Dave's 80:1 RC mid drive kit build log

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
dtx
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Re: Dave's 80:1 RC mid drive kit build log

Post by dtx » Feb 05, 2018 6:59 am

Could you post a few pics of that setup? Might be a nice way to build a hidden on off/power switch

totolito
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Re: Dave's 80:1 RC mid drive kit build log

Post by totolito » Feb 07, 2018 11:45 am

Hello guys!

I'm glad to announce that I ordered the 6kW Tangent Kit :D :D

I was just being buy the battery but I have a small doubt.

I had planned to use the 6kW as a 3kW by limiting the max current, and so preserve my small battery which, up to this morning, was 4s+4s+6s built with Multistar 16000mAh lipo packs.

From HK:
(16Ah 10C) 4s: 80$ - 1390g
(16Ah 10C) 6s: 112$ - 2044g
--> So 14s1p 16Ah 10C for 272$ / 4.824kg

Now, I looked for increase the discharge rate (too hard to not use the full power of the 6kW :roll: )

From HK:
(8Ah 10C) 4s: 45$ / 0.705kg
(8Ah 10C) 6s: 50$ / 1.025kg
--> So 14s2p 16Ah 20C for 280$ / 4.87kg

Does it means that 14s1P is finally a bad choice !!!???




I also search for a meanwell able to charge the 14s (with three BattGo BG-8S for monitoring), but still not found. If someone have a solution for a bulk charge...
Waiting for my Tangent 6kW Kit :D

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tangentdave
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Feb 07, 2018 1:36 pm

https://www.aliexpress.com/wholesale?ca ... 4s+charger

You will want to balance charge the cells every chance you get, so I'd also think about: https://www.aliexpress.com/wholesale?ca ... s+bms+150A

8Ah of capacity is just not enough for 120A, I don't care what the C rate is, you want at least 16Ah for 120A. Remember, the engine is just a conversion device, it can only convert the power fed by the battery, so don't skimp. Voltage sag is the power killer destroyer of batteries.
Peregrine DH/Tangent 8kW
tangentmotors.com

12-C
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Re: Dave's 80:1 RC mid drive kit build log

Post by 12-C » Feb 08, 2018 12:47 am

totolito wrote:
Feb 07, 2018 11:45 am
Hello guys!

I'm glad to announce that I ordered the 6kW Tangent Kit :D :D

I was just being buy the battery but I have a small doubt.

I had planned to use the 6kW as a 3kW by limiting the max current, and so preserve my small battery which, up to this morning, was 4s+4s+6s built with Multistar 16000mAh lipo packs.

From HK:
(16Ah 10C) 4s: 80$ - 1390g
(16Ah 10C) 6s: 112$ - 2044g
--> So 14s1p 16Ah 10C for 272$ / 4.824kg

Now, I looked for increase the discharge rate (too hard to not use the full power of the 6kW :roll: )

From HK:
(8Ah 10C) 4s: 45$ / 0.705kg
(8Ah 10C) 6s: 50$ / 1.025kg
--> So 14s2p 16Ah 20C for 280$ / 4.87kg

Does it means that 14s1P is finally a bad choice !!!???




I also search for a meanwell able to charge the 14s (with three BattGo BG-8S for monitoring), but still not found. If someone have a solution for a bulk charge...

I used 5ah packs paralleled for total 20ah. running 14s. The benefit of more packs is that you are effectively drawing less amps per pack and smaller batteries with better quality cells are less expensive then the comparable larger capacity (at least that's how it worked out when I was looking for these...) This way I see minimal Vsag and minimal Vripple.

I charge with a http://www.revolectrix.com/GT1000DUO_de ... on_tab.htm
It can provide 40A per port, I use some server power supplies to power the charger. The power supplies are incredibly robust and really cheap used!

You need to remember that the reason you are buying a 6Kw motor is so you can ride like a maniac, and riding like a maniac get you less then nominal capacity when you are using high current rate, again another reason why using several smaller capacity packs in a larger parallel arrangement may be more beneficial once again.... your overall capacity may slump less even for the same choice of throttle use :D

totolito
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h

Post by totolito » Feb 08, 2018 3:32 am

tangentdave wrote:
Feb 07, 2018 1:36 pm
8Ah of capacity is just not enough for 120A, I don't care what the C rate is, you want at least 16Ah for 120A. Remember, the engine is just a conversion device, it can only convert the power fed by the battery, so don't skimp. Voltage sag is the power killer destroyer of batteries.
Hello Dave,

I was not enough clear in my previous post. I plan to use 2 8Ah in parallel instead of one 16Ah :wink:

Thanks to 12-C for the confirmation.
Waiting for my Tangent 6kW Kit :D

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tangentdave
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Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Feb 08, 2018 12:08 pm

Pic of Mike's clever ebrake/glove solution:

20180207_141022.jpg
20180207_141022.jpg (178.85 KiB) Viewed 393 times
Peregrine DH/Tangent 8kW
tangentmotors.com

12-C
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Re: Dave's 80:1 RC mid drive kit build log

Post by 12-C » Feb 08, 2018 12:40 pm

That's very neat.

I wonder if it might be possible to place a sensor under the rubber of the partial twist grip throttle....

Mugenski
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Re: Dave's 80:1 RC mid drive kit build log

Post by Mugenski » Feb 17, 2018 2:50 am

I like that grip safety, pretty slick. Would have saved me from my own stupidity at least once :wink:

Dave how have your IGH setups held up in the long run?

Also I wonder what type of temps this little res/pump can handle.
Last edited by Mugenski on Feb 19, 2018 12:14 am, edited 2 times in total.
Giant Glory Tangent 6kw @ 44v - Soon to be 52v

aCeMadMod
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Re: Dave's 80:1 RC mid drive kit build log

Post by aCeMadMod » Feb 17, 2018 9:32 am

hi Dave is your new gearbox only 20.1 or are sill makeing the 40.1 gearbox if ask for 8)



and what the Mike's clever ebrake/glove solution: for ? is a cut off I guess
thank you

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