Learned a little bit more today

[Smitty911]

Well as luck would have it the Machine Shop was busy so I decided to try my hand at steel. Unknown type, I just needed a 50x50x50mm cube for a test I was running. How hard would it be to wipe out the old X-2 and make some chips.

Well first things first. Ran down to R.L. Steven for a 4 fluted cutter (machine shop guys said to use it), Bought a set of 8 for 45.00 donated the biggest four to the machine shop. 4 flutes, 3/8 cutter running ??? 500-700 rpm. CHATTER, CHATTER everywhere, so from reading other post it shouldn't of had a problem.

About 1/2" to go I run to get the experts. After the laughing stopped it was determined that the machine should be bolted to a solid frame, not sat on top of the floor of the carton sitting on the roll round work table. I also found out that with steel you should take heavier cuts .050 or so. The finish looked a lot better on the heavy cuts than the .005 light cuts.

Looks like it's time to build a solid table. I have a piece of 3/5 steel about 4'x3' and would make a good, although heavy to move bench.

Now for the question 4 legs or 3?

It may sound like a silly question but I seem to remember that you can capture three points of contact for some kind of base. I forget what it's called, but on all the bottoms of the points are ball and two of the three go into 90 degree out of phase v-slots.

So much to learn, so little time. Recommendations?

Thanks

Smitty

[tai42]

It may sound like a silly question but I seem to remember that you can capture three points of contact for some kind of base. I forget what it's called, but on all the bottoms of the points are ball and two of the three go into 90 degree out of phase v-slots.

I believe you're talking about a kinematic mount. (The three points are at 120 degrees.) The main advantage of a kinematic mount is that it allows for expansion/contraction without the center changing position. It also requires a fair amount of preload so the balls don't walk out of the grooves.

While it is true that anything with more than 3 legs is "over constrained" it can also be more stable. (Ever sat on a 3 legged stool?) I'd suggest you just want something heavy and sturdy with four legs and height adjustable feet so that you can level it. (A good test would be to sit on the table and wiggle around. If the table "feels" solid, you're probably good.) Bolt the machine to the table top and you should be good to go.

[Smitty911]

Thanks for the response, I can start work on it this weekend, maybe.

Four legs and welded up with triangle braces should do the trick. This thing my never move again once it's in place.

Thanks so much.

Smitty