Thin wall 303 sst

[BenK]

I'm cutting a 303 sst part that is 1.52 tall .7 wide and 1.56 long. it has a .45wide slot that goes 1.22deep and leaving one end of the slot still closed. My fixture is only holding onto about .125 of my work piece using Mitee-bite pitbull clamps. My endmill for the outside is a .625 sgs v-carb in an Albrecht holder and a .02 finish pass. and for the inside I'm using a dynamic path and a .25 v-carb relieved to 1.3 in a ER-16 holder and my finisher is the same setup using a .02 finish pass. My problem is my finish is really chattering both inside and out. Any suggestions?

 

Here is my fixture showing the stock. I cant show the part.

 

 

 

[McLaren]

Cut your spindle speed in half. And I'd go down to like a .005" finish pass.

And I'd try a 7/16" endmill and plungemill to rough it out.

[Reko]

^^^^^

+1 to the plunge mill for roughing it out.

[K2csq7]

5/8 dia. cutter on the outside...

I would try to go smaller maybe down to 3/8 dia...

Can you use depth cuts to finish the inside? how tight is the tolerance for the width of the slot?

[BenK]

Right now my depth cuts for finishing the inside is .2 and the outside is .3. I have *-.005 on the outside and +.005-.000 on the outside.

[Dtm]

I would finish the part in layers to keep the part rigid and when you start getting to the bottom use spring cuts.

[kh012]

^^^+1

 

try plunging the slot with a 3/8 em. rough the outside leaving about .05 per side if possible.

the use the 1/4 em to step down, chaining the slot and outside as one chain if possible.

this will leave the thicker section below the cut for support.

i've done this on thin walled parts before to get rid of chatter and tool deflection.

 

Ken,

[BenK]

I switched to a z-carb endmill and it looks good now. I guess the v-carb isn't the endmill to use in 303sst.

[BenK]

double post