# Tail Shaft Question



## SCEV (Apr 10, 2012)

Does the tail shaft do a DC motor spin only when the main/drive shaft is spinning, or is it independent? Reason I'm asking is I'm thinking of using the tail shaft to turn a belt connected to my stock AC compressor, but if both shafts are connected, how do you turn the compressor when stopped?


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## RIPPERTON (Jan 26, 2010)

SCEV said:


> how do you turn the compressor when stopped?


You dont.
You could get away with it, stopping the compressor when when at the lights.
You would notice a slight rise in cabin temp if you were stopped for a minute
or more.
Ive often turned my AC off but kept the fan running and still get cold air for a minute.


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## DIYguy (Sep 18, 2008)

SCEV said:


> Does the tail shaft do a DC motor spin only when the main/drive shaft is spinning, or is it independent? Reason I'm asking is I'm thinking of using the tail shaft to turn a belt connected to my stock AC compressor, but if both shafts are connected, how do you turn the compressor when stopped?


It's all the same shaft. If you want to run AC while stopped from the aux shaft, you need to buy an EVnetics controller. AFAIK, it's the only one with an idle function.


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## GuySmily (May 11, 2012)

DIYguy said:


> It's all the same shaft. If you want to run AC while stopped from the aux shaft, you need to buy an EVnetics controller. AFAIK, it's the only one with an idle function.


That's a good point. I never thought I would need idle capability, but here in Sacramento, the stoplights are too long and the summers too hot (up to 110F, but maybe someone outside of California will make fun of me).

Maybe Tesseract or someone with experience will chime in: What happens if you "stall" the motor by braking to a stop in gear? I don't remember seeing much info on the idle behavior in the Soliton manual.


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## Ziggythewiz (May 16, 2010)

110F? That's like what, 80 in Houston?


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## GuySmily (May 11, 2012)

I prefer temps around 60-70F, 75 max before I start looking for a fan or AC. I grew up in the fog near San Francisco (San Bruno, Pacifica, Daly City, etc), and I never got used to warmer weather. Don't think I would survive out in TX.

Anyway, to continue on about my AC dream...
It'd be ideal if the idle function could be turned on/off on the fly / while driving (like if I click the AC on, the idle would also be enabled).

I can see a few different options for resuming idle if I brake to a total stop with the AC (and thus idle) turned on:
Option 1. Shift to neutral (neutral sensor required) and have the motor idle up by itself (after a few seconds delay, maybe).
Option 2. Shifting to neutral (neutral sensor NOT required), and leave the motor "stalled" until I tap the gas pedal.
Option 3. "Start" the car again (Start input required). Not sure if the Soliton uses a continuously-on start signal here, or if it accepts a pulse (equivalent to cranking an engine or push-button start), but that might affect whether or not this is a viable option.

Can the Soliton do this? The programming for this actually sounds like it'd be fun (not that the end user would ever see/do it besides enabling it - it just seems like Qer has a cool job). What language is the Soliton's software written in anyway?

The majority of the time that I'm running the AC, I would probably drag the motor down to 0 rpm (no clutch/neutral) just to emulate "auto-stop." If I get too hot, I could follow whichever option (above) to get my AC going again, but otherwise I could leave it off to save battery.


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## dougingraham (Jul 26, 2011)

GuySmily said:


> Maybe Tesseract or someone with experience will chime in: What happens if you "stall" the motor by braking to a stop in gear? I don't remember seeing much info on the idle behavior in the Soliton manual.


I dont know what the controller will do. Probably it will increase the current to to try to maintain the idle rpm up to the point where something breaks. But why would you do this. Just step on the clutch like you would with an ICE. I suppose you are doing a clutchless conversion which would answer that.

I've been using the Soliton 1 idle function to break in my brushes so I have a little experience with the feature. There is no way currently to dynamically turn it on and off that I can see.


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## GuySmily (May 11, 2012)

My real concern was someone forgetting that they turned the AC/idle on, and they braked to a stop because they're not used to shifting to neutral like they would in an ICE car. I'll be keeping my clutch and I don't think forgetting will be an issue personally. However, handling a "stall" situation is still something that the controller designer would have to account for to prevent damage or danger (and I'm sure Evnetics has handled it somehow).


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## njloof (Nov 21, 2011)

"No A/C compression while stopped" isn't that bad -- early generation Priuses worked that way too. The A/C still blows cool for a minute or so.


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## z_power (Dec 17, 2011)

How about having separate 1.5-2 kW motor coupled with A/C compressor? Pump motors from small pallet lifts woul be suitable, the problem is that you'd need another controller to feed it with pack voltage (these motors usuallly are fed with 12-24v) or powerful DC/DC converter from pack V to 12/24V. Hardcore version would be using compressor from hybrid Toyoda or Honda coupled via small VFD to high voltage battery... just thinking out loud  Oh, and you can find compressor/motor combos in cooling agregats for fridge vans...


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## somanywelps (Jan 25, 2012)

z_power said:


> How about having separate 1.5-2 kW motor coupled with A/C compressor? Pump motors from small pallet lifts woul be suitable, the problem is that you'd need another controller to feed it with pack voltage (these motors usuallly are fed with 12-24v) or powerful DC/DC converter from pack V to 12/24V. Hardcore version would be using compressor from hybrid Toyoda or Honda coupled via small VFD to high voltage battery... just thinking out loud  Oh, and you can find compressor/motor combos in cooling agregats for fridge vans...


Just feed from your 12v bus...

You already have a DC-DC


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## DIYguy (Sep 18, 2008)

GuySmily said:


> I prefer temps around 60-70F, 75 max before I start looking for a fan or AC. I grew up in the fog near San Francisco (San Bruno, Pacifica, Daly City, etc), and I never got used to warmer weather. Don't think I would survive out in TX.
> 
> Anyway, to continue on about my AC dream...
> It'd be ideal if the idle function could be turned on/off on the fly / while driving (like if I click the AC on, the idle would also be enabled).
> ...


Just my opinion, . . .but, u don't want to set up some kludgy operational method for a car specific to your car alone. Make it work like a normal car as much as possible, then anyone can drive it. 
Obviously, clutch less and idle function are mutually exclusive. If u r using the clutch then, drive it like a regular standard car. 
What do you mean by "shifting to neutral like an ICE car"?. Most people just shift to 1st gear and leave the clutch depressed. . . unless it is unusually long stop.
Otherwise, go with the A/C kit from Masterflux or fit one from an OEM car with electric A/C. 
Here is a list of them from 2008;
Chevrolet Tahoe Hybrid
GMC Yukon Hybrid
Honda Civic Hybrid
Lexus GS 450h
Lexus LS 600h
Lexus RX 400h
Nissan Altima Hybrid
Toyota Camry Hybrid
Toyota Highlander Hybrid
Toyota Prius

I agree that short stops won't bother u too much if the AC is not driven.


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## subcooledheatpump (Mar 5, 2012)

Get a seperate compressor, then a reversing valve. Now you have heating and cooling. 

Someone mentioned using a VFD and a high voltage compressor and a high voltage battery. Thats exactly what I intend to do with my van. As others have said though, a lower voltage seperate compressor would probably be best. There are 12v compressors on the market/ebay. They aren't very big but they could do the job. As long as they can take R-134a you are good to go


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## Tesseract (Sep 27, 2008)

GuySmily said:


> ...
> Maybe Tesseract or someone with experience will chime in: What happens if you "stall" the motor by braking to a stop in gear? I don't remember seeing much info on the idle behavior in the Soliton manual.


 Idle is described on p18 of the manual.

You can stop idle by stalling the motor and re-engage it by accelerating the motor past its idle RPM setting.


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