*Knee Mill Retrofit*

[IJ.]

This was a great thread, but the posted decided to remove his post for no good reason, I'm very sorry for this I wish I could have prevented this from happening, but this will never happen again, as I have put into place safety mmeasures to prevent this.

CNCadmin

[duluthboat]

Great looking project, we’ll be watching with interest.

Gary

[HuFlungDung]

Good luck, IJ.

Are you going "4 axis" on this unit? By this, I mean a quill Z drive on the spindle as well as the knee drive you have already built? Powered table up would be a nice feature, but perhaps not something that would be used during a single part program.

That table is heavy to lift up and down much, especially if you are doing much in the way of drill cycles. You might find it desirable to attempt to counterweight the table assembly. I would be concerned about wearing out the vertical ways on the back of the apron. The lube system to the vertical ways is sometimes of questionable value, ie., it could be nigh on impossible to prevent metal to metal contact.

[Kookaburra]

Keep em coming bud, looking forward to follow the story.

[Kookaburra]

LOL Ian,

How much cast iron ended up in your eyes?
Sounds like your 700w motors will do the job just fine then.

[Kookaburra]

Good Showing Ian,

You really take pride in your work, it's good to see. Can't wait to see the next stage.

[Kookaburra]

Ian,

That sounds OK since you are using a 25mm Ballscew, however, make sure you are not going to end up with whip in it as the controller you have will be able to spin it a 3700 rpm. It may pay you to talk to lee abount the RPM and maximum overhang when the ballscrew nut is at one end. That is of course if you are wanting to run it at supersonic speed. It is possible to de tune your drive to the speed that your ballscrew is happy with but I don't want you to get disappointed if it is not the speed you want, so , before you cut it too short make your mind up, or if you can, leave the screw a bit longer incase you have to turn an end bearing journal in the future.

Good luck

[Kookaburra]

You beauty!!!

Go Get 'em dude.

[Kookaburra]

Ian,

Overbuilt is good, much better than under built.

I have no problems with you posting pics of our controller.

[NEATman]

IJ, I am following this thread closely, and I am interested in what controller you are planning to use for this project. It appears that you are using industry standard BLDC drives that accept ±10vdc. I have a machine very simmilar to this, with motors, drives and an outdated control. The controller is the part that I would like to update. My problem is that all of the software that I have found outputs step and direction. The drives that I have only accept ±10vdc. I realize that Rutex makes a converter board, but I thought that you might have a more elegant solution, or a more sophisticated software. If so, please let me know what you are planning on using.
Thanks-
NEATman

BTW, I like the Kollmorgen Silverline motors that you are using. Brushless DC is definetly the way to go. The only thing to wear out is the ball bearings.

[ty1295]

Where did you get the ballscrew for the knee, what work did you have to do to it?

More pics of knee would be helpful for me as I am about to embark in retroing my mill also.

[ESjaavik]

IJ:
What are those drives?
I'm very interested because I have 3 SST-1500-ACX on the shelf waiting for testing.
They look very much like yours, except for the silk screen printing. But I have only 2 motors, one very small and one small, both Technics motors. I'd be happy to hear about how you set up those motors with the drives if they are the same as mine. If you replace the capital letter words in my sig below, you have my email address, as this may not be very interesting to the others.