Settings for 4035-560KV on Goblin 700

[mba83]

Hi guys,

Just had a first flight with this motor on a Goblin 700. It was bogging significantly for me, but would also overspeed when returning to zero pitch.

Do I need to increase the gov gain? Or any of my settings off?

I'm using IKON governor:
Gear ratio 10.2, pinion 20T
Headspeeds 1900-2000-2100
IKON gov gain 60% (default)

ESC settings (CC Ice2 120HV):
Start power: medium (59)
Motor timing: Normal (5)
PWM: 8KHz

Logging showed max current is 52A for the test flight.

Any tips on what to try?

Thanks!

[Michaelinpr]

52 amps and you having bogging? That seems strange.

I haven't used an IKON in years, but try moving up on the gain. What you describe sounds like low gain symptoms. The settings you have for the motor are fine.

I always have to ask, are you lipos new or in good condition? Point being whenever you have have a power issue or bogging, don't just assume motor or gov. Tired lipos can cause many issues that nonamount of tuning will fix.

[mba83]

Thanks! I will try playing with the gain.

Lipos are perfect, IRs around 2. And previous flight with them was great.

[Smoggie]

The motor is on the small side for the G700. That's actually the recommended motor for the G630 so it might well struggle maintaining headspeed with the bigger 700 blades especially if flown hard.

Also the 20t pulley is what you would fit to a 520Kv motor so a slightly smaller pulley might be in order for the higher Kv.

This wouldn't explain the low amps though.

[mba83]

Thanks!

[RasmusDK]

Sounds very strange

At that low amp draw, you arent even close to bug it.

How are your flight level?
Are you good with pitch management and so?

[mba83]

Yeah I fly 3D. I haven't flown it yet since, but I raised the gov gain and also mounted 630mm blades with 630 boom & belt. I may consider stretching back to 700 later with a different motor.

[Michaelinpr]

There was a time when a 4035 motor was considered standard for a 700 heli. Sure we have bigger motors now that are considered the norm but they aren't always needed.

Recently I set up a friend's 700 with a 750MX. This motor is typically run in a 600E. Works great. Before had a 700MX. Wasn't awesome but it worked fine.

Just saying you don't necessarily need a big ass motor to have a heli preform well

[mba83]

OK flew the heli with 630mm blades yesterday. Definitely is flyable now

A little more punch would be nice though.

Should I try 21T pinion with 2200 headspeed? I currently run up to 2100 with 20T. Or would that be too hard on the motor?

Thanks

[Michaelinpr]

Not sure. What is the tooth count for all the gears? I will need to calculate it.

[mba83]

Current gear ratio is 10.2, with 21T pinion it would be 9.7.

Gear teeth are Z20 motor pinion pulley, Z60 pulley, Z20 gear, Z68 main gear.

Thanks

[mba83]

I think I found the problem. I was using the wrong option in MrMel - HS Calculator for calculating the headspeed. Should have been using "SAB Goblin UPDATED (204)" instead of "SAB Goblin (215T)"


So I should probably keep my 20T pinion and raise my governed headspeeds

[Michaelinpr]

Stick with the 20T.

[mba83]

Update: All I needed to do to get the punch I wanted was to significantly raise the headspeed I settled on 2400 - though I think it may be less, and my ratio is wrong - I'll need to verify it.

[Michaelinpr]

Ummmm.....Yeah 2400rpm will get you some punch. I would need some clean shorts after that though.

[mba83]

Um sorry forgot to mention this is with 630 boom and blades.

[Michaelinpr]

Oh ok. I went back to the first post and saw 700. I forgot you changed to 630.

I just noticed you are in Portland. Any plans to go to the RCHN 4 funfly in September?

[mba83]

Yeah I definitely plan to go

[Michaelinpr]

Nice. See you there.

[mba83]

BTW decided to convert it back to 700. Piroflips feel a lot better with 700 blades vs 630 blades. Posted some 630 parts for sale if anyone is interested