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RCHover . ZoomsHobbies . Autography FlightPower

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e-Electric Conversions > eRaptor 50 pinion
 
 
RS2K
Heliman
Location: Wichita, KS

I have an eRaptor 50 that is getting ready to fly but I don't know what do do about the gear ratio.

Here is my setup:
Raptor 50 with eCCPM upgrade
3 9252s on swash
1 gy401/9253 on rudder
1 Hacker A50-12S
1 CC85HV
1 medusa BEC
86T main gear
9T pinion
10S2P A123 pack

It seems I can only get 1550 RPM out of this setup. If I want to use 10S2P A123s then it seems I need to get another pinion. What kind of effect will this have? Where can I get the pinion? What diameter pinion do I need? I think that putting an 11 tooth pinion will do what I need to do. Or I may have to consider running 15S1P A123s and use a separate RX bat.
09-21-2007 06:09 AM
 
 
stanc
Veteran
Location: Conroe, TX

With a converted Raptor 50, your stuck with either an 86/9 or an 85/10. What conversion did you use, if you used the tppacks.com conversion then the only two pinions that you can use are the stock Raptor pinions because they fit inside the stock bottom starter bearing and there is no adjustment. If you look at my thread about the Belt Drive, you'll see I have the ability to use a variety of gear ratios.

Stanc

Stan
Will Work for Electrons
09-21-2007 11:18 AM
 
 
RS2K
Heliman
Location: Wichita, KS

It is the tppacks conversion. It looks like I'll need to run a 12S A123 pack to get the head speed I need while still allowing the BEC to work. The problem is that I only have 20 A123 cells so I can only make a 12S1P pack. Any idea what the flight time might be on that?

I think I need to get the 8.5 gear ratio and use the 10S2P pack for now.

Opinions?
09-21-2007 02:16 PM
 
 
RS2K
Heliman
Location: Wichita, KS

I just picked up a 10 tooth pinion and an 85 tooth main gear... Let's see how this works!
09-22-2007 12:57 PM
 
 
stanc
Veteran
Location: Conroe, TX

Is this tppacks conversion, the older direct drive or the conversion to make it like the e620? If its the e620 conversion where the motor is mounted in the rear on top, then you can use different pinions. I think you will find the Hacker runs to hot and you will lose efficiency toward the end of the flight as the motor heats up.
If the A50-12S is 500kV, a 10S will give a HS of a little over 2100 at 100%. The Z-Power motors run cooler and I have found them to have a lot more power.

A50-12S
500 x 36 (12x3) / 8.5 = 2117 @ 100%

Z50A-600
565 x 36 / 8.5 = 2392 @ 100% (85/10)
565 x 36 / 9.55 = 2129 @ 100% (86/9)

If you are going to run the ESC in governor mode, you will need to dial down your throttle curve to give the governor some head room. If your wanting to run around 21 to 2200 HS then the Z50A-600 with the 10T pinion is the best choice.

I would expect the flight times to be from 5 minutes to 7 minutes, depending on how you fly.

Stanc

Stan
Will Work for Electrons
09-24-2007 12:12 PM
 
 
RS2K
Heliman
Location: Wichita, KS

How about this? The hacker A50-12S has 492kv so I am thinking of keeping my battery pack a 10S2P A123 and getting a Z-Power Z50A-800 at 780kv. With a 9.55 gear ratio I should get a head speed of 2200 - 2300 RPMs at 100%. I can then dial it down to 2100 RPMs. I can then use the Hacker on an airplane.
09-26-2007 03:42 AM
 
 
stanc
Veteran
Location: Conroe, TX

At 30v, the head speed would be 2450. However the 3v per cell want last long with A123 cells, so what a lot of guys do is set Idle1 at say 85 andIdle2 at 95 or even 100 and when the HS starts to drop because the voltage is dropping they switch to Idle2. I think you will like the Z50A-800 a lot more than the Hacker. Now if tppacks can get some stock, you'll be in good shape.
Let me know if you need a motor quick.

Stanc

Stan
Will Work for Electrons
09-26-2007 04:45 AM
 
 
RS2K
Heliman
Location: Wichita, KS

I think I read somewhere that at speeds above 2300 I need metal blade grips. I have a metal head block but I don't have metal blade grips. What kind of flight times would I get at such a fast head speed? Will I loose much efficiency by lowering the head speed to 2000 - 2100? I never remember head speeds like this with my nitro helis.
09-26-2007 04:56 AM
 
 
stanc
Veteran
Location: Conroe, TX

You would need metal blade grips anyway in my opinion. By lowering the HS you gain flight time. If your concerned about flight time you don't need to build an electric heli with A123 cells, even if you do a 10S2P.

Stanc

Stan
Will Work for Electrons
09-26-2007 11:09 AM
 
 
RS2K
Heliman
Location: Wichita, KS

My ears are used to having a nitro engine in the background. I just tached my head speed and got 1840 at spool up and 1800 the rest of the flight. I thought I was only running 1600 or so. I was not impressed with the setup yesterday but after increasing the pitch from +/- 10 to +/- 12 I am now very pleased! I can tell it has more power than my nitro Raptor 50 did at the same head speed. The motor did not bog on full collective pull outs like I thought it would.

I am not too concerned about flight time. I flew the A123s until I could barely hover. I then did a full recharge at 20 amps and 15 minutes later I'm ready to fly. It's also nice to be able to charge the batteries in the aircraft frame.
09-26-2007 04:09 PM
 
 
stanc
Veteran
Location: Conroe, TX

I think the max amps charge is 8 or 10 amps, what kind of charger did you use to put out 20.

Stanc

Stan
Will Work for Electrons
09-27-2007 03:28 AM
 
 
RS2K
Heliman
Location: Wichita, KS

I am charging these batteries using a mastech 5020. Maximum charge rate is 10 amps per 2300 mah so I charge the 10S2P at 36.2 volts and 20 amps. It takes 14 minutes to do a full charge
09-27-2007 05:16 AM
 
 
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e-Electric Conversions > eRaptor 50 pinion
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