Is This Normal ?????

[mblake01]

Hi There,

I've just finished putting my Raptor 50 v2 together, followed all the instructions and had no bits left over at any stage, I still haven't put a motor in or any of the electrics just built the kit without the main rotors on. Any how the head was moving very freely until I put the tail boom on and connected the belt to the gears, now I wouldn't say it was binding but its deffinately tighened up is this normal ? My Trex 450 Se v2 will turn in the wind but this one just seems so different and I'm not sure what to expect.

Boy what a beast of a machine, makes my Trex look like a toy now !!!!!

Thanks for your responses,

Mike.

[archiebald]

A certain amount is inevitable on any belt drive tail. This is especially true when everything is new. A couple of hovers and you'll find it will loosen up considerably.

However, you should check for;
1) Make sure the belt is installed correctly - no extra twists.
2) Belt is not overtightened.
3) Does the autorotation bearing move freely one way when the the belt is tensioned.

I use tri-flow oil spray (contains PTFE) on the belt teeth - it helps them release from the main pulley.

[mblake01]

I'm not rally sure how tight is too tight when you setup the belt ? I've pulled the boom back and there is a little bit of flex in the belt but I dont know whether this will stretch the same as the rubber ones on my Rex after a few flights or not. The autorotation bearing is free when turned the apropriate way and I have some silicone lube which I use on my rubber belts so may give it a blast of that up the boom to see if that helps any. It might be a while before I can get it out to hover as the engine and electrics are about three months away (Going to pick them up on vaction in Florida) so I can save a few pennies which will all help towards my spares supplies.

Thanks,

Mike.

[vandelescrow]

You said you built a V2, this kit does not come standard with the driven tail autorotation gear. To tell the difference, the gear below the main, if white it is a driven tail, if red it is not. Be aware of how this will effect aborted auto's.

Belt tension in the Raptor is allot different then on your T-rex 450. on the 450 you want to run it where you can flex the belt to about the center of the boom at the pinion gear. On the Raptor, press on the belt between the autorotation gear and the idler, you should be able to move it slightly but not much. It should be like a fan belt on your car.

Also since this is a new build, may I recommend a modification to the frame. The frame halves do not clamp the tail boom tight enough to prevent the belt from loosening up over time. You need to remove some material from both sides of the frame where it clamps the boom. Since this is already assembled, Here is what I've done. Take the boom off and remove the 4 bolts that clamp the frame around it. Take a hack saw blade and saw down the seam of the two frame halves. Your not cutting anything, just making the seam wider so it can clamp better. Go slow sawing by hand, ensure you follow the seam in a straight line, top and bottom. Once done clean any shavings from the seam and around the area and reassemble. While assembling, put all 4 bolts in but leave the top 2 vary loose, tighten the bottom. If you did it right and removed enough material, there should be a slight gap remaining in the seam on the top. Go ahead and tighten the top bolts.

This mod will prevent the boom from sliding in the clamp and help keep the belt tight. However, you still need to check the belt tension periodically and remember metal booms will shrink and expand due to ambient temperature effecting belt tension..

[Jim T]

You said you built a V2, this kit does not come standard with the driven tail autorotation gear. To tell the difference, the gear below the main, if white it is a driven tail, if red it is not. Be aware of how this will effect aborted auto's.


My V2 kit came standard with the white gear. I built it a few years ago, but have never installed the electronics to get it flying.

Jim

[archiebald]

vandelscrow,
I don't know how tight your car fan belt is but comparing mine, that would be FAR TOO tight for a Raptor tailbelt.

If the belt is too loose, you can hear teeth catching on spool up inside the tailboom (doesn't do any harm though) I run mine as loose as I can without getting the spoolup "dings".

Personally, I've never found a problem with the tailboom sliding in the frames yet. But if you are tightening your belt as much as you seem to be describing, then its not surprising you have this problem.

[mblake01]

My kit came with the white gear as standard and when i push the belt in from the back of the gear before it gets to the guide pulley i'd say I have abot 5mm play. If I spin the head on my Trex it will turn a couple of full turns, on the Raptor it goes around once. This is why I thought it might be tight. One more thing when you put the bblade grips together there is a small tapered washer that goes on last, I've put it so that the tapered edge is touching the bearing and not the screw is this the right way around ?

Thanks,

Mike.

[BarracudaHockey]

The only thing that comes with the red non driven tail gear is the 30. The current 50s (v2, Titan, SE) all come with the driven tail white gear.

The wide section of the washer should go against the bearing.

I'd also reccomend you buy a PV0499 and replace the grub screw tail assembly, its cheap peace of mind.
You might find this article helpful http://www.rcuniverse.com/magazine/article_display.cfm?article_id=836

[mblake01]

Thanks for the tips, I've turned the washers around in the blade gribs and read through the Titan review. I will order one of the tail rotor hubs as a spare for early replacement also will keep an eye on the one way bearing on the main shaft (didn't know these were a problem) still I just put a little oil on as recommended in the review and will do so on a regular basis.

Thanks for the advice,

Mike.

[sammy64]

Is there a tail driven White gear for the 30V2 ? or are we stuck with the Red ??

[vandelescrow]

Sorry to stear anyone wrong. I forgot that my first raptor was a 30V2 with the 50 upgrade so it came with the red gear. On the comparison with the car fan belt, you should be able to push the fan belt about an inch, granted that would be to loose for the Raptor but it should be able to deflect about the same in comparison to the size difference. Here is what raptortechnique says: http://www.raptortechnique.com/belt.htm

I have the Raptor mentioned above in an Airwolf body and the belt gets loose after just 2 flights. Loose enough where turning it by hand you can hear it slipping a tooth. Just Saturday I did the mod mentioned above but have not flown it yet. On my other Raptor 50SE, I sanded both sides of the frame prior to assembly with a carbon boom and have not had a problem. Oh, the one in the Airwolf is a metal boom, that may be a factor in why it slips.

Yes you can put the white gear on a 30. 30s and 50s are exactly the same heli except for motor mount, boom/belt/blade length and gear/pinion ratio, okay if you want to get technical, the graphics are different.

[BarracudaHockey]

I believe you can fit the driven tail pulley from the 50 though I would be hesitant to do so as 550 mm blades carry a good bit less inertia than 600 and 620's

[ghtracey]

You may not want to use that TR hub as a spare. You're best bet is to put it on immediately. There have been many reports of the grub screws on the stock hub shearing off, some while sitting on the ground spooling up, some in the air. Its a 5 minute job and a cheap part that could save you a lot in repair costs.

[sammy64]

What do you think would happen with the smaller Blades on the 30V2 (550) . they do sell it as a 30V2 item http://www.amainhobbies.com/product_info.php/cPath/2_375_542/products_id/10472
I would hate to start my Auto's knowing that there could be an issue

[vandelescrow]

What happens in a driven tail is the tail will take some of the energy away from the main blades, meaning less room for error. The only difference (while in the auto) is with a driven tail you are able to turn the tail, not really a big deal. The difference in an aborted auto, with a driven tail it is already spooled up, somewhat, with a non driven tail, the tail will get a sudden burst of energy and can/will spin around on you to where the gyro will not be able to keep up and correct. Sorry I do not know which direction, perhaps some one here can answer that, that way you can antisipate it and correct if/when it happens.