Frank
100 W
This looks great!
Electrom1 Long Wheelbase Recumbent Light Electric Vehicle
- Thread starter tigcross
- Start date
tigcross
100 W
Thanks Guys. It has been a long process, but one can't expect to change the world overnight anyway :wink:
https://youtu.be/eOCEYzSumjE
I watch new electric scooter, after new electric scooter, come to market.
http://www.wowescooter.com/Wow_Model.asp
When will they figure out what Tig has?...that scooters want to be recumbents!!!
FF motorcycle designer, Royce Creasey has been going on about this for months now.
http://bikeweb.com/
http://bikeweb.com/image/tid/10
https://www.facebook.com/groups/feetfirstvehicles/
I watch new electric scooter, after new electric scooter, come to market.
http://www.wowescooter.com/Wow_Model.asp
When will they figure out what Tig has?...that scooters want to be recumbents!!!
FF motorcycle designer, Royce Creasey has been going on about this for months now.
http://bikeweb.com/
http://bikeweb.com/image/tid/10
https://www.facebook.com/groups/feetfirstvehicles/
tigcross
100 W
Thanks Warren,
Here's a new video of the Electrom for you all.
[youtube]DqrQDBZ-efA [/youtube]
Here's a new video of the Electrom for you all.
[youtube]DqrQDBZ-efA [/youtube]
tigcross
100 W
A quick demo going over the Electrom Controls
[youtube]2b3d3Tnzsvk[/youtube]
[youtube]2b3d3Tnzsvk[/youtube]
Good on you for developing this to this point!
I would actually be tempted to order one if I didn't already have something similar that does the job for my commuting needs.
I'm looking to make an off-road recumbent soon, so this wouldn't really work for that.
Cheers
I would actually be tempted to order one if I didn't already have something similar that does the job for my commuting needs.
I'm looking to make an off-road recumbent soon, so this wouldn't really work for that.
Cheers
tigcross
100 W
Actually the Electrom is pretty good off-road. Of course it would suck to crash it and damage the bodywork.
tigcross
100 W
I made a fixture to allow me to tow my MTB with the Electrom. [youtube]JNzp3O-STiM[/youtube]
tigcross
100 W
A video of the Electrom on BC Ferries. Did you know that there are power plugs at the front and back of the boat that are available for charging your bike? Bring an extension cord.
[youtube]FgxMRCUXqD8[/youtube]
[youtube]FgxMRCUXqD8[/youtube]
tigcross
100 W
Work continues on bringing the production Electrom to the first customers. Here's a video detailing the new molded carbon fiber fenders, bubble support and swingarm covers.
[youtube]FNn3gcB4zFU[/youtube]
[youtube]FNn3gcB4zFU[/youtube]
tigcross
100 W
Thanks. Yes. the plan is to deliver the first customer bike by the end of February.
tigcross
100 W
Many of you have probably already seen this on the various FB groups I post to, but I felt bad about neglecting the granddaddy of all ebike site so here's some info.
I've recently upgraded the Electrom test bike to All Wheel Drive. It is running a Golden Magic Pie Direct Dive motor in the back, and now a Bafang G311 up front. Both are running on Grin Phaserunner controllers at 72 volts.
I feel like this is the best of both worlds when it comes to Hub motors, I have the effeminacy and Regen of the Direct Drive, plus the extra power for starts, and hill climbs from the geared hub motor in front. The front motor is set up to shut down once the bike is up to 30 kph, this way I don't have the extra losses of an additional motor once I am up to speed.
My medium-power setting efficiency has actually gone up, I suspect because the geared hub motor is more efficient at low speeds and helps get the DD motor up into it's efficient RPM band.
I was started down this road in a quest for better traction, which the Electrom now has. Here's a video of riding in the snow.
[youtube]n-I0vmWjqgg[/youtube]
I've recently upgraded the Electrom test bike to All Wheel Drive. It is running a Golden Magic Pie Direct Dive motor in the back, and now a Bafang G311 up front. Both are running on Grin Phaserunner controllers at 72 volts.
I feel like this is the best of both worlds when it comes to Hub motors, I have the effeminacy and Regen of the Direct Drive, plus the extra power for starts, and hill climbs from the geared hub motor in front. The front motor is set up to shut down once the bike is up to 30 kph, this way I don't have the extra losses of an additional motor once I am up to speed.
My medium-power setting efficiency has actually gone up, I suspect because the geared hub motor is more efficient at low speeds and helps get the DD motor up into it's efficient RPM band.
I was started down this road in a quest for better traction, which the Electrom now has. Here's a video of riding in the snow.
[youtube]n-I0vmWjqgg[/youtube]
Cool.
Your powertrain choice could use a little refinement though.
Because the magic pie has a taller stator with more poles, in a 20 inch wheel, it has a higher amount of cogging and end turn loss than say, a run of the mill 30mm wide 203mm tall DD. The magic pie is a better motor in a 26"+ wheel.
Swapping out the magic pie for a typical 9C clone type motor would provide you a sizeable benefit in efficiency. Around a 5% gain.
The bafang G310 also has RPM limits which you're likely exceeding on a small wheel. The consequence of exceeding the RPM of the motor + making it hot is the magnets seperating from the metal ring. AAK catastrophic failure.
A single reduction front hub would be better in terms of reliability, and perhaps provide a tiny efficiency boost.
Again, this is because you are running a 20" wheel. Different motor choices need to be made for our smaller wheels.
Your powertrain choice could use a little refinement though.
Because the magic pie has a taller stator with more poles, in a 20 inch wheel, it has a higher amount of cogging and end turn loss than say, a run of the mill 30mm wide 203mm tall DD. The magic pie is a better motor in a 26"+ wheel.
Swapping out the magic pie for a typical 9C clone type motor would provide you a sizeable benefit in efficiency. Around a 5% gain.
The bafang G310 also has RPM limits which you're likely exceeding on a small wheel. The consequence of exceeding the RPM of the motor + making it hot is the magnets seperating from the metal ring. AAK catastrophic failure.
A single reduction front hub would be better in terms of reliability, and perhaps provide a tiny efficiency boost.
Again, this is because you are running a 20" wheel. Different motor choices need to be made for our smaller wheels.
tigcross
100 W
Hi Netronix,
I respectfully disagree. It is a question of priorities, my goal was dependability and to have as much torque possible per legal wattage, as opposed to pure efficiency. I was aware of the issues you mention, but in my case they were features, not bugs.
The 273 mm stator in a 20 inch wheel gives the bike an amazing amount of hill-climbing capability. I also have to say that the Magic Pie 20 inch cast wheel is amazingly strong, sheds heat well, and it is nice to not have to worry about spokes. It also has a 35 mm wide rim that the 16 inch moped tires mount to very nicely.
It is true that the G311 has some issues with magnet separation at high rpm, but that is not an issue in this build because it is set to shut down at speeds over 30 kph (thanks Phaserunner). The primary function of the front motor is for traction and extra hill climbing torque at low speeds. Once the bike is in excess of 30kp/h the Magic Pie on the back has more than enough power. As the goal was to produce the most torque-per-watt, the G311 double stage reduction fits the bill nicely, and as it shuts down at cruising speed the efficiency point is moot.
I do appreciate that this is a learning forum though, and I think it's a good thing that you brought up these points, especially the G311 magnet issue as it is important that builders know about these things. In my case the speed limits were not a problem, but others seeking higher RPMs out of these motors need to be aware of the shortcomings.
I respectfully disagree. It is a question of priorities, my goal was dependability and to have as much torque possible per legal wattage, as opposed to pure efficiency. I was aware of the issues you mention, but in my case they were features, not bugs.
The 273 mm stator in a 20 inch wheel gives the bike an amazing amount of hill-climbing capability. I also have to say that the Magic Pie 20 inch cast wheel is amazingly strong, sheds heat well, and it is nice to not have to worry about spokes. It also has a 35 mm wide rim that the 16 inch moped tires mount to very nicely.
It is true that the G311 has some issues with magnet separation at high rpm, but that is not an issue in this build because it is set to shut down at speeds over 30 kph (thanks Phaserunner). The primary function of the front motor is for traction and extra hill climbing torque at low speeds. Once the bike is in excess of 30kp/h the Magic Pie on the back has more than enough power. As the goal was to produce the most torque-per-watt, the G311 double stage reduction fits the bill nicely, and as it shuts down at cruising speed the efficiency point is moot.
I do appreciate that this is a learning forum though, and I think it's a good thing that you brought up these points, especially the G311 magnet issue as it is important that builders know about these things. In my case the speed limits were not a problem, but others seeking higher RPMs out of these motors need to be aware of the shortcomings.
I have operated both of these motors in 20 inch wheels and my opinion comes from many years of experience.
Yes, the 273mm stator has amazing initial torque but peters out in the mid-high RPM ranges and loses efficiency to iron and copper losses. You'll see it in the ebikes.ca simulator and i have experienced it in real life running 48-125v in a 20 inch wheel.
This is even noticeable at 48v.
This is just an inherent nature of the motor dimensions themselves.
The slightly taller 9C clone, the RH212 or whatever it's called, suffers of this too, to a lesser degree.
Again, both of these motors make more sense in a 26 - 29 inch wheel.
The typical 9C clone is most ideal in a 20-24 inch wheel.
Impressive low RPM torque is absolutely available from the 9C type motors. No problem. Set an appropriate phase amp to battery amp ratio and you are good to go.
Okay, you have eliminated a mechanical motor limitation with electronics but there are still better motors for your front wheel which have higher efficiency. Unfortunately the difference in winding between your two motors prevents torque full time vectoring AWD from being part of your design. AWD can be an excellent safety feature for a vehicle. Having a safety feature be intermittently available is a shame.
I've stated my case and i hope you at least consider it.
Your vehicle is impressive to me and i am watching your thread closely to glean experience from what you are doing, as i am building a bike in a similar vein.
Yes, the 273mm stator has amazing initial torque but peters out in the mid-high RPM ranges and loses efficiency to iron and copper losses. You'll see it in the ebikes.ca simulator and i have experienced it in real life running 48-125v in a 20 inch wheel.
This is even noticeable at 48v.
This is just an inherent nature of the motor dimensions themselves.
The slightly taller 9C clone, the RH212 or whatever it's called, suffers of this too, to a lesser degree.
Again, both of these motors make more sense in a 26 - 29 inch wheel.
The typical 9C clone is most ideal in a 20-24 inch wheel.
Impressive low RPM torque is absolutely available from the 9C type motors. No problem. Set an appropriate phase amp to battery amp ratio and you are good to go.
Okay, you have eliminated a mechanical motor limitation with electronics but there are still better motors for your front wheel which have higher efficiency. Unfortunately the difference in winding between your two motors prevents torque full time vectoring AWD from being part of your design. AWD can be an excellent safety feature for a vehicle. Having a safety feature be intermittently available is a shame.
I've stated my case and i hope you at least consider it.
Your vehicle is impressive to me and i am watching your thread closely to glean experience from what you are doing, as i am building a bike in a similar vein.
tigcross
100 W
As long as we are talking about experience, I should let you know that while I didn't join Endless Sphere until 2015, I was referencing it and other sites from the beginning, and I do mean The Beginning; I built my first electric assist recumbent in 1998 and started working on the predecessor to the Electrom in 2003. I've worked in bikeshops my whole life and owned and operated a mountain bike shop for 10 years from 1992 to 2002
I always listen to advice, but we have different priorities. You apear to have a focus on efficiency, light weight and speed whereas I am seeking to build a street legal, reliable, and safe human/electric hybrid that is simple to operate. The Golden Magic Pie motor fits my criteria well and that is why I choose to use it.
I'm not sure you have fully considered the parameters I am looking for. As I am building a street legal machine for sale to the general public, High starting torque for hill climbing and starting out is far more important to me that high speed efficiencies. The top legal speed for an ebike here in BC is 32 kph, the top legal speed for an ebike in California is 28 mph. The Golden Magic Pie is efficient enough at 72 volts in these speed ranges. An efficiency difference of 5% is not enough to outweigh the other advantage is this wheel.
Again, my machine needs to operate within the bicycle legal power parameters, simply upping the power is not always an option. When it comes to Direct Drive motors it is a question of simple leverage, the biggest stator in the smallest rim is going to yield the best starting torque.
I don't think you really read my previous response. The double stage gear reduction in the G311 yields more torque per watt than a single stage reduction, which allows for hill climbing power within the legal power limits. The motor shuts down at 30 kph to save power and it has the added benefit of not challenging the magnet adhesion (BTW, this is one of the motors that Grin re-glued the magnets on). I do concede that this motor will not be used in production because it has proven to be unreliable at high RPMs and I have no control over the setting once the bike is in the customer's hands.
AWD is not the same on a two-wheel vehicle as it is on a car. It would not do much for you in a slippery situation over 30 kph. It is true that a higher power bike might inadvertently spin the back wheel at high speed, but in this case adhering to the bicycle power limits makes this unlikely. If the best efficiency per motor is around 85%, why would waste 15% running a motor that is unneeded at cruising speed.
Absolutely, I'd be a fool to post here if I was not going to consider the opinions offered. I will say that with the extra torque of the front geared hub motor I am tempted to go with a lighter DD rear motor, but I do really like the heavy duty build of the Magi Pie. I will also be trying out the GMAC hub motor on the rear as it has amazing re-gen braking.
Thanks, I appreciate your input. I've checked out your Maxaraya build and I'll try to get some of my initial thoughts down for you.
I hope you do not see me as hounding you over this. I just want to lend you the experience i have so your project could be a success. If i was not a seasoned builder of bikes myself, i would be looking to buy one of your first production units. I think your project kicks ass and i want to see more vehicles on the street like this.
Using a less tall DD stator with higher phase current can give you the same initial torque at the expense of slightly more watts inputted from 0 to ~100rpm, with the advantage of a big improvement in efficiency while you are moving, which is >90% of the time.
This does not conflict with your legal speed requirement, will improve your range, and with the 30mm DD, will shed at least 2lbs of weight, improving rear suspension action in the process.
One needs to consider the entire powerband when assessing efficiency, and where the user of the vehicle will spend most of their time. The 'trade' here makes a lot of sense.
The dual geared hubs are just like the magic pie. High initial torque per watt, but even poorer efficiency when rolling due to gear friction losses. I have experienced this in a 20 inch wheel with two geared motors. My efficiency at speed in a semi recumbent was atrocious even with the smaller MAC variant, the eZee. Friction losses were dominating the load, as evidenced by the efficiency actually INCREASING when climbing hills.
You can verify my statements by playing with the ebikes.ca motor simulator.
The GMAC is a less efficient motor than your magic pie. It is also less powerful and thus cannot handle as much regen. It has severe thermal limitations as well. The gears are also a weak point. I love MACs but would never use them in a rear wheel of such a heavy vehicle. I would most absolutely never run them on a 20 inch wheel.
.. i hate to throw in a 'look at my experience' claim, but if you have been watching me over the years, you'd know that i am part of the reason people know about MAC motors on this forum. I created Paul of em3ev's first website and his logo also. Along this process, i got all the juicy engineering details on the MAC. The GMAC is just a MAC with a fixed clutch and some other goodies. AFAIK it does not include the 0.27mm laminations that the MAC has which is a huge downer.
I built a bike to go up pike's peak on a magic pie in a 20" wheel on 72v in ~2012. I encountered the high RPM efficiency loss ( versus a 9C DD ) on flat ground. It was the ideal DD at the time to climb a hill in a small wheel due to it's efficiency curve that favors low RPM. It is also better at dissipating heat VS the 9C clones due to the sheer amount of metal. The advice on the motor was given to me by liveforphysics, one of, if not the smartest person here.
The leafmotor 9C clones are still the most efficient hubs on the market that i know of. Justin's all axle motor may supersede the power per weight ratio and even efficiency of the leafmotor clones in time... but he does not sell a rear motor version and it only comes in ~28mm width.
And now for what you're really not going to like to hear.
A hub motor in this size wheel is subject to more water and salt from the road than in a 26" wheel. AFAIK no means to properly seal hub motors has been invented still. This will create long term motor durability problems.
Since you have the ability to build/modify a frame, the best drive mechanism, in terms of durability and weight, for your rear wheel is a single reduction ratio chain driven rear motor, ideally mounted to the rear swingarm near the swingarm pivot, or just ahead of the pivot on the frame, but that would require a tensioner. The bike will get stealthier, lighter, and have better rear suspension as a result of removing ~90% of the unsprung weight.
Using a less tall DD stator with higher phase current can give you the same initial torque at the expense of slightly more watts inputted from 0 to ~100rpm, with the advantage of a big improvement in efficiency while you are moving, which is >90% of the time.
This does not conflict with your legal speed requirement, will improve your range, and with the 30mm DD, will shed at least 2lbs of weight, improving rear suspension action in the process.
One needs to consider the entire powerband when assessing efficiency, and where the user of the vehicle will spend most of their time. The 'trade' here makes a lot of sense.
The dual geared hubs are just like the magic pie. High initial torque per watt, but even poorer efficiency when rolling due to gear friction losses. I have experienced this in a 20 inch wheel with two geared motors. My efficiency at speed in a semi recumbent was atrocious even with the smaller MAC variant, the eZee. Friction losses were dominating the load, as evidenced by the efficiency actually INCREASING when climbing hills.
You can verify my statements by playing with the ebikes.ca motor simulator.
The GMAC is a less efficient motor than your magic pie. It is also less powerful and thus cannot handle as much regen. It has severe thermal limitations as well. The gears are also a weak point. I love MACs but would never use them in a rear wheel of such a heavy vehicle. I would most absolutely never run them on a 20 inch wheel.
.. i hate to throw in a 'look at my experience' claim, but if you have been watching me over the years, you'd know that i am part of the reason people know about MAC motors on this forum. I created Paul of em3ev's first website and his logo also. Along this process, i got all the juicy engineering details on the MAC. The GMAC is just a MAC with a fixed clutch and some other goodies. AFAIK it does not include the 0.27mm laminations that the MAC has which is a huge downer.
I built a bike to go up pike's peak on a magic pie in a 20" wheel on 72v in ~2012. I encountered the high RPM efficiency loss ( versus a 9C DD ) on flat ground. It was the ideal DD at the time to climb a hill in a small wheel due to it's efficiency curve that favors low RPM. It is also better at dissipating heat VS the 9C clones due to the sheer amount of metal. The advice on the motor was given to me by liveforphysics, one of, if not the smartest person here.
The leafmotor 9C clones are still the most efficient hubs on the market that i know of. Justin's all axle motor may supersede the power per weight ratio and even efficiency of the leafmotor clones in time... but he does not sell a rear motor version and it only comes in ~28mm width.
And now for what you're really not going to like to hear.
A hub motor in this size wheel is subject to more water and salt from the road than in a 26" wheel. AFAIK no means to properly seal hub motors has been invented still. This will create long term motor durability problems.
Since you have the ability to build/modify a frame, the best drive mechanism, in terms of durability and weight, for your rear wheel is a single reduction ratio chain driven rear motor, ideally mounted to the rear swingarm near the swingarm pivot, or just ahead of the pivot on the frame, but that would require a tensioner. The bike will get stealthier, lighter, and have better rear suspension as a result of removing ~90% of the unsprung weight.
tigcross
100 W
Thanks for the clear advice netronix, I had been on the fence about which direction to go on the production version of the Electrom (I'm making two for customers right now) based on your information I'm thinking that my best combination of start-up-torque and high-speed-efficiency would come from a smaller stator DD rear wheel, and a decent geared hub motor that shuts down above a certain speed. This way we eliminate the losses from a 2nd motor at high speed, but still have that geared-motor torque available start up and hill climbing.
I do like the strength of the Magic Pie II, but I think that a lighter DD and more efficient DD rear hub would make up for the loss in strength.
I do like the strength of the Magic Pie II, but I think that a lighter DD and more efficient DD rear hub would make up for the loss in strength.
SlowCo
1 MW
tigcross said:
Isn't your start up torque limited immensely just by the low (phase)current that the Magic Pie internal controller can provide? An external controller on a Leaf DD motor in a 16"or 17" moped rim that can be programmed for much higher amps on start up would eliminate the need for a geared front hub motor. That way eliminating the extra cost, complexity and maintenance it would add. Just a thought.
tigcross
100 W
Actually I'm using the External Controller version of the Magic Pie with a Grinfineon 40 amp, 72 volt controller (I guess I should have clarified that somewhere).
The issue is not how much total power the magic Pie can handle, but how much "legal" power I can put into the system. The maximum peak here in BC is 1500 Watts. The geared hub motor helps by providing far more torque with the legally available power.
Now, of course if it was just for me I would just crank up the watts and go for it, but as I'm trying to make a consumer product I have to make it functional under legal power limits.
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