PaulD's lightweight mid drive development

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PaulD   100 W

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Re: PaulD's lightweight mid drive development

Post by PaulD » Feb 17 2020 12:40am

Nobreaks wrote:
Feb 13 2020 6:17am
Great work!
Very interested in buying a Midrive kit as well
Is Australia to far for u to freight once you have stock to sell
Thanks Nobreaks! We can only ship the kit without battery to Australia. Battery shipping overseas is a mess.

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Re: PaulD's lightweight mid drive development

Post by lightrush » Mar 11 2020 9:23pm

But the BAC500 supports 48V. Wouldn't it just work if I plug in my 48V battery?

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 12 2020 12:06am

lightrush wrote:
Mar 11 2020 9:23pm
But the BAC500 supports 48V. Wouldn't it just work if I plug in my 48V battery?
Controllers are programmed for a specific voltage. It is certainly possible to program it to work over a wide range of voltages, but you lose the ability to cutback current/power at low SOC and to prevent regen from causing an over voltage (not a problem with a mid drive like this). It's best practice to have the controller provide these rollbacks and cutouts rather than your BMS.

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Re: PaulD's lightweight mid drive development

Post by lightrush » Mar 13 2020 6:28pm

Yes. Totally.

So when can we buy one?

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 13 2020 10:40pm

lightrush wrote:
Mar 13 2020 6:28pm
So when can we buy one?
Parts are trickling in. Just received freewheel parts today. Mounting plates should be here Monday, but they need to go out for anodizing. These parts are to accommodate the new torque sensor that is more robust than the Sempu. We should have kits ready in 2 weeks.

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Re: PaulD's lightweight mid drive development

Post by neptronix » Mar 13 2020 11:18pm

i'm interested in one sans battery still.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: PaulD's lightweight mid drive development - Looking for Beta Testers

Post by Danny Mayes » Mar 14 2020 2:49am

Hey Paul,

Things have been a bit quiet around here (i have not been back for quite some time myself) but its nice to see you have been planning/scheming/working away in the back ground developing this product and still carrying the torch of innovation! Very tidy, I commend you on your effort and vision.

By the way, how did you become one of the chosen ones? Just a little jealous....
PaulD wrote:
Jul 04 2019 11:42pm
justin_le wrote:
Jul 04 2019 3:57pm

Hey Paul, what's that cute looking battery package I see there!? :wink:
:) That's our Grin inspired potted battery pack. 10S3P LG MJ1 cells with Grin's amazing full featured LIGO bms. It's potted in super tough UL 94 V-0 polyurethane. With our stealth quick release mounts it's a pretty tidy package.

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Re: PaulD's lightweight mid drive development

Post by lightrush » Mar 14 2020 4:18pm

PaulD wrote:
Mar 13 2020 10:40pm
lightrush wrote:
Mar 13 2020 6:28pm
So when can we buy one?
Parts are trickling in. Just received freewheel parts today. Mounting plates should be here Monday, but they need to go out for anodizing. These parts are to accommodate the new torque sensor that is more robust than the Sempu. We should have kits ready in 2 weeks.
What new torque sensor?

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Re: PaulD's lightweight mid drive development

Post by Joost5000 » Mar 14 2020 8:24pm

PaulD wrote:
Mar 13 2020 10:40pm
lightrush wrote:
Mar 13 2020 6:28pm
So when can we buy one?
Parts are trickling in. Just received freewheel parts today. Mounting plates should be here Monday, but they need to go out for anodizing. These parts are to accommodate the new torque sensor that is more robust than the Sempu. We should have kits ready in 2 weeks.
Great news can’t wait!

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 15 2020 3:10pm

lightrush wrote:
Mar 14 2020 4:18pm
What new torque sensor?
I've been having good results with the Erider for the last 6 months, so we are going with it. Here it is with the new freewheel hub.
IMG_20200315_094502_copy_2024x1518.jpg
IMG_20200315_094502_copy_2024x1518.jpg (333.19 KiB) Viewed 500 times

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Re: PaulD's lightweight mid drive development

Post by Nobreaks » Mar 15 2020 11:23pm

Sounds fine to me .
I will sorce a battery locally.
The male power supply plug for the battery connection
!
Will you be able to supply a female to fit to the battery I supply and possibly another male plug to fit to whichever battery charger I end up using ?

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Re: PaulD's lightweight mid drive development

Post by neptronix » Mar 16 2020 1:11am

quick question, does one pedal have more outward offset than the other? if so, how much?

wanna know if th q factor is even.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: PaulD's lightweight mid drive development - Looking for Beta Testers

Post by PaulD » Mar 16 2020 11:33am

Danny Mayes wrote:
Mar 14 2020 2:49am
Things have been a bit quiet around here (i have not been back for quite some time myself) but its nice to see you have been planning/scheming/working away in the back ground developing this product and still carrying the torch of innovation! Very tidy, I commend you on your effort and vision.
By the way, how did you become one of the chosen ones? Just a little jealous....
Hi Danny, apologies for not keeping this thread updated and thanks for the compliment. I've been to busy, but I'll try harder to keep posting. Regarding the battery, are you referring to being a chosen one to use the Ligo BMS? Well, I've known Justin since college, we met at UBC probably 15 years ago. Also, I was the principal battery engineer at an e-moto company for many years, so he trusts I will build a design a quality pack with Grin's electronics.

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Re: PaulD's lightweight mid drive development

Post by Joost5000 » Mar 16 2020 12:48pm

Not to take you away from the work, One other quick question as I’m looking for a used full suspension mountain bike. What’s the front chainring 42 tooth?

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 16 2020 1:44pm

neptronix wrote:
Mar 16 2020 1:11am
quick question, does one pedal have more outward offset than the other? if so, how much?

wanna know if th q factor is even.
With the new torque sensor, Q-factor is about 180mm for a 73mm BB. I measure about 90mm each side +/- a few mm. I switched from Miranda 4mm offset cranks to 0mm since the Erider BB spindle is longer than the Sempu.
Q-factor for a 68mm BB is about 175mm.
edit: I noticed the Erider datasheet says driveside is 3mm longer, so there is a small offset.
Last edited by PaulD on Mar 16 2020 1:52pm, edited 2 times in total.

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 16 2020 1:50pm

Nobreaks wrote:
Mar 15 2020 11:23pm
Will you be able to supply a female to fit to the battery I supply and possibly another male plug to fit to whichever battery charger I end up using ?
Yes, I can include this with kits shipped without batteries. We use an XT60 connector which is quite common.
Joost5000 wrote:
Mar 16 2020 12:48pm
What’s the front chainring 42 tooth?
In the first batch of kits, I included a chainring that was suitable for the bike type and wheel size. For example, for a 29er mtb, it included a 32T. For a 700C road bike, a 44-46T. This is a bit of a hassle since I have to stock a lot of chainrings, so I might switch to maybe 3-4 stock sizes soon. For now, I'll provide what I think will work best for each application.

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Re: PaulD's lightweight mid drive development

Post by neptronix » Mar 16 2020 7:51pm

PaulD wrote:
Mar 16 2020 1:44pm
With the new torque sensor, Q-factor is about 180mm for a 73mm BB. I measure about 90mm each side +/- a few mm. I switched from Miranda 4mm offset cranks to 0mm since the Erider BB spindle is longer than the Sempu.
Q-factor for a 68mm BB is about 175mm.
edit: I noticed the Erider datasheet says driveside is 3mm longer, so there is a small offset.
Oh darn, that's not compatible with my bizarre leg issues ( i know this from riding other mid drives ), glad i asked before ordering.
GL with your really cool drive system otherwise.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: PaulD's lightweight mid drive development

Post by lightrush » Mar 16 2020 10:13pm

PaulD wrote:
Mar 15 2020 3:10pm
lightrush wrote:
Mar 14 2020 4:18pm
What new torque sensor?
I've been having good results with the Erider for the last 6 months, so we are going with it. Here it is with the new freewheel hub.
IMG_20200315_094502_copy_2024x1518.jpg
Interesting. That looks a lot like Sempu but not quite. How's it better? I have the Sempu I got from you some time ago and I have an idea of how it behaves.

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Re: PaulD's lightweight mid drive development - Looking for Beta Testers

Post by Danny Mayes » Mar 16 2020 10:39pm

PaulD wrote:
Mar 16 2020 11:33am

Hi Danny, apologies for not keeping this thread updated and thanks for the compliment. I've been to busy, but I'll try harder to keep posting. Regarding the battery, are you referring to being a chosen one to use the Ligo BMS? Well, I've known Justin since college, we met at UBC probably 15 years ago. Also, I was the principal battery engineer at an e-moto company for many years, so he trusts I will build a design a quality pack with Grin's electronics.
No need to apologise, i know how busy life is. I'm enjoying the updates FWIW :)

Heheh, yeah I was referring the the LiGo BMS! Well, good for you, it's such a great solution. I adore my LiGo.

D

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 16 2020 11:22pm

neptronix wrote:
Mar 16 2020 7:51pm
Oh darn, that's not compatible with my bizarre leg issues ( i know this from riding other mid drives ), glad i asked before ordering.
GL with your really cool drive system otherwise.
Is it the q-factor or the offset that's an issue for you?
lightrush wrote:
Mar 16 2020 10:13pm
Interesting. That looks a lot like Sempu but not quite. How's it better? I have the Sempu I got from you some time ago and I have an idea of how it behaves.
It's very similar. Not sure who copied who. The main advantage is that the cadence signal is more robust (or so it seems). The Sempu T4 sometimes has issues if your BB shell hasn't been faced properly. Also, the wire exits the left BB cup, so no need to drill a hole in your frame!
Danny Mayes wrote:
Mar 16 2020 10:39pm
No need to apologise, i know how busy life is. I'm enjoying the updates FWIW :)
Heheh, yeah I was referring the the LiGo BMS! Well, good for you, it's such a great solution. I adore my LiGo.
Good to hear and thanks for the support. Yes, the Ligo is pretty amazing piece of engineering.

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Re: PaulD's lightweight mid drive development - Looking for Beta Testers

Post by Danny Mayes » Mar 17 2020 12:59am

Danny Mayes wrote:
Mar 14 2020 2:49am

Things have been a bit quiet around here (i have not been back for quite some time myself) but its nice to see...
I feel like a doof, I was making a comment about ES at large (or the Non-hob thread at least) saying it was quiet, as in from the good ol days at least, attempting to commend you on NOT being quiet! :lol:

D

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Re: PaulD's lightweight mid drive development

Post by neptronix » Mar 17 2020 1:34pm

PaulD wrote:
Mar 16 2020 11:22pm
Is it the q-factor or the offset that's an issue for you?
Probably both. A BBS02 with it's 10-15mm offset on one side caused me to develop patellafemoral syndrome on the opposite leg, which was disabling until i did physical therapy. This happened within 100 miles of riding it over the course of 2 weeks.

When my gym switched their exercise bikes to ones that had an additional inch of pedal width ( 7 inches vs the previous 6 ), i stopped using them because they hurt on both legs.

I have minor bone deformities so i'm a weird case. I thought your design was more narrow than it actually is. Darn.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 17 2020 3:25pm

neptronix wrote:
Mar 17 2020 1:34pm

Probably both.
When my gym switched their exercise bikes to ones that had an additional inch of pedal width ( 7 inches vs the previous 6 ), i stopped using them because they hurt on both legs.
A 3mm offset can be easily overcome with a pedal washer on one side, but yes, a 6" (152mm) q factor is hard to find outside of a pure road bike. My non-e mountain bike has a 178mm q-factor which is pretty normal.

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Re: PaulD's lightweight mid drive development

Post by neptronix » Mar 17 2020 10:24pm

PaulD wrote:
Mar 17 2020 3:25pm
A 3mm offset can be easily overcome with a pedal washer on one side, but yes, a 6" (152mm) q factor is hard to find outside of a pure road bike. My non-e mountain bike has a 178mm q-factor which is pretty normal.
I just measured my bikes and it looks like your q factor is only +5mm of my widest setup, nice.

Apparently the narrower the better for biomechanics. Compared to most mid drives your system is pretty narrow. Kudos on that!
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

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Re: PaulD's lightweight mid drive development

Post by PaulD » Mar 17 2020 10:45pm

neptronix wrote:
Mar 17 2020 10:24pm
I just measured my bikes and it looks like your q factor is only +5mm of my widest setup, nice.
Apparently the narrower the better for biomechanics. Compared to most mid drives your system is pretty narrow. Kudos on that!
Yep, for some people narrow is really important, I totally understand. I really want to do a custom torque sensor some day, just not sure if I'll ever have the time.

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