Paul B & Braedin B (GliderPilot & Glydrfreak) Flights & Build Modifications

I think we are pushing the limit of wire length between the batteries and ESCs. Remember that long wires cause voltage spikes because of induction and that’s the reason why ESCs have capacitors in them. But those capacitors aren’t enough to support extra long wires. I’ve tried to keep my wires as short as possible including the leads of the batteries (this also keeps them out of the props). After I added added wire to connect two more batteries (total of 6) I had an ESC go bad on my first flight with that setup. I think the extra wire pushed it over the edge in combination of one year worth of previous wear from voltage spikes.

I replaced the bad ESC and added two more capacitors in parallel as close as possible to each ESC. The capacitors are identical to the ones inside the ESC. I covered the solder connection with liquid electrical tape and then used some 3D printed parts to secure them.

Here are the files:
Capacitor Holders - Top.stl (212.6 KB)
Capacitor Holders - Bottom.stl (190.3 KB)

Here is a link to the capacitors:
http://d.digikey.com/WS09IpX0N0g0K7k00RHoa01

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I saw the following… This guy combined a few BMS to get all cell voltages! Expensive and still not enough space on the display…


Looking forward for a solution from Pdwhite or you…

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I think the same and commented about this in the forum. If you use more than 4 Lipo’s, the wire
length is just too long. I bought these 63 v 5000uF (5x1000uF) Capacitors and will solder them to my ESC’s just to be on the safe side.
Open%20ppg%20electric%20313

Keep up the good work!

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I don’t want to display all cells. I only want to know the lowest cell and maybe a graph of all cells as a baseline for comparison.

@GliderPilot

On the picture with skies where you tested voltage alarms -

As you could not hear it would it be good if the throttlecontroller would vibrate shortly while the beep? My remote of the drone does so i like it.

Those alarms are a separate off the shelf item that have no way of being connected to the system controller. A custom monitoring system could feed a signal to the controller and make it vibrate. My plan is to have a display on the gooseneck bar that will flash to get your attention.

Is the low voltage alarm on your drone a separate system that could be purchased and adapted to OpenPPG or is it part of your drone?

No its part of the prebuild drone:

I hope that maybe in batch 4 that i have just ordered yesterday they could integrate it to the new alarmsystem…

Here you can see and hear some alarms

That concept is really good but it doesn’t help us that it’s integrated into your drone and can’t be purchased separately. Did you order the BMS with your batch 4? That will communicate individual cell voltage to your controller.

Just to be clear… OpenPPG shows system voltage on the controller. The thing it has been lacking is individual cell voltage which will be part of the batch 4 BMS. I added the alarms for now to let me know if I have a low cell.

Yes i did order the baterymanagement too.

I just thought when the droneguys can build such a system someone here could do it too…

I did read your comments about waiting for batch 4 or trying something right now on your own…

And you are right the lowest cell is the most important…

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Why 5000uF vs Paul’s matching 330uF?
Cheers

Did you 3d print the black circles for the black wires? Do they connect to the flush mount plug?

I soldered a 1/4”-20 brass bolt to an Xt 150 connector. I ran a tap into the connector first because the bolt was slightly too big. After soldering I cut it to the right length. Now the wires bolt directly to the connector with brass nuts (zinc plated nuts shown in the picture but I used brass). Now the connector cover is part of the surface mount holder.

Here are the files:
Xt 150 Mount Black - Face.stl (197.9 KB)
Xt 150 Mount Black - Middle.stl (141.5 KB)
Xt 150 Mount Black - Base.stl (304.1 KB)
Xt 150 Mount Black - Two Wire Cover.stl (293.2 KB)
Xt 150 Mount Black - Three Wire Cover.stl (316.2 KB)

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This is the thread with all the links to read>

2 x 330uF Capacitors = 660uF / 220uF for every 4 inch extension of battery cable!

I searched for 7 x 63V 330uF capacitor packs (2310uF) and they are not available, but the
63V 5000uF packs were available and so I bought them. Are they overkill - maybe, but I am on the
safe side.

When I build my batch4 I will use 100A ESC’s and thinking about putting the ESC’s inside with
fan blowers…

Hello Paul,
I want to order a few parts at 3d hubs from your designs…

Is this material/infill/layer height correct?

Thank you for your time…

I ordered the parts in PLA / 100% infill / Layer height 200 in black.
Here are the prices I paid in $ - I will report back how the quality is when I receive them…

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I’ve used 3D hub many times for parts for openppg in pla, they turned out well for me.

Dang thats a lot of cash for those, I could print them out for you free plus shipping costs

I edited Paul’s capacitor holder a bit so it could stay bolted to the arm.

Connector Cover - Bottom v2.stl (54.6 KB)

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The battery incidents I am familiar with were the result of poor manufacturing quality and quality control systems. In general, Lipo are considered fairly safe from what I’ve read. (more safe than Li-on)
I believe the reason they are so heavily used in EPPG is because they have a very high discharge rate, which is needed to deliver the power PPGs need, and there aren’t many other options out there. Most of the other electric options are far too heavy which would result in increased wing size/drag requiring bigger motors and more batteries.
Someone just posted about the new Aerostak H2 power cells which are designed for aviation… I’m really interested to learn more about that. Previous power cell designs have been far too heavy to be viable… this one’s just going to be really expensive I suspect :wink: (Entire power cell weighs less than 2lbs… fuel would be another 15lbs or so)

Paul,
I’ve been trying to locate these on Amazon, but can’t find the same size as you used. Do you have an item number? They only have 35 mm that I can find. Thanks.