A positive rake tool would do much better, 303 does not tend to work harden to my experience, have made hundreds of pounds of chips with it; call it screw machine stainless. I use TPG inserts with it in 3/8 and 1/2 I.C. sizes in C-2 grade.
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Finishing 303 Stainless
- Thread starter Kroll
- Start date
As an example of unstable work holding.
I did this last year, 28" diameter burnout in 304 stainless, face, drill a center hole then bore a 8+" diameter counter bore about 1/2" deep.
The stock is only 3/4" thick.
34" aluminum disk bolted to a 24" faceplate, gap removed from lathe, boring bar held upside down with the spindle ran in reverse in order to span the gap.
This is EXTREMELY DODGY work holding. This lathe does not support CSS which made it virtually impossible to achieve a uniform finish across such a large facing operation as can be seen. It did not even come close to the flatness requirement on the drawing but was not red tagged by the customer.
Dodged a bullet on this one.
It took over 18 hours from start to finish including set up.
I did this last year, 28" diameter burnout in 304 stainless, face, drill a center hole then bore a 8+" diameter counter bore about 1/2" deep.
The stock is only 3/4" thick.
34" aluminum disk bolted to a 24" faceplate, gap removed from lathe, boring bar held upside down with the spindle ran in reverse in order to span the gap.
This is EXTREMELY DODGY work holding. This lathe does not support CSS which made it virtually impossible to achieve a uniform finish across such a large facing operation as can be seen. It did not even come close to the flatness requirement on the drawing but was not red tagged by the customer.
Dodged a bullet on this one.
It took over 18 hours from start to finish including set up.
Thanks guys for the help,I do want to kinda get setup with the correct tooling for making parts out of 303 so I will give other inserts a try with a smaller nose radius.Maybe I also need to come up with a different way of making these disk which are for fine adjustments for DP.What I did is take 12" 1.5 rod cut into disk on band saw,then I chuck up the disk and drill,tap for the threaded rod.Next I chuck up a 1/2-20 bolt with rod coupling so that the jaws had something solid.The bolt would only protrude just enough out past jaws to allow me to screw on the disk.Maybe my plan is wrong on how to make these.
But from these suggestions I need to better support the part,use/try different insert smaller radius or HSS. Here's few pics of my setup so if ya'll see any problems or know better way to support please let me know.Thanks for all the help
But from these suggestions I need to better support the part,use/try different insert smaller radius or HSS. Here's few pics of my setup so if ya'll see any problems or know better way to support please let me know.Thanks for all the help
In my experience the dealer doesn't always know what he is supplying !
Guys looking in my Shars catalog I see that the insert I am using is for medium finish on SS so I am going to order 424-1051 which is for finishing and has a 7* positive rake which has a nose radius of 1/64.So maybe this will help out some but I know I still need to take a bigger cut,well its to late for this part but I have 3 more that I would like to take a finish cut to where be easier to put little polish on them.If anything that I learn is having the right insert can make a big difference plus speed/feed so no more hand feeding for me
A 1/64" nose radius is rather large for such an unstable operation, try a .008" NR tool.
That is a positive rake insert.
Sorry for not getting back sooner,I look for a name on it but found nothing.The tag that is seen on front just says Make In China with their symbol.Name may be on back side,when I take chuck off when start cleaning up lathe little bit I will see if names on back side.