The New South Bend 10K

[uncle harry]

Like many of us here, I'm not big on following directions unless I agree with them!
R

You have reminded me of my ex-spousal unit.

 

[rwm]

10-4. No ground it is.
Robert

 

[rwm]

So I sent a CAD file to my brother at Miller Motorsports. He has a CNC plasma that he uses to build off road race vehicles.

http://www.millerrockracing.com/

Here is my new motor mount!

I hope it fits! Looks about right.

Robert

 

[rwm]

I got my motor mount!



I have decided to use the one without holes and drill more precise ones. I do not have the capacity to do this on a mill with a rotary table so I will sue my trusty 56C template/drill guide:



The template was cut from the bottom of a pump housing. It worked great!

Need to add one of these:



R

 

[rwm]

It was kind of a ***** to drill countersinks this large but I finally got them done. The mounting holes line up perfectly! Painted with epoxy and ready to install.


I was using a 6 flute countersink and I don't think I had enough HP to drive it on my drill press. What is the best countersink for large work? Single flute, multiple flute, or zero flute? I also had a lot of chatter with the "chatterless" 6 flute. Interestingly, none with the single.

Unfortunately the actual conversion will have to wait until after TG. Check back then!

Robert

 

[rwm]

Well the conversion is done:



Looks tiny without a motor attached.









New control setup:



So it looks great. Runs forward and reverse with great speed control and rapid dynamic braking. I can shift on the fly from forward to reverse.
But there is one annoying problem! The major problem is noise. I was assuming this would be a smooth quiet drive. This is loud as crap and way louder than the factory motor. I am not exactly sure why. Most of the noise occurs during stopping and starting and is a loud hum that gets transmitted and seems to induce secondary vibration. On stopping this is definitely related to the "regenerative drive" powered stop. It is much quieter on coast to stop. Is this a function of the 180v motor? Would 90v be quieter for the same HP?

Robert

 

[rwm]

Here is a video of the first run:

It is hard to tell about the noise level from the video. It's pretty loud during stop/start. At speed it is not bad and much as I expected. The final stop at the end is a good example of the sound.
Robert

 

[rwm]

I have to say...other than the noise it works pretty well. I am just concerned the vibration may affect the finish. Here is some more video at 1500 rpm.

Robert

 

[BriancCc]

This looks great. Does the KB speed controller have all the breaking on the board or does it have an external breaking resistor?

 

[rwm]

The KB drive I chose is an SCR drive. As such, it needs no resistor for braking (everything on one small board) . It feeds braking energy back to the power line. But see my comments about noise/vibration above.
Robert