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ericrechlin · 08-27-2015, 05:09 PM

Im starting with a trex500 dfc pro. I bought the Castle Talon 90 esc. I'm switching the head to a non dfc head for lower head speed. What KV motor should I go with? The brand of motor doesn't matter. I'm trying to not go with a scorpion. Also is there a proper pinion and main gear size I should start with? Thank you and I appreciate any input

TR450ZS · 08-28-2015, 12:26 AM

What headspeed do you want to run at, what heli is this going into? Need to know this before we can give any advice.

Andy01 · 08-28-2015, 04:19 AM

Yup, need details as above. Current gears, flying style, # of blades etc ?

RPM = kV x (3.7V x # of cells) x 0.9 x pinion teeth / main gear teeth = rpm at 100% towards the end of the flight.

For CC ESCs you want to run the governor between 90-95%.

My 500 sized UH-1N runs at 1700rpm - not sure if this what you had in mind with "low headspeed" ?

Colin

ericrechlin · 08-28-2015, 11:34 AM

I'm new to this for sure. I just want my 500 set up right the first time so I don't need to keep switching out anything as I go. Scale is what I've always wanted to do. Thank you for your input

ericrechlin · 08-28-2015, 11:36 AM

I'm going with the AS350 fuse from RC Areodyne. I'm looking maybe 1200 or so for head speed. Starting with a 2 blade non dfc head. I don't have the pinion and main gear yet. I just would like to set up my trex500 pro the right way out the gate.

Andy01 · 08-29-2015, 03:20 AM

I would not recommend going as low as 1200rpm on a 500, especially with only two blades. It may fly, but I suspect that you will have a number of problems, starting with poor tail response.

I am afraid I can't be of more help until the number of variables are narrowed down. Looking at the calculation above that only that seems even potentially known is that it is likely to be 6s - with no gearing it is impossible to determine a motor kV.

Perhaps set yourself up a spreadsheet where you can input the available gear data, and get some options for a motor. I think you may struggle to find a 500 sized motor that is around 800kV ( a guess).

Good luck with your project and keep us updated with how it goes.

Colin

ericrechlin · 08-29-2015, 07:34 AM

Thank you for the response. I'm trying to get any info I can but I'm guessing I'll set it up with what I have for a motor and test things as I go. I'm new to all of this is my problem. Thank you for your input again. I greatly appreciate any response.

08-27-2015, 05:09 PM	#1 (permalink)
ericrechlin Registered Users Join Date: Aug 2011	Scale helicopter low head speed question Im starting with a trex500 dfc pro. I bought the Castle Talon 90 esc. I'm switching the head to a non dfc head for lower head speed. What KV motor should I go with? The brand of motor doesn't matter. I'm trying to not go with a scorpion. Also is there a proper pinion and main gear size I should start with? Thank you and I appreciate any input

08-28-2015, 12:26 AM	#2 (permalink)
TR450ZS Registered Users My HF Map location Join Date: Apr 2013	What headspeed do you want to run at, what heli is this going into? Need to know this before we can give any advice. __________________ Allan TREX 250 PRO,Talon15, GPRO, Zeal ----TREX 500 EFL PRO, GPRO, RAILS ----2x TREX 450PRO V2, 1xGPRO&1xBRAIN, Talon35, RAIL , Zeal ---- SAVOX powered TREX500 EFL in Roban scale UH1-N ---- TREX 600 EFL PRO, GPRO, RAILS ---- DX9 ----

08-28-2015, 04:19 AM	#3 (permalink)
Andy01 Registered Users Join Date: Apr 2008	Yup, need details as above. Current gears, flying style, # of blades etc ? RPM = kV x (3.7V x # of cells) x 0.9 x pinion teeth / main gear teeth = rpm at 100% towards the end of the flight. For CC ESCs you want to run the governor between 90-95%. My 500 sized UH-1N runs at 1700rpm - not sure if this what you had in mind with "low headspeed" ? Colin __________________ Vario Long Ranger 700e Seahawk 600 UH-1N 500 Baumann EC-145 800+ (coming soon )

08-29-2015, 03:20 AM	#6 (permalink)
Andy01 Registered Users Join Date: Apr 2008	I would not recommend going as low as 1200rpm on a 500, especially with only two blades. It may fly, but I suspect that you will have a number of problems, starting with poor tail response. I am afraid I can't be of more help until the number of variables are narrowed down. Looking at the calculation above that only that seems even potentially known is that it is likely to be 6s - with no gearing it is impossible to determine a motor kV. Perhaps set yourself up a spreadsheet where you can input the available gear data, and get some options for a motor. I think you may struggle to find a 500 sized motor that is around 800kV ( a guess). Good luck with your project and keep us updated with how it goes. Colin __________________ Vario Long Ranger 700e Seahawk 600 UH-1N 500 Baumann EC-145 800+ (coming soon )

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08-28-2015, 11:34 AM	#4 (permalink)
ericrechlin Registered Users Thread Starter Join Date: Aug 2011	I'm new to this for sure. I just want my 500 set up right the first time so I don't need to keep switching out anything as I go. Scale is what I've always wanted to do. Thank you for your input

08-28-2015, 11:36 AM	#5 (permalink)
ericrechlin Registered Users Thread Starter Join Date: Aug 2011	I'm going with the AS350 fuse from RC Areodyne. I'm looking maybe 1200 or so for head speed. Starting with a 2 blade non dfc head. I don't have the pinion and main gear yet. I just would like to set up my trex500 pro the right way out the gate.

08-29-2015, 07:34 AM	#7 (permalink)
ericrechlin Registered Users Thread Starter Join Date: Aug 2011	Thank you for the response. I'm trying to get any info I can but I'm guessing I'll set it up with what I have for a motor and test things as I go. I'm new to all of this is my problem. Thank you for your input again. I greatly appreciate any response.

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