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Oct 07, 2019, 01:23 PM
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Trex 450 with scale fuselage and 4 blade head


So I am working on a scale heli and I put a 4 blade rotor head on it. Do you think my stock motor and ECS will be good enough the power it or will I need something different? I'm not doing 3D with it just casual flight.

I was told Keyrigger could help.
Thank you in advance
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Oct 07, 2019, 01:26 PM
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Here's the heli and fuselage. I will be running 4 of the same blades but not those ones
Oct 07, 2019, 05:47 PM
Love my scale Whirlybirds
Keyrigger's Avatar
Hi:

Although the stock motor can power the helicopter, I would recommend that you move to a smaller pinion. It's been a few years since I did anything with a 450 but I would change, at least, to an 11 tooth pinion vs. the stock 13 tooth that is common to Align 450 installations. The factory motor kv is 3700, which when used with a 13 tooth pinion and the 150 tooth main gear, will give you a very high 3053 rpm governed at 92% (3301 rpm wide open) which will put a lot of strain on the head. Your four blade head was not meant to take that type of load. Dropping it to an 11 tooth main will bring you down to 2580 rpm governed at 92% (2791rpm wide open) and will take a lot of wear and tear from the head. This is all based on setting up your ESC in a governed mode so that you will be running a constant rpm and flying by pitch. You can setup a motor curve if you cannot set your ESC up in a governed mode and this is what I would recommend.

I would set a motor curve up for Normal at 0 - 45 - 65 - 70 - 70. For Idle 1, set it to 70 - 70 - 65 - 70 - 70. For Idle 2, try 80 - 75 - 70 - 75 - 80 and see how these three feel. Do not exceed 90 on your throttle curve or it will spin the four blade head a bit too fast. If you are wanting to keep the rpm down to a more sedate level, then try the motor that I have in my A109 that has a four blade head. I have the Scorpion 2221-12 motor that is 2580kv and uses the stock 13 tooth pinion and 150 tooth main. I has been a few years now since I have flown it but recently I spooled it up for some pictures and it is as smooth as silk. I run my A109 with a throttle curve and not governed so I know it works in the real world. Hope this helps.

Don
Last edited by Keyrigger; Oct 07, 2019 at 05:53 PM.
Oct 07, 2019, 07:50 PM
Registered User
Thread OP
Quote:
Originally Posted by Keyrigger
Hi:

Although the stock motor can power the helicopter, I would recommend that you move to a smaller pinion. It's been a few years since I did anything with a 450 but I would change, at least, to an 11 tooth pinion vs. the stock 13 tooth that is common to Align 450 installations. The factory motor kv is 3700, which when used with a 13 tooth pinion and the 150 tooth main gear, will give you a very high 3053 rpm governed at 92% (3301 rpm wide open) which will put a lot of strain on the head. Your four blade head was not meant to take that type of load. Dropping it to an 11 tooth main will bring you down to 2580 rpm governed at 92% (2791rpm wide open) and will take a lot of wear and tear from the head. This is all based on setting up your ESC in a governed mode so that you will be running a constant rpm and flying by pitch. You can setup a motor curve if you cannot set your ESC up in a governed mode and this is what I would recommend.

I would set a motor curve up for Normal at 0 - 45 - 65 - 70 - 70. For Idle 1, set it to 70 - 70 - 65 - 70 - 70. For Idle 2, try 80 - 75 - 70 - 75 - 80 and see how these three feel. Do not exceed 90 on your throttle curve or it will spin the four blade head a bit too fast. If you are wanting to keep the rpm down to a more sedate level, then try the motor that I have in my A109 that has a four blade head. I have the Scorpion 2221-12 motor that is 2580kv and uses the stock 13 tooth pinion and 150 tooth main. I has been a few years now since I have flown it but recently I spooled it up for some pictures and it is as smooth as silk. I run my A109 with a throttle curve and not governed so I know it works in the real world. Hope this helps.

Don
Yes thank you. This is my first scale build and kind of new to heli's. I flew a little about 15 years ago with a Raptor 30 and a 400 electric but got too busy with work and now I'm getting back into it. I haven't flown much on throttle up yet. Just normal mode with pitch curve and throttle curve together. I'll look for an 11 tooth to start with.
Oct 09, 2019, 06:00 PM
Registered User
Thread OP
Quote:
Originally Posted by Keyrigger
Hi:

Although the stock motor can power the helicopter, I would recommend that you move to a smaller pinion. It's been a few years since I did anything with a 450 but I would change, at least, to an 11 tooth pinion vs. the stock 13 tooth that is common to Align 450 installations. The factory motor kv is 3700, which when used with a 13 tooth pinion and the 150 tooth main gear, will give you a very high 3053 rpm governed at 92% (3301 rpm wide open) which will put a lot of strain on the head. Your four blade head was not meant to take that type of load. Dropping it to an 11 tooth main will bring you down to 2580 rpm governed at 92% (2791rpm wide open) and will take a lot of wear and tear from the head. This is all based on setting up your ESC in a governed mode so that you will be running a constant rpm and flying by pitch. You can setup a motor curve if you cannot set your ESC up in a governed mode and this is what I would recommend.

I would set a motor curve up for Normal at 0 - 45 - 65 - 70 - 70. For Idle 1, set it to 70 - 70 - 65 - 70 - 70. For Idle 2, try 80 - 75 - 70 - 75 - 80 and see how these three feel. Do not exceed 90 on your throttle curve or it will spin the four blade head a bit too fast. If you are wanting to keep the rpm down to a more sedate level, then try the motor that I have in my A109 that has a four blade head. I have the Scorpion 2221-12 motor that is 2580kv and uses the stock 13 tooth pinion and 150 tooth main. I has been a few years now since I have flown it but recently I spooled it up for some pictures and it is as smooth as silk. I run my A109 with a throttle curve and not governed so I know it works in the real world. Hope this helps.

Don
Hello Don I also currently have a Raptor 50 and an MD 500 canopy it's a Nitro heli I would like to convert it to electric and have enough power to power the scale fuselage if you can tell me the Spec's for the motor and motor mount that I need and possibly pinion gear?
Thank you in advance
Oct 11, 2019, 07:37 AM
Love my scale Whirlybirds
Keyrigger's Avatar
Hi:

I really don't have any experience with the nitro helicopter conversion. I would check what gear ratio you have , like 9:1, for example, and do a bit of math. You should look for a final head speed of 1500 to 1700. On a .50 size helicopter, a 6s system is possible but look at others like 8 to 12s as candidates.

I can give you a couple of examples that can help you figure out what direction you might go. I have a 600EFL Pro that uses 12s for power. The motor is a 450kv 4035 series Scorpion. It is coupled to an 10 tooth pinion and a 118 tooth main gear. I used to have a 550 size that I used a 15 tooth main gear and a 170 tooth main gear coupled to a 960kv Scorpion 4025 series motor. I am not sure about what gears might be available but I doubt there are too many spares around these days. Hope this helps.

Don
Oct 11, 2019, 07:40 AM
Registered User
Thread OP
Quote:
Originally Posted by Keyrigger
Hi:

I really don't have any experience with the nitro helicopter conversion. I would check what gear ratio you have , like 9:1, for example, and do a bit of math. You should look for a final head speed of 1500 to 1700. On a .50 size helicopter, a 6s system is possible but look at others like 8 to 12s as candidates.

I can give you a couple of examples that can help you figure out what direction you might go. I have a 600EFL Pro that uses 12s for power. The motor is a 450kv 4035 series Scorpion. It is coupled to an 10 tooth pinion and a 118 tooth main gear. I used to have a 550 size that I used a 15 tooth main gear and a 170 tooth main gear coupled to a 960kv Scorpion 4025 series motor. I am not sure about what gears might be available but I doubt there are too many spares around these days. Hope this helps.

Don
Yes thank you


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