Stripped Main Gear

[tilburyboy]

Hi Guys,

Got quite a new Raptor 50SE here, i have been messing around with gaer ratio's to get the response i want for extreme 3D.

Changed the ratio from tha standard 8.5 to 1 and now at 7.73 to 1
Heli responce is superb and tic-tocs are spot on, lost a bit of torque, but i'm happy with that. Flying with 1950 rpm on gv-1

Anyway, out flying doing my stuff and all of a sudden the for no reason the engine sounds like it's coughing , i quickly took it out of idle up, but that was a mistake as i was about 15 feet and the head speed dropped very quickly, probably due to the gears stripping as i hit the idle switch, only cost me the skids-shaft-spindle , usual stuff.
Checked over model, everything looks fine and moving well, took crank case of engine and no failures their.

Something has obviously got locked for the gears to strip.

I had the same thing happen with my 90 .

Any help please guys.

[hawkman]

Gear meshing incorrect? if the gear meshing is too tight you will get problems for sure....you replaced both main gear and pinion gear? as well?

To check the meshing, feed a peice of paper...normal A4 paper is thick enough...feed this into the gears...and adjust the meshing....re feed a new bit of paper....the paper should come out crinkled...but not ripped....the meshing should be ok.

Rob

[tilburyboy]

Thanks hawkman.

I will do what you say whenever replacing gears or pinions.

Regards...Gary

[tilburyboy]

Originally Posted by hawkman

Gear meshing incorrect? if the gear meshing is too tight you will get problems for sure....you replaced both main gear and pinion gear? as well?

To check the meshing, feed a peice of paper...normal A4 paper is thick enough...feed this into the gears...and adjust the meshing....re feed a new bit of paper....the paper should come out crinkled...but not ripped....the meshing should be ok.

Rob

Hi Hawkman,

I used the paper through the gears method and everthing seems
to be fine, i have also past this onto other members in the flying club.

Thanks.

P.S.
Test flew my T-REX 600 Nitro this weekend, must admit that it way out fies the Raptor 50. I will probably be getting shot of them and replacing with the T-REX.

[hawkman]

With gears there needs to be a gap between the teeth....if you look carefully you will notice that the teeth shouldnt reach the bottom of the opposite gear...too tight will see too much friction.

Some people use something like a small plastic bag....a typical parts bag for a kit heli will do....this is cut into a strip and used just like the paper method...I have used just the one strip of paper and the meshing has given no problems.

Tail take offs for shaft driven tail rotor systems need a bit of backlash too....I have just set this by feel....ie lock the main gear up and rotate the shaft drive....with tail gear box removed....a bit of backlash is ideal.

Rob

[hawkman]

Yeah...quite a suprise with Align producing a nitro Rex....whatever next!!!!

what are the parts costs compared to say...a sceadu? I dont bother with nitro anymore....its rare and a pain to ship because of insurance etc...thats why I bit the bullet and got the Predator with the petrol engine.

The TRex 600 nitro looks good though.

Rob

[tilburyboy]

Hello Hawkman.

Parts for other models i do not know.
I have been T-REX and Raptor for quite some time now.
However the Raptors are going, i have messed around with gear ratio's
on my Raptor 50's and 90's for a long time and spent lots of money in the process to get a heli flying something like you see on the internet sites, also changing servo all over and blades, but the t-rex nitro flies just how i want straight out the box with no messing, i am running it richer than the raptor as only had 4 flights and not got the head speed up to it's max as yet, i want to get a few more flights under my belt before realy pushing this heli, but as it is tic-tos - rainbows - climb's out way faster than the raptor and funnels with no effort, these moves seemed a bit of a battle with the raptors, it may just be CCPM that makes all the differance , can't wait for the other one to arrive.
When i have a heli that flies better than my 90, who needs a 90.
It may sound like i'm sponsered, but i'm not.

However, i will need to find out if the 600 has any short or long term faults as they are new out, none i hope, i will be gutted when this bites the dust and that as we know is only a matter of time.
I also have the T-REX 600 electric, this will have to go also as to get the same performance will require a bigger motor and 8-10 cells, that i don,t want.

Spec;
T-REX 600 Nitro pro version
OS 50 hyper
3x Ace 1015 high torque and fast servo's on swash
611 gyro
Futaba 149 receiver
20% fuel

with honesty

Regards,, Gary