# Tesla P85 dual shaft?



## Kevin Sharpe (Jul 4, 2011)

Snakub said:


> Is it possible to put a shaft on the other end of a telsa motor?


Almost anything is 'possible' but this would be classed as extremely difficult by most people.

A more realistic approach IMO is to use modified gearing in the transmission case. This allows you to play with final drive ratios and remove the differential if you require a fixed drive shaft.

Chris Hazell is doing a lot of work inside the Tesla drive unit... watch this space 

http://www.diyelectriccar.com/forums/showpost.php?p=990569&postcount=23


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## Snakub (Sep 8, 2008)

Well I'm trying to connect about 6 of them together in series mechanically. Any idea how?


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## Hollie Maea (Dec 9, 2009)

Snakub said:


> Well I'm trying to connect about 6 of them together in series mechanically. Any idea how?


I doubt the shaft is rated for six times as much torque...


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## steveob (Nov 10, 2017)

Snakub said:


> Well I'm trying to connect about 6 of them together in series mechanically. Any idea how?


Ask yourself if the motor shaft of the one on the load end can handle 6x the torque for starters.


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## Karter2 (Nov 17, 2011)

Snakub said:


> Well I'm trying to connect about 6 of them together in series mechanically. Any idea how?


 ?? Radial arrangement around a central power take off gear ?
Similar to the way AMG did it with their "Eboat" (only 3 motors though)
https://goo.gl/images/EJZzmA
Its going to be a big unit,....but it will be that either way you configure them.


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## steveob (Nov 10, 2017)

man that is some fckery. I mean if you are into cable porn for it's own sake, maybe, but what the hell?!?


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## Jimbo69ny (Feb 13, 2018)

And here I am building a range extending battery trailer... This must be the thread for billionaires. lol


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## Karter2 (Nov 17, 2011)

To be honest, im not sure that AMG /Cigarette boat ever got beyond someones CGI renderings . I dont think its ever been seen in public .
But the design concept and details are impressive,


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## PAXtss (Dec 16, 2017)

I wonder what they are using for sound. No such thing as a quiet cigarette boat.


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## Jimbo69ny (Feb 13, 2018)

PAXtss said:


> I wonder what they are using for sound. No such thing as a quiet cigarette boat.


I figured they would be playing this the whole time.
https://www.youtube.com/watch?v=R7yfISlGLNU


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## Snakub (Sep 8, 2008)

Correct me if I'm wrong but on most model s if not all arent two motors hooked together at a gearbox anyway. So then the output shafts can already handle twice the output.


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## electro wrks (Mar 5, 2012)

What looks like a second motor on the rear drive of the S and X is actually the enclosure for the motor control inverter. Look-up Tesla inverter and you'll see inside the cylindrical enclosure.

The new Roadster has dual rear motors (and a single in front).


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## Kevin Sharpe (Jul 4, 2011)

Snakub said:


> Correct me if I'm wrong but on most model s if not all arent two motors hooked together at a gearbox anyway.


further to electro_wrks post you'll find lots of useful photos and videos on Damiens thread;

http://www.diyelectriccar.com/forums/showthread.php/diy-tesla-controller-185753.html


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## boekel (Nov 10, 2010)

Snakub said:


> Is it possible to put a shaft on the other end of a telsa motor?


If you can work with the reduced RPM, this might be possible:

http://www.diyelectriccar.com/forums/showthread.php?t=117849


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## steveob (Nov 10, 2017)

Karter2 said:


> But the design concept and details are impressive,


To me it looks like the rube goldberg version of a fan motor. I mean I get having some redundancy, but they seem to have taken it to places it was never meant to go. two packs and two motors and controllers would do nicely (and be more efficient), but they have 12 motors and 12 "controllers" and there is another controller looking thing upstream from the controllers, perhaps to reconfigure the battery or something, and wires everywhere. I don't know if "impressive" is the word I would use, especially with the efficiency hit and over-complicated layout.


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## Snakub (Sep 8, 2008)

The Tesla drive does seem to be quite expensive and the concept I had in mind hinged mainly on finding them salvaged. Is there anything of similar power ac off the shelf preferably with dual shaft?


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## Karter2 (Nov 17, 2011)

steveob said:


> To me it looks like the rube goldberg version of a fan motor. I mean I get having some redundancy, but they seem to have taken it to places it was never meant to go. two packs and two motors and controllers would do nicely (and be more efficient), but they have 12 motors and 12 "controllers" and there is another controller looking thing upstream from the controllers, perhaps to reconfigure the battery or something, and wires everywhere. I don't know if "impressive" is the word I would use, especially with the efficiency hit and over-complicated layout.


 I think you missed the point..
They could have done many things differently, different motors, batteries, drive units, evn the colour could have been "different" 
....but the thing was a "showcase" for AMG/Cig" technology, ...deliberately laid out and presented to draw attention and comment.
If they wanted it to be practical and competitive, it would likely have had 4 Lamborghini 7 ltr marine ICEs !
Remember the OP was asking for ideas on how to couple 6 Tesla motors to one output....the boat was just an illustration to suggest how it could be done.


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## brian_ (Feb 7, 2017)

Snakub said:


> Is there anything of similar power ac off the shelf preferably with dual shaft?


I don't think you'll find any modern EV motor with a dual-ended shaft, because there is no reason to want two shaft outputs. In those rare cases where a motor is designed to be stacked end-to-end (transmitting each motor's output through the next motor's shaft), it will probably have a female spline in one end, rather than two protruding shafts. The YASA 400 is an example of a motor which has a female spline right through it, so multiple motors can be stacked on one splined shaft.

Typically "pancake" style motors (relatively large diameter and axially short) are more likely to be designed to stack; YASA is an example.



Snakub said:


> The Tesla drive does seem to be quite expensive and the concept I had in mind hinged mainly on finding them salvaged.


Tesla Model S/X motors are the most common EV motors which are available in salvage and have a high power rating in the original vehicle. On the other hand, most EV manufacturers rate their motors for continuous duty, and some of those motors may be just as capable as Tesla's.

At some point the costs of extra mechanical complexity and multiple inverters will probably exceed the cost of just getting the right motor to start. That silly cigarette boat is designed to be visibly expensive - it's all about conspicuous consumption.

There are some really big motors made for large vehicles. Pushed to higher than rated power for brief periods (and a Tesla motor can only produce its rated power for a brief period), just one of them might be a better solution. TM4 makes some big stuff for trucks and buses, but I don't know how to get them at retail.


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## brian_ (Feb 7, 2017)

electro wrks said:


> The new Roadster has dual rear motors...


... and even then, each motor will presumably drive a separate wheel; it would make no sense for Tesla to use to motors to drive one shaft.

The Fisker Karma does have two motors driving the rear axle, but that was likely a matter of what off-the-shelf motor and inverter they could get, and perhaps the difficulty of finding the right location for one really large motor. These two motors are not directly connected to each other - they drive two separate inputs of one gearbox.


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