What ESC for damped starting and stopping?

[David Hall 9]

I would like to find an ESC that will be better for my F5J type gliders than my present devices.

The ESC will draw 40-50A and, as they have a folding prop and drive through a gearbox, would be better to have a soft start option. As they have to brake when stopped, the normal braking on budget ESCs tends to be quite severe, so some softening of the braking will be needed.

I realise that many higher end ESCs might suit this use, but I'm looking for cheaper options. For other reasons (battery backup and weight reduction), I would chose an OPTO ESC.

The obvious choice is a BLHELI / BLHELI_S / BLHELI_32 ESC.

I've used some small BLHELI ESCs in my smaller gliders, but these are now pretty well replaced with BLHELI_S and BLHELI_32 devices, the S variant also becoming more rare.

Is there a preference for S vs 32 for my use?

[Phil Green]

If you cant find one, use a servo-slow in the ESC lead, preferably one with a selectable speed setting for each direction (slow on, immediate off)

[Dickw]

Posted by David Hall 9 on 24/08/2020 11:02:28:

I would like to find an ESC that will be better for my F5J type gliders than my present devices.

The ESC will draw 40-50A and, as they have a folding prop and drive through a gearbox, would be better to have a soft start option. As they have to brake when stopped, the normal braking on budget ESCs tends to be quite severe, so some softening of the braking will be needed.

I realise that many higher end ESCs might suit this use, but I'm looking for cheaper options. For other reasons (battery backup and weight reduction), I would chose an OPTO ESC.

The obvious choice is a BLHELI / BLHELI_S / BLHELI_32 ESC.

I've used some small BLHELI ESCs in my smaller gliders, but these are now pretty well replaced with BLHELI_S and BLHELI_32 devices, the S variant also becoming more rare.

Is there a preference for S vs 32 for my use?

Have a look at the YEP range as they are effectively the same as the YGE I use and have an adjustable bake speed if you use the programming card.

A spinning prop is an airbrake, so I want my props to stop spinning as soon as possible and use the hardest quickest brake I can get on my "geared motor" gliders - but that does depend on the strength of the gearbox and prop you are using.

An alternative is the ESCs from 4-max which also have adjustable brake strength when using the programming card.

For "soft start" I use a timed ramp up (servo slow) in my Tx.

I know nothing about BLHELI, so can't comment on that.

Dick

[Simon Chaddock]

David

I may be missing something but Is there a reason why you can't open and close the throttle slowly?

The 'severity' of the brake is proportional to about the square of the rpm.

[Frank Skilbeck]

David, one option if you are using a switch for the motor control would be to put the ESC on an aux channel rather than throttle and then check if your transmitter has the option to apply a slow to the control. I know on my MPX transmitters you can dial in a slow value, but that only works on opening the throttle and closing is done at full speed, but if I used an alternative control for the ESC I can apply a slow value in either direction. Although i must admit that I put my electric gliders motor control on a slider so I can smoothly power up and down.

[Richard Wills 2]

I can recommend the YEP ESC's, excellent esc for the money, well just excellent regardless.

[Steve Balaam]

FRSKY Neuron ESC's are reasonably priced and can be programmed whatever way you want via BL-Heli

[David Hall 9]

Thanks for your suggestions... I use OpenTx on my Taranis Tx, so could set up a slow response for the throttle.

My mixes for my F5J gliders are fairly simple, but there are a lot of them, making it all look complex. The throttle is run from the throttle stick. I use flight modes, so in one mode (power) the throttle stick is CH1 (THR), in the next mode, it is not assigned to any channel and in landing mode the throttle stick is the flap control via CH6 & 7 (FLA) (and CH8/9 in one plane).

A delay can be programmed in, but some very odd things happen when switching modes if a delay is configured. In one case, the throttle "blips" when it should have been off (-100). This is enough to get disqualified from that round as it is seen as a throttle use during the comp. However..... if the altitude/timer device (AltisV4+) switches the throttle off at the configured time or height, this will also be instant, so whatever has been set up in OpenTx is made redundant. .. so it is far easier to use an ESC soft start/stop than to have to deal with a whole bunch of config stuff that might not be possible to fix.

There are several OPTO ESCs available at the moment. I can program a BLHELI_S via a Naze32 but I might struggle with a BLHELI_32 as (I think) different hardware is needed to use the "passthrough" facilty of Cleanflight.

Does BLHELI_32 offer better functionality than the S for start/stop functions?

 

Edited By David Hall 9 on 24/08/2020 19:18:53

[Ron Gray]

I use Jesper's Soar OTX program for my F5J flown with a Taranis and it is superb! The motor is a Leomotion L3013-43550 with a 6.7:1 gearbox and a YEP esc and on either 3s or 4s I don't have a problem with throttle up (controlled on from momentary button and throttle on throttle / flap stick) or braking.

[Trevor Crook]

Another vote for YEP escs, haven't checked whether HK have them in stock at present. Worth looking at one of the YouTube videos on using the programming card.

[robert chamberlain]

Hi, I may be off track here(done that before) but there is a product called "GO-SLOW". A small box , a little bigger than a receiver which allows something like the flaps, controlled by a two or three position switch, to realistically go up or down at a scale speed.

[robert chamberlain]

Reference my last post, I will do some checking as to where I saw the Go-Slow and post the location if I can find it again. Maybe I can, maybe not, but I will search tomorrow. ---------------Bob C

[Frank Skilbeck]

Posted by robert chamberlain on 25/08/2020 08:16:23:

Reference my last post, I will do some checking as to where I saw the Go-Slow and post the location if I can find it again. Maybe I can, maybe not, but I will search tomorrow. ---------------Bob C

This one?

[Denis Watkins]

[Phil Green]

full circle

Edited By Phil Green on 25/08/2020 16:43:25

[David Hall 9]

Thanks to all for the suggestions.

I found this nice discussion on the braking options for BLHELI_32. It allows variable damping, apparently. 

Regenerative braking...wow! 

So, a BLHELI_32 device seems to be a good way to go rather than the more limited BLHELI_S.

Configuring the _32 is the next problem.... but that's another thread, I guess.

 

 

 

Edited By David Hall 9 on 25/08/2020 16:56:46

[robert chamberlain]

I finally found the "Go Slow" unit I was referring to before. Go to Sonic-Tronics / Mcdaniels R/C for several units they have. I think it was originally for gear and flaps ,but it may solve the jarring power of the motor on start up with a folding prop. Might give them a call in case I am wrong on this.-----Bob C

[Bob Cotsford]

I have a few Neuron ESCs and can't fault them. The S version is quite compact and has a 5A BEC instead of the 7A one on the larger Neuron but otherwise has the same features. You have a Taranis so if you use OpenTX 2.3.9 then you will get more telemetry than you will know what to do with. It's BL_Heli_32 programmable so you get the slow start, damped/undamped modes, current limiting etc. and it has a built in current sensor. The ESCs that I've bought from T9Hobbysport recently came with the USB adaptor to program them with included in the box.

[Bob Cotsford]

ps - BL_Heli_32 with undamped mode set to off stops the prop instantly on closing the throttle. That might be ok with the smaller lighter props used on a multirotor but it's a bit of a traumatic event with the 15" props I use on 6S. Even undamped mode and 50% braking is pretty abrupt for a 430kv motor and 15*8 prop!