Blade 120 SR The mod list......post em' here!!

[Heli Bones]

I have had the 120 sr for about a week,and i have done a few simple mods.
Here are a few......



Post up mods that you have done to your 120 SR




Ok first up is the tail motor bearing keeper.
Have you seen the tiny bearing between the tail rotor and tail motor that is one small bearing,and it always flys off in a crash.
Finding it in the house might be possible,but if it comes flying off outside it's gone and very difficult to find.

Here is an easy fix

It is a small peace of plastic that slides over the tail motor shaft and fits in between the tail motor and the plastic tail motor mount to keep the bearing on the shaft while still alowing clearance for the tail rotor to spin while not altering the cog or cause any binding with the tail rotor.
I'll let the pics explain.....

At spool up the heli can slide around a bit,and on landings it sometimes will slide around on the skids a bit.
That can make precise spot landings tough,sometimes you need to land on a spot and have the heli stay put....not skid around.
Cut some small O rings from some nitro fuel tube.Cut four of them the same size and slide one over the front and rear of each skid....this will keep the heli steady and prevent twisting/skidding on spool up and landing .



The main motor could be rocked front to back....the frame is flexing.
This could upset gear mesh.
A ziptie or a thin length of enamel wire around the main motor and around the rear of the mainshaft will prevent the motor from being able to flex the frame/chassis,the pics will show what i am talking about.


Here is some cf rod cut to length to fit in the groove on the bottom of the flybar.
It helps to keep the flybar rigid as it should be.
Just cut some carbon fiber rod to the right length and use some ca glue to secure it in the flybar groove.




If you have a mod for the 120 sr that you have done...post it up for all of us to see!

[WBFAir]

I'm still trying to figure out what that little bearing is for.

In swapping out a replacement blade, it at least seemed to me that the whole in the blade seems to have a bottom out point to where the blade can't go on anymore, which still leaves a pretty good gap between the hub of the blade and that bearing. So its not like that blade could be pushed up against the motor.

And even more so if that whole thing were gone, it would be really far away.

And given how the rubber thing holds it, it can't being of any support for the motor shaft.

If I had to take a wild guess it almost seems like it might be that the rubber thing is just a kind of a cover or shield so that stuff doesn't get wrapped around the shaft more then if it wasn't there and then the bearing is just a way to support that.

It seems silly I know but considering I can't see any other reason for it, that's all I can think its for.

I guess my point is, it think if you were to loose it I wouldn't worry to much about it.

Unless someone can figure out a necessity reason for it then, by all means worry about it.

Really like the other stuff though especially that tie wrap holding the motor thing. I was looking at that an saw how flexible it was but it never dawned on me that its flexing could dig into the main gear.

An I could see how that would be even worse in a crash.

So good thinking on that one.


Now for a few of my contributions, and sorry I don't have any pics but one, I felt that main blade grips to the feathering shaft hub clearance was kinda sloppy with to much side to side play.

I took it apart an found that is had some very thin brass washers in there that when I replaced them with some stainless steal ones that I had that were just about the same size, that they were just a hair thicker and really took up the slack.

At first I tried a few washers as the slack seemed like it would need that but found it doesn't need much more then the brass ones and the single SS ones on each side were perfect.

Next and this is just a suggestion but, to me those little stranded wires the come from the solids to power the tail motor just after the plug to the motor I know already were a source of a one failure for me an I think several others too.

Its been my experience with leads this thin that if wiggled enough, don't need much to break inside.

So my suggestion would be to add a bit of a small globe of silicon between the plug and into the rear motor housing to kinds keep those from bouncing around so much.

I don't think it would need much just enough to keep it secure. An not to much that it all seeps down behind the motor.

This would be easy to remove too if the helo ever had to be sent back to HH and or if you had to replace the motor.

Hope that helps some, and keep um coming.

Thanks

[nunyabizniss34]

WBF, I also noticed the excessive play in the blade grips. My solution was to take some mSR canopy grommets, cut them into two equal halves right down the middle so I had two very small o-rings, and slid them over the feathering shaft. These are made of rubber, so they dampen head vibration too. They fit perfectly and have reduced the play in the grips, plus reduced vibration in the head. I have noticed a lot of 120SR owners also own the mSR, and if you look in the little bag that came with the mSR (it contains the swash leveler, spare flybar etc) you will see 4 spare canopy grommets. It's a free fix

[Heli Bones]

I have noticed that the left servo can become damaged in a crash from the landing skid ,where it mounts to the frame on the left rear can contact the big servo gear

On a hard landing or a crash the landing skid will destroy the left servo gear,and mabey even ruin the whole servo itself or crack the 5 in 1

So to fix it just trim the left rear skid mount so it sits flush with the frame

You will need to use a dremel because there are metal pins in the end of the part of the landing skid that goes into the frame.

I think this is the most important mod you could do.

If you don't do it............. you wil break the left servo/gear on a hard landing eventualy and mabey more.

Heli Bones...flying high

[nunyabizniss34]

That is an excellent idea, I just did it too. I would never have noticed that if you hadn't pointed it out. Great job noticing it

[WBFAir]

Yeah thanks for that one Heli Bones, you da man.

Btw did your tiewrap trick today, really tightens that up nice.

Snugs up the batter tray too a bit.

[Heli Bones]

Thanks guys

Yeah if you don't trim the left rear landing skid mount like that it would only take one time and then

WBFAir....If your a stickler for weight savings then you can replace the ziptie with a thin enamel wire.
The ziptie i used is one of those long ones that is narrow....actualy it is one of the ones that came in the t rex 450 kit,anyway it only weighed 0.03g not very much and certainly not enough to reduce runtime .

Heli Bones...flying high

I'll keep looking over the heli ,i'm happy to pass on anything i find that can help.

[WBFAir]

Yeah I used the same one and I don't think the weight will be a issue and I think the tie wrap does a much better job at holding with less pressure just as securely and if not better and in a more spread out way that wont dig into anything in a hard crash.

[Heli Bones]

Originally Posted by WBFAir

Yeah I used the same one and I don't think the weight will be a issue and I think the tie wrap does a much better job at holding with less pressure just as securely and if not better and in a more spread out way that wont dig into anything in a hard crash.

I agree 100%

The only reason i also used the enamel wire was to settle a debate with someone who was trying to tell me the ziptie would add to much weight
IMHO the ziptie is the better choice of the two.

Heli Bones....

[garagebiitz]

Originally Posted by Heli Bones

I have noticed that the left servo can become damaged in a crash from the landing skid ,where it mounts to the frame on the left rear can contact the big servo gear

On a hard landing or a crash the landing skid will destroy the left servo gear,and mabey even ruin the whole servo itself or crack the 5 in 1

So to fix it just trim the left rear skid mount so it sits flush with the frame

You will need to use a dremel because there are metal pins in the end of the part of the landing skid that goes into the frame.

I think this is the most important mod you could do.

If you don't do it............. you wil break the left servo/gear on a hard landing eventualy and mabey more.

Heli Bones...flying high

This mod is a must do!!!, on my second battery I had a hard landing and buggered my servo. 10$ later and back in the air thanks Heli Bones

[TAGFL]

Originally Posted by Heli Bones

I have noticed that the left servo can become damaged in a crash from the landing skid ,where it mounts to the frame on the left rear can contact the big servo gear

On a hard landing or a crash the landing skid will destroy the left servo gear,and mabey even ruin the whole servo itself or crack the 5 in 1

So to fix it just trim the left rear skid mount so it sits flush with the frame

You will need to use a dremel because there are metal pins in the end of the part of the landing skid that goes into the frame.

I think this is the most important mod you could do.

If you don't do it............. you wil break the left servo/gear on a hard landing eventualy and mabey more.

Heli Bones...flying high

Will do mine before my next flight.

[Heli-Yeah!]

120 SR MOD (tail motor protective sleeve tether) (3 min 22 sec)

Heres my bearing sleeve keeper solution.

[jetskier]

I saw your post about the the landing gear hitting the servo, did not have a driemel so I put 4 canapy grommets on the landing gear seems to take up the space and also acts like suspension.

[singingperry]

Originally Posted by Heli Bones

I have had the 120 sr for about a week,and i have done a few simple mods.
Here are a few......



Post up mods that you have done to your 120 SR




Ok first up is the tail motor bearing keeper.
Have you seen the tiny bearing between the tail rotor and tail motor that is one small bearing,and it always flys off in a crash.
Finding it in the house might be possible,but if it comes flying off outside it's gone and very difficult to find.

Here is an easy fix

It is a small peace of plastic that slides over the tail motor shaft and fits in between the tail motor and the plastic tail motor mount to keep the bearing on the shaft while still alowing clearance for the tail rotor to spin while not altering the cog or cause any binding with the tail rotor.
I'll let the pics explain.....

At spool up the heli can slide around a bit,and on landings it sometimes will slide around on the skids a bit.
That can make precise spot landings tough,sometimes you need to land on a spot and have the heli stay put....not skid around.
Cut some small O rings from some nitro fuel tube.Cut four of them the same size and slide one over the front and rear of each skid....this will keep the heli steady and prevent twisting/skidding on spool up and landing .



The main motor could be rocked front to back....the frame is flexing.
This could upset gear mesh.
A ziptie or a thin length of enamel wire around the main motor and around the rear of the mainshaft will prevent the motor from being able to flex the frame/chassis,the pics will show what i am talking about.


Here is some cf rod cut to length to fit in the groove on the bottom of the flybar.
It helps to keep the flybar rigid as it should be.
Just cut some carbon fiber rod to the right length and use some ca glue to secure it in the flybar groove.




If you have a mod for the 120 sr that you have done...post it up for all of us to see!

Man, the tail bearing retainer mod is a MUST DO! I test flew my heli in my living room and when the tail rotor bumped the carpet it flew off post haste and so did the bearing. Could not find it! Put a spare bearing on (It only comes with a complete tail kit not just a spare rotor blade). I made my retainer with two long mounting tabs and stretched out a ring of my largest heat shrink tubing with a pair of needle nose pliers, unplugged the tail motor slipped on the tubing and quickly slid on the retainer tabs under the ring of tubing, shrank it and tacked on a tiny amont of CA for insurance. Found the spare bearing attatched to the magnetic part of the tail motor.I feel sorry for the unwary, Thanks for the heads up Bones!

[Pfloyd]

Show a pic of what you did please!

[singingperry]

Man I wish I could, have no satisfactory camera. Sorry dude! The best description is that I took some plastic from a large pack of AA batteries you often see for sale at Walmart and cut it with a pair of scissors to look essentially like the shape of the emblem you see on the sides of WWII aircraft. (You know, the circle with a star in it and the bars on either side with the stripe in the middle.) However you'll need to make the bars extra long and trim them down after its done. Drilled a hole in the center of the plastic strip that is much larger than the motor shaft but justsmall enough to keep the bearing from sliding off. Folded the "bars" back to the sides of the motor, slid the heat shrink tubing over the bars (tabs) and shrank the tubing on.Works very well.To stretch out heat shrink tubing that is a little too small, just insert the tip of some needle nose pliers inside of the tube and gradually spread the tips of the pliers apart till you get the size you need then quickly slide it on.heating it will finish the job.

[singingperry]

With the landings I have I decided to line the underside of the landing struts with CA then zapped it to keep the glue from running. So far so good. Looks like the bearings are available individually, my bad, Agood idea to get some more spares.

[singingperry]

Man using a Dx6i correctly programmed turns the 120 into a very good flying and managable heli. Flies indoors very similar to an MSR or CX2

[ticklegs]

Thanks Heli bones, for figuring that one out. Happened to me, Fix is being applied now.

[singingperry]

Originally Posted by Pfloyd

Show a pic of what you did please!

Got em ready (2 sets) just give me your address.no charge.got some rings of heat shrink that are larger and shouldn't need stretching.Includes an illustration.