[NSRCA-discussion] Braking question

Tue Mar 1 17:18:05 AKST 2016

Yeah but how does all of that apply to braking? Under non-braking conditions the motor speed is assumed to be directly related to the commutation rate. The only tricky part is getting it all to start moving. You sometimes see speed controllers that have problems doing this but for the most part – on airplanes anyway – it’s not much of an issue. Braking is a lot different. Maybe I’m over-thinking this – you certainly have a LOT more experience tuning Pattern motors  & speed controls than I do. What gives you the most difficulty when you’re tuning the braking parameters and why? I’m going to have to learn all of this the hard way this year. J

John Pavlick

Cell: 203-417-4971

idslogo2

Integrated Development Services

From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Dave Lockhart via NSRCA-discussion
Sent: Tuesday, March 01, 2016 8:48 PM
To: 'Jas'; 'General pattern discussion'
Subject: Re: [NSRCA-discussion] Braking question

The rate of commutation increases as RPM and pole count increase.

If an ESC can commutate at say 180,000 times per minute, it could run a 4 pole motor (geared inrunner like Neu) at 45,000 RPM or a 28 pole motor (some of the Q80s) at 6,428 RPM.  In practice, if an ESC can not commutate fast enough, it may still work ok at partial throttle, or it may behave erratically throughout the throttle range – hesitations, stuttering, surging, etc.

Regards,

Dave

From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Jas via NSRCA-discussion
Sent: Tuesday, March 01, 2016 2:34 PM
To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
Subject: Re: [NSRCA-discussion] Braking question

Only thing is the OS/Futaba esc's don't like 28-pole motors. Not sure why.

Sent from my iP

On Mar 1, 2016, at 1:35 PM, David Harmon via NSRCA-discussion <nsrca-discussion at lists.nsrca.org> wrote:

Hi John….could be but the OS 1100HV and Futaba MC 9100A work great without screeching or any other operational problems.

The brake is very effective and I have had the brake setting adjusted between 50 and 90 on various 2 and 3 blade props as large as a Mejzlik 22 x 12 2 blade and Mejzlik and Falcon 3 blades.

The hand held ‘loader’ is small enough to put into the transmitter case and you can make quick changes at the field between flights without a computer or other hardware.

Both ESC are clones to each other…they look exactly alike except for the mfgrs sticker.

The loader is also clone across both mfgrs and operationally are exactly alike….in fact I have only one loader and use it on both ESC.

All available at RC Japan….tower does not have them anymore because they said sales was too slow…arrgh

I am using the Plettenberg Advance motors at 15 degrees timing.

73

David Harmon

K6XYZ

Sperry, OK

From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of John Pavlick via NSRCA-discussion
Sent: Tuesday, March 1, 2016 12:19 PM
To: 'General pattern discussion' <nsrca-discussion at lists.nsrca.org>
Subject: Re: [NSRCA-discussion] Braking question

The reason this is so touchy BTW is because you guys are using sensor-less brushless motors. Commutation takes place in the speed control. This works fairly well when the speed controller is driving the motor. When it’s the other way around however – not so much. I bet if someone came out with a motor that had position sensors and a really expensive speed controller to drive it, more people would get  interested in Pattern again… LOL

John Pavlick

Cell: 203-417-4971

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Integrated Development Services

From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of David Harmon via NSRCA-discussion
Sent: Tuesday, March 01, 2016 10:28 AM
To: 'Jon Lowe'; 'General pattern discussion'; 'Jamie'
Subject: Re: [NSRCA-discussion] Braking question

This is exactly my experience as well.

David Harmon

Sperry, OK

From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Jon Lowe via NSRCA-discussion
Sent: Tuesday, March 1, 2016 7:48 AM
To: Jamie <jstrong49923 at gmail.com>; NSRCA <nsrca-discussion at lists.nsrca.org>
Subject: Re: [NSRCA-discussion] Braking question

ESC dependent. Castle ESC braking doesn't work well over 30% in my experience, without screeching. I set my OS controller at 65%, and it works fine. Jason goes as high as 90% with an OS. Some other controllers don't work well with braking at all, such as the YEP controllers from HobbyKing.

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