about stainless steel tubing cutting process.
jc
I need to cut out straight 1mm or 1.5 mm slice from 10" long annealed
stainless tubing 1-1/2"OD{A} x1.370"ID"{B}x.065"{C}----304.
I am going to use sherline lathe machine.
If I make my own tool bit from tungsten or HSS blank,or maybe diamond
tip??? what shape of tip is good?
I'd be very appreciated if anyone has good idea and advice or
suggestion for this cutting process.
Thanks in advance.
Yoshi.
Ned Simmons
wrote:
I'm afraid the best tool is a don't-even-bother-trying shaped cutter.
You need a lot more power and rigidity than you have available.
--
Ned Simmons
DoN. Nichols
> Hi,all
>
> I need to cut out straight 1mm or 1.5 mm slice from 10" long annealed
> stainless tubing 1-1/2"OD{A} x1.370"ID"{B}x.065"{C}----304.
> I am going to use sherline lathe machine.
Hmm ... rather large for a Sherline. Since it won't feed
through the spindle (1-1/2" OD would not quite do so even on my 12x24"
Clausing) you'll need a steady rest. Does one come with the Sherline,
or is it an extra cost option?
A bit of web searching says that it is Sherline's part number
1074.
A bit more searching says that if you got the 'B' or 'C' package
deals you got the 1074 steady rest. Otherwise, unless you separately
bought it, you don't have one. Oh yes -- if you got the "Ultimate
Machine Shop" package (lathe and mill combined) you also got the 1074
steady rest.
Otherwise, it will apparently cost you $40.00
And I think that you will want to open the chuck up inside the
tubing to grip on the steps of the chuck instead of trying to open it far
enough to use the normal gripping approach. Though you can reverse the
jaws on the Sherline 3-jaw chuck (part numbers 1040 and 1041 depending
on which you have), so you can grip on the outside.
In any case -- for that thin a material I would suggest turning
a plug which would barely fit inside the tubing (if gripping it from the
outside) to prevent deflection of the tubing walls and resulting poorer
grip.
If you are expanding the jaws inside the workpiece, turn a ring
which just barely slips over the OD of the workpiece to again control
deflection.
> If I make my own tool bit from tungsten or HSS blank,or maybe diamond
> tip??? what shape of tip is good?
Diamond should be avoided in any ferrous metal.
You really want something like a parting tool (thin blade which
is tapered from top to bottom so it does not bind).
They list one as their part number 3002 "Cutoff tool and
holder), and they charge $50.00 for that.
If you want to see what it looks like, go to their web page:
<http://www.sherline.com/accessor.htm>
and scroll down to 3002 and click on the ".html version" or the ".pdf
version" to get an instruction sheet. This will show you what the blade
looks like, which is what you really need.
To see what the steady rest looks like and how to use it, from
this same page click on one of the choices for 1074 ("Steady rest").
You could also use the "Follower Rest" (part number 1090) instead
of the "Steady Rest". That one costs $70.00 -- a bit more, but perhaps
more convenient for parting off multiple rings as you appear to plan to
do.
> I'd be very appreciated if anyone has good idea and advice or
> suggestion for this cutting process.
You have my suggestions above.
Good luck,
DoN.
--
Email: <dnic...@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
jc
> (too) near Washington D.C. |http://www.d-and-d.com/dnichols/DoN.html
> --- Black Holes are where God is dividing by zero ---
thank you, Don
I have steady rest and grip with 3 jaw reverse grip and cutting tool.
I thought and I feel this cutting tool is too wide its like cross to
2mm wide cutting tip.
So that's why I was seeking something more thin point and strong
material for slice stainless tube.
can you just tell me why not good for diamond tool for steel?
Thanks.
Yoshi.
DoN. Nichols
> On Apr 17, 7:59 pm, "DoN. Nichols" <dnich...@d-and-d.com> wrote:
>> On 2010-04-17, jc <yoshidesi...@gmail.com> wrote:
>>
>> > Hi,all
>>
>> > I need to cut out straight 1mm or 1.5 mm slice from 10" long annealed
>> > stainless tubing 1-1/2"OD{A} x1.370"ID"{B}x.065"{C}----304.
>> > I am going to use sherline lathe machine.
[ ... ]
> thank you, Don
> I have steady rest and grip with 3 jaw reverse grip and cutting tool.
O.K. You probably should make a plug to fit inside the chuck
end of the tube to mimimize collapse of the tube.
> I thought and I feel this cutting tool is too wide its like cross to
> 2mm wide cutting tip.
2mm is pretty thin, but is still going to have problems with the
stainless steel with your small lathe.
You could take a plain 3/8" or 1/2" HSS tool bit and grind the
end to make a short parting tool. 1/8" of working length is probably
all that you will need, and you might be able to make it as thin as 1mm
or a bit less. Having the length very short will increase the strength,
and *maybe* you can get enough torque to cut with the Sherline. I don't
know for sure.
One problem which you may be encountering is work hardening.
Stainless steel hardens when you let the tool tip rub instead of cut.
You need a fairly aggressive feed to keep it cutting, and that might
stall your lathe. I don't know how much torque you can get from the
lathe.
And you don't say which stainless steel alloy. Some are a lot
worse than others. My own preference when working with stainless steel
is 416 -- a fairly free machining one. If you need a more stainless
alloy, 303 might be good. 304 is one of those which really likes to
work harden. Of course, you already have the tubing, and may have no
way of determining which alloy you have.
> So that's why I was seeking something more thin point and strong
> material for slice stainless tube.
Hmmm ... perhaps a flexible shaft Dremel with a cutting disc
could grind through the stainless steel fairly cleanly. Gentle feed
with that after making a holder for it on the cross slide. That would
not require the torque which you need for direct single point cutting,
but you want to cover the bed of the lathe to protect it from the
abrasive particles.
Does the Sherline have a spindle reverse switch? With a
threaded chuck mount, it may well not have that. But it is best for the
wheel and the workpiece material to be moving in opposite directions
when they meet, so that calls for either the spindle running in reverse,
or the handpiece of the Dremel facing towards the headstock which will
limit how short a tube you can work with.
> can you just tell me why not good for diamond tool for steel?
Diamond is a crystalline form of carbon.
When steel is hot (e.g. from cutting forces) it tends to absorb
carbon and harden more.
This means that you will very quickly burn away the carbon
(diamond) and dull the cutter.
Carbide or CBN don't have that problem, but you will have
problems finding them thin enough for the available torque on your lathe.
Good Luck,
DoN.
--
Email: <dnic...@d-and-d.com> | Voice (all times): (703) 938-4564
Harold & Susan Vordos
"DoN. Nichols" <dnic...@d-and-d.com> wrote in message
news:slrnhsl4tk....@Katana.d-and-d.com...
<snip>
>
> One problem which you may be encountering is work hardening.
> Stainless steel hardens when you let the tool tip rub instead of cut.
> You need a fairly aggressive feed to keep it cutting, and that might
> stall your lathe. I don't know how much torque you can get from the
> lathe.
That can be overcome by grinding a serious positive rake on the parting
tool. I'd make the tool no more than .06" wide, and, maybe, 15 degrees of
positive rake. Run at the top end of acceptable surface speed, but a light
feed, say .001"/.002"/rev. Lubricate well and the cut will be like magic.
> And you don't say which stainless steel alloy. Some are a lot
> worse than others. My own preference when working with stainless steel
> is 416 -- a fairly free machining one. If you need a more stainless
> alloy, 303 might be good. 304 is one of those which really likes to
> work harden. Of course, you already have the tubing, and may have no
> way of determining which alloy you have.
I believe he's talking about 304. It is highly unlikely he would find
tubing made of 416, which is the best machining grade of stainless, or 303,
which is next best. 304 is tough, but it is not hard. It does work
harden, as you suggested, but it responds VERY well to positive rake,
assuming you keep the feed rate low. Sort of contradicts the idea of
avoiding work hardening, but it works, and *VERY* well. Lubrication is
important, to prevent overheating the thinned cutting edge.
> Diamond is a crystalline form of carbon.
>
> When steel is hot (e.g. from cutting forces) it tends to absorb
> carbon and harden more.
> This means that you will very quickly burn away the carbon
> (diamond) and dull the cutter.
That is highly unlikely due to the limited temperatures involved. One must
approach red heat.
The absorption of carbon would not be a problem with the stainless. It does
not harden by the carbon cycle. It would be a problem with the diamond
tool, however. It would most likely shatter the moment it experienced
chatter, which is sure to come from parting on a light machine, especially
with the material in a steady. It's unlikely the tubing will be round, so
the steady will not perform well. Chatter is a given.
Harold
Karl Townsend
> That can be overcome by grinding a serious positive rake on the parting
> tool. I'd make the tool no more than .06" wide, and, maybe, 15 degrees of
> positive rake. Run at the top end of acceptable surface speed, but a
> light feed, say .001"/.002"/rev. Lubricate well and the cut will be like
> magic.
>
Harold, great suggestion. You always have great stuff I didn't know about
> The absorption of carbon would not be a problem with the stainless. It
> does not harden by the carbon cycle. It would be a problem with the
> diamond tool, however. It would most likely shatter the moment it
> experienced chatter, which is sure to come from parting on a light
> machine, especially with the material in a steady. It's unlikely the
> tubing will be round, so the steady will not perform well. Chatter is a
> given.
>
>
> Harold
Harold and DoN have the best suggestions possible. But, IMHO, Ned has the
best
advice. Prove us different, but this ain't gonna work on your lathe. You
just haven't
got a rigid enough setup.
The long part makes it far worse. I'd hack off a short piece that you can
still chuck,
put a plug in it and work right next to your spindle. This will make a major
increase
in rigidity.
But, i still think Ned is right.
Karl
jc
wrote:
Thanks all, hum not enough set up? I thought so.
I will try after cut in half by hack saw...
Thanks again.
Yoshi.