LR Big Block Motoped

How do you think this new motor would compare to the D7500? Yours weighs less but your motor casing is much smaller so id assume this has similar copper fill and the new IPM can increase RPM greater than d7500?

Max speed 4500Rpm
Rated speed 4000Rpm
Rated output 7.5 kW 72V
Max output 10,000W
Rated Torque 50Nm
Max Torque100Nm
Rated Amp 120A
Standard hall sensors (+5V)
Temperature sensor
Diameter: 145 mm
Length: 127mm + 47mm (axle)
Weight: 7.25 kg

The old Big Block was more similar to the D7500 than the new IPM motor. The D7500 makes 4000 rpm from 72V, my motors make around 4500. The big difference now is that with internal magnets and field weakening the IPM Big Block easily screams up to 8500 rpm. So similar low end power, but twice the max rpm and more top end power from the Big Block. An advanced controller makes all the difference. The D7500 is a square wave motor, my IPM motors are FOC compatible.

LR, I'm looking to get this IPM second hand from shortcircuit .. any chances you might be willing to sell me some mounting brackets for a motoped frame? sometime soon?? and maybe some 219 jackshaft sprockets, etc??? also, do you have any recommendations on fitting a temperature sensor?? and can this IPM be run easily in either direction for right or left hand drive?? just with controller settings or requiring disassembly and modification??? finally, what are some other possible controller options besides asi, nuc, mobius.. maybe something from the low to mid level while waiting and saving for the higher end.. thanx ND

I have two sets of Motoped brackets available. I had five sets cut at Big Blue Saw and three are sold. I can get more made any time. The more you buy and the less of a hurry you're in, the better the price I can get for you. I do also have Motoped jackshaft specific 219 sprockets and a smaller #420 driver to lower the final drive reduction. Both are stainless steel. I use the Grin Tech 10k thermistor and JB Weld it to the stator plate near the windings. I can fit the thermistor or you can. Direction of rotation can be reversed just by changing the wiring sequence of the hall and phase wires. I have the sequences for the Lyen and PowerVelocity controllers.
As I write this Alan Hu at ERT is down with unknown health issues. For customers wanting a sine wave controller right now, or a more moderately priced sine wave, I'm recommending the 12 FET PowerVelocity for my small block motors and the 18 FET for my big block motors. They're powerful, have a great Bluetooth programming app that puts ASI to shame, and Vad at PV provides rock solid support. Vad is also working on a high end clean sheet FOC that he says will be a game changer. There is always room for more and better controllers!

LR, plz pm me a paypal quote for the IPM motoped mounting brackets, 219 and 420 jackshaft sprockets that you have in stock or within ~2 weeks delivery.. (and anything else relevant?) thanx ND
(we spread the word.. so may turn into more sales..)

LR, will you be selling the ASI controllers with your motors on your site separately from your complete drives?

I never planned to sell ASI controllers myself. My hope was that I could refer customers to ERT for controllers that were pre-configured for my motors. Alan Hu has disappeared, citing health problems. Hopefully he will be back.

Interesting.

So if that doesn't pan out do you have a calibration file matched to your motors so you could sell them?

I really don’t want to sell controllers. It’s not the selling them really, it’s doing tech support on them. I would so much rather let someone who wants that business to have it. Edward Lyen was perfect for me. He just wanted to sell controllers and accessories for them, I just want to make mid drives. Edward’s product just got out of date and he isn’t interested in updating (I’ve asked repeatedly). Vad at PowerVelocity has a good solid line of sine wave controllers and also provides solid support. If Alan really is done I’ll probably see if Martin at ASI will help me out as an OEM. Alan invested a ton of time and energy in getting my motors to run with the super fussy ASI controllers. I’m not going to give up on him until I have no choice.

Thanks for the reply.
That all makes perfect sense. Someone on another thread had mentioned your new ipm motors had been run with an ASI and I got excited about the prospect of them being available from a reputable vendor with an easy to use website. As of right now the ASI stuff isn't quite turnkey from anywhere.

The new IPM motors are sine wave compatible. That means PowerVelocity, ASI, Adaptto, Nucular and so on. The original Big Block was a great motor except that it had terrible hall signals and would not run right with sine wave controllers.
I was right there with Alan battling the ASI demons. They are very advanced controllers with a ton of potential but they are not consumer ready as sold by ASI. Alan was trying to develop a programmable display when he got sick.

LightningRods said:

I never planned to sell ASI controllers myself. My hope was that I could refer customers to ERT for controllers that were pre-configured for my motors. Alan Hu has disappeared, citing health problems. Hopefully he will be back.

Click to expand...

From many dozens of reports, I would not rely on him for anything critical to your business model, certainly not distribution/fulfillment on an ongoing basis.

So the current Big Block is IPM / FOC or just the XL version?

Sounds like Lyen's biggest trap + the old Big Block would be easy/reliable ?

Can get variable regen?

What are the main downsides going that way compared to the new FOC hotness?

I have a 3” wide, 7 lb motor good for 50A- “Small Block”. 4” wide, 11 lb good for 120A- “Big Block”. 4.25” wide, 13 lb good for 150A- “XL Big Block”. All have the same IPM layout, all have the same improved hall layout.
The new motors are the same price as the old ones and should be more reliable, especially at high rpm because the magnets can’t come loose from centrifugal force. The old Big Block would do that if you over revved it (8000 rpm +).
The Lyen controllers are still a good inexpensive controller. Edward is 100% solid. The PowerVelocity are more money, have more features, and are sine wave. I believe that both the Lyen and PV have adjustable preset on/off regen. Variable regen was one thing I was looking forward to on the ASI.
Your point about being too dependent on any one supplier is valid. I’m in the process of exploring the controller options for my customers.
I no longer stock the old motors because there is no advantage to them and the price is the same. The advantages of the Lyen is dealing with Edward, price, CA3 compatibility, known reliability. The main disadvantage is it’s “kick in the ass” throttle curve that becomes increasingly exciting with more power. A Domino throttle helps, changing the throttle out uprate in the CA3 helps, but it’s still going to be there. No field weakening either, which is huge on these IPM motors.

Glad to hear you're not going to put ERT Alan in the critical path, and wish ASI would also get a better alternative channel stateside.

I hope he gets better of course and is able to continue to contribute his talents as appropriate, just apparently not suited to a customer facing role.

I think a huge business opportunity exists for someone to provide hourly consulting and annual service contracts on the high end FOC side of the controller biz, could be a worldwide market.

Not just ASI, but supporting Sevcon too, maybe Nucular and PV if they want third parties involved, Lebowski waiting for development into a business IMO.

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OK, back to reality

So, it sounds like the Lyen units can be made to work with your new motors.

I would do that as a stopgap, until my ticket comes up in the Nucular waitlist, and/or the ASI / Sevcon programming hurdles are cleared.

Or PV, but I do really need variable regen for drag braking. FW no interest at all, but FOC's greater efficiency and precise control at low rpm seems a must-have upgrade.

The need for CA3 compatibility goes away apparently with more sophistication in the controller programming? The Nucular crowd is vehemently opposed to the idea. . .

Separate issue, I realize would lose regen:

Let's say I wanted to use one of your motors in right-hand mode, driving a Rohloff IGH.

Spec'd limit of 130 N.m at the hub, shear pins protecting but I'm not carrying a vice into the bush with me.

Use case is a heavy tandem / cargo bike in mountain country, so really would like to get up to that 129.99 N.m limit and hold it pushing 500+lbs up over a pass in the Rockies.

What would you recommend as a solution, prevent breaking the Rohloff?

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relevant thread, not LR specific, but would **really** appreciate your clearing up the wheel-size vs torque issue there, sorry for my noobidity:

Rohloff & other IGH at high power - measuring & limiting torque? https://endless-sphere.com/forums/viewtopic.php?p=1541984

(Edit: came across this reference to devices specifically designed to limit torque? https://endless-sphere.com/forums/viewtopic.php?p=1550029#p1550029)

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And this one, I now realize your usual left-hand setup might normally accommodate regen there?

Big mid-drive motor, bypass IGH? https://endless-sphere.com/forums/viewtopic.php?t=105857

A number of people have done builds with my Big Block and Rohloffs. To my knowledge none of them have broken. The stock shear pins are plastic. You can upgrade to aluminum pins which increases the torque limit and reduces your chances of getting stranded with blown pins. The aluminum should still fail before the steel gears are damaged, but I don’t recommend spinning your wheel in a rut on a steep hill to test them.

The easy way to take some strain off of your driveline is to have a simple multifunction switch with different power settings and throttle ramps. Startup is where the worst damage is typically done. Start off pedaling if you can or at a lower power setting. If you want to do burnouts you need one of my single speed #219 or #420 chain setups.

A smaller wheel is like lower gearing. It reduces top speed and increases torque. That’s mostly a hub motor issue since that’s the only way they can change gearing. With a mid drive, choose the wheel size you want and then choose the correct sprockets for the gearing you want.

I’m working on a bolt on brake rotor/sprocket solution for LHD that will allow regen as well as all of the unmolested pedal gears on the right side. Yes I designed a LHD single stage drive a couple of years ago. I’m still working on that design and refining it.

.....A smaller wheel is like lower gearing. It reduces top speed and increases torque......

Click to expand...

Not intending to be pedantic or critical, but that comment is misleading..(as im sure you are aware )
Reducing the wheel diameter will reduce the speed, but does not change the “torque” (Nm) at the wheel, it simply reduces the “torque arm” , or the distance from the axle to the tire tread radius.(the “m” in Nm)
Since torque is ..Force X radius.., that reduction in radius , effectively increases the traction force (F), available at the tire/road surface....from the SAME Torque at the wheel hub
But changing the gearing, either at the wheel or the motor, will alter the torque and rpm available at the wheel.

Hillhater said:

.....A smaller wheel is like lower gearing. It reduces top speed and increases torque......

Click to expand...

Not intending to be pedantic or critical, but that comment is misleading..(as im sure you are aware )
Reducing the wheel diameter will reduce the speed, but does not change the “torque” (Nm) at the wheel, it simply reduces the “torque arm” , or the distance from the axle to the tire tread radius.(the “m” in Nm)
Since torque is ..Force X radius.., that reduction in radius , effectively increases the traction force (F), available at the tire/road surface....from the SAME Torque at the wheel hub
But changing the gearing, either at the wheel or the motor, will alter the torque and rpm available at the wheel.

Click to expand...

The man hates hills, and knows his stuff! As Hillhater says, sure LR knows also. But its good to know and understand the physics involved.

Another often overlooked influence of wheel/tyre diameter is that same radius length is a factor in the rotating mass you are trying to accelerate (spin) and slows or affects the rate at which the system will accelerate as more weight at a greater radius takes more energy to accelerate in rotating speed.

Therefore a thin light but large dia tyre might spin up at the same rate as a larger/fatter/heavier but smaller tyre/hub combo. But like for like in tyre forms a smaller diameter is always going to spin up faster.

Less influence on overall performance but a considerable portion of acceleration is affected by it. And electric drives don't need as much mechanical traction as an equivalent powered and geared ICE because the smooth delivery is much more forgiving on the grip to not break traction. A simple example is look at tyre widths on a Tesla Vs a Corvette. As fast as each other (for our comparison) but the Tesla needs half the tyre contact area.

Sorry for sidetracking your thread LR!

Cheers
Tyler

LightningRods said:

A number of people have done builds with my Big Block and Rohloffs. To my knowledge none of them have broken. The stock shear pins are plastic

Click to expand...

Good to know, thanks for that!

> A smaller wheel is like lower gearing. It reduces top speed and increases torque. That’s mostly a hub motor issue since that’s the only way they can change gearing. With a mid drive, choose the wheel size you want and then choose the correct sprockets for the gearing you want.

THANK YOU for explicitly confirming that!


> You can upgrade to aluminum pins which increases the torque limit and reduces your chances of getting stranded with blown pins.

Sounds good, so long as they are certain to still protect the hub's gearing - are they engineered by, or at least informally accepted by Rohloff itself?

> I don’t recommend spinning your wheel in a rut on a steep hill to test them.

Well not intentionally

> The easy way to take some strain off of your driveline is to have a simple multifunction switch with different power settings and throttle ramps.

That sounds perfect! Would allow the gearing ratios to be selected more towards optimum performance once underway

with the (maybe greatly) reduced power settings available for protection during those uphill-facing standing starts

take maybe even a few minutes to get up past that 8-10mph "hump", then "shift" up to full power to get to 15mph, if the weight/grade allows.

My understanding is, once at those more reasonably high speeds, that each speed increase is requiring a safer lower amount of torque?

I have no interest in burnouts using such strong chains, in fact, I'm thinking the Gates belt drive might help absorb the "shock effects" of low-rpm high startup torque - what do you think?

LightningRods said:

Single speed #219 is definitely the way to go if I use a fixed LH drive to get regen for drag braking.

Click to expand...

Relevant thread: Big mid-drive motor, bypass IGH?
https://endless-sphere.com/forums/viewtopic.php?t=105857

> I’m working on a bolt on brake rotor/sprocket solution for LHD that will allow regen as well as all of the unmolested pedal gears on the right side. Yes I designed a LHD single stage drive a couple of years ago. I’m still working on that design and refining it

Well if that could be done leaving a Rohloff specifically unmolested for human-pedal power only

given my use case (heavy tandem / cargo bike climbing up over a pass in the Rockies.)

outlined in detail here

john61ct said:

Big mid-drive motor, bypass IGH? https://endless-sphere.com/forums/viewtopic.php?t=105857

Click to expand...

I may well be your guinea pig help fund testing.

Do you think having one fixed gear would be too limiting? I mean I am all about low rpm torque here and your Big Block XL seems ideal for that

but in that scenario maybe need to add a front hub drive for once over 15mph, kV maybe set for a top speed of 25mph?

At this point, is it safe to say I do not need to pursue this type of mechanical torque limiter?

john61ct said:

Came across this reference to devices specifically designed to limit torque? https://endless-sphere.com/forums/viewtopic.php?p=1550029#p1550029

Click to expand...

> A smaller wheel is like lower gearing. It reduces top speed and increases torque. That’s mostly a hub motor issue since that’s the only way they can change gearing. With a mid drive, choose the wheel size you want and then choose the correct sprockets for the gearing you want.

THANK YOU for explicitly confirming that!

>Thank you for raising intelligent, relevant points.

> You can upgrade to aluminum pins which increases the torque limit and reduces your chances of getting stranded with blown pins.

Sounds good, so long as they are certain to still protect the hub's gearing - are they engineered by, or at least informally accepted by Rohloff itself?

> The times the aluminum pins were used on my builds the Rohloffs were sourced from Cycle Monkey. Check with CM as to the particulars of this option.

> The easy way to take some strain off of your driveline is to have a simple multifunction switch with different power settings and throttle ramps.

That sounds perfect! Would allow the gearing ratios to be selected more towards optimum performance once underway
with the (maybe greatly) reduced power settings available for protection during those uphill-facing standing starts take maybe even a few minutes to get up past that 8-10mph "hump", then "shift" up to full power to get to 15mph, if the weight/grade allows.

> The strain of starting out from a standstill is huge. Gradual acceleration without abrupt jolts to the driveline hugely extends it’s life. It’s not the 3000 watts that does the damage. It’s the 0 to 3000 watts in 0.5 seconds that does it. You don’t have to take minutes to get up to speed. Just be smooth and avoid slamming the driveline.

I have no interest in burnouts using such strong chains, in fact, I'm thinking the Gates belt drive might help absorb the "shock effects" of low-rpm high startup torque - what do you think?

> Gates belts don’t stretch enough to save bicycle chain and sprockets. Again, be smooth with power application.

> I’m working on a bolt on brake rotor/sprocket solution for LHD that will allow regen as well as all of the unmolested pedal gears on the right side. Yes I designed a LHD single stage drive a couple of years ago. I’m still working on that design and refining it

Well if that could be done leaving a Rohloff specifically unmolested for human-pedal power only given my use case (heavy tandem / cargo bike climbing up over a pass in the Rockies.)

> I’ve already made a 4 bolt adapter plate to attach a 219 sprocket left side on a Rohloff. For climbing super steep grades and for trying to extend range as much as possible I’d go ahead and trust the Rohloff internal gears at 3000 watts. The setup that I made was for street riding at higher power.

Do you think having one fixed gear would be too limiting? I mean I am all about low rpm torque here and your Big Block XL seems ideal for that. But in that scenario maybe need to add a front hub drive for once over 15mph, kV maybe set for a top speed of 25mph?

> With an XL Big Block geared for 25 mph one gear should do everything. It’s the combined expectation of tree climbing ability combined with a 50 mph top speed that requires multiple gears. Personally I would still run through the Rohloff if you’re going to that expense.

At this point, is it safe to say I do not need to pursue this type of mechanical torque limiter?

> The slipper clutch is Matt Shumaker’s design. He invested a ton of time in it’s development and seems to believe in it. I have huge respect for Matt and have learned a lot from him. In this instance I’m not in favor of a slipper or torque limiting clutch. I prefer a solid, direct link and using electronic means to limit the torque delivered to the driveline. To me slipping means wasted power and wear on the slipping parts. Definitely read everything Matt has to say on the subject and make up your own mind.

Hope you don't mind me refactoring the quoting for clarity

LR: A smaller wheel is like lower gearing. It reduces top speed and increases torque. That’s mostly a hub motor issue since that’s the only way they can change gearing. With a mid drive, choose the wheel size you want and then choose the correct sprockets for the gearing you want.

Jct: THANK YOU for explicitly confirming that!

LR: Thank you for raising intelligent, relevant points.

Jct: (blush)

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LR: You can upgrade to aluminum pins which increases the torque limit and reduces your chances of getting stranded with blown pins.

Jct: Sounds good, so long as they are certain to still protect the hub's gearing - are they engineered by, or at least informally accepted by Rohloff itself?

LightningRods said:

The times the aluminum pins were used on my builds the Rohloffs were sourced from Cycle Monkey. Check with CM as to the particulars of this option.

Click to expand...

Thanks for that lead, will check them out.

LR: The easy way to take some strain off of your driveline is to have a simple multifunction switch with different power settings and throttle ramps.

Jct: That sounds perfect! Would allow the gearing ratios to be selected more towards optimum performance once underway
with the (maybe greatly) reduced power settings available for protection during those uphill-facing standing starts take maybe even a few minutes to get up past that 8-10mph "hump", then "shift" up to full power to get to 15mph, if the weight/grade allows.

LightningRods said:

The strain of starting out from a standstill is huge. Gradual acceleration without abrupt jolts to the driveline hugely extends it’s life. It’s not the 3000 watts that does the damage. It’s the 0 to 3000 watts in 0.5 seconds that does it. You don’t have to take minutes to get up to speed. Just be smooth and avoid slamming the driveline.

Click to expand...

Well so I guess that makes FOC, or at least sinewave, critical for my use case?

And this is the feature called "ramp up speed" control, is that right?

Or do you mean my (human) sensory / muscular coordination to achieve this smooth and gentle touch?

Obviously also depends on whether hand throttle or PAS, I do not know enough, can these be combined so a hand control is used for takeoff from stopped

So I could stand up & push hard, pulling up on the handles etc in the early takeoff, without signaling anything to the electric side, at the same time very gently manually throttling

then PAS taking over once past say 5mph?

Sorry I have no idea if this is crazy/outlandish, or totally standard stuff.