Please help pick a motor

[JonasP]

Hello, I've been working on a 3d printed project for the past couple of weeks, and I bought myself this here motor:

https://www.amazon.co.uk/Dilwe-Brushed-Motor-Poles-Sensorless/dp/B07DHDHCLQ/ref=sr_1_8?crid=KRAO4UQZ8S1O&dchild=1&keywords=brushed+rc+motor&qid=1628090559&sprefix=brushed+rc,toys,165&sr=8-8&th=1

a RC Car Brushed Motor, 4 Poles Alloy 540 Sensorless Brushed Motor (80T) - if amazon link doesn't work.

Sadly it is too fast for what I require, and also stutters when trying to run at lower speeds. As you can see in this video:

Could anyone recommend a motor that would have less RPM? Also not sure what torque would work the best, but considering this will have 12x legs and all of the joints are 3d printed plastic, I'd imagine there's gonna be a decent amount of friction going on.

Also I'm still fairly new to the world of RC, and definitely not a tech person, so Amazon link would be greatly appreciated!

Thanks!

Edit:
for anyone wondering what I'm attempting to build here:

 

[Chubaka]

Droping voltage or changing pinion is one way to slow it down. If its hooked up to a esc, does the esc have settings? If not, maybe a potentiometer?

I know 85t is up there, and the higher the turn, more torque less rpm.

Not too sure on your project, but maybe a smaller sized motor? You have a 550. They also make 380 sized motors.

 

[JonasP]

Droping voltage or changing pinion is one way to slow it down. If its hooked up to a esc, does the esc have settings? If not, maybe a potentiometer?

I know 85t is up there, and the higher the turn, more torque less rpm.

Not too sure on your project, but maybe a smaller sized motor? You have a 550. They also make 380 sized motors.

I have no idea about the ESC settings, I got this one. Doesn't really look like it could have any type of tweakability, certainly no way to connect it to a PC.

I'll check out the 380 size motors though, thanks

 

[Greywolf74]

What you have is fine, you just need a transmitter and receiver that will allow you to adjust the end point for the throttle. Youve got about as high a torque motor as you're gonna find without going to something bigger. a 380 is smaller and will have less torque. You can control the speed by using smaller pinion, less voltage, or setting a cap for the throttle on a programmable transmitter/receiver combo.

The "stuttering" problem to me just looked like a gear mesh issue because the motor isnt mounted and being held perfectly still.

 

[tntpoof]

You can run less voltage with a different battery as in going down in cells.. maybe a 1 cell lipo. but dropping voltage is going to increase amps needed to run motor.it will be a little less than half the speed its running at now..not sure that tamiya plug will handle that current

 

[JonasP]

Thanks! a couple of people pointed out a smaller pinion, so will definitely give that a go.
I've got this transmitter with a receiver that it came with. Not sure if it's possible to cap throttle with it, but will google around:
https://www.amazon.co.uk/gp/product/B00Q496BZY/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

Thanks again for the ideas

 

[tntpoof]

no way to set endpoints on that radio. but you will have a throttle so you can ease throttle in easier...

 

[JonasP]

no way to set endpoints on that radio. but you will have a throttle so you can ease throttle in easier...

Ah I guess that might work. Combined with a smaller pinion and a proper mount.
As for battery voltage. I really don't trust myself not to burn / destroy something. So probably gonna leave that alone.

 

[Greywolf74]

Thanks! a couple of people pointed out a smaller pinion, so will definitely give that a go.
I've got this transmitter with a receiver that it came with. Not sure if it's possible to cap throttle with it, but will google around:
https://www.amazon.co.uk/gp/product/B00Q496BZY/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

Thanks again for the ideas

With that trasmitter you can just slowly turn the throttle up to where you want it on the left stick and leave it there. No need for end point adjustments using that kind of radio

 

[tntpoof]

You can also print a reduction gear and add it to your motor mount if you need to .. 1 2 3 whatever you need to slow revolutions down when it ingangs with main gear.

 

[JonasP]

You can also print a reduction gear and add it to your motor mount if you need to .. 1 2 3 whatever you need to slow revolutions down when it ingangs with main gear.

Yeah thought about that, but running out of space already. The center "trench" is going to be filled with batteries and electronics. + it already has "axels" running through it. Technically I could mount the engine much higher, but I want to print a body for it later, and that might cause issues.

I was also running a couple more tests yesterday, and decided that the speed isn't too bad. Will print a smaller pinion gear, and that should be fine I think.

Also really don't want to re-print the main chassis. as it took ages, and a tonne of filament.

 

[Greywolf74]

View attachment 130517
Yeah thought about that, but running out of space already. The center "trench" is going to be filled with batteries and electronics. + it already has "axels" running through it. Technically I could mount the engine much higher, but I want to print a body for it later, and that might cause issues.

I was also running a couple more tests yesterday, and decided that the speed isn't too bad. Will print a smaller pinion gear, and that should be fine I think.

Also really don't want to re-print the main chassis. as it took ages, and a tonne of filament.

Just gonna point out that you have the motor mount on the wrong side of the motor at least from a traditional RC stand point anyway. Maybe you already have some alternate mounting method figured out but I dont believe theres anyway to mount the engine from the back side. Typically the motor is mounted on the pinion side which is why there are screw holes on the side. Even if you have a way to mount the motor from the backside its going to have to be rock solid because if theres any flex in it you could destroy your gears.

 

[JonasP]

Just gonna point out that you have the motor mount on the wrong side of the motor at least from a traditional RC stand point anyway. Maybe you already have some alternate mounting method figured out but I dont believe theres anyway to mount the engine from the back side. Typically the motor is mounted on the pinion side which is why there are screw holes on the side. Even if you have a way to mount the motor from the backside its going to have to be rock solid because if theres any flex in it you could destroy your gears.

Oh ignore that grey box at the end of the motor, it's just there to represent the volume that these connectors take up.
I was just thinking of squeezing the motor inbetween a couple bits of plastic, tightened with screws, and maybe wrapped with some insulation tape for better grip. But if that doesn't work, will probably just buy a mount from amazon.

 

[Greywolf74]

View attachment 130526
Oh ignore that grey box at the end of the motor, it's just there to represent the volume that these connectors take up.
I was just thinking of squeezing the motor inbetween a couple bits of plastic, tightened with screws, and maybe wrapped with some insulation tape for better grip. But if that doesn't work, will probably just buy a mount from amazon.

Gotchya

 

[JonasP]

Thanks guys for helping out, here's the first prototype: https://www.artstation.com/artwork/3dJZ5m
Probably going to change quite a few things for v2 (adding a reduction gear is definitely on the list!)

 

[Greywolf74]

Thanks guys for helping out, here's the first prototype: https://www.artstation.com/artwork/3dJZ5m
Probably going to change quite a few things for v2 (adding a reduction gear is definitely on the list!)

Thats really cool man. Seems like it worked out pretty good