Boring Issues

[freeqgeek]

there's the source o f your chatter. Drill the hole out to .875 and bore the rest in four or five passes.

Unfortunately I don't have a drill that goes up to that size but plan on acquiring a couple larger bits tomorrow. So this is likely the route I am going to take.

 

[freeqgeek]

Think I would have gotten larger stock and drilled then reamed that ID to size . Then use plugs and turn the OD down concentric to the bore . JMI .

AND , I just saw a .010 finished wall thickness ? Better fill that bore with something , lead shot , bbs etc , to help stabilize that wall cuz it will chatter !

I have been looking at reamers recently. They can get quite expensive... Do you have a preference for straight or spiral flutes and is there a benefit of one over the other?

 

[rock_breaker]

It wasn't said but a larger boring bar may improve the rigidity. No experience with stainless so lots of luck.
Ray

 

[Liljoebrshooter]

A larger bar would probably help a lot.
One way to get rid of the chatter is to move the bar into the bore and cut grooves by hand, feeding the cross slide out. Make a cut, move left a small amount, make a cut, over and over again.
Joe Hynes

 

[Liljoebrshooter]

Oh and 304ss can be a real bit#$ to get a good cut. But it can be done.

 

[Liljoebrshooter]

You didn't say what style bar and insert you were using, but I would guess a CCMT. That is most likely the problem. With the 304 you would be better off with a sharp edge cutter of some style.

 

[freeqgeek]

You didn't say what style bar and insert you were using, but I would guess a CCMT. That is most likely the problem. With the 304 you would be better off with a sharp edge cutter of some style.

I have been wondering about this actually. I am a bit of a junkie and always wanting more tools...

Dead on. I am currently using the CCMT style. But with so many other shapes I don't know where to begin. What insert style would you recommend for SS?

 

[Liljoebrshooter]

I have the best results with a ccgt insert. You have to figure out if the bar will accept them. They have more angle to them and some of the pockets won't fit them right and when you tighten the screw down they break. Ask me how I know that.
I also have the best results with a solid carbide bar, the micro 100 ones. They are expensive and very unforgivable. If you crash them they just snap like a toothpick. I got a few of them on the bay for a few bucks each.
Joe Hynes

 

[Liljoebrshooter]

Here are some telescoping stands I have made. Lots of boring on the bushings for these.

 

[Liljoebrshooter]

This is what I'm making.