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crazy fast 1s micro glider, RET only
- Thread starter smirkracing2024
- Start date
Not yet - I was looking at the power system he is using. I'm pretty sure he is custom winding his motors, but think some of the baby quad 1S motors these days might do the trick. He does do some special work to make sure he maintains voltage for the receiver and servos.
smirkracing2024
Strong User
Yes, I read about that part as well. I think he is MEGA-optimizing this build (mostly for fun, because he has the right skills and can do it). To his credit I think he has actually gone past the point of "very good" and is in well in the territory of "insanely great" performance. I think most of us (maybe I should just speak for myself) would be content with "very good".
Specifically, he has a very light glider flying very fast for a very long time. I would relax the last constraint. I don't need or want 15 min of on-power capacity. In fact, if I have a plane which delivers more than 7 min of motor time, I will usually reduce the size of the battery (because the plane will fly better with less weight).
The 18650 has crazy power density (I read it was double the Wh/gram of a LiHV pack). I would ditch that cell and switch to a 2s 550mah LiHV at 29 grams. That should provide enough power for lots of on-power motor time and would avoid any complexity with radio gear and servos. Ideally, the servos would be HV you wouldn't even need a BEC.
I think the starting point for this would be the airframe. What's a good airframe for this? After that, motor, battery, and esc with trimmed wire leads could all be off the shelf.
smirkracing2024
Strong User
You've done it a few more times than I have, so I defer to you! (my count for planes designed from scratch is pegged at zero
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smirkracing2024
Strong User
Just for reference here is the battery he is using.
46 grams
3000mah
1s
Motor is Emax Eco 1407 4100kv
Perfect: https://alofthobbies.com/collections/motors/products/emax-eco-1407-4100kv
Lower kv than what he used is better as voltage will double. As low as 2000kv could work but the 3300kv that Aloft has might be fine too. Can just reduce pitch on a prop a little.
Obviously not constrained to using what he used but just trying to get the baseline.
By the way I love this guy’s design philosophy. He talks about wanting to get the maximum amount of stick time on his plane, and for that, the plane has to be flyable in windy conditions. I assume that boils down to making it heavier with a higher wing loading. I will update the thread once I get the info from his videos.
46 grams
3000mah
1s
Motor is Emax Eco 1407 4100kv
Perfect: https://alofthobbies.com/collections/motors/products/emax-eco-1407-4100kv
Lower kv than what he used is better as voltage will double. As low as 2000kv could work but the 3300kv that Aloft has might be fine too. Can just reduce pitch on a prop a little.
Obviously not constrained to using what he used but just trying to get the baseline.
By the way I love this guy’s design philosophy. He talks about wanting to get the maximum amount of stick time on his plane, and for that, the plane has to be flyable in windy conditions. I assume that boils down to making it heavier with a higher wing loading. I will update the thread once I get the info from his videos.
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smirkracing2024
Strong User
We stock that battery.
He's using the Emax Eco 1407 4100kv in stock form, or rewound?
He did a little bit of extra work to deal with low voltage going to the radio gear. Used a small off the shelf voltage step up.
He has done an astonishing job documenting everything he did and sharing it with the world.
Battery: what do you think about using a 2s lipo and then also using high voltage servos? Then everything will run at 7.4v and no additional components needed. Can also run a super light esc with no bec (just tap off main battery into receiver).
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zeo0nie1
Strong User
Where is the documentation? I might have I missed a link on his videos?
FWIW he says here that for the fast one he rewound the motor. I think?
Reddit - Please wait for verification
www.reddit.com
smirkracing2024
Strong User
Where is the documentation? I might have I missed a link on his videos?
FWIW he says here that for the fast one he rewound the motor. I think?
Reddit - Please wait for verification
Documentation: I didn't mean literal documentation, I just meant describing the build in videos.
Rewinding motor: Shoot. I think I got confused. He talks about using all stock electronics here:
However, I realize now that he's talking about his endurance model, not his speed model ;(
I just assumed he re-used the same basic set-up (I'm not all the way done watching all the videos)
Glad you found the reddit post. That's why I'm writing down my notes here - so we can all capture the correct info together.
Thanks.
From the reddit post we can get some rough numbers together:
So his rewind of the t-motor is at least 2200kv.
We stock the EVE 40PL cell, it is the big brother of the 30:
alofthobbies.com
I wanted to stock the t-motors, but the US government has trade sanctions against the company for selling to Russia. I just brought in this motor:
https://alofthobbies.com/collections/new-products/products/rcinpower-gts-v4-2207-2040kv.
This is a tiny bit smaller than the F60 stater. (.5mm shorter)
The F60 is a very nice motor to start with, and one of their features are very good wires and very good magnets. He seems to be targeting a very precise KV to get the performance he is after. I think we could start with the motor above, and focus in on changes based on how she is performing.
So his rewind of the t-motor is at least 2200kv.
We stock the EVE 40PL cell, it is the big brother of the 30:
EVE INR 21700-40PL 4000mAh Li Ion -Tabless Structure upto 70 amps!
This Eve cell supports up to 70 amps and features a huge capacity. Yes, 70 amps! These high capacity Lithium Ion batteries feature a tabless structure to obtain lower impedance and higher sustained power. A constant amp rating of 70 is impressive! The EVE INR21700-40PL is a popular choice for...
alofthobbies.com
I wanted to stock the t-motors, but the US government has trade sanctions against the company for selling to Russia. I just brought in this motor:
https://alofthobbies.com/collections/new-products/products/rcinpower-gts-v4-2207-2040kv.
This is a tiny bit smaller than the F60 stater. (.5mm shorter)
The F60 is a very nice motor to start with, and one of their features are very good wires and very good magnets. He seems to be targeting a very precise KV to get the performance he is after. I think we could start with the motor above, and focus in on changes based on how she is performing.
smirkracing2024
Strong User
Your GTS motor seems great. 30 grams and very powerful. Are you thinking about using the 1s EVE 40PL cell?
smirkracing2024
Strong User
Oh I meant were you set on 1s vs 2s.
I think going to 2S will throw away all performance. Everything will have to jump up in size.
Was just talking with Jarron and think we have a build method for the wing. I have never been a big fan of sanding a plank of wood as it invites a ton of errors from builders. Hold the press, just came up with a better and easier solution.
Ok, think we have enough to move forward with in terms of power systems and structures. I'll get to doodling.
Ok, think we have enough to move forward with in terms of power systems and structures. I'll get to doodling.
smirkracing2024
Strong User
@Wayne totally defer to your judgement but just for my own education, can you help me understand the tradeoffs?
I have some small planes (sub 800mm wingspan, sub 200 gram AUW) which use 3s 300mah packs weighing about 28 grams. Some other small planes use 2s 300mah packs weighing 20 grams.
Why would using packs like those, or other small packs like those, require an increase in size? I've also used 3 180mah packs in my UMX-Conscendo just for kicks, short motor time but phenomenal glide.
I have some small planes (sub 800mm wingspan, sub 200 gram AUW) which use 3s 300mah packs weighing about 28 grams. Some other small planes use 2s 300mah packs weighing 20 grams.
Why would using packs like those, or other small packs like those, require an increase in size? I've also used 3 180mah packs in my UMX-Conscendo just for kicks, short motor time but phenomenal glide.
Yotaman1985
Very Strong User
Having fun following this thread. Dont really have anything to add but love my UMX Conscendo so something similar would be awesome
Well, that would be a very different power system, would have to figure out a workable combo.
The modern 18650 is going to pack 3,000 mah and can safely provide 60 amps. That is impressive. You would need a much larger lipo pack to match this., pretty sure you will find it hard to match for similar size and weight. I'm too lazy to do the math right now, but this is what this little plane is taking advantage of. We are seeing some drones do similar things with these cells. There is a lot of energy stored in that single cell that weighs about 47 grams.
Can we go to two of these cells or multi lipo packs? Sure, but that is a hunt for a good combo, and prop may well be the limiting issue. For example we went with a smaller motor and 4S lipo for the balsa bullet. That gives about 90 mph and around 10 to 15 minutes of flight. This guy in his economy build is getting 2 hours of very sporty flying. That's pretty interesting setup if you ask me.
For me this build will be more about learning what we can do with these new cells. A sporty fun plane will hopefully be the end result.
The modern 18650 is going to pack 3,000 mah and can safely provide 60 amps. That is impressive. You would need a much larger lipo pack to match this., pretty sure you will find it hard to match for similar size and weight. I'm too lazy to do the math right now, but this is what this little plane is taking advantage of. We are seeing some drones do similar things with these cells. There is a lot of energy stored in that single cell that weighs about 47 grams.
Can we go to two of these cells or multi lipo packs? Sure, but that is a hunt for a good combo, and prop may well be the limiting issue. For example we went with a smaller motor and 4S lipo for the balsa bullet. That gives about 90 mph and around 10 to 15 minutes of flight. This guy in his economy build is getting 2 hours of very sporty flying. That's pretty interesting setup if you ask me.
For me this build will be more about learning what we can do with these new cells. A sporty fun plane will hopefully be the end result.
smirkracing2024
Strong User
Sounds like a super fun journey! Agree that what this guy has accomplished is pretty remarkable, and well worth exploring. To his credit, he has developed not one but two distinct set-ups, one for crazy endurance and one for crazy speed, both delivering performance specs I've never seen in any other plane before.
Yes, the overall watt-hours contained in that cell are pretty astonishing.
Let me know how I can help.
Yes, the overall watt-hours contained in that cell are pretty astonishing.
Let me know how I can help.
