It's in one piece again.... finally. I put the fly-bar head on it for now since it may be a few more weeks till I get a Brain (no pun intended). Thankfully, there was a complete set of parts for the fly-bar head assembly. I love that there is zero slop in any of the links.
I did discover that 12t is the absolute smallest pinion that will work and still be able to properly set belt tension. For now I will run my best 3S motor until I get everything I need to go 6S..... mainly 6S packs and a new full function charging station so I can properly maintain the packs.
I have yet to fit servos, Rx, and ESC, but will probably get that done this evening.

 

Wow.... learn something new everyday. I didn't notice that the motor mount plate was adjustable and that belt tension is set at both the motor and tail. Go MSH!

 

Yes, this belt tension is critical... not too tight, not too loose. The slack (around 5mm deviation pushing in from front of belt and rear) shoud be roughly the same.

 

Yeah, I figured that out @smakmeharder . There has to be equal tension at each side of the main gear (fore/aft) or it loads the belt incorrectly and makes excess friction.
..... otherwise, bird is ready to fly. I'm impressed with how clean the thing looks. Even the wiring practically fell into place due to the arrangement of the frame.

 

Maiden was a success.
With gear ratio set at a more docile 12:1, I went with my usual conservative 2S setup for trim flight..... easy enough. Bird flew nice and smooth with very little kicking of the Tx trims....
Then came the brand new 3S pack.
Spool up was slightly intimidating as it was at around 3000, then came lift off.
I had to back off the tail gain a bit to remove the jitter.... easy enough, hovered around for half a minute or so, then punched the collective-
Jeesus Louisus!! The thing shot up fast!! Even with the little 3S motor and a cheap 40A ESC the thing had more power and collective authority than I expected! Could it be the stretch blades?? It was like maidening a 450 for the first time all over again. The shakes set in that I haven't felt in months!
Smooth and quiet...... I love it!!
(Note to self- Back off the pitch curves so the collective isn't so touchy.)

 

1300Kv motor arrived...... one step closer to 6S.

 

Thinking out loud here.
Toying with the math for 6S:
(1300Kv x 22.2v) / (8:1 ratio 15t/120t) = 3607.5 HS
That's intimidating given the plastic blade grips.... regardless of how good the plastic is. Take it a step further by adding 85% governor setting for a more reasonable HS:
3607.5 x 0.85 = 3066.375 HS
So the question here is:
Is 3000 (ish) a good target RPM for a stretched Mini Protos flying mostly sport or mild 3D?
Because surely MSH didn't intend to have the mini run at full-out 3600 HS..... or did they??

 

2800 to 3000 would be alright.. I fly close to 3200 for my mini protos for 3d

Sent from my SM-G920I using Tapatalk

 

That's what I thought. Thanks.
.... so confirming the need for me to delve further into governor setups.

 

3K would be fine @Beaver. And as for the plastic bladegrips I ran plastics at 3400 - 3700 for a long time with no issues. So did @thedude and so did @Radar (3200). Never an issue though i understand your concern.

 

Today was the first day I've been able to make it to the park, despite the prevailing wind that's been blowing for the last few days. Up to today, I've only hovered the Protos a few times just to check trim.
I didn't do much but fly two packs worth of easy circuits around the park and practiced station-keeping against the wind.
The Protos was expectedly smooth, quiet and predictable, despite the wind and having a fly-bar head. The thing flies like a whisper compared to the CX450 with the K-Bar, which now seems noisy and a bit sloppy compared to the Protos. I'm considering selling the CX450 now.

 

Yep... you have progressed to a stage where you can see the value in different builds of helicopters. Nothing wrong with clones, but when you progress to a certain point you can feel the difference. Its not just one thing, its lots of little things that add up to a quality build.

 

A few nights ago, I observed belt static as I run my finger along the belt while the Protos was spooled up (no blades) and was generating 4mm sparks with the other finger near the screws to the motor mount. I didn't think much of it at the time.
Last evening as I was hovering in the wind, I noticed a few odd tail twitches, but figured it was wind induced.
This morning, the tail gyro lost Heading Hold.
This evening, after further investigation, I found the tail gain channel (RX Ch-6 output to gyro gain) had lost half sweep output as If an FET had gone bad in the output, which is odd considering there is no real load to that channel.
I may have had my first static related failure!

 

Hmm.. belt static. From down here no one has ever experienced a belt static issue. However - and this is just a thought - check the wires going to the motor. Once i had the symptoms you are experiencing and there was a short from one of the motor wires. If they are shorting to the frame all sorts of wierd stuff can happen. Infact any wire which is shorting can cause an issue. The way the wires come out of the mini-p makes them very susceptible to shorts unfortunately. Check this first....

 

That would be my only real complaint about the Protos so far..... lack of adequate space under the battery tray and around the motor for ESC/Motor wiring. With the stretch tail though, I have no choice but to keep things where they are in order to keep CG right.
I'll be going over that wiring shortly (no pun intended hopefully)........

 

Found no wiring issues in the inspection.
The Rx lost the upper half of the Ch-6 output sweep, so I can't get the tail gyro into lock mode. I didn't like that tail gyro much anyway.... it had a slight drift to it.
I gave in and put the K-Bar on last night, but didn't have time to put the FBL head back on the Protos.
Today I dialed the swash-gain all the way down and gave it a go just for curiosity. Someone said the FBL and flybar would fight with each other and be dangerously unstable, but I had already anticipated that and dialed-down the K-Bar. The thing flew stable enough despite the FBL-Flybar setup, and oddly enough on first test flight, hovered rock solid in place almost as if it was on autopilot at one point (no wind at that moment), but no matter..... the FBL head is going on tonight. It was an interesting little experiment.
I'm still getting a Brain Ikon first chance I get sometime in the next week or so.

 

Gone full FBL with K-Bar...... temporarily.
Bird flies nice despite the K-Bar. I have it dialed in with moderate agility for now, but it's responsive enough I can fly with moderate to a bit gusty wind and still keep it under control.
If it weren't for a little bit of blade noise, the thing would be almost silent compared to gear drives. I love it!
(hoarding money for Brain/Ikon and new KST DS215MG servos)

 

Woo hoo! Trigger pulled..... Ikon ordered.

 

Ok so the tail issue is sorted? And btw you heli shouldnot be thowing sparks. I have seen this only once before where there was a short inside a motor in this case. BUT the same thing could occur if one of the motor wires is somehow contacting the frame - somewhere - but you have already checked for that. @thedude had this spark issue occur on his heli as well.

 

The

The static spark- it might have just been incidental when I was rubbing my finger on the belt.... of course its going to generate some static under THAT condition. It might not have been static... It may have just been that the Rx was ready to go bad or something. It was an older AR6115 from a B450-3D.
The tail was sorted out by removing the tail gyro and defective 6-Ch Rx and installing K-Bar and FBL head on the Protos. Everything is as it should be. I just made a flight 30 minutes ago..... no issues.
I still don't like the K-Bar on the Protos, but that is only temporary. The Ikon V1 should arrive by end of this week, then the K-Bar will be removed as soon as possible.