways
There may be (not sure) a fancy way of doing it on this TX using the virtual switch and swapping memory ,but that's pushing it really.
Protocooler is offline Find More Posts by Protocooler
Reply With Quote
Old Jan 10, 2011, 05:15 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,105 Posts
Quote:
Originally Posted by davidleitch View Post
How much extra motor run time does ramping provide?
I went from 21 seconds to 26 seconds by removing the stall of the prop. I could use more ramp and gain more motor time but there is little point.

Ihmo, i think that the energy that goes into the prop above the point where it starts to stall is pritty much wasted. You are getting a bad return on the energy spent. Better spend it later in the climb.
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Jan 10, 2011, 05:39 PM
Registered User
Joined Oct 2010
119 Posts
hy joe,
thx for sharing your diagram, what dimension is us?

on the highest point of the blue curve you reach 1820us, what means us?


thx., thomas
blumebernburg is offline Find More Posts by blumebernburg
Last edited by blumebernburg; Jan 10, 2011 at 05:55 PM.
Reply With Quote
Old Jan 10, 2011, 06:03 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,105 Posts
Thomas, us = nanoseconds and it has to do with pulse wipth of reciever signal.

If you have Unilog you can use your TX and RX and play around and you will see the same stuff. Don't even need a drive connected for this part.

If you don't have Unilog..... GET ONE !!!

Joe
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Jan 10, 2011, 06:13 PM
Registered User
Joined Oct 2010
119 Posts
thank you for your answer,


no, i have no unilog... i am waiting for the new schulze esc with data logging...maybe it will make an unilog expendable.


thomas
blumebernburg is offline Find More Posts by blumebernburg
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Avoiding throttle control accidents xiaoyu80305 Electric Plane Talk 15 Nov 19, 2010 02:20 PM
Discussion Traction control - anti wheelie devices Dez82 Motorcycles 70 May 16, 2010 01:09 PM
Help! Control linkages for throttle control: not enough throw arukum17 Beginner Training Area (Fuel) 11 Dec 24, 2007 11:56 AM
Dual Throttle control/separate throttle control duhaas88 Electric Ducted Fan Jet Talk 3 Oct 19, 2005 04:15 PM