Search found 42 matches

by nowholeself
May 24 2020 10:00pm
Forum: E-Bike Technical
Topic: Front freewheel torque: spragg vs pawl
Replies: 2
Views: 42

Re: Front freewheel torque: spragg vs pawl

The star ratchet design is definitely cool. But unlike the csk35 spragg bearing, I am unaware of any star ratchet product on the market that can be as easily adapted into a front freewheel. In addition, I love the silence of spragg clutches, a feature not offered by other designs.
by nowholeself
May 24 2020 8:22pm
Forum: E-Bike Technical
Topic: Front freewheel torque: spragg vs pawl
Replies: 2
Views: 42

Front freewheel torque: spragg vs pawl

Can a spragg clutch bearing like the csk35 take enough torque to work just as well or even better in a front freewheel design that is not driven by an engine, but rather just cranked by average human power? We know from the old Elation design that the csk35 is not enough to work in a front freewheel...
by nowholeself
Mar 05 2020 12:59am
Forum: Motor Technology
Topic: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+
Replies: 159
Views: 32916

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

My Neumotors 8025 has just arrived. It is so small! My original plan was to attempt to at least match, if not beat, the power of an ASI BAC800 controlled BBSHD. But can something so tiny really do that!?!? Maybe I should have gone with the 8038...
by nowholeself
Mar 05 2020 12:56am
Forum: Motor Technology
Topic: What's so bad about low impedence?
Replies: 30
Views: 1534

Re: What's so bad about low impedence?

@ op, did they tell you a number for inductance? At which voltage and RPM you would like to use it? One idea, which probably would make it running, would be to split the delta winding and connect it in star. By doing so you would get about 3 times higher inductance. The loss of RPM (1,7x less) you ...
by nowholeself
Feb 28 2020 1:13pm
Forum: Motor Technology
Topic: What's so bad about low impedence?
Replies: 30
Views: 1534

Re: What's so bad about low impedence?

ASI are pretty conservative with their ratings. I ran their bac4000 controller with the 100kv wind of the 8057. Did the auto tune and set up as per the manual and everything worked. Your thread was actually one of two that encouraged me to try out the Neumotors engines. I was especially excited to ...
by nowholeself
Feb 28 2020 4:49am
Forum: Motor Technology
Topic: What's so bad about low impedence?
Replies: 30
Views: 1534

What's so bad about low impedence?

So I sent ASI an email about using their controllers with the Neumotors 80xx series engines, adapted with hall sensors. They responded that the motor is "one of those low inductance/impedence" motors, and indicated that it would be difficult, if not impossible, to make it work with their controllers...
by nowholeself
Feb 25 2020 3:33pm
Forum: Motor Technology
Topic: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+
Replies: 159
Views: 32916

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Made yet another revision, this time to allow building of the hall-sensor module off of the motor, and for much better wire routing. This is after tumbling it to deburr in our 4-foot diameter vibratory tumbler with polyester tetrahedrons. Edit: I can't change the orientation of the image for some r...
by nowholeself
Feb 23 2020 3:12pm
Forum: Motor Technology
Topic: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+
Replies: 159
Views: 32916

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

This looks great. I'd vastly prefer to go this route if it works as well.
by nowholeself
Feb 18 2020 8:50pm
Forum: E-Bike General Discussion
Topic: CYC X1 'Gear' version
Replies: 3
Views: 371

CYC X1 'Gear' version

I like the idea of the final reduction being like the (nylon?) 'gear' version of the CYC X1. Does anyone know how well it holds up? Does anyone have a lead on some aftermarket parts to make that happen for my own design?
by nowholeself
Feb 18 2020 3:25pm
Forum: Motor Technology
Topic: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+
Replies: 159
Views: 32916

Re: Neumotor 8057/75 middrive project, belt drive, adding halls, 10kW+

Here a pic of the resolver. It is 3D printed with ABS so that it doesn't melt at higher temperatures. Don't think that this was that easy.. It took 4-5 redesigns in CAD and prints to make everything fit togehter (especially to get 3x4mm magnets into the slots). Luckily the printing time was not lon...
by nowholeself
Feb 04 2020 9:16pm
Forum: E-Bike Non-hub Motor Drives
Topic: Astro vs Revolt engines
Replies: 16
Views: 1490

Re: Astro vs Revolt engines

I'll note that, as you've probably guessed, I don't need to go that far. In any case, I'd like whatever engine I build to not need a huge battery to blast down the street. how are the molicel p42a holding up? you must have quite a few cycles on them by now They're holding up reasonably well. The pa...
by nowholeself
Jan 15 2020 2:58pm
Forum: E-Vehicles General Discussion
Topic: 10:1 right angle gearbox?
Replies: 5
Views: 1254

Re: 10:1 right angle gearbox?

Thanks for the suggestion but the lightest 10:1 gearbox listed weighs almost seven pounds and is rated at much lower rpms. https://www.mcmaster.com/right-angle-gear-boxes I should be working in sales for McMaster-Carr. Order at 6:00pm. It's on my porch the next day in the morning :? Order received. ...
by nowholeself
Jan 12 2020 2:48pm
Forum: E-Vehicles General Discussion
Topic: 10:1 right angle gearbox?
Replies: 5
Views: 1254

10:1 right angle gearbox?

I need a 10:1 right-angle gearbox that can handle a max of 8nm input and 10,000rpms, but is less than 4 pounds. Any ideas? Everything I've found online so far is way too heavy.
by nowholeself
Nov 24 2019 6:16pm
Forum: E-Bike General Discussion
Topic: Beltbox?
Replies: 14
Views: 1049

Re: Beltbox?

Not to over generalize here but usually attempts to cheat physics by playing the kv game don’t work out so well. Try to think of the kv only as a way to match the motor to the voltage and nothing else. There are some differences in efficiency between different windings but the rpm required to make ...
by nowholeself
Nov 24 2019 4:37pm
Forum: E-Bike General Discussion
Topic: Beltbox?
Replies: 14
Views: 1049

Re: Beltbox?

Much more talented designers than me have not utilized such a system. So I have to be missing something. What is it? What am I missing? Why is this suboptimal? Surely my inexperienced 'duh just use two belts' is a headsmackingly dumb idea. But why? Roast me! I believe the problem or the reason why ...
by nowholeself
Nov 24 2019 4:31pm
Forum: E-Bike General Discussion
Topic: Beltbox?
Replies: 14
Views: 1049

Re: Beltbox?

Its not a dumb idea and you don't deserve a roast. It is a formidable engineering challenge. The secret to any of these high RPM mid drives is understanding the interplay between torque, power, and RPM. It's easy to get beyond common off the shelf belts and pulleys as well as end up with impractica...
by nowholeself
Nov 24 2019 3:58am
Forum: E-Bike General Discussion
Topic: Beltbox?
Replies: 14
Views: 1049

Beltbox?

I've been trying to design a gearbox around the Neumotor 8057 to drive the chainwheel from an all internal assembly a'la BBSHD. Every otherwise workable design I finish has the same unnacceptable flaw: it weighs a ton. However, I've been following an older thread on here involving a single reduction...
by nowholeself
Nov 13 2019 8:14pm
Forum: E-Bike Non-hub Motor Drives
Topic: New Approach to 4500W Mid Drive
Replies: 61
Views: 8784

Re: New Approach to 4500W Mid Drive

I'm watching this thread with great interest. I love what you've done so far. I'm particularly impressed by how lightweight your design is. I'm curious to know if that particular engine will be able to be run hard for very long, even with a light rider on a light bike (e.g. no more than 200lbs total...
by nowholeself
Nov 10 2019 8:26pm
Forum: E-Vehicles General Discussion
Topic: Worm gear reducers/gearboxes?
Replies: 11
Views: 1738

Right angle reducers/gearboxes?

My search for a decent worm gearbox has yet to yield results. I'm expanding so as to include any right angle gearboxes under 2 lbs that can handle a Neumotors 8057. Do y'all have any leads? I fear my search is quixotic.
by nowholeself
Nov 04 2019 9:27pm
Forum: E-Vehicles General Discussion
Topic: Worm gear reducers/gearboxes?
Replies: 11
Views: 1738

Re: Worm gear reducers/gearboxes?

The plan is a gear reduction from a Neumotor 8057 to a bike chainwheel. A wormdrive is quiet, and also offers the ability to mount the motor 90 degrees off the bottom bracket axle, which helps with the design I'm tinkering with. This may not be what you were planning , but before the current tsunam...
by nowholeself
Nov 04 2019 9:25pm
Forum: E-Vehicles General Discussion
Topic: Worm gear reducers/gearboxes?
Replies: 11
Views: 1738

Re: Worm gear reducers/gearboxes?

be aware though that worm gears are very inefficient, particularly at high reductions/high rpms. There's a reason that people use multistage chains, and car diffs use gears rather than worms Ah good to know. How inefficient with a single 10:1 reduction though? Keeping things ultra quiet may be wort...
by nowholeself
Nov 03 2019 3:23am
Forum: E-Vehicles General Discussion
Topic: Worm gear reducers/gearboxes?
Replies: 11
Views: 1738

Re: Worm gear reducers/gearboxes?

What will you be using the gear box reducer for? The plan is a gear reduction from a Neumotor 8057 to a bike chainwheel. A wormdrive is quiet, and also offers the ability to mount the motor 90 degrees off the bottom bracket axle, which helps with the design I'm tinkering with. Also, your user name ...
by nowholeself
Nov 03 2019 3:20am
Forum: E-Vehicles General Discussion
Topic: Worm gear reducers/gearboxes?
Replies: 11
Views: 1738

Re: Worm gear reducers/gearboxes?

Balmorhea wrote:
Nov 02 2019 10:56pm
Electric wheelchair motors usually have worm gear reductions. I imagine there are plenty of scrapped motors from those things somewhere.
Interesting. Thanks!
by nowholeself
Nov 02 2019 6:42pm
Forum: E-Vehicles General Discussion
Topic: Worm gear reducers/gearboxes?
Replies: 11
Views: 1738

Worm gear reducers/gearboxes?

Any recommendations for worm gear reducers/gearboxes that can handle 4nm max input torque? The lighter the better, of course. My apologies if this has already been discussed. I've been unable to find much searching the forum so far. Thanks y'all!
by nowholeself
Nov 02 2019 3:34pm
Forum: E-Bike General Discussion
Topic: AVIAN featherweight mid drive
Replies: 119
Views: 21821

Re: AVIAN featherweight mid drive

I love this thread. This project is impressive and a bit inspiring. How noisy is the cycloidal reducer? The small size is killer but the Tangent drive, as cool as it is, sounds like a weed-eater. Is that kind of noise just an unfortunate drawback to such a system, or is there some way to avoid it? T...