4025 motor on low headspeed 700

[Yfbb]

How adequate is a 4025 motor for a 700 heli running around 1400-1600 rpm? I was thinking about building a low headspeed 700 and if a 4025 would do, I could save some cash.

[Nikki5]

I fly my Low Headspeed 700 with a 600 520kv motor, its works fine for me

Nikki

[Yfbb]

Great. Do you think I could get away with a 70a esc as well?

[Nikki5]

What heli is it? and what weight? I have buy a amp/watt meter so i will soon do a test on my 700 what max amp i use then i can post it here..I fly 1300 rmp and just sport flying..no 3D. I use 100/120 Amp esc on my 600/700 helis, but its might overkill. Its also a matter of how you do your setup.. If your on 85-100% throttle, if your on low th values you generally need higher Amp esc unless your esc have freewheeling.

Nikki

[Yfbb]

I was going to run 1600 rpm with 11 degrees pitch at 75% rpm with a scorpion 3536 510 or 4025 550. The heli is a protos max v2 with 690 blades. The weight should be under 5kg easy.

[trillian]

Originally Posted by Yfbb

Great. Do you think I could get away with a 70a esc as well?

If you could run it on 12s and gear it for low headspeeds then 70 amp would just be on the margin. But on 6 or 7s I don't think it will be enough, not at 1600 anyway.

I have a Jive 80HV in my TDR and it works great but I'm running it on 12s and at about 1260 headspeed.

When I first setup my Triabolo I checked the logs and it was drawing about 30-35 amps average on 12s, with some very short peaks a little bit above that. But to get the same headspeeds on 6s the amps would roughly double. (and this was at 1400 headspeed and very smooth flying).

[Yfbb]

Nice. I am doing a custom low rpm 12s build so I'm hoping I can squeeze by. How much pitch did you use? I was thinking 10-11 degrees on collective should keep the draw fairly low.

[trillian]

Originally Posted by Yfbb

Nice. I am doing a custom low rpm 12s build so I'm hoping I can squeeze by. How much pitch did you use? I was thinking 10-11 degrees on collective should keep the draw fairly low.

I have a lot of pitch but probably don't use it all. I think all three of my 700 electric helis have about +/- 13 ish. I have them setup for fairly low headspeeds on 12s, so hovering at about 1000 and idle-1 roughly 1300 ish. The TDR was tachoed at 1260 and I'm just guessing the headspeed on the Faifa based on Mr Mel's calculator.

The TDR has an Align 750mx/450 motor, the Faifa has a Hacker A50 rewound for approx 420KV and the Triabolo has a Pyro 700 wound for 530 KV.

[Nikki5]

Generally there is over powering on motors..because most setups are capable of hard 3d flying. So for a low headspeed setup a smaller motor is just fine.. For example a 600 motor for a 700. This will also save weight who is a important matter on a good low headspeed setup.

You could test your heli setup with a $12 watt/ampmeter so you know how near the limit you are.


BA

[gwright]

If you can gear it deep enough and/or get a low enough KV, then it should work.

I use a slightly larger motor (roughly 16 oz versus the roughly 11 oz size you mention), in a 700, geared for 1750ish max. 12S and 1750/1500/1250 flight modes with 16/16 collective and 12/12 cyclic (due to the 1250 mode). Use an edge 80 ESC in it. Telemetry shows i never hit 80 amps. Average is only a fraction of that, as I prefer the lowest rpm most of the time. 12/4350 provides over 10 minute flights , usually 12ish, occassionally 14,.. using a mix of rpms.

[Yfbb]

After some more digging, I think I may have to use a scorpion 4035 330kv. There just aren't any 600 motors with a kv low enough on 12s. This way, I have motor that is rated at 60a, and 70a esc, and I can get 1600 at 90%, and 85% gets 1500 and 80% gets 1420. The ESC should be pretty happy, thought I really wish the motor could have been a bit smaller.

[Nikki5]

My friend who fly the same heli as me but 600 blades, and same 600 520kv motor just calculated his average Amp To 17 on 6s Low headspeed


Nikki

[madog]

I'm running the Nick Maxwell motor, Scorpion 160a OPTO. The gearing is for 12s as that is what I fly. I do like the run 1500 hs.

I have a video of it on the Synergy/electric models/stickies/e series videos

It handles 16 pitch great. Temps are low. Very versatile combo.

Sent from my SM-N920V using Tapatalk

[im4711]

Just as a general comment - on the 750 size machine I went down to a pyro 700 motor for testing and all ok. Even a 650 pyro would do the job.

Trick is how clean your inputs are. If very smooth than you are ok even with a lower amp ESC. On low rpm smooth flying I normally stay in the 30-50 Amp range. However. If you get an ups mom t and try to pull out quick you could get some peaks and a low amp ESC could kill you

If I would run a fully d dicated only extreme low rpm machine I would go with a 100 - 120 Amp ESC and a small 650 size motor on a 700+ size heli.
The ESC to cover for the ups moments.

[Number]

My 6HVU drew about 60A peaks on 6s at around 1250rpm. So on a 700 I'd probably put a HobbyWing 100 V3 or 120 V4 or something like that. A 70 might handle it but it would probably get pretty warm. I'd guess 80-90A peaks.

4025 should work perfectly on a 700 LHS.