Replacement brushless motor shaft material

[Danjr1]

Hi all,

My cheap and cheerful FW runs NTM motors in argos gearboxes (http://www.hobbyking.com/hobbyking/s...trSearch=28-26). It works surprisingly well apart from the motor shafts just aren't up to the job. I've had one snap so am looking to replace them with something stronger. Whilst I don't know what material the current shafts are made from, I was considering making some out of silver steel and wondered what the more educated engineers on here think?

Cheers

Dan

[typhoon_driver]

silver steel will be fine

[overkill]

Where is the shaft snapping? The motor doesn't have enough torque to break the shaft so maybe there is another problem.

[Danjr1]

It snapped on the circlip where the shaft exits the motor.

[maddox10]

That is a very strange failure, the shaft has about no strain at all at that point.

[typhoon_driver]

I've had shafts snap on me in the past. Generally they taper the shaft down as it exits the motor. Apply some tension to the belt running around the pulley on the shaft and it's applying a cyclic load to the shaft.

[Hiphopbots]

"NTM motors in argos gearboxes "

I assume it is this drill: http://www.argos.co.uk/static/Product/partNumber/7112946.htm
Did the pinion gear fit from the original motor og where did you get a matching pinion from? and how was the mounting onto the drill gearbox?

I would like to try brushless drive also

[Danjr1]

That's the one. To get the pinion to fit, you need to grind a flat on the motor shaft and to mount you need to drill some new holes in the motor mount part. However these holes need to be very exact so I've had some replacements with the required holes 3d printed as my drilling was never that perfect!

Using the 28-26 NTM motors from hobbyking, don't be expecting mega speeds using the argos gearbox. On 4s, its slightly slower than the stock brushed motors but i found it easier to drive with plenty of torque to push things around. Main reason I went for it though was the space and weight saving. For my next bot, I'm planning on using the same drive but will try slightly overvolting them in small increments to maintain the same speed as i'll be using smaller wheels.