5/16 Tool Bits
Bob La Londe
available in 5/16 as 1/4. I was wondering about that since so many cheap
mini lathes come setup for 5/16 now. Then I realized, they all want you to
spring for a quick change tool post kit right away. A quick change tool
post is definitely in the immediate future for me (or some custom tool
holders made on the mill), but when the lathe arrived I just wanted to cut
something. I wonder if that is marketing or if there is some other reason.
(Yes I know. Grind your own and don't worry about it, but I wanted some
good standards to cut to match from since I don't have one of those fancy
grinding/sharpening machines.)
dca...@krl.org
>
> (Yes I know. Grind your own and don't worry about it, but I wanted some
> good standards to cut to match from since I don't have one of those fancy
> grinding/sharpening machines.)
You do not need a fancy grinding/sharpening machine. Just need a
bench grinder with aluminum oxide wheels.
Dan
Mark Rand
>I have been noticing that except for a couple places there isn't as much
>available in 5/16 as 1/4. I was wondering about that since so many cheap
>mini lathes come setup for 5/16 now.
They're not set up for 5/16", they're set up for 8mm :-)
Mark Rand
RTFM
Snag
Hey Bob , if it'll help , I've got a sheet that shows common profiles and
the associated angles . If you want a copy send me your snail mail addy (my
reply-to is good) and I'll send you one .
--
Snag
"90 FLHTCU "Strider"
'39 WLDD "PopCycle"
BS 132/SENS/DOF
Wild_Bill
pre-ground sets, not long ago.. if that's what you're referring to.
I guess too many mini-lathe users are trying to struggle along with brazed
carbide or inserts, and the pre-ground 5/16 HSS weren't popular enough to
keep in stock.
The pre-ground HSS sets have a couple of cutting tools that wouldn't be
easily made. They were offset/dogleg in shape, as ground from a larger piece
of HSS.. not an extremely difficult task, but time consuming.
The 8-piece 1/4" HSS sets, such as those sold by Walden Specialties would be
suitable for use wih a mini-lathe, but they end up being too low to the
cenerline.
Instead of fuzing around with a bunch of shims, a friend showed me how to
make a few "adapters" that allow the cutting tools to be height adjustable.
By taking an appropriately sized section of square stock, and milling a
ramped slot in it, this allows for some height adjustment of the cutting
tool.
When I got my 9x20 lathe, I made a set of three of the gizmos, each with a
different taper in the bottom of the trough.
I had 2 sets for 5/16" and 3/8" for my other lathe.
I've emailed Walden and LMS to see if they have any of the 5/16" sets.
For hand grinding blanks, you might want to consider a small project for
holding the blanks while you grind. I've found them to be very worthwhile.
http://www.kwagmire.com/tools/broach_tool.html
One very handy accessory that can be made for a lathe, is a boring bar
holder. They're versatile for holding boring bars made from worn out taps or
reamers.
--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html
"Bob La Londe" <no...@none.com> wrote in message
news:ftK2n.16648$DY5....@newsfe08.iad...
F. George McDuffee
Or even a bench type belt sander with a correct belt. If you
have the belt/disk combo sander you can get fine grit disks at
most auto supply stores that sell body working supplies that will
put a mirror finish and razor edge on the tool after roughing on
the belt. FWIW even tools directly from the belt sander are
perfectly acceptable.
For a hand honed edge without the hassle, get a blue nylon
abrasive bristle brush for your drill press. Hardware store ones
will have a 1/4 shank. A quick pass is all that is required.
Unka George (George McDuffee)
..............................
The past is a foreign country;
they do things differently there.
L. P. Hartley (1895-1972), British author.
The Go-Between, Prologue (1953).
sta...@prolynx.com
associates.us> wrote:
> On Mon, 11 Jan 2010 12:03:59 -0800 (PST), "dcas...@krl.org"
>
> <dcas...@krl.org> wrote:
> >On Jan 11, 6:54 pm, "Bob La Londe" <n...@none.com> wrote:
>
> >> (Yes I know. Grind your own and don't worry about it, but I wanted some
> >> good standards to cut to match from since I don't have one of those fancy
> >> grinding/sharpening machines.)
>
> >You do not need a fancy grinding/sharpening machine. Just need a
> >bench grinder with aluminum oxide wheels.
>
> > Dan
>
> Or even a bench type belt sander with a correct belt. If you
> have the belt/disk combo sander you can get fine grit disks at
> most auto supply stores that sell body working supplies that will
> put a mirror finish and razor edge on the tool after roughing on
> the belt. FWIW even tools directly from the belt sander are
> perfectly acceptable.
>
> For a hand honed edge without the hassle, get a blue nylon
> abrasive bristle brush for your drill press. Hardware store ones
> will have a 1/4 shank. A quick pass is all that is required.
>
> Unka George (George McDuffee)
I use the belt grinder, 1x42, then hone the final edge with a small
diamond plate. Use a pretty coarse belt, like 40-60 grit. You want
to move the material, not polish it. I prefer that to a regular bench
grinder, lots easier to get angles done right.
As far as tool blanks, both Enco and MSC carry a variety, cobalt in
various percentages and M2. I've had some good cobalt and some bad
cobalt from Enco, the bad stuff broke easily and dubbed off, the good
stuff would keep an edge far beyond regular HSS. You take your
chances there.
Stan
Bob Gentry
wrote:
----------------------------------------------------------------
Bob
A 'fancy grinding/sharpening machine' may be nice to have/use but is
_not_ required <g>. For the basics of 'How To' take a look at the
following Sherline URL.
http://www.sherline.com/grinding.htm
I started with a Sherline (still got/use it) and found the Sherline
site to be a wellspring of information. When I moved up to an 11"
Logan the majority of what I learned from them was aplicable(sp),
including grinding my own HSS tools.
HTH
rgentry at oz dot net
Jim Wilkins
> I...but when the lathe arrived I just wanted to cut
> something. ...>
> (Yes I know. Grind your own and don't worry about it, but I wanted some
> good standards to cut to match from since I don't have one of those fancy
> grinding/sharpening machines.)
What do you have now?
I used an "American" or rocker style tool post and Enco's "Armstrong"
type bit holders for years. until I found a cheap second-hand quick-
change one. They work fine, they are just slow to adjust. The tool
post was one of my first projects. I made it out of a large bolt.
You can grind HSS bits to the same shape as brazed carbide bits or
triangular inserts, with the tip rounded a little more. Really the
horizontal profile doesn't matter much as long as it cuts a chip. The
angle on the end of a new HSS bit is about right for the vertical
relief angle below the cutting edge, though you can get away with much
less.
jsw
Bob La Londe
"Jim Wilkins" <kb1...@gmail.com> wrote in message
news:81deb4cd-d3e5-4bb4...@s31g2000yqs.googlegroups.com...
> On Jan 11, 1:54 pm, "Bob La Londe" <n...@none.com> wrote:
>> I...but when the lathe arrived I just wanted to cut
>> something. ...>
>> (Yes I know. Grind your own and don't worry about it, but I wanted some
>> good standards to cut to match from since I don't have one of those fancy
>> grinding/sharpening machines.)
>
> What do you have now?
An ancient bench grinder with the original generic wheels about half wore
out, and one dressed down square.
> I used an "American" or rocker style tool post and Enco's "Armstrong"
> type bit holders for years. until I found a cheap second-hand quick-
> change one. They work fine, they are just slow to adjust. The tool
> post was one of my first projects. I made it out of a large bolt.
Actually I am looking at setting up a chuck for a 3" diamond wheel on my
lathe, and using a Wilton style 3 axis vise mounted on a slide to get the
same results as a fancy sharpener for a fraction of the cost.
Bob La Londe
news:4i2nk5ha4r0cujei9...@4ax.com...
5/16 = 0.3125
8mm = 0.3149
For a guailo its probably close enough eh? ;^)
Wes
>They're not set up for 5/16", they're set up for 8mm :-)
I use alot of 5/32" tubing. Must be because it is just about 4mm ;)
Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller
Jim Wilkins
> "Jim Wilkins" <kb1...@gmail.com> wrote in message
>
> An ancient bench grinder with the original generic wheels about half wore
> out, and one dressed down square.
> lathe, and using a Wilton style 3 axis vise mounted on a slide to get the
> same results as a fancy sharpener for a fraction of the cost.
This is the tool post I made.
http://picasaweb.google.com/KB1DAL/Tools#5302259874580966978
Somewhere, not on this computer, I have a photo of grinding a
threading bit to the correct angles in a fully articulated Univise on
my surface grinder, but I grind all normal HSS turning bits by hand on
a cheap 6" bench grinder I bought at a yard sale. They simply aren't
worth the trouble to set up a fixture for the front rake, then the
side rake and finally the top rake each time I want to touch up the
edges. The bits were all ground differently to solve some new problem
and the angles aren't written on them, so I'd have to carefully
measure them first.
Besides, the acceptable tolerances are huge. You really could take a
new bit, grind the bevel on the end for a few seconds to sharpen the
top edge and start cutting with it. If you ground a similar bevel for
a short distance along the left side of the end it would work pretty
well to turn a cylinder. Tighten the angle between the left and end
cutting edges somewhat, say to 80 degrees, and it will cut up to a
square shoulder and then face it.
It's difficult to grind an edge lengthwise along the bit, like the AR
holder:
http://www.wttool.com/product-exec/product_id/31965/nm/Indexable_Carbide_Turning_Tool_Sets_USA_
The easy alternative is to grind off both corners to make a spear
point, like the BR or E, and rotate the bit in the tool post. As long
as the angle between the cutting edges is less than 90 degrees it can
cut up to a shoulder in both directions, parallel to the ways and
straight out.
These were all ground freehand:
http://picasaweb.google.com/KB1DAL/Tools#5304243778674022866
I roughed out the discolored one with a 7" angle grinder and you can
see the finish it left on the narrowed shank. I cleaned up the smaller
internal threading bit with a 1" belt sander, for my resume kit.
The round-nosed one at the top was the traditional shape of forged
carbon steel tools for general turning. That one makes half-round
pulley grooves.
The one under it rounds the end of freshly cut threads with the left
end and digs most of the metal out of deep narrow grooves with the 30
degree point on the right. I ground the concave surface with a
slightly tapered stone in a die grinder.
Notice that the rounded bits have flat tops. Top rake makes a bit cut
better but it is NOT essential, and is generally left off formed
shapes like those to preserve their geometry.
Probably the hardest part of freehand grinding is judging the angle of
the steel against the wheel. I set the bit the way I want by pressing
it against the motor housing and then shift over to the wheel with my
legs, so my arms don't move. I let the bit float a little to keep the
whole surface in contact and get a hollow grind that's easier to touch
up with a whetstone.
jsw
Michael Koblic
<big snip>
> Probably the hardest part of freehand grinding is judging the angle of
> the steel against the wheel. I set the bit the way I want by pressing
> it against the motor housing and then shift over to the wheel with my
> legs, so my arms don't move. I let the bit float a little to keep the
> whole surface in contact and get a hollow grind that's easier to touch
> up with a whetstone.
I found free-hand grinding, especially of the 1/4" bits which I use
exclusively, a "bit" too much. None of the bench grinders that I looked here
came with a decently adjustable tool-rest, except the DeWalt.
I spent $50 on the Veritas adjustable tool rest. I liked it so much that I
bought another one for the second grinder.
The other big help was clamping the bits in the Taig toolpost to hold them.
--
Michael Koblic,
Campbell River, BC
Harold & Susan Vordos
"Bob La Londe" <no...@none.com> wrote in message
news:ftK2n.16648$DY5....@newsfe08.iad...
<snip>
>
> (Yes I know. Grind your own and don't worry about it, but I wanted some
> good standards to cut to match from since I don't have one of those fancy
> grinding/sharpening machines.)
What fancy grinding machine?
Have you ever read my long post on grinding HSS tool bits?
All you need is a (proper) grinding wheel with a protective shroud. I don't
even recommend a work rest, which is nothing but in the way.
Understand that the wheel commonly found on pedestal or bench grinders is
not even remotely suited for grinding HSS. Also, pay close attention to
this. Ed Huntress, long ago, expounded on the use of green silicon carbide
grinding wheels for HSS, saying they serve quite well. What he failed to
mention is the fact that silicon carbide dissolves in ferrous alloys at high
temperature (like when you grind), dulling the abrasive rapidly. The
dulling, of course, causes the wheel to slough off quickly, constantly
exposing fresh grain, which, in turn, is also rapidly dulled by dissolution.
The net result is a poor wheel life, and a life threatening cloud of silicon
that can be devastating.
Choose the correct grade of aluminum oxide, along with a desirable size of
abrasive and wheel hardness and you can grind HSS almost effortlessly.
Harold
Jim Wilkins
> "...
> Have you ever read my long post on grinding HSS tool bits?
I tried to, but I have dialup.
> All you need is a (proper) grinding wheel with a protective shroud. I don't
> even recommend a work rest, which is nothing but in the way.
I don't use the rest either. I haven't been able to teach anyone else
how to grind freehand as smoothly as the samples I showed. Perhaps I
have unusually good fine motor skills, in exchange for below average
gross ones.
> Understand that the wheel commonly found on pedestal or bench grinders is
> not even remotely suited for grinding HSS. ...
> Choose the correct grade of aluminum oxide, along with a desirable size of
> abrasive and wheel hardness and you can grind HSS almost effortlessly.
>
> Harold
When I do contract jobs I have to use whatever equipment they have.
Often it's the wheel that came on the cheap grinder, small company
shop managers may not have the budget or time to do everything
"right". I got the idea of using SiC for the fine wheel from a sheet
metal shop that did very little lathe work and used it only for
occasional touch-up. I don't dispute Harold, it's a compromise for
when you have only one grinder and don't use it much.
For me at least the wrong wheel isn't that bad, if it's too coarse
I'll use a belt sander to finish the bit, if too fine I'm more careful
about overheating. If it's glazed I look for a piece of old pipe to
dress it. (If they had a proper wheel dresser handy it wouldn't be
glazed).
What do you suggest for the correct wheel for a home shop grinder,
lets say a 6" 1/2HP 3450 RPM one like mine?
jsw
dca...@krl.org
> Choose the correct grade of aluminum oxide, along with a desirable size of
> abrasive and wheel hardness and you can grind HSS almost effortlessly.
>
> Harold
Grinder manufacturers sell grinders with cheap wheels. Replacing the
wheels with better quality ones makes a big difference. 6 inch dia 1
inch wide wheels at MSC run from about $16 each for the least
expensive bench grinding wheels. So buying both a coarse and fine
wheel will set you back over $30. But they will last the home shop
machinist many years. The coarse wheel will let you rough out the
shape quickly without getting the tool bit really hot. With the right
wheels you do not have to hold the tool bit with vise grips because
you do not need to use a lot of pressure. Holding the tool bit in you
hands gives better feel.
You can find a bunch of posts that say do not cool the bit with water
as it will cause microcracks. But in practice it is not a problem.
When the tool bit starts to get too hot to hold comfortably, I stop
grinding, let it cool in air for about thirty seconds, and then cool
it in water. And have never had any tool crack or chip. Besides you
only get the tool bit hot when taking off a bunch with the coarse
wheel. After that you grind off a bit with the fine wheel getting the
shape just like you want it. And so grind off enough to get rid of
any microcracks. With a good wheel the tool bit does not get hot
while finish grinding.
Dan
Wild_Bill
8-piece 5/16" pre-ground HSS sets, but they do have a 6-piece 1/4" set.
Walden Specialties' email indicated that the 5/16" sets are a popular
seller, although they don't expect to have them back in stock until April
(or possibly early May).
"Wild_Bill" <wb_wi...@XSPAMyahoo.com> wrote in message
news:5sM2n.81270$N07....@en-nntp-05.dc1.easynews.com...
>I believe there were at least a couple of dealers selling the 8-piece 5/16"
>pre-ground sets, not long ago.. if that's what you're referring to.
>
>
Wild_Bill
tools by Harold is only about 500kb in PDF form, even with pichers 'n stuff.
http://twoloonscoffee.com/download/
Tool_Grinding_by_Har.. is the one.
With a good quality grinding wheel and a wheel dressing stick, hand grinding
is almost effortless.
--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html
"Harold & Susan Vordos" <vor...@tds.net> wrote in message
news:YsW2n.4084$cW....@newsreading01.news.tds.net...
Jim Wilkins
> The great tutorial concerning grinder wheels and hand grinding HSS cutting
> tools by Harold is only about 500kb in PDF form, even with pichers 'n stuff.
>
> http://twoloonscoffee.com/download/
>
> Tool_Grinding_by_Har.. is the one.
Thanks, got it. Good thing I don't need to know all_about_coffee.
jsw
Doug Miller
>An email reply from LMS LittleMachineShop stated they no longer stock the
>8-piece 5/16" pre-ground HSS sets, but they do have a 6-piece 1/4" set.
>
>Walden Specialties' email indicated that the 5/16" sets are a popular
>seller, although they don't expect to have them back in stock until April
>(or possibly early May).
Grizzly Industrial has these:
http://www.grizzly.com/products/8-pc-HSS-5-16-Mini-Tool-Set/H5871
http://www.grizzly.com/products/8-pc-Ground-HSS-Tool-Bit-Set-5-16-/H5690
Mark Rand
I not Guailo, I Yong-gook :-)
If it's a cheap mini lathe, it's normally been designed and built in the
largest (metric speaking) country in the world...
Mark Rand
RTFM
Mark Rand
>On Mon, 11 Jan 2010 17:23:29 -0700, "Bob La Londe" <nos...@nospam.no> wrote:
>
>>"Mark Rand" <ra...@internettie.co.uk> wrote in message
>>news:4i2nk5ha4r0cujei9...@4ax.com...
>>> On Mon, 11 Jan 2010 11:54:03 -0700, "Bob La Londe" <no...@none.com> wrote:
>>>
>>>>I have been noticing that except for a couple places there isn't as much
>>>>available in 5/16 as 1/4. I was wondering about that since so many cheap
>>>>mini lathes come setup for 5/16 now.
>>>
>>> They're not set up for 5/16", they're set up for 8mm :-)
>>
>>5/16 = 0.3125
>>8mm = 0.3149
>>
>>For a guailo its probably close enough eh? ;^)
>>
>>
>>
>
>I not Guailo, I Yong-gook :-)
>
Having said that. The gweilos probably don't notice the difference, and it's
simpler to just not tell them!
Mark Rand
RTFM
Wild_Bill
afternoon, the 1/4" and 5/16" sets.
I don't know yet which size I'll prefer using with the mini-lathe, which is
still in it's box.
--
WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html
"Doug Miller" <spam...@milmac.com> wrote in message
news:hiif96$f09$1...@news.eternal-september.org...
Harold & Susan Vordos
"Bob La Londe" <nos...@nospam.no> wrote in message
news:hige92$f8e$1...@news.eternal-september.org...
>
snip--
>
> Actually I am looking at setting up a chuck for a 3" diamond wheel on my
> lathe, and using a Wilton style 3 axis vise mounted on a slide to get the
> same results as a fancy sharpener for a fraction of the cost.
>
Bad idea. Diamond is NOT an acceptable grinding media for steels unless it
is applied at low speed, so no red heat is created. If you are hell bent
on doing what you suggest, you should shift your attention to a CBN wheel.
Further, I suggest you lose the idea of grinding on a lathe. The swarf
created is very damaging to the machine. It's fine and gets under wipers,
where it accelerates wear.
Best of all, read about off-hand grinding HSS tool bits using a proper
aluminum oxide wheel. It takes a little effort up front, but once
mastered, you are set for life. You will never be free until you have
mastered the art.
Harold