7x10 cnc questions

[Endofab]

Hi,

In the very near future I am going to convert my harbor freight 7x10 to cnc so as I gear up to that I have some questions that I haven't been able to find out via searches.

First does anyone have a good design for a tool post riser to get rid of the unstable compound rest?

With the cnc conversion do I need an optical sensor on the spindle to let the cnc know it spinning?
Would it be possible to put a brushless motor and brushless controller this and run the spindle cnc?

Good cad cam software recommendation?

Well I think thats all I have right now I will ask more as I think of them.

Thanks

[doorknob]

I am planning to convert my 7x10 mini lathe to CNC soon.

I do not plan to do threading on my lathe, so I do not plan to monitor the spindle position, however if you wanted to automate that capability you would need to hook up something like an optical interruptor sensor and mechanical interruptor to generate an index pulse that the computer can track.

I have seen photos of such replacement toolpost risers on this site, but don't have a link to any threads handy.

The parts that I intend to produce are fairly simple, and so I'm expecting to write gcode myself.

[blades]

The toolpost riser is a piece of cake... so much so that I didn't make a drawing for it. I used a piece of 2" dia. round stock, measured the stack-up height of the current compound slide, and faced off both sides to that dimension. Drill & c'bore 2 holes for the hold-down screws (measure center distance from removed assembly), drill & tap a hole in the top for the tool post screw (10mm, IIRC), and whatever size hole in the bottom for the centering pin on the lower mount (this part will make more sense once you've taken it apart and see the pivot pin sticking up from the mount).

Tips:
When you drill & c'bore for the 2 hold-down screw holes, drill them from the bottom of the riser for better alignment accuracy. This isn't so critical if you have access to a nice vertical mill with readouts... but if you're drilling them on a drill press, drill from the bottom.

Make sure you get a good, flat finish on both ends of the riser when you machine it. Best case would be to surface grind both faces, if you have access to a surface grinder.

[Endofab]

Blades. This is pretty much what I planned on doing. I don't have access to a surface grinder so I will face it a few times for a really nice flat finish.

I was kinda hoping for some dimensions as I have had to lock the gibs on my compound rest as it was causing me a lot of heart ache.

I will be picking up some stock later this week so I will we what comes of it.

[blades]

Regretfully, I sold my lathe several months ago so I can't help you with the overall height dimension, but that's easy enough to get anyway. Depending on what size tools you plan on using on the 7x, you can adjust this overall height for best alignment of your particular tool size.

Here's the best pic I've got of the riser (taken from my 7X10 THREAD) It doesn't show much, but you can get the idea.