Need help buying the correct parts for my first racing drone.

[1ikhan]

@HighTechPauper @rtkDarling
Uh minor panic here. So I was applying loctite to the motor screws with wet hands, and now one of the motors feel noticeably more sluggish when I spin it with my fingers. Do I need to oil it?

 

[HighTechPauper]

We don't usualy oil them, attracts dust and dirt into the bearings, check for a screw or a clip at the bottom of the prop shaft that holds the bell on, if a screw, loosen it JUST A SMIDGE and see if it turns better. I doubt you got anything anywhere, tightening everything has probably caused some minor flexing in the base plate, if a c-clip instead of a screw on the bottom, try loosening the 4 motor screws and see if it improves. If the motor spins then you didn't glue anything, even if you got it somewhere, running the motor will wear it off. BTW, when the bearings do go, you will either replace them, or more than likely do a motor upgrade, they are sealed bearings and will last a while, even if they get noisier/notchier. Please let me know what troubleshooting yields, if it is spinning a little slower and/or stopping a little sooner it should just be binding or the bell screw/shims are too tight.

 

[1ikhan]

We don't usualy oil them, attracts dust and dirt into the bearings, check for a screw or a clip at the bottom of the prop shaft that holds the bell on, if a screw, loosen it JUST A SMIDGE and see if it turns better. I doubt you got anything anywhere, tightening everything has probably caused some minor flexing in the base plate, if a c-clip instead of a screw on the bottom, try loosening the 4 motor screws and see if it improves. If the motor spins then you didn't glue anything, even if you got it somewhere, running the motor will wear it off. BTW, when the bearings do go, you will either replace them, or more than likely do a motor upgrade, they are sealed bearings and will last a while, even if they get noisier/notchier. Please let me know what troubleshooting yields, if it is spinning a little slower and/or stopping a little sooner it should just be binding or the bell screw/shims are too tight.

Thanks for the reply!
So it's a screw, I loosened it just a bit and it did get better but still noticeably more stuck than the rest. So I unscrewed the bottom screw and took off the bell, and found no dirt on the magnets besides the balancing putty at the bottom. When I slowly reattached the bell, the bottom bearing fell off, and it seems like the top bearing is the problem since the bell spins characteristically with only that bearing. Everything back together, the motor is still a little stuck compared to the rest. What could this mean?

 

[HighTechPauper]

It is a little hard to say without being able to feel the difference, if it is somewhat minor, in that it does spin but less than the other 3, I would say not to worry yet. It is a little odd that the bottom bearing fell out when you went to put the bell back on, usually the bearings are in pretty solid and need an arbor press or some similar action to "press" them in and out. A very very small amount of oil (like a light sewing machine oil) may improve things and then wipe any excess off once the bearing frees up. If it is a minor (even though very noticeable) stiffness, then I may wait until I can test the motors to see that they spin well and if use frees up the bell any. I notice this often in builds, that one or more motors do not spin as freely as the others, but it has never been a real issue and the motor was fine in flight. I would however reevaluate the free spinning and any heat build in that motor compared to the others when I first start testing and flying the quad. Wish I could be more definitive, but it is hard to be without feeling it myself, but I would say, unless it is clearly bound up and doesn't turn, wait until you can test the motors before doing anything drastic. If the bearings come out so easily perhaps put the bottom bearing in the top side and check the spin on that one.

 

[1ikhan]

It is a little hard to say without being able to feel the difference, if it is somewhat minor, in that it does spin but less than the other 3, I would say not to worry yet. It is a little odd that the bottom bearing fell out when you went to put the bell back on, usually the bearings are in pretty solid and need an arbor press or some similar action to "press" them in and out. A very very small amount of oil (like a light sewing machine oil) may improve things and then wipe any excess off once the bearing frees up. If it is a minor (even though very noticeable) stiffness, then I may wait until I can test the motors to see that they spin well and if use frees up the bell any. I notice this often in builds, that one or more motors do not spin as freely as the others, but it has never been a real issue and the motor was fine in flight. I would however reevaluate the free spinning and any heat build in that motor compared to the others when I first start testing and flying the quad. Wish I could be more definitive, but it is hard to be without feeling it myself, but I would say, unless it is clearly bound up and doesn't turn, wait until you can test the motors before doing anything drastic. If the bearings come out so easily perhaps put the bottom bearing in the top side and check the spin on that one.

Alright, big brain time. So what's happening, I think is that since I left the motor wires desoldered for cleanup, the motor wires would touch and that's what caused the sluggishness. Im stupid. Crisis averted.

 

[HighTechPauper]

Alright, big brain time. So what's happening, I think is that since I left the motor wires desoldered for cleanup, the motor wires would touch and that's what caused the sluggishness. Im stupid. Crisis averted.

I'm sorry @1ikhan, I didn't even think to ask if the motor wires could be touching each other, yup that will cause that. When the wires touch the magnetic force created from spinning will feed into another stater and cause it to magnetically produce force, after all, apply voltage to a motor and it spins, spin a motor and it produces voltage, that's how generators work

 

[1ikhan]

@HighTechPauper Hey I hope you are well man. Gave up on my drone because I accidentally soldered off some component from my fc when I went to scratch my nose. Now I am back again, just gotta wait for things to settle so I can rebuy the fc and get back to it

 

[1ikhan]

@HighTechPauper Alright so I have made considerable progress in my build. Ordered the same fc, but somehow got sent a newer version of it (CLracing F7 v2.1 MPU instead of V2 MPU. 2.1 has more straight forward config from what I can tell). Also went ahead and ordered t-motor pacer 2207.5 1750kv because I figured might as well upgrade the motors to something nicer, although I really didn't need to. Was an impulse buy, but now I have 4 extra for a Dove light frame in the future. One thing though, when just hovering, using the gemfan 5166.6 props, the motors get warm. Is that normal? I really would have thought t-motors would be cooler when just hovering 3 feet of the ground?

 

[HighTechPauper]

It is completely normal to get a newer version of the same board, minor revisions happen, and if you order at just the right time you may get the newer one. It is NOT unusual for motors to be warm, but too hot to grab and hold onto is NOT good. You seem to misunderstand how "just hovering" uses a ton of power, in fact just hovering uses much more than you would think. When we are moving there is added lift as we fly into "clean" undisturbed air, plus we tend to give it some gas (power) and then lower the throttle (rest) but none of that happens in a hover, in a hover we are at a fairly constant throttle and sitting in highly disturbed air. It is also possible that a 5.1 inch long blade ALONG WITH a 6.6 inch pitch (very high) is helping to make the motor warm anyway. The steeper the prop, and 6.6 is very steep, is hard for the motor to spin due to a very large blade/pitch resistance. Also, I assume you know a 1750kv motor is solidly in 6s territory, running 4s would be pretty sluggish.

 

[1ikhan]

It is completely normal to get a newer version of the same board, minor revisions happen, and if you order at just the right time you may get the newer one. It is NOT unusual for motors to be warm, but too hot to grab and hold onto is NOT good. You seem to misunderstand how "just hovering" uses a ton of power, in fact just hovering uses much more than you would think. When we are moving there is added lift as we fly into "clean" undisturbed air, plus we tend to give it some gas (power) and then lower the throttle (rest) but none of that happens in a hover, in a hover we are at a fairly constant throttle and sitting in highly disturbed air. It is also possible that a 5.1 inch long blade ALONG WITH a 6.6 inch pitch (very high) is helping to make the motor warm anyway. The steeper the prop, and 6.6 is very steep, is hard for the motor to spin due to a very large blade/pitch resistance. Also, I assume you know a 1750kv motor is solidly in 6s territory, running 4s would be pretty sluggish.

Ah I didn't know hovering was so taxing, interesting! Yeah the motors are warm, doesn't burn when I hold the bell with two fingers, so I guess I shouldn't be worried until they get actually hot as you said. Yep, using 6s, and I might go down a pitch to gemfan 51433 next time I buy props. I might even swap the motors with the old xing-e 2207s I have just to see which get hotter while hovering. Man, so close to actually flying, just gotta get out of the lockdown.

 

[1ikhan]

Ah I didn't know hovering was so taxing, interesting! Yeah the motors are warm, doesn't burn when I hold the bell with two fingers, so I guess I shouldn't be worried until they get actually hot as you said. Yep, using 6s, and I might go down a pitch to gemfan 51433 next time I buy props. I might even swap the motors with the old xing-e 2207s I have just to see which get hotter while hovering. Man, so close to actually flying, just gotta get out of the lockdown.

@HighTechPauper an update, two of the pacer motors already starting to show signs of wear, when I spin the motors by hand it makes scraping noises on the inside, and the vibrate a lot more than the good ones. I didn't crash into anything hard either, been messing around on grass and dirt. Opened up the motors, but there wasn't anything visibly wrong. Switched back to the xing-e 2207 1800kv, and they seem just as smooth as the pacers when they were new and doesn't get as warm. Odd. I will not buy anything more expensive than the xing-e.

 

[HighTechPauper]

Sometimes dirt is worse than asphalt or concrete, dust and dirt can get into the bearings.