Impressions on 4S maiden

[Lompma]

Just maidened my new 4S setup. Here is what I have.

TP 4S batts (New so maiden flights I went easier than normal)
Stretched tail
325 stock blades
15T Pinion
Gov store mode
PWM 8 mHz (will try 9 mHz)
2010 KV motor
Mini V-Bar

Comparing this to my 3S Trex 450.
I wish now that I had gone 6S. Maybe when the batts are broken in they will get some more pop. Plus I did not go full bore because they are brand new. Has more power than the Trex 450 but I was lookin for a little more. I will tach it later to see where my head speed is at. Running 90% IU2. Flies lighter than my Trex for sure.

Issues:

1. Phasing issue. I have the Mini V-Bar perfectly square and the swash follower cant really be adjusted.
2. V-Bar log show some "Extreme vibrations"! Yikes. I think I will rebuild the tail.
Any suggestions?

[Lompma]

Just tached it and 90% was getting me 3800!! So backed down to 80% for 3250. Vibration levels down but still to many entires back to back for " raised vibration" in the V-Bar log. I get that in all my helis but not a whole string of 15 entries back to back.

[SMJT]

Check belt tension
to tight and it can cause a lot of vibration it should feel smooth when it rotates

[Lompma]

It is loose compared to my 500

[Lompma]

Just took it apart and I have two main bearings that are bad. Maybe the excessive head speed not sure. I made sure that the main shaft did not bind at all and slide up and down through the bearing blocks with no binding during build. Hmm. So did 3800 Plus head speed wreck my main bearings?

[beans07]

How was the alignment when you installed the main shaft?

I am only new to the mini p, maybe the plastic main bearing housing's flex under load?

[desertstalker]

Originally Posted by beans07

I am only new to the mini p, maybe the plastic main bearing housing's flex under load?

Not at all likely, they are extremely rigid, if they flex then Al would too. No one else has reported such issues.

Most likely causes for premature bearing failure are improper installation (too much force on the inner race when installing) or simply dud bearings.

[beans07]

The second hand heli I bought had the lower main bearing (middle) stuffed when I took it apart. I didn't know exactly how many flights or the actual install method on it but it hadn't had any crashes. The others were very smooth. I don't know what caused it but maybe the belt had too much tension on the front part.

There is not that much to stuff up on the install expect if the shaft doesn't glide through smoothly. They just pop in with light finger pressure. Personally I have had plastic housings in the past flex (on previous helis) and prefer the metal beaing blocks.

Maybe a little goop or CA on the outer race will help too.

Maybe better quality bearings would be beneficial.

[Lompma]

Originally Posted by beans07

The second hand heli I bought had the lower main bearing (middle) stuffed when I took it apart. I didn't know exactly how many flights or the actual install method on it but it hadn't had any crashes. The others were very smooth. I don't know what caused it but maybe the belt had too much tension on the front part.

There is not that much to stuff up on the install expect if the shaft doesn't glide through smoothly. They just pop in with light finger pressure. Personally I have had plastic housings in the past flex (on previous helis) and prefer the metal beaing blocks.

Maybe a little goop or CA on the outer race will help too.

Maybe better quality bearings would be beneficial.

I used goop on mains to prevent spinning in place. I have the alum blocks coming from Pete tom. Not that Trex 450 is a better heli but I never had any problems with the metal bearing blocks on that heli and I have 2 of them. Pete from Electro RC looked at it during my build and said it looked fine. Bearings were good I know because I checked them. Quality of bearings is way better than Align for sure. I must have screwed something up along the way. I will report back with the alum blocks.

[baui2000]

Wow, that's some headspeed!
I'm afraid the alu blocks will carry wibes much better than the plastic ones, but you'll see. I have never had a problem with the pastic ones until I crashed the heli so bad the whole main shaft bearing assembly...disassembled

I had similar issue on mine. Vibes went down by hundreds once I tightened the vBar down with a velcro strap. Check your blade balance, not all of the stock blades are perfect. Too tight belt on the motor side produces ridiculous amounts of vibrations too.
Did you check the frequency of your vibes in the spectrum analyzer?

[Lompma]

Originally Posted by baui2000

Wow, that's some headspeed!
I'm afraid the alu blocks will carry wibes much better than the plastic ones, but you'll see. I have never had a problem with the pastic ones until I crashed the heli so bad the whole main shaft bearing assembly...disassembled

I had similar issue on mine. Vibes went down by hundreds once I tightened the vBar down with a velcro strap. Check your blade balance, not all of the stock blades are perfect. Too tight belt on the motor side produces ridiculous amounts of vibrations too.
Did you check the frequency of your vibes in the spectrum analyzer?

1. I am very anal about CG and blade balance. Balance per Finless and use a Dubro prop balancer to balance entire head with blades on.

2.I use the 3M double sided tape with the V-Bar. I ran it on the analyzer with no mains and pushed down on the V-Bar to see if they went down and they did not. I know what you mean by freq. that can give you an idea of where to start looking for issues. I think it was the 2 bad main bearings.

Now I just reassembled my mini with the new Alum bearing block for all 3 and I can attest that it is much smoother action with the main shaft. I wrestled with the stock and just was never happy with it. Sorry for all the purists out there but I prefer these over the stock ones. WIll have it flying again soon for a flight report.

[scott s]

I am now working on my 3rd mini stretch build and I will attest that the aluminum servo blocks are just so much more precision. I alway's used the aluminum 3rd lower bearing block and ALWAY's struggled to get a perfect main shaft alignment with the plastic servo blocks and actually never could get it perfect. All 3 minis I have done with the aluminum servo blocks are perfect. As amatter of fact on the current build I am doing I was carrying the heli into another room with the main shaft all the way thru all 3 bearings and tiped the heli over in my hand. When I got to the other room the main shaft was no where to be found. It just slid right out! Plus I did not have to dink with anything. I bolted the ds 95's up to the blocks with the servo cases bottomed on each block with a main installed and tourqed down the screws. Then instaleed into frame one side then added other side and simply tourqed down the screws and had perfect alignment. I have messed for hours with the mini plastic servo blocks and could never even get close to what I have now.

[Lompma]

Well just took her out again and WOW. The TP's have about 5 cycles each and woke up a bit. I did not hold back. Lots of power. Just flew my Trex 450 and then this puppy and there is no comparison. I think now that the 4S will hold me for this season. I will not be able to out fly her for awhile. Maybe 6S next year. Great heli. VIb warnings in the log very minimal. Looks like my son gets my Trex 450.

[scott s]

ya the tp;s woke up along with a true running mainshaft under no load all by itself. Wait till you go 6s. I don't care what the majority think but the aluminum blocks are a must to get this heli to its full potential along with the cnc belt pulley guides and a cnc tail gear. It just is not that expensive to do correct!

[Lompma]

what CNC tail gear? I have never seen this.

[scott s]

Originally Posted by Lompma

what CNC tail gear? I have never seen this.

Here ya go
http://elektrorc.com/product_info.ph...oducts_id=1366

[beans07]

Originally Posted by scott s

ya the tp;s woke up along with a true running mainshaft under no load all by itself. Wait till you go 6s. I don't care what the majority think but the aluminum blocks are a must to get this heli to its full potential along with the cnc belt pulley guides and a cnc tail gear. It just is not that expensive to do correct!

I got a bad CNC tail gear out of the packet that wobbles and is causing vibration. I am not so sure that metal is needed my logo600 has had 400 flights on it and only ever plastic gear and is smooth as silk.

[baui2000]

You guys made me think... Well, no, not think. Alu upgrades go on the list, I have to try these! It's not like 50 sized alu upgrades that cost loads of cash "just to try" either

[beans07]

Nothing wrong with some bling

I am sure the metal parts are upgrades and do help. I know the plastic works fine but for I like to buy the whole thing ready to build and not add extras or upgrades to it. I know it is not feesable but I would have liked a kit with FBL low rider head, all metal upgrades in the one kit. If you remove the bits not neeed and add the needed bits the changeover or extra price would be not a lot.

Let us know how the upgrades go.

[baui2000]

My words exactly. I could use the FB parts laying around the house to build myself at least 3 badass collective pitch ceiling fans Maybe I'll do that, who knows. The MiniP is still well worth it, though.