Greg's Batch 4 build, maintenance, repairs, upgrades

…exactly what I used to do with model airplanes. Disaster there resulted only in the fun of getting to repair your aircraft. Still, things were learned! :slight_smile:

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Thank you. Very helpful.

For the record, at 4500 feet my batch 2 will draw more amps than the ESCs are rated for even with the standard propellers. When I bought mine I thought I was going to need a higher pitch because of the altitude but I’m glad I didn’t get them. If I overdraw at my altitude then guys at sea level would overdraw even worse. The overdraw of amps was fixed with batch 4 with the lower KV motors to allow higher volts and lower amps.

I don’t totally agree with your “recipe for disaster” statements although you did make some good points about flying with instruments, which we do. I have modified mine to display amps while I fly and batch 4 does that as well. As long as you operate within the amps and volts the speed control is rated for it won’t hurt anything to change the pitch a little. Changing the pitch is simply an adjustment to get the desired amp draw. It really is that simple as long as you carefully monitor amps and volts. It’s not a total redesign… it’s simply the next size up or down of pitch. If you run the amps too high you will fry a speed controller so don’t do that… but even if you do that’s not a disaster, it’s a 60 dollar part.

With that said, always fly like you know your motor could quit at any moment. If a motor goes out you should always have enough altitude to glide to a safe landing zone. That’s my number one rule no matter how much I trust my equipment.

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Full power static (leaning back) my 150kv motors, 12s batteries, and stock 22X10 props, draws almost 220 amps at sea level, 5C, probably close to standard pressure :grin:. Have not flown enough to get a estimate of my cruise power draw. Climb is good enough to get clear of the trees.

Found myself doing that automatically. The little field I’m at here is surrounded by bad choices so I can’t really go anywhere from it. Here’s a couple views of the area.


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Got a third flight in. 15 minutes. I’m charging to 4.1v / cell only. Hopefully my expensive batteries will last a couple years. Full power climb was showing 220 amp draw on the second climb with warmed up batteries. Level flight seems to be about 150 amps.

Looking at some video my helper got from the ground and reviewing a couple pics. It seems my thrust angle is downward under power. Here’s a close-up from my first flight. Pretty sure I was under nearly full power. How does this angle look? I’m getting a nice straight forward push under power with no pitch-up at all. Kinda like how my high wing model airplanes used to be setup. Some down thrust. This looks maybe excessive? I’m at the rear hang point on the arms. Move to the center?
closeangle

That looks terribly uncomfortable as well as inefficient. You don’t want any down thrust. Should be reclined about 5 degrees. More than that can be dangerous with a single prop but with counter rotating props you could go back even more for comfort.

Thank you for confirming my thought. Definitely going to move to the center hang position before next flight.

I’m 190 lbs and am very comfortable using the front hang points. I started with the center ones, but I was sitting straight up while flying…it was uncomfortable.

I’m around 170 plus coat and boots this time of year so definitely I’ll move to the center and feel it out. Weather has been IMC and rain so I’m grounded for a while.

Got a short eight minute flight today. Way better from the center hang slots on the arms! Got into the seat and settled in to enjoy the scenery a bit. Fresh snow on the mountains. Launched easier too. Landing was terrible. So comfy and focused on the spot I forgot to lower the gear so powered up and landed long (on my feet).

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Can you show pictures, of how you have changed the hangpoint position?

I am using the softlink, pushed through the bigger center hole in the arms… and I don’t see how you would be able to push the softlink through any of the other, smaller holes…

I use the Dudek soft links that I purchased from the OpenPPG store. Here is a photo of mine in the front position. I hope this helps.

Per 1066’s pic. You should be using one of the three oval holes, not the triangular ones.

Heck, that picture helps tremendously!!
I am indeed using the dudek softlinks as well.

But it seems that I am using (can’t confirm right now, posting this from the office)
the largest triangular hole, instead of those oval ones.
It seems I never really paid attention to that, but I will correct this ASAP.

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Got a couple more flights in this week. Just practicing approaches to my field. It has become clear that I need a better/faster battery strap-in setup. Thinking I should strap them together at home then strap the set onto the frame at the field. It’s just too much fiddling at the field strapping in four individual batteries.

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I didn’t like attaching individual batteries either, so, I created my own version of Rob Catto’s (SimLoop’s) battery mounting system. I had a 3mm CF plate cut to act as a “battery plate”. Plastic Spider ( great3d.com ) took my file and had it to me in about three or four days…very fast. I put a round (top position) and a triangular (bottom position) key on the back of the plate just to let me know when I lift the assembly into the proper position…and also to hold it a bit while I strap it down to the back. I installed 4 round spacers just to lift the plate above the bolt heads on the back of the OpenPPG. ( They are 2 or 3mm shorter than the “keys”. ) At the present I’m using a Cobra quick release buckle at the top that I can reach while strapped in the OpenPPG. The whole plate assembly with batteries fits nicely into my battery bag.

Here is a link to my build…scroll down near the bottom and you will see the details of the battery plate, yellow spacers, yellow keys and quick release velcro strap. I hope this helps. It makes my setup and flying more enjoyable…and I think safer.

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Here are the files that I used:
battery plate.stl (330.7 KB) bottom battery plate key.stl (40.6 KB) top battery plate key.stl (26.3 KB) battery plate spacer.stl (26.3 KB) bottom block.stl (15.7 KB)

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You have a very sweet setup there. I tend to place weight savings high on my priority. How much does the battery plate weigh? Do those parts work for six cell packs? Also, are those t shirts still available?!