thanks moe for getting back to me on this. iām thrilled to hear that the mod 1.5 gears can withstand being run at that power levels, for that long, without fuss & muss
@b264 looks to me like steel-on-steel gears is the future of esk8
1 Like
First, use a pair of xt60 conected to solder, otherwise you may melt, especially the male side and theyāll fit weirdly. They are high temp nylon in theory but most are clones of clones of clones.
Then, pre-flux and tin both the wire and the connector end, warm up the cable with the iron and press it in the connector, it will slowly melt and sink in the solder you left in the connector.
Add more solder if you notice gaps.
You will need something to hold the connector pair
1 Like
That technique wont work well. Gear pullers and some ingenuity will get it done
I think theres pics floating about of sid removing a MT 6380 motor using gear pullers
nvm just realised how age of the post
2 Likes
how to select the right belt?
is it a case of building then measuring after?
i have 15 tooth motor drive wheel, dickios m mounts and his motors, and his abec 44thooth drive wheels? maby someone has the same?
thanks
Does anyone know of a belt length caculator that also tells you the teeth in mesh, bbman doesnāt seem to work for that anymore
i was going to recommend the bbman tool but it looks kinda broken. the fact that you have dicky parts is good in a sense that @Anubis probably can help you.
1 Like
Below is screenshot of post from Rcgroups.com
Letās say I have a 170 Kv motor and 800 Kv motor on identical setups (gear ratio, wheels, battery, ESC). Could I make the two setups perform the same (acceleration/top speed) by adjusting the voltage and current sent to motors? Like higher voltage on the low Kv motor to match top end speed of high Kv motor and higher current on high Kv motor to match the torque on the low Kv motor (for sake of discussion letās say the battery and ESC arenāt limited in any way to allow for adjustments).
Yes but the overlap would be very small if not already out of the range of the motors. We also need to define that acceleration and top speed are 2 separate (and often inversely related things).
Focusing on speed/topspeed first, the math is quite easy:
If itās speed we talking about, the voltage ratio will be 170:800 or 17:80. So for whatever cell count/voltage you choose for the 170KV, the 800KV will need to be paired with 17/80 of it. The opposite would be whatever cell count/voltage you choose for the 800KV, the 170KV battery will need to be a factor of 80/17 of it.
This however is kind of unlikely. Letās say for the 170KV, I choose 10S, that would mean the 800KV would need 10S * 17/80 or roughtly 2S. Conversely, if you choose 6S for the 800KV, you would need 6S * 80/17 or roughly 28S. You can see how difficult this would be to achieve with batteries. A much more economical and arguable safer way to achieve same speed would be through gearing. This is assuming that the motors donāt just choke on torque and are able to attain max KV (ie mythical perfect motors. Will never be the case). This is also assuming that all other motor characteristics are equivalent or very similar.
Acceleration is a little more complicated. What youāre really asking is the torque of the motors. Even different motors of the same KV can have different torque. This is dependent on many things like motor poles, number of windings/winding thicknes, phase termination, can length. In general, a outrunner will have more torque than in an inrunner for the same amount of space and length. This is because an outrunner has a bigger magnetic moment arm.
But yes, you could dump current into the 800KV to get similar torque output to the 170KV. Good luck not frying all of your electrical components. This is highly dangerous as even at 10S voltage levels, 10A can cause some severe damage.
In the RC post, they take into account that the motors are of similar length and probably similar phase termination, etc. The only difference is probably number of windings/winding thickness. In the case where you fix all other variables, yes, you can compensate a high KV motor for more torque with more current, and you can compensate a low KV motor for more speed with more voltage.
Not an expert in this field though. Just a guy whoās gone through a decent amount of physics and EE classes. Plus some anecdotal experience 
1 Like
For a 1000kv vs 100kv motor if u 10x increase the voltage and have an esc that can put out the 10x amps u will have the same exact performance if the motor km is the same and also they magnetically saturate at the same torque. It will be more inefficient in the esc only with the lower voltage set up (assuming same copper in motor n therefore same km)
Kv (the speed constant) and itās inverse kt (the torque constant) encompass a lot. U can have a tiny 100kv motor or a giant 100kv and they will produce the same ātorque per ampā regardless of size, poles, termination, this, or that. The only other variables are the motor km (the size constant) which relates to the resistance of the windings and torque produced and with a small motor there will be higher electrical resistance and a subsequent voltage drop that will effect performance a hair and it will also produce more heat. the only other variable between the two motors (same kv, big vs small) is the amount of iron in the stator and can only make steel into a magnet of 1.7 tesla before starts to not be linear relationship n goes south so bigger motor is more iron and greater maximum torque
4 Likes
lol no worries man. Sk3ās have tiny screws that hold the can in place, got em tho!
1 Like
In theory yes, in an ideal world where winding resistance and magnetic saturation arenāt a thing.
In practice, no. To get good performance out of a high-KV inrunner you have to let it spin faster, which means higher gear ratio.
2 Likes
loctite needs to have air in the bottle
1 Like
Is the reason why heat sink sleeves arenāt put on outrunner because the stator is inside instead of on the surface? Still, Iād imagine keeping the magnets cool would help right?
how safe is it to spraypaint motors a different colour? thinking of joining the flipsky GB, but the colourway is hideous
2 Likes
Just vinyl wrap them.
1 Like
ah ok. alsoā¦as noob all is hear is āFlipsky motors sucksā etc ā¦do these new motors show promise?
It would help keep the magnets cool, but since the magnets are already on the outside spinning in fresh air, they already have the best cooling of anything in the motor.
Some of the more powerful outrunners have water cooling channels in the stator to help cool the coils, and Iāve been tossing around the idea of using thin copper tubing (e.g. capillary tubing for refrigerators or similar) instead of wires to build a directly-water-cooled ultra-high-power-density outrunner.
2 Likes
Is it okay to run 14t/44t pulleys on belt drive in terms of achieving adequate pulley engagement with belt?
1 Like
Yes.
15T or higher is recommended for HTD5M teeth. 14T or even down to 12T will work but the more past 15T you go, the less the belt lifetime and teeth in mesh and engagement.