Search found 238 matches

by PaulD
Jan 18 2018 12:18pm
Forum: E-Bike Non-hub Motor Drives
Topic: Design a Freewheel Crankset for Direct Mount Crankests
Replies: 27
Views: 5833

Re: Design a Freewheel Crankset for Direct Mount Crankests

Have you guys seen this ? Rocky Mountain made exactly what I am looking for: a freewheel that can be mounted on a RaceFace cinch crankset. It is on their new eBike called Altitude Powerplay. What I don't know though is if the spindle is custom made and what's its length. I am guessing it is for a 7...
by PaulD
Jan 16 2018 2:25pm
Forum: E-Bike Non-hub Motor Drives
Topic: Design a Freewheel Crankset for Direct Mount Crankests
Replies: 27
Views: 5833

Re: Design a Freewheel Crankset for Direct Mount Crankests

I do not see Shimano changing , except for perhaps keeping the 24mm ID , Outer Bearing and just making a switch to a 3 piece design using direct mount chainrings , but Keeping a 24 mm OD spindle size so as to keep selling their bearings. Any news about date of ability ? Price ? weight ? The nice th...
by PaulD
Jan 16 2018 1:17pm
Forum: E-Bike Non-hub Motor Drives
Topic: Design a Freewheel Crankset for Direct Mount Crankests
Replies: 27
Views: 5833

Re: Design a Freewheel Crankset for Direct Mount Crankests

The two people here in the U.S. who are doing the custom larger mid-drives do not know at this time how to design one, and the other person who is making a mid-drive here has said months ago he is looking into using Direct Mount Cranksets on his mid-drive , SamD ... but he has gone silent for a few...
by PaulD
Dec 02 2017 11:32am
Forum: Battery Technology
Topic: Ultrasonic tab welding
Replies: 29
Views: 2588

Re: Ultrasonic tab welding

Nice job getting that working! Have you tried to peel any of those welds apart?
by PaulD
Nov 15 2017 7:14pm
Forum: Battery Technology
Topic: Ultrasonic tab welding
Replies: 29
Views: 2588

Re: Ultrasonic tab welding

Ultrasonic welding is awesome, but my recommendation is to just punch holes in the tabs and put a few screws and nuts with washers or plates to sandwich the tabs... unless you are going into mass production. Bolted connections are pretty good. You'll want some kind of anti-ox on the joints unless th...
by PaulD
Oct 13 2017 12:21pm
Forum: Battery Technology
Topic: Ultrasonic tab welding
Replies: 29
Views: 2588

Re: Ultrasonic tab welding

Cool. Looks like that might work. The machine I was referring to is $40K and doens't belong to me! At 2000W, not sure how it could run off of 110V. Quick Details Type: Other Voltage: AC 110V or 220V +/-10%, 50/60Hz Current: Request Rated Capacity: 2000W Rated Duty Cycle: Request Dimensions: 360mm(L)...
by PaulD
Oct 12 2017 6:14pm
Forum: Battery Technology
Topic: Ultrasonic tab welding
Replies: 29
Views: 2588

Re: Ultrasonic tab welding

I would recommend asking the welder vendor what materials and thicknesses the machine can weld. The little ones for welding current collector foils likely don't have the power to do thick tabs. Just as a reference point, I nearly maxed out a 1.5kw welder doing 3X 0.2mm copper tabs to 1.6mm copper bu...
by PaulD
Aug 09 2017 9:15pm
Forum: Motor Technology
Topic: Current Sensors How to select a good one or roll your own.
Replies: 56
Views: 7657

Re: Current Sensors How to select a good one or roll your ow

HighHopes wrote:
tesla method, is that a copper bus bar some how fused to a piece of ceramic (i.e. the "resistor") ?
Manganin is often Electron Beam Welded  to copper for this purpose. Not sure if that's the case here. It has a low temp coefficient.

Sent from my Pixel using Tapatalk
by PaulD
Jun 29 2017 5:30pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

Hi Paul, very elegant design, I think it'd go great on my Yeti SB5.5. Regarding a freewheel, since you're going PAS only, could you not bypass having a freewheel altogether. A torque sensor could be added to the lower/return side of the #25 chain where it would only be feel the torque from pedallin...
by PaulD
Jun 26 2017 11:13am
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

Since you are designing a Motor Kit , Just Design around the newer make it your self battery pack , ( VRUZEND , Mlt34 ) I want a pack that will fit where a standard size water bottle fits... and I want it lightweight. Since this is a low power system, I can get away with smaller 30 cell battery. I ...
by PaulD
Jun 22 2017 4:21pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

PaulD, What is the Progress level ? What all will you be selling with the kit ? ( Sram Direct Mount Crankset as well ? ) ( Any other sources for a Direct Mount Crankset besides Sram at this time ? ) Many of use 12 s packs, or even 14 s packs, so the controller will be adjusted for Voltage, and Amp ...
by PaulD
Jun 13 2017 5:00pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

Your build here looks really nice and is now proven! Congrats! I'll be following this thread! I agree with you on Torque Sensing with a mtb. Just shifting in general sound goofy with a simple PAS system. I looked at the NCTE BB. One model had "Direction of Rotation" as one of the sensors. I thought...
by PaulD
May 23 2017 6:42pm
Forum: Battery Technology
Topic: "Batlab" ..18650 cell condition tester ?
Replies: 19
Views: 1916

Re: "Batlab" ..18650 cell condition tester ?

Nope, still waiting... as expected from a Kickstarter campaign..
by PaulD
Apr 28 2017 4:10pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

The solution that I have been thinking about for a while now, to cut down a pound or more off the BB/Crankset , and , to have better quality BB Bearings and better quality Cranksets , Is To Design a inner sprocket/feeewheel, that bolts right onto existing , Modern 2 piece Cranksets. ( BB30 / Shiman...
by PaulD
Apr 28 2017 2:04pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

Thanks Ron and Luke! I think its feasible to make a winning bike for next year. Flathill - Theoretical torque at the crank is 60 Nm with the current settings. I haven't confirmed. The limiting factor will be the gear reduction. Gear reduction is a compound planetary 1st stage is helical, second is s...
by PaulD
Apr 27 2017 9:03pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

Well, the race was a blast, and the bike performed great except for a jammed chain which cost me 4 minutes... That's an easy problem to fix. In my rush to complete the bike, I adjusted the chain line without realizing I made the perfect size slot between the chainring and powered secondary sprocket ...
by PaulD
Apr 27 2017 11:25am
Forum: General Discussion
Topic: YOUTUBE RECOMMENDS :
Replies: 972
Views: 73085

Re: YOUTUBE RECOMMENDS :

LockH wrote: Electric mountain bikes are racing ahead
Awesome footage. That's me at 0:42-0:44 :) .... had a great time (except for the part where my chain jammed, and I lost 4 minutes loosening my chainring to unjam it :oops: )
I think I was the only one riding a converted bike.
SOC2017race2small.png
SOC2017race2small.png (188.71 KiB) Viewed 1476 times
by PaulD
Apr 19 2017 7:28pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

Re: PaulD's lightweight mid drive development

Ha! Thanks Luke! There are some super fast guys that do the emtb race. Last year a former world champion won! .. funny you mention riding unpowered. Apparently last year, Adam Craig (super fast pro racer) just taped an extension cord to his bike and finished mid-pack. Lol. Sent from my Pixel using T...
by PaulD
Apr 19 2017 5:41pm
Forum: E-Bike Non-hub Motor Drives
Topic: PaulD's lightweight mid drive development
Replies: 72
Views: 9604

PaulD's lightweight mid drive development

Hey ES, I've been working on this for a while, so I thought I should share a bit. I have been developing a mid-drive system with the intention of converting most road and mountain bikes with minimal weight increase. Specs as they are now: 250-350W, ASI FOC controller, torque sensing BB, 36V, 11ah, a...
by PaulD
Mar 20 2017 9:24am
Forum: Battery Technology
Topic: good quality spot welding electrodes?
Replies: 9
Views: 886

Re: good quality spot welding electrodes?

redilast wrote: Do you get electrode sticking when welding pure nickel?
I did until I sanded a larger flat spot on the tip. Having the larger surface are seems to prevent sticking, although I haven't really done a controlled experiment.
by PaulD
Mar 19 2017 11:42am
Forum: Battery Technology
Topic: good quality spot welding electrodes?
Replies: 9
Views: 886

Re: good quality spot welding electrodes?

For electrodes, I get 182 chromium copper rod (1/8" dia) from McMaster-Carr and just cut to length and file/sand the desired shape for the tip.
by PaulD
Mar 19 2017 11:12am
Forum: E-Bike General Discussion
Topic: Taipei Cycle Show 2017
Replies: 9
Views: 1259

Re: Taipei Cycle Show 2017

liveforphysics wrote:I'm sadly not going to make Taipei until the 26th or 27th. Work priorities conflict with making the show, but I will still visit Ben and Shenta.
That's too bad Luke, I fly out on the 26th. Hopefully I'll be able to meet up with Justin and other attendees.
by PaulD
Mar 16 2017 8:45pm
Forum: General Discussion
Topic: 3/16" tab punch
Replies: 7
Views: 724

Re: 3/16" tab punch

I bought one of these. https://www.amazon.com/gp/product/B00OM4GVX0/
Works ok. The $100 one from McMaster that I have at work is better.
by PaulD
Mar 10 2017 1:51pm
Forum: E-Bike General Discussion
Topic: Shimano Steps, need some feedback please
Replies: 10
Views: 2823

Re: Shimano Steps, need some feedback please

emco5 wrote: PaulD, what is your Steps minimum happy speed when climbing. I assume it doesn’t like low rpm loads any more than a hub motor does.
Depends on how hard I want to pedal :-) With a mid-drive, you just shift down and go slower to prevent low RPM generating a lot of heat and wasting energy.
by PaulD
Mar 09 2017 9:29pm
Forum: E-Bike General Discussion
Topic: Shimano Steps, need some feedback please
Replies: 10
Views: 2823

Re: Shimano Steps, need some feedback please

Contrary to bike shop endearments, from a guy who rode a Trek Lift I’ve been told that the Shimano Steps system isn’t very strong on hills. Granted, it’s only 250w, but with its internal gearing and electronics feeding a 32t rear cog it should have some muscle. Where does it stand, is it comparable...