Novak 5mm Replacement rotor - RC-Monster Forums

SpEEdyBL · 07.13.2008, 03:44 AM

Maybe the the 5mm shafted rotor is smaller in diameter than the orginal 1/8" shafted sintered rotor. Novak said something about a smaller airgap causing the rotor to oversaturate the stator and create heat, which could be why they went with an even smaller rotor. The kv of the 4.5 went from 4800 to 5000 and the kv of the 6.5 went from 3100 to 3400 after the 5mm change which hints a smaller rotor.

NovakTwo · 07.13.2008, 11:35 AM

The 5mm upgrade rotor requires a new endbell also.

Quote:

For increased durability, Novak is offering an HV Brushless Motor 5mm Upgrade Kit to specially equip your existing 4.5 and 6.5 HV High-Voltage Brushless Motor with a sturdy 5mm output shaft. The existing output shaft on the HV motor is the industry-standard 1/8”, but upgrading to the 5mm rotor can increase a motor’s resilience and race life. This heavy-duty upgrade kit includes a Nickel-plated, high-strength, sintered rotor featuring a 5mm output shaft to decrease the likelihood of damage to the shaft in harsh driving conditions, and a front endbell and bearing replacement that is specially designed to accommodate the larger diameter output shaft.

HV Brushless Motor 5mm Upgrade Kit

JThiessen · 12:11 PM

So, Novak Two, did you just confirm that the rotor I just installed SHOULD have been smaller in diameter than the one I pulled out (assuming that my 4.5 is in fact an older non-sintered rotor)?

Quote:

You did used the plastic sleeve to guide the rotor in place?

Yes, I did. But once the larger portion of the shaft left the sleeve, it became very difficult to control - you know, magnetics and all........

Thanks for the replies.

NovakTwo · 07.13.2008, 12:22 PM

The 4.5 and 6.5 HV motors always had sintered magnet rotors, with the original shafts. Apparently, we have never listed the rotor dimensions for the HV rotors as we have for the Vel/SS Pro motors, where rotor dimensions are a point of serious interest.

Good catch. I'll check and get back to you. It's definitely something we need to add to the descriptions, now that we have the new 5mm shaft rotor.

JThiessen · 07.13.2008, 03:04 PM

I'm fairly certain the motor on this one is one of the originals. I purchased it used from someone on this forum about 2 years ago.
I just ran it up and down the street a couple times, seems to run ok. Its not flipping on its lid like my Revo does, but that may be due to the G-Maxx chassis. I have more tuning to do on the chassis than I do with the motor right now.

NovakTwo · 07.13.2008, 03:09 PM

Maybe it's one of the original 4400 HV motors sold with the bonded rotor--the orig owner may have upgraded to sintered?

Quote:

Originally Posted by JThiessen

I'm fairly certain the motor on this one is one of the originals. I purchased it used from someone on this forum about 2 years ago.
I just ran it up and down the street a couple times, seems to run ok. Its not flipping on its lid like my Revo does, but that may be due to the G-Maxx chassis. I have more tuning to do on the chassis than I do with the motor right now.

JThiessen · 07.13.2008, 03:46 PM

Quote:

Originally Posted by NovakTwo

Maybe it's one of the original 4400 HV motors sold with the bonded rotor--the orig owner may have upgraded to sintered?

I just checked - yes it is a 4400 HV motor. I have no idea if it was upgraded. I guess it doesn't really matter what the old rotor is/was - I just need to know if this new rotor is going to work. I'll leave it sitting until I know for certain.