Search found 744 matches

by Buk___
Jun 02 2018 5:53pm
Forum: E-Bike General Discussion
Topic: Q128C sources?
Replies: 25
Views: 1123

Re: Q128C sources?

I love my Q128 H 201 rpm rear motor. Unfortunately in a moment of stupidity I tackled one hill to many and stripped the gears. The hill was steep and rough gravel about a half mile long. It was too rough to keep my speed up so I assume that the motor got hot enough to soften the plastic gears. I ma...
by Buk___
May 25 2018 2:22am
Forum: E-Bike General Discussion
Topic: Q128H right-hand side outer bearing size?
Replies: 0
Views: 107

Q128H right-hand side outer bearing size?

Anyone here happen to know (or have a dissassembled Q128H to hand) the size of the bearing on the right hand side, between the outer cover and the axle?

If anyone knows (or can measure) it would allow me to order a new one and not disassemble until I got it. Thanks.
junk71.jpg
junk71.jpg (24.88 KiB) Viewed 107 times
by Buk___
May 21 2018 2:22am
Forum: E-Bike General Discussion
Topic: E-trike Aluminum vs steel frame
Replies: 30
Views: 1204

Re: E-trike Aluminum vs steel frame

I wouldn't worry about stressing the frame over time issue one bit. I'd trust that the makers have done the appropriate engineering to make that point moot. Many folks seem to get fixated on the fact that there is no fatigue limit for aluminum while not giving appropriate consideration to these two...
by Buk___
May 20 2018 2:50am
Forum: E-Bike General Discussion
Topic: Ideas about charging batteries
Replies: 8
Views: 409

Re: Ideas about charging batteries

Since you've paid attention to detail cell voltages, how much out of balance is typical? If it's small, then you can generally just bulk charge and occasionally take them off to check the details. Since the only risk of out of balance conditions is over-charging or over-discharging your pack, your ...
by Buk___
May 17 2018 4:48pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Interesting concept, but the most basic simplicity is often the key to the best designs of durable dependability. Latest iteration: SpringPlateTAAssemblyView1.jpg SpringPlateTAAssemblyView2.jpg No drilling, screws or jubilee clips or extra tools required. One wrap-under plate (lighter blue lower im...
by Buk___
May 13 2018 10:06pm
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

Ok, nice work, and correct me if I am wrong,....Are we viewing your gif as from the inside of the torque arm that is next to the motor? No. If you follow the link to the bigger version, it also includes a ghost of the axle that shows the view is from the outside. If you're worried about the directi...
by Buk___
May 13 2018 7:57pm
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

I'm quite interested as well in seeing what a detailed FEA shows in comparison to the actual real world testing. I've had to shrink this using lossy compression in order to get it down to a size that will upload here (the original 15MB), which has made it rather small and fuzzy, but you can still s...
by Buk___
May 06 2018 8:44pm
Forum: E-Bike General Discussion
Topic: It's now Spring 2018.. Why haven't e-bikes gotten cheaper?
Replies: 74
Views: 3308

Re: It's now Spring 2018.. Why haven't e-bikes gotten cheaper?

MadRhino wrote:
May 06 2018 7:40pm
Yep, but many of those would still be riding them bikes if they had started on a good one. Cheap crap bikes are responsible for a lot of gas burnt after they discouraged newbies off biking.
BS.
by Buk___
May 06 2018 9:18am
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

In forged dropouts it's difficult to model the real grain structure related strength... Closed die forging -- hot or cold -- produces very desirable and repeatable grain structure: http://www.bmfcorp.com/images/Drawings/GrainFlowSketch.jpg http://www.dropforging.net/image/f1-1037.png Which is why i...
by Buk___
May 06 2018 1:26am
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Is that a motor behind there? It looks like an ordinary wheel. No motor in this pic,... jus a good closeup that depicts my exact dropout plate. Ah. Okay. I would have dismissed the thought except that for all the world, that looks like a tabbed torque washer under your domed nut. Three thoughts: Th...
by Buk___
May 05 2018 6:24am
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

DRMousseau wrote:
May 05 2018 2:15am
As you can see, I have plenty to work with,.... jus no room for much of thickness beyond a few thin plates that would replace existing washers, as my axle is much shorter than what appears here.
Is that a motor behind there? It looks like an ordinary wheel.
by Buk___
May 05 2018 6:13am
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

I agree that simulation can be very beneficial to a design concept. However, Grin already has the testing equipment and the torque arms. Acquiring a few used forks for the propose of testing the standard torque arm in comparison to the un-torqued-arm forks would be very easy. No need for computer i...
by Buk___
May 04 2018 7:27pm
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

I am looking forward to tests with a Grin torques arms myself. Maybe using the type of fork that failed earliest. I was hoping that by modelling Justin's failed attempt, and showing that the results of the simulation produced similar results, I might demonstrate the efficacy of simulation testing. ...
by Buk___
May 02 2018 10:56am
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

I reached the conclusion that there is so much variation in the shape and size of both front and rear dropouts that coming up with a single pattern that would fit a reasonable number of them would only be possible by recreating the existing, clunky, two-part designs that requires jubilee clip or so...
by Buk___
May 02 2018 10:01am
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

$15 for a set of two when you buy a pair of training wheels with these brackets included at Walmart or any other store these are way stronger than any other torque arms you'll find on the market secured with a u bolt that goes around the fork. No need to wait for shipping. And only about fifteen th...
by Buk___
Apr 30 2018 12:53pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Care to suggest where you guys think the redesign should be? Above my capability. On a tangent, but still a redesign idea, can this approach be made to work for front motors in a fork? Lots of lower powered conversions use front motors and the consequences of a dropout failing are more severe for a...
by Buk___
Apr 28 2018 10:48pm
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

justin_le wrote:
Apr 03 2018 4:01am
Image
Justin, Any chance you could post a dimensioned version of this design?

I'd like to try and re-create your physical results in simulation, and the more accurate the model, the more likely I am to get something close.

Thanks, Buk.
by Buk___
Apr 27 2018 3:52pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

What diameter are your motor axles and how much axle protrudes beyond the dropouts? Theyre the MXUS 3K (45H / 4503 and 4504), with 14mm diameter IIRC (still 10mm flats). IIRC the axle length is 30mm? 40? then about 5mm for the outboard dropout thickness, and I think its 8mm for the inboard dropout....
by Buk___
Apr 26 2018 4:11pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Nowhere in this screen shot does it show where the 200N is applied nor does the picture of the part resemble the one being discussed. (The screen grab was truncate on the right; it's the same part.) Here for your delectation is an animation showing how a single layer distorts (exaggerated x20) as t...
by Buk___
Apr 26 2018 3:02pm
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 135
Views: 7470

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

What do you think to this design for (say) sub 2k hubs? https://endless-sphere.com/forums/download/file.php?id=231872 See for the description. Also, how do you plan to make the kinks? Whenever I designed anything similar in the past -- a long time since -- the method for forming the bends was eithe...
by Buk___
Apr 26 2018 2:08pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

It looks simpler, Im still imagining how it might be manufactured in a way I could do here, but I think I *might* be able to by hand, though ti would require fitting and filing till they matched each other. Not a mass production method, but something I could at least test on one wheel, and see if i...
by Buk___
Apr 24 2018 2:06pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Nowhere in this screen shot does it show where the 200N is applied nor does the picture of the part resemble the one being discussed. It does! Both faces to which the load boundary condition are being applied are clearly named. And that it what I'm up against. When you have loud-mouthed senior memb...
by Buk___
Apr 23 2018 11:41pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Translation: "Technical generalist" -- Jack-the-lad-of-all-trades; master of none.
by Buk___
Apr 23 2018 11:38pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

200 N That's not a torque, son. My thought also. In the diagram, it is not evident to me where this 200N is applied, so you need to help us out. I am interested in what the amount of torque would be at that stress for comparison reasons. I know how much torque my hub motor can make. I want to know ...
by Buk___
Apr 23 2018 8:58pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 120
Views: 4759

Re: The ultimate torque arm (For <2kW and standard axles)?

Chalo wrote:
Apr 23 2018 8:08pm
Buk___ wrote:
Apr 23 2018 7:29pm
200 N
That's not a torque, son.
No sh...ugar, Dad. (You cannot specify a torque, so you have to specify the force per unit area that would result from the torque acting on the face!)

But that'll be over your head.