In wheel motor info and issues

[mario-chabot]

Is the in-wheel motor a radial flux type?

[paul-schultz]

I’m not sure. But, you can check out the options on the elaphe site. The M700 matches the Aptera specs.

https://in-wheel.com/en/solutions-2/direct-drive-in-wheel-motors/

[kerbe2705]

I’ve found several sources that mention Elaphe as a maker of radial flux motors – it is the most common type for in-wheel mounting.

[donald-kraper]

I don’t post a lot but try to keep and eye on things. I am also an investor.

After reading several posts as well as watching the Aptera SWOT Youtube video, the thought of a “New American Sports Car”has stuck in my head. (well done Ifi7929501)

Aptera is quick, light, and power to weight ratio is excellent. With 70hp at each wheel (x3), and the 250 mile range battery pack, it will be the quickest set up from the factory.

I have been wondering:

Does Elaphe manufacture a hub motor that will fit the Aptera with more Horsepower?

Is there the capability to allow the batteries to dump maximum energy to the hub motors?

If so, this could be something special. One of the most efficient cars out there for $25k…that, with a change of hub motors could be a rocket on wheels, and still be considered very efficient. I have no idea if Elaphe has a motor that could work, nor do I know the price of each one if they were available. But if they were, I might be first in line to do the swap. Even if the costs of the motors were,$5k-7k a piece, you could end up with an extremely quick ride for under $45k.

These are random thoughts, wondering if anyone else is thinking along these lines…(maybe I’m just trying to relive my days of stuffing a big block in a Vega)

[bruce-mengler]

APTERA charges $2,500 to upgrade from 2WD to 3WD; which adds a third motor to rear wheel.

[kevin-molloy]

Sorry if this has been asked before…but what about a failure of one of the in wheel drive motors? Will you still be able to continue driving with the one or two motors remaining, (depending on what you orderd)? I don’t want to site a specific failure as I am not familiar with how they might fail. Is there a way to disconnect the failed motor so that the wheel can rotate freely? Just throwing this out there for the experts to answer! Thanks!

[paul-schultz]

I can report that the Lordstown Motors Endurance pickup truck that uses 4 Elaphe in-wheel motors can operate with a motor malfunction. At least from some of their reports… nothing like a validation video exists though. But, Apteral is using the same in-wheel motor tech so I would think that they can still have the vehicle operate if one of the motors fails. At least in a ‘limp mode’ to avoid being stranded.

Paul

[peter-jorgensen]

In theory the AWD version could manage to limp around by powering the rear motor to push it forward while the front two didn’t do much. Or if the rear failed it’d be symmetrical and not an issue. The FWD version might be able to “limp” to the shoulder but it would be hard. I’d be more worried about losing control while driving if one side suddenly went full regen without the other side.

I don’t know how much of that they’d actually write into the programming. In general I think this is an extremely rare failure case that we may not ever see in the real world given the reliability of electric motors.

[g-n]

They made a couple videos going into the testing conducted on the in-wheel motors – they’re clearly thinking about the same hazards you are. After watching those, I’m not tremendously concerned.

They also claimed that some fancy electronics will help minimize the effects of high unsprung weight. They’re also obviously going to great lengths to reduce motor (and entire wheel assembly) weight. I’ll be very interested in what impartial reviews conclude regarding whether that challenge has been sufficiently tamed.

[john-trotter]

I have not found much mention of the interior space advantage of in-wheel motors. It seems to me that could be considerable, especially in small vehicles like Aptera or something like the proposed, smallest, Tesla. Even if it was just more frunk/trunk space.

[x2164j]

<div>Hi Guy,</div><div>

The link below is to a post by “Aptera Reboot” of an Aptera webinar in which

Steve and Chris are discussing with two of Elaphe’s principles the use by Aptera

Elaphe’s hub motors. Finding a link to an original version of the webinar directly

from Aptera eluded me.

</div><div>

I’m not sure this copy of the webinar, due to the first 15 minutes not being available,

mentions that the motor’s seals would have to o be replaced at around 30,000 to

40,000 kilometers though one of the Elaphe principles speaking mentioned

that the change interval had been changed to greater number. Some useful

feedback in the comments to the video.

Pete

</div>

[g-johns]

I just rewatched a video were Steve said the 3 wheel car has been tested with each motor individually used. I hope at certain times when conditions for good traction exsist to just use the rear wheel for motive power and use less than the 100Wh. He said that they hope to be able to have the option to also freewheel the rear wheel so no magnetic drag. That’s great news for me because those are all an options I hoped for.

[peter-jorgensen]

What do you mean 100 WH? I don’t understand.

The battery size is 100 kwh. (Like gallons of gas)

Each motor has 50 kw of power. (Like horsepower)

50 kw (kilowatt) of power for 1 hour is 50 kwh (kilowatt-hour).

100 wh is about the capacity of a handheld battery charger bank for a cell phone.

• This reply was modified 2 years, 3 months ago by  Peter Jorgensen.
• This reply was modified 1 year, 8 months ago by  Gabriel Kemeny.

[joshua-rosen]

The stated objective is 10 Miles/KWh which is 100Wh per mile. What G is saying is that he hopes that by just using the rear motor the energy consumption can be reduced still further. Don’t know how much that would help, is it more efficient for one motor to provide all of the power vs two or three. When cruising along at a steady speed, especially with the Aptera’s .13 COD, you won’t need much power, one motor would only be using a fraction of it’s capacity so you won’t need to run more than one motor but is a single motor putting out X power more efficient than two motors each putting out 1/2X or three motors putting out 1/3X?

Are the Elaphe motors induction or permanent magnet?

• This reply was modified 2 years, 3 months ago by  Joshua Rosen.

[dean-mcmanis]

Chris did mention that if a motor was not powered it would act as a generator. But even though it would seem that running just the rear motor (on the AWD model) would reduce the energy use, but the powertrain losses are minimal for wheel motors. So having 3 motors use 5kWh each, or one motor using 15kWh to maintain a speed may not be such a great benefit. Chris estimated that the AWD models would consume 10% more than FWD models. It is fun to think about the possibility of additional energy savings, but I think that the gains would be relatively small. Tesla had initially thought that their AWD models would have greatly reduced range having twice the motors. But they said that there was some load balancing that could be done which greatly reduced the overall power usage. Also regen power recovery is higher with all 3 motors in use. I ordered the AWD option because I want the added power and control. Hopefully the extra energy use won’t be that much much.

[n-bruce-nelson]

I just emailed a contact I have at Elaphe regarding the motors used in Aptera and got the following reply:

For IWM’s they are radial flux, very high efficiency, high-torque-density (Elaphe proprietary winding design and active core designed for Aptera’s mission!) = light weight, robust.

Many people make this error, since Axial gets a lot of press lately (for inboard applications). Not the best design for in-wheel applications though, very fragile and quickly loses the benefits if you try to make it more robust…

No axial flux IWM deisgn (sic) has so far came close to the level of robustness, torque, weight or efficiency. Axial is great, but for inboard pancake style… (YASA, etc…). usually requires a reduction gear and CV joints to a wheel, since they are higher speed 5000-6000 rpm.

[gary-greenway]

I just watched a conversation between Aptera and Elaphe indicating motor seals need to be changed every year or two depending on mileage. Will this be something I can do in my driveway? What about bearing replacement interval? Not exactly what I call maintenance free. I really hope I misunderstood this or the problem will be resolved soon.

[KayleighVenne]

Hi! Which conversation are you referring to, Gary?

We’re still looking to publish more accurate data in regard to our in-wheel motors and we look forward to giving you more information. I can assure you we think the “right to repair” should be applied to every large purchase and we are very supportive of “do it yourself” rights. This exemplifies how Aptera is leading the revolution to transform the future of transportation through solar mobility, freedom, and continuous innovation.

[john-malcom]

Technical concerns expressed by forum members deserve an authoritative technical answer from an official Aptera representative. An example of that kind of response in this case might be “The in wheel motors currently require a change of seals every xx miles but we are looking at ways to extend the interval. We expect testing data to be available on xx and will publish the data on the forum”.

This kind of response fosters trust in both the engineering process and customer response organization. Anything less than a specific, technical response lays a foundation of doubt in the capability of both organizations to be responsive to inquires.

[KayleighVenne]

I understand and agree, John. Rest assured, when I have the data and information to give a more technical answer, I will. I’ll be speaking with the Engineering team about this inquiry.

[gary-greenway]

Kayleigh, look at 26:45 in this video. https://youtu.be/X0LYZCiez5Y

[john-malcom]

This video was made some time ago so the current relevance is suspect. Additionally, you will note that there is some misunderstanding/disagreement within Elaphe over the replacement interval for the seals.

Aptera has noted that they are requesting a customization for the Elaphe wheel motors for the Aptera. We do not know what the features of the requested customization are, but they will result in a different wheel motor configuration than the “Standard” commercial version. We should not judge what will be provided to Aptera by what is on the commercial market.

I certainly can’t speak for Aptera Engineering but a good engineer would make a note of the disagreement in the video and put some tasks in the development plan to examine this potential weakness. I think we can all agree that the Aptera engineers are good engineers, so I am sure they have done this. I also believe, because of their strong commitment to quality, extending the life of the vehicle, and Right to Repair, they will make sure there are high standards for each component of the vehicle, to including the seals, and that testing will verify implementation of strong design and performance standards.

I believe once the testing is complete, regardless of the timeframe in their testing plan, that the results will be published and that we will be more than satisfied with the results.

[john-malcom]

No question that you will do that and conscientiously Kayleigh!

Forum members are anxious for all technical information on the Aptera. Most are use to dealing with traditional automotive companies who do not announce a vehicle until all design, engineering, and testing is done and all specs finalized.

Aptera is different. Is is a startup that is giving insight into the development, testing and production of the vehicle. An unusual and refreshing approach which we all appreciate. But this means that some of the data to answer technical questions is not available yet and may not be available for some time. As a result, speculation without knowledge or basis becomes rampant.

There are misrepresentations of facts even in this short thread. In the video, they represent the change interval for the motor seals as 30,000 kilometers. Somehow that gets translated into 30,000 miles in the posts here.

Bottom line, Peter has the best answer at the bottom of his post.

[KayleighVenne]

Hi John! Thank you very much for your understanding. I’m passing your kind words along to the Aptera Team! It’s our pleasure to bring you all along “for the ride,” so-to-speak, as we work to bring our solar electric vehicles to the market and to your driveways! We certainly value and admire all of your questions while do this. We so appreciate your understanding that although we may not have all of the concrete information, we’re doing our best to share what we know, and will be transparent about what we don’t know! 🙂

[gary-greenway]

Since this thread has gone all over the place, I’ll clarify my question a bit. I wasn’t asking if I MAY do it, but instead, CAN I do it? Is it a job for a home shop or does it require specialized and expensive tooling? Hopefully its no more difficult than doing a brake job or replacing a hub bearing.

[Steve]

Elaphe motors horsepower of each motor to be used in the aptera?

[kerbe2705]

At present they are using 50 kW motors – 67 HP – so FWD is 134 HP and AWD is 201 HP

[KayleighVenne]

Hi all! The peak power for each wheel of the Aptera is about 50kW. So you’d get 100kW for the front-wheel drive and 150kW of power from the all-wheel-drive version.

We will provide detailed specifications closer to the production ramp up as we are still undergoing further testing!

[curtis-cibinel]

Steve from Aptera Owners Club posted an Elaphe Webinar looking at system efficiency. It is very dry but makes some major claims about efficiency advantages due to reduced number of components subject to temperature sensitive components; specifically in winter. It is possible this could offset the efficiency disadvantages of a non heat pump system for the cabin. Reducing components and having a highly efficient drivetrain allows the system to do more practical work with less energy. The first 15 minutes is mostly intro but they get into efficiency graphs and analysis around 22 minutes in.

One interesting thing is the efficiency graphs show a weakness in the IWM at low speeds so it might be closer to 35-40 mph where Aptera will run optimally for hypermiling (vs 20 mph used in a Tesla). Oddly Aptera would probably be less efficient overall at speeds under 35 mph because wind resistance is nearly negligible and the drivetrain will run less efficiently than other EVs in those rpm ranges.

https://www.youtube.com/watch?v=b1m_QeJHMvU

[RajGiandeep]

Didn’t consider the cold range loss would be less with in-wheel motors. Another positive for Aptera. Strange they didn’t post this to their YouTube channel

[benjamin-dreidel]

The cold range loss may be less in terms of efficiency or kwh, but the cold range loss in miles will almost certainly be a relatively high %. In any other EV, a kwh that goes to heating the cabin/battery will only lose you 3-5 miles of range but in the Aptera it will lose you 10 miles.

[kerbe2705]

During one of the early Aptera webinars we were told that the aero advantage doesn’t really come into play at speeds under 45 mph.

[curtis-cibinel]

The following is my range estimate calculation tool; make a chippy to play with values. You can use this see see aerodynamics impact on range. Going from 20-40 mph is a ~4x increase in air resistance while auxiliary load and rolling resistance remain unchanged. The tool assumes a static drivertrain efficiency percentage (which this article shows isn’t true) and does not account for auxiliary load (radio, displays, and heater). Rolling resistance might be to high based on other sources (but none that are official exist); I used typical car rolling coefficient of 0.1.

We have 4 factors to consider overall :

– auxiliary load which varies mainly by temperature

– rolling resistance which varies only be vehicle /passenger weight

– air resistance which varies by speed (and equals rolling resistance at about 47 mph)

– drivetrain efficiency which varies by temperature, speed and torque (weight) – this is what elaphe just covered

https://docs.google.com/spreadsheets/u/0/d/1Tuu7avKH2dS_JPk7aiP2av09a1f1WE0OvvNH6fdHpiQ/htmlview#

• This reply was modified 2 years ago by  Curtis Cibinel.