Search found 2671 matches

by speedmd
Mar 26 2018 11:29am
Forum: Food and Drink
Topic: Maple Syrup season is here !
Replies: 16
Views: 1133

Re: Maple Syrup season is here !

First season for us. We have been doing it some three weeks now between freeze ups. Fun stuff. Have a few gallons made so far. Best tasting stuff we have ever had. Farmer up the road does it commercially and warned me that it can easily become a sickness. :)
by speedmd
Mar 24 2018 6:46pm
Forum: E-Bike Technical
Topic: EBike Toolbox - Bargains! $
Replies: 141
Views: 44676

Re: EBike Toolbox - Bargains! $

Some data, corrosion factors on some common SS. http://jiano.typepad.com/fbc/0310_stainless_steel_and_corrosion_resistance/chart.gif by common types https://www.cartech.com/globalassets/alloy-techzone/technical-solutions/technical-articles/selectaloydiagramrevapr20061.gif Cold worked! Note big chang...
by speedmd
Mar 22 2018 6:30pm
Forum: E-Bike Technical
Topic: Wire gauge thickness?
Replies: 15
Views: 902

Re: Wire gauge thickness?

Got it. One thing to plan on is that when running fewer packs in parallel, you will up the current demand per pack. You may want to base your wire gauges on that higher demand if you plan on going back and forth, just by swapping jumper cables. Look forward to seeing the build.
by speedmd
Mar 22 2018 5:04pm
Forum: E-Bike Technical
Topic: Wire gauge thickness?
Replies: 15
Views: 902

Re: Wire gauge thickness?

That motor will run 12s at 70 amps. https://hobbyking.com/en_us/turnigy-aerodrive-sk3-6374-149kv-brushless-outrunner-motor.html Not sure why you would run them at 5s. 10s or 15s if you can deal with the rpms. Parallel strings personally I would not go below 14g. Series 8 or 6 gauge and all as short ...
by speedmd
Mar 22 2018 8:28am
Forum: E-Bike Technical
Topic: Wire gauge thickness?
Replies: 15
Views: 902

Re: Wire gauge thickness?

Its a ridgid 4ah battery pack https://www.ridgid.com/ca/en/ac840087-18v-4amp-lithium-ion-pack I really can't imagine needing 12 gauge, when you take the tool apart the wires are somewhat thin, maybe 16 gauge max. With a dozen batteries in parallel i doubt i'll be pulling 40amps from each battery, m...
by speedmd
Mar 21 2018 6:44pm
Forum: E-Bike Technical
Topic: Wire gauge thickness?
Replies: 15
Views: 902

Re: Wire gauge thickness?

What are the batteries makeup- c rates. Lithium tool packs? 5s2p with 18650 cells? They could put 40 amps out if so. Would stick to 12awg if so.
by speedmd
Mar 16 2018 8:31pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

Not sure that 440c would be better than 410, 409 or 12c27 in this app. Yes it is stronger, harder, and overall a much better pc of metal, but the increase in chrome is not what you want here IMO. You need some strength at temperature in these thin highly cutout rotors and don't want them to change h...
by speedmd
Mar 16 2018 9:43am
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

Looked into a few of the proven stainless alloys and I think now it is more than just overall cosmetic issues. It is a huge family of materials these days. Lots of considerations in surface scale and deterioration over time- use. The proven grades do also share many of the alloying elements that mak...
by speedmd
Mar 15 2018 10:08pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

As far as grabbing power with the same caliper, same amount of pull on the lever, does a 203mm rotor have substantially more than a 160mm rotor? Or is the difference just in heat dissipation? You would see a sizable increase in stopping power. 101/80mm radius would be roughly 1.26 times the leverag...
by speedmd
Mar 15 2018 9:44pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

I would think a non or low chromium high tungsten grade HSS (High speed steel) best for a light rotor app. It needs to be bendable so you can align it (because nothing is perfect). And it should fail in a way that doesn't produce razor sharp fragments. HSS gets poor marks in both regards. What hard...
by speedmd
Mar 15 2018 10:50am
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

Nice looking rotor. Bigger is better and Certain to help. Big family of materials in the Stainless grouping. Many are not good at all for the app. May explain some of the crumpling fails. The H or HR (heat resistant) grades would be better but still too broad a product range to address all the perfo...
by speedmd
Mar 12 2018 10:28pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

spoke flanges way too close together. You get stronger brakes at the cost of a weaker wheel
Closer flanges should make a stronger wheel vertically and should also be stiffer-stronger under brake and drive loads. Laterally certainly not as good. Interested in how the dual 8's work out.
by speedmd
Mar 12 2018 5:35pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

In the world we inhabit, bicycle disc brakes can't dissipate as much gross energy as bicycle rim brakes. Tiny 140 -160 mm ones are certainly at a great dis-advantage. No argument. Super thin ones are also poor examples of their potential. Those twin 8" rotors your playing with, it gets close. When ...
by speedmd
Mar 12 2018 9:37am
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

Rim brakes are great for slow mo, but will never come close in ultimate performance. Not even!
Image
by speedmd
Mar 11 2018 11:20am
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

Agree Luke, that moto brakes are the way to go on high speed setups. What we are seeing in the fails is not tensile fail, but what looks more to me like compression buckling of the brake pad contact area of the rotor. High heat would certainly accelerate this as would stacking spoke loads to it. IMO...
by speedmd
Mar 10 2018 10:52pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

The spoke design is specified such that the mechanical stresses and the thermal stresses occur in opposite orientations, attempting to cancel each other out and lowering the total stress in spokes as opposed to adding together. The heat stress tensile loads the spokes and mechanical loads are in co...
by speedmd
Mar 09 2018 5:42pm
Forum: E-Bike Technical
Topic: Specific heat absorption capacity of disc brakes
Replies: 147
Views: 7102

Re: Specific heat absorption capacity of disc brakes

Odd folks think your rotors are mounted backwards. As a man who has overheated and wadded up a half dozen bicycle brake rotors into a hot mess of steel, I found mounting them they way you did so it pulls on the rotor spokes vs pushing on the rotor spokes enabled them to survive much longer at extre...
by speedmd
Mar 07 2018 2:16pm
Forum: E-Bike General Discussion
Topic: Want to change from SLA to lithium
Replies: 27
Views: 1102

Re: Want to change from SLA to lithium

Below, when the battery itself is froze, you must thaw it, which will take forever, before you use it, or charge it. It does not take a ton of insulation to keep a battery warmer than 32F, if its only 25F overnight. So the best way to go is not letting it freeze solid unless its under long term sto...
by speedmd
Mar 06 2018 5:53pm
Forum: E-Bike General Discussion
Topic: Want to change from SLA to lithium
Replies: 27
Views: 1102

Re: Want to change from SLA to lithium

Most Li cells are safe to charge down to freezing temps. Below that some types will be damaged. Some types can be charged safely at low current levels below freezing. Looks like some battery preheating should be standard operating procedure in colder areas for those using regen.
by speedmd
Mar 04 2018 3:44pm
Forum: E-Bike General Discussion
Topic: Want to change from SLA to lithium
Replies: 27
Views: 1102

Re: Want to change from SLA to lithium

They are balance leads. There is a negative and others connect to each cell voltage step (positive side of cell or - cell group if that voltage step is made with more than one cell in parallel) in increasing order. You use them to charge, monitor when balance charging or monitor individual cell volt...
by speedmd
Mar 04 2018 2:29pm
Forum: E-Bike General Discussion
Topic: Want to change from SLA to lithium
Replies: 27
Views: 1102

Re: Want to change from SLA to lithium

6s (six lithium polymer or ion cells in series) will be slightly less voltage (4.2 x 6 = 25.2v hot off the charger) than the 2- 12v ( 2x 13.6v = 27.2v hot off the charger) lead bricks. This will not be very noticeable as your lead bricks drop quickly and sag much more than the LI bricks will. You al...
by speedmd
Mar 02 2018 8:44pm
Forum: E-Bike Technical
Topic: (possibly naive?) battery question
Replies: 12
Views: 699

Re: (possibly naive?) battery question

I use the 8ah zippy bricks. Started with 4, in 2p-2s and went to just 2 as your thinking on my bbs02 bike, which is much like your demand. It is plenty and much lighter that way. Easy to double up if you want, need more range down the road.
by speedmd
Mar 01 2018 8:12pm
Forum: E-Bike General Discussion
Topic: Heavy cargo and steep hills: Will my plan result in injury and carnage?
Replies: 20
Views: 1011

Re: Heavy cargo and steep hills: Will my plan result in injury and carnage?

Would think a Big advantage of a trike is that it does not need to be kept from crashing to the ground when it has a 300 pound load. Don't have a clue what you would do with such a load when coming to park on uneven ground and not having a well thought out stand setup on a bike. Trailer would solve ...
by speedmd
Mar 01 2018 8:23am
Forum: E-Bike Non-hub Motor Drives
Topic: 2016 GNG Premium belt mid drive kit MAX AMP
Replies: 3
Views: 466

Re: 2016 GNG Premium belt mid drive kit MAX AMP

Belt drive Thread started in 2012. Some nice builds along the way. http://52.25.253.50/forums/viewtopic.php?f=28&t=42785&sid=8f8e4abd29730ba609d33b8c1b082d25 Also, check with lightning rods as he has lots of experience with the gng belt drive and can advise what to expect on real power limits of the...
by speedmd
Mar 01 2018 12:14am
Forum: E-Bike General Discussion
Topic: Heavy cargo and steep hills: Will my plan result in injury and carnage?
Replies: 20
Views: 1011

Re: Heavy cargo and steep hills: Will my plan result in injury and carnage?

Trike? Some heavy duty motor axle types. 2 speed axles are common that would allow them to crawl up steep stuff and cruse along nicely on the flats. http://www.cyclesmaximus.com/hillwashingmachine.jpg http://img.weiku.com/a/002/568/3_wheel_Flatbed_tricycle_with_CE_9887_2.jpg https://image.made-in-ch...