Anyone regeared a RAPTOR 50 with OS HYPER, how can I change

[Rodan]

Thanks!

With the scale body, I would like to run a little lower headspeed, but with the extra weight, I would think it would be good to have the engine near it's power peak. I know I'm not going to be doing 3D, but it would be nice to have the power if it's needed.

9.56 gears would put the OS hyper at 17000 with a headspeed of ~1780

16,500 = 1725

16,000 = 1673

This was about what I was thinking of... then again, I'm totally new to nitro helis, so I may be out to lunch here... :dontknow

[BarracudaHockey]

Personally I dont think you need to mess with the gears to run a scale body. I'm getting the stuff together for a TT MD530 and I'm not worrying about replacing the gears infact I'm saving money and putting a stock OS50 non hyper in it, it just does not need the power that a hyper can make let alone cranking it up to 17K to tow around a scale body unless you live in the mountians of Switzerland or in Denver or something, even then the only thing I would do is run a hyper.

[HelicopterJohn]

Hi Rocket Man,

You said:

The tail pulleys are the same for both models, so you couldn't change that anyway.

That is true as TT doesn't offer a different tail rotor ratio.

I made a mod to all my Raptor 50's 2 V1's and 1 V2.

Raptor 50 Custom Tail Drive Speed up Gear

Raptor 50 (8 Tooth Rear Timing Belt Pulley) to replace the OEM 9 tooth pulley. The 8 tooth timing gear stock is available from SDP. You can drill the center to 5mm, machine the ends to accept tail belt guides, cross-drill the timing gear stock on one end to key to the tail rotor shaft and machine away the gear portion of the pinned end and enlarge OEM ID to fit new pulley. Use the OEM tail belt guide on the end opposite the pinned end. Here are a few pictures to show what I am talking about.

Tail Rotor Speed Comparison

1800 Headspeed X 4.30 = 7740 (TR) RPM (Excel)
1800 Headspeed X 4.66 = 8388 (TR) RPM (Tempest)
1800 Headspeed X 4.55 = 8190 (TR) RPM (OEM R50) 9 tooth pulley
1800 Headspeed X 5.12 = 9216 (TR) RPM (Mod R50) 8 tooth pulley
1850 Headspeed X 5.12 = 9472 (TR) RPM (Mod R50) 8 tooth pulley
1900 Headspeed X 5.12 = 9728 (TR) RPM (Mod R50) 8 tooth pulley
1950 Headspeed X 5.12 = 9984 (TR) RPM (Mod R50) 8 tooth pulley
2000 Headspeed X 5.12 = 10240 (TR) RPM (Mod R50) 8 tooth pulley

Important Safety Note: As you can see the Tail Rotor RPM's at 2000 headspeed are 10240 which is 1140 RPM over the OEM RPM of 9100.
Here is a link to the SDP page: http://www.sdp-si.com/D780/HTML2/D780Belt045.html Then go to the second (next) page (2-46). The page advance is up at top left. Part # 6A 2M08XL15 5.08mm Pitch, 8 Teeth, 200mm Long, Aluminum Pulley Stock Price $17.21 Plus shipping and handling. This price is a couple of years old and may have increased by now. Please verify this item for suitability prior to ordering. I originally got this information from John Benario. SDP Phone # 1.800.819.8900

DISCLAIMER: I can't attest to its suitability for use on the Raptor series of helicopters. Anyone considering making one of these units should carefully evaluate any and all safety and engineering concerns prior to its use. I assume no responsibility/liability as it pertains to its suitability for use.

One other individual has made some of these hubs and has experienced problems with the tail belt shredding after about 5 gallons of use. I personally have not encountered this issue and have about 2 ½ years of use on the unit I am currently running on my machine.. Anyone considering this modification should run the tail belt tight and monitor the tail belt for shredding. The hope is that with the extra RPM that tail rotor control will improve. I am currently running the stock TT tail blades. The "possible danger" is that with the extra RPM's the tail rotor hub may not be able to stand the extra load which could result in the loss of a tail rotor blade which could result in damage to the helicopter or personal injury.

I personally would not use the PV0031 tail hub (V1) as it has a very limited grip range for the screws utilized for the tail blade holders.

Just thought I would share this information for anyone that is interested in increasing the tail rotor RPM.

Here a few pictures of what I did.

[flyinfool]

Or if you do not have access to a lathe to make the tail pulley there is an 8 tooth pulley available from Gohbee. (http://www.gohbee.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=50139&Category_Code=1100)
As John said, do not use the stock raptor hub with the 8 tooth pulley.
I recommend either the steel hub from TT or the new heavy duty hub and grips with three bearings per grip, also available from Gohbee. (http://www.gohbee.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=50170&Category_Code=1100)

[Rocket Man]

Wow, this sure brings back some memories.

Back in 1981 - 1983, I was a Field Rep for American RC Helicopters (Revolution, Mantis, Supermantis, etc.). We were always doing experiments and changing gears. I may have been one of the first people to put an OS 50 into a helicopter back then. It was an odd sized engine and not popular with the plank guys, but it gave me the grunt I wanted to fly the old 40 size Supermantis. I worked with a company out in Long Island, NY and still have a bag full of gears.

Right now, I'm quite pleased with the new gear set on the Raptor 50 and the stock T/R drive works fine. (I run the Quick UK T/R blade holders.)

Like Andy, I have a Hughes (MD) 500 body (mine is the Funkey 500D) and will simply shove a stock Raptor 50 inside. I can always tear it down and change gears later.

Ron

[Rodan]

unless you live in the mountians of Switzerland or in Denver or something, even then the only thing I would do is run a hyper.

I do live at 5000ft so altitude is an issue... I guess I neglected to mention that...

I'm also planning on the TT MD530, converted to civilian. I just want to keep the headspeed around 1700, but still have enough power with the scale fuselage for decent climbout and to save things if necessary.

As a long time drag racer, I can tell you, having the right gearing for your torque curve is a beautiful thing! :mrgreen:

[Seeker]

So would changing the gears on a non-hyper 50 pay off too or not?

One of my raptors has a TT50 and the other is a non-hyper 50.

[jongurley]

Has anybody tried the new gears yet,,,

[Seeker]

I'll be trying them this week with the hyper 50 on a non-titan.

[jongurley]

Let us know how it is,,,

[Seeker]

I've made a few flights but don't have it tuned in yet... I would guess I'm running around 1900 headspeed and it's pretty constant through my maneuvers even though I'm not very good in collective management yet. I can hold a tumble with it forever now (I couldnt hold it forever before the re-gear as I lost headspeed). I need some good weather and the kitchen finished before I can get out there again and give you some numbers on the headspeed. I'm not running a gov.

I definitely had to change the throttle curves and give more rpm to the engine after I re-geared.

[BarracudaHockey]

I have the gears and a 611 for my Raptor 50 I'm just hesitant to mess with it as its flying so well right now.

[Seeker]

OK... i have about 1.5 gallons on the new geared hyper raptor.

I'm runing 1900 (plastic head) on the headspeed and rarley lose any headspeed (I'm not running a gov).

Running the OS Hyper with the MP2 pipe and the new gearing lets the engine rev to it's sweetspot so the power is awsome. Before I had to lower the throttle curve due to over speeding the head (over 2k without the lower gears).

The point here is the new gears allow the hyper with the MP2 run in the sweet spot of the engine/pipe and i have tons of power.

[Rodan]

Oops, forgot about this thread... :oops:

I'm running the lower gears (8.73:1) in my MD500 scaler. With the extra weight of the scale fuse, and my 5000ft altitude, it definitely helps. I still don't have the power I'd like, and may turn the headspeed up a bit more (at 1850 now).

I'm also running the MPIIQ pipe, and 30% cool power. Altitude's a b**ch! :bomb:

[KillerKanopies]

It seems the trend now is 2000+ head speeds to store up as much energy as possible, and +/- 13º of collective, so that when the collective stick is jabbed the heli will bite hard and leap. Why is everyone wanting to slow it down? I know the stock head components can't hold up the high head speeds. It seems to me to get better components and get that head wound up so the Hyper is happy and the blades will bite.

[Rodan]

I'm slowing it down for scale... for others it may be plastic head parts?? :dontknow

[Seeker]

I'm not doing anything that crazy... flips rolls and loops.. practicing inverted flight and I have a plastic head... I have enough head speed for what I fly and tons of power.

[KillerKanopies]

After getting my Raptor head all beefed up with metal head and grips, G-force mixing arms, and one piece fly bar cage, I cranked up the headspeed. With the 8.5:1 gears I could still kill the head speed and I still don't have the zippy collective I'm seeing with other helis. Now I have a new set of 8.7:1 gears setting on the bench to be installed. Hopefully by the end of this weekend I can find out if I've wasted my money.

[Raptile]

Report if there is a big diference ;)

[jongurley]

Yeh KillerKanopies let us know what happens over the weekend,

[KillerKanopies]

I got 5 tanks run thru the Raptor with the new gears. I think it was a good purchase. :glasses2:

[jongurley]

What can you tell the difference is if any,,

[UpInTheAir]

Hey just a note on the 50 gear ratio change. I put the titan tail boom, belt, optional gear set (8.72:1) and 620's on and what a differance. It is hard to bog it down with 14 degrees of pitch( it is possible, if I stay in it long enough though).

Running headspeed 1850 : 1950 for ballistic
I love it and won't go back.

Just my 2cents

[Lottomunch]

It cracked me up reading Rodan's comments about being a drag racer and how much gear ratio's "are a beautiful thing". I raced (just informal races) motorcycles up huge sand hills in the desert for years and if you took the time to change the rear sprocket on the bike to optimize the powerband to the transmission gears you made a huge difference in speed. Many times it was a difference of 3-4 bike lengths. I'd love to see a 8.9 and maybe even a 9.1 ratio for us to use. I'm honestly suprised they arn't out there. I'm personally scared of high head speeds. I'd rather be running a super torquey 1850 and 620 blades vs. a 2000 plus HS with 600's.

[KillerKanopies]

What can you tell the difference is if any,,

Oh yeah! Way less bog if I peg the collective and hold it there. I'm going to bump up the head speed a little more.

I think the last bit of icing for the cake will be a super fast servo for the collective control. Right now I've got an 8411. I'm going to try one of those JR DZ9000S's.