milling machine

[Emanuel Berg]

What do you think guys, maybe this one is
a good choice?

https://www.youtube.com/watch?v=jML8nVSntuE

:)

--
underground experts united
http://user.it.uu.se/~embe8573

[John B.]

On Mon, 19 Mar 2018 00:35:20 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>What do you think guys, maybe this one is
>a good choice?
>
> https://www.youtube.com/watch?v=jML8nVSntuE
>
>:)

The beginning scenes - no loose clothing, no rings or wristwatch, etc.
is good advice. I once worked with a guy that caught a ring on
something when he jumped down out of the bomb bay and tore the skin
off the back of his finger. Just pealed off a strip all the way from
the base of his finger to the fingernail. An Electrician, working on
the same airplane shorted out the main battery bank with his wedding
ring. Melted the gold ring right off his finger (that didn't do the
finger any good either)

As a young Airman those experiences convinced me that jewelry and
working are a poor combination and even today I automatically remove
rings and watches when going to work.
--
Cheers,

John B.

[Emanuel Berg]

John B. wrote:

> The beginning scenes - no loose clothing, no
> rings or wristwatch, etc. is good advice.
> I once worked with a guy that caught a ring
> on something when he jumped down out of the
> bomb bay and tore the skin off the back of
> his finger. Just pealed off a strip all the
> way from the base of his finger to the
> fingernail. An Electrician, working on the
> same airplane shorted out the main battery
> bank with his wedding ring. Melted the gold
> ring right off his finger (that didn't do the
> finger any good either)
>
> As a young Airman those experiences convinced
> me that jewelry and working are a poor
> combination and even today I automatically
> remove rings and watches when going to work.

Yep. I like the name of the brand - Luna -
because I can't think of anything cooler than
to have your own base on the Moon :) Well,
maybe a time machine/battlecruiser/science
vessel/spaceship all in one...

[Frank Krygowski]

I know of a trade school that had its carpentry students building a
house, that the school later sold as a fund raiser.

I was told that one long-haired student was on the 2nd floor, drilling
holes for wiring through the studs in the naked stud walls. He leaned
over as he drilled, and his long hair wrapped around the chuck of the
drill. The drill pulled his head down fast enough that he knocked his
head on the drill, then fell through the open stud space. He was rescued
while hanging by his hair about 8 feet above the ground.


--
- Frank Krygowski

[Jeff Liebermann]

On Mon, 19 Mar 2018 00:35:20 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>What do you think guys, maybe this one is
>a good choice?
>
> https://www.youtube.com/watch?v=jML8nVSntuE

A good choice for doing what?

If you're thinking of buying a mill, either get one with servo drives,
or one that is easily converted to CNC by adding servo drives. (I
don't like steppers). CNC makes things much easier.

That also means ball screws for the table. If the machine is sloppy
when operated manually, it will still be sloppy when driven by a
computah.

As for the safety lecture, it's all good advice. I would roll up my
sleeves, or use a velcro strap to keep them in place. The only real
accident I can recall was getting a sleeve caught in an industrial
sewing machine. Also, if you're using coolant, you'll never be able
to keep the machines as clean as the one in the video.



--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Jeff Liebermann]

On Sun, 18 Mar 2018 21:14:30 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>If you're thinking of buying a mill, either get one with servo drives,
>or one that is easily converted to CNC by adding servo drives. (I
>don't like steppers). CNC makes things much easier.

I'm currently helping a friend with this CNC mill conversion:
<http://www.learnbydestroying.com/jeffl/pics/CNC-conversion/index.html>

[John B.]

Depending on how much hair the drill grabbed I would have expected to
find the guy on the floor with a nasty red place on his scalp where
the hair got pulled out :-)

When I was in the A.F. they were almost fanatical about safety. You
could actually be demoted for failure to comply with the safety
manual. When I retired and went to work for a civilian company I found
that while they gave lip service to safety they were actually far more
lax then the A.F.
--
Cheers,

John B.

[John B.]

On Sun, 18 Mar 2018 21:14:30 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>On Mon, 19 Mar 2018 00:35:20 +0100, Emanuel Berg <moa...@zoho.com>
>wrote:
>
>>What do you think guys, maybe this one is
>>a good choice?
>>
>> https://www.youtube.com/watch?v=jML8nVSntuE
>
>A good choice for doing what?
>
>If you're thinking of buying a mill, either get one with servo drives,
>or one that is easily converted to CNC by adding servo drives. (I
>don't like steppers). CNC makes things much easier.
>
>That also means ball screws for the table. If the machine is sloppy
>when operated manually, it will still be sloppy when driven by a
>computah.
>

Out of curiosity what do you reckon it will cost to convert a milling
machine to CNC? Replacing the feed screws with ball screws, installing
servos or stepper motors, the computer installation, etc.?

>As for the safety lecture, it's all good advice. I would roll up my
>sleeves, or use a velcro strap to keep them in place. The only real
>accident I can recall was getting a sleeve caught in an industrial
>sewing machine. Also, if you're using coolant, you'll never be able
>to keep the machines as clean as the one in the video.
--

Cheers,

John B.

[Jeff Liebermann]

On Mon, 19 Mar 2018 12:47:21 +0700, John B. <sloc...@gmail.com>
wrote:

>Out of curiosity what do you reckon it will cost to convert a milling
>machine to CNC? Replacing the feed screws with ball screws, installing
>servos or stepper motors, the computer installation, etc.?

Some photos:
<http://www.learnbydestroying.com/jeffl/pics/CNC-conversion/index.html>

Badly half done web page:
<http://www.learnbydestroying.com/jeffl/CNC%20Conversion%20Project/CNC.html>

Link to docs, manuals, and details:
<https://drive.google.com/drive/folders/1B_FtnU1LHjr0O7aoJoUVwbGOQRujyNnC?usp=sharing>

I can get you the exact specs, prices, and sources (later) when I find
where I buried my notebooks.

There are kits available that are essentially plug and play
conversions for well known mills, such as Bridgeports. If the mill
doesn't have ball screws, you'll need a conversion kit for $1,000 to
$1,500. The Shizuoka ST-N mill already has ball screws, so this was
not needed.

So far, we have about $1,600 into the controller, 3 drivers, 3 servos,
and 3 added servo brakes. The servos are the biggest available.

We only have one phase 220VAC power available, so add in a phase
converter for the spindle motor for about $150 to $400 depending on
power.

We also need to add 5 inductive limit switches at about $20/ea.

I get the fun job of rewiring the machine with new wires, flex
conduit, relays, and sockets (coolant, tool changer, etc) for about
$15/ea. My guess is about 8 relays and who knows how much wire.

I'm also adding a 24V 6A DC power supply to run the brakes and relays.
I have some of these, but my guess is about $50 for a decent switcher.

Grand total should be under $2,500. Prior to going the do it thyself
route, we received estimates for complete systems, that started at
about $10,000.

We made a huge mistake by purchasing the various components from
different vendors in order to save money. Despite my demands that the
owner obtain the manuals on everything before purchasing, the owner
decided he was in a hurry. All the manuals are in either Chinese or a
bad Google translation of Chinese into English.

[John B.]

On Sun, 18 Mar 2018 23:34:39 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

To be honest I can't think of anything I ever did on a horizontal or
vertical milling machine that would have benefited by having CNC :-)

A lathe, yes, if only turning the balls to put on the ends of a vise
handle, but all the milling I can remember doing was pretty much
straight cuts.

What does the guy plan on doing with the mill?
--
Cheers,

John B.

[AMuzi]

South Bend Lathe manual, 1914, inside back cover, "Before
starting to work on a lathe, roll up your sleeves and remove
your necktie."

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[Frank Krygowski]

On Monday, March 19, 2018 at 10:53:04 AM UTC-4, AMuzi wrote:
>
> South Bend Lathe manual, 1914, inside back cover, "Before
> starting to work on a lathe, roll up your sleeves and remove
> your necktie."
>

From back in the days when machinists wore neckties! They were classier back then.

They probably didn't wear eye protection in 1914 either.

Yep, googling yields https://www.umassd.edu/about/historyofumassdartmouth/

Things have gotten much safer since then, of course. Safety inflation is real,
and obviously not bad up to a point. I taught an intro to machine shop lab
(just bare basics) and would come down very hard on a student who omitted
eye protection.

But I know the full-time machinist in that lab sometimes worked without eye
protection, just as I sometimes do on my basement lathe. It's a risk we take
based on our judgment of the circumstances.

OTOH, I don't think I've ever obeyed the "Never use without eye protection!"
warnings that seem to come on things like Harbor Freight screwdrivers. That
company probably puts warnings on its rubber erasers.

Kind of like this: https://www.youtube.com/watch?v=7gzDC-2ZO8I

I put plastic hats in the same category.

- Frank Krygowski

[Emanuel Berg]

Jeff Liebermann wrote:

>> What do you think guys, maybe this one is
>> a good choice?
>>
>> https://www.youtube.com/watch?v=jML8nVSntuE
>
> A good choice for doing what?

In another thread was the question, how do they
cut aluminium tubes so that they fit together
before welding, e.g. the top and down tube to
the head tube? And the answer is a
milling machine (and not a press drill).

I'm sure the Luna is a good choice for
"doing it" only the person who has to pay for
it might disagree :)

[Jeff Liebermann]

On Mon, 19 Mar 2018 14:13:04 +0700, John B. <sloc...@gmail.com>
wrote:

>To be honest I can't think of anything I ever did on a horizontal or
>vertical milling machine that would have benefited by having CNC :-)
>
>A lathe, yes, if only turning the balls to put on the ends of a vise
>handle, but all the milling I can remember doing was pretty much
>straight cuts.
>
>What does the guy plan on doing with the mill?

Small production runs. He's the retired owner of Santa Cruz
Precision:
<http://santacruzprecision.com>
Some of the machines from the old business are now in his garage.
Most of the stuff he did was designed on a computah using and old
version of SmartCAM.
<http://www.smartcamcnc.com>
Some of the complex shapes could not have easily been done without the
computer. Same with making multiple parts for short run manufacture.
What inspired this project is that he's getting requests for quotes
from former customers where the profits from 1 or 2 jobs would easily
pay for the CNC conversion. Since the old Bandit CNC controller was
almost dead, it seemed like a good way to go. Right now, we're a bit
stalled due to various personal commitments.

More on the mill:
<http://www.buildyouridea.com/cnc/Shizuoka/Shizuoka.html>

My payment for doing the computers, electrical and motors is that I
get to use the mill to make custom knives. Something like this:
<https://www.youtube.com/watch?v=98ly5-1bhHU> (0:00 to 4:30)

[Jeff Liebermann]

On Mon, 19 Mar 2018 19:47:27 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>Jeff Liebermann wrote:
>
>>> What do you think guys, maybe this one is
>>> a good choice?
>>>
>>> https://www.youtube.com/watch?v=jML8nVSntuE
>>
>> A good choice for doing what?

>In another thread was the question,

I don't read every thread.

>how do they
>cut aluminium tubes so that they fit together
>before welding, e.g. the top and down tube to
>the head tube? And the answer is a
>milling machine (and not a press drill).

It's called "mitering":
<https://www.google.com/search?q=mitering+bicycle+tubes>
A mill with an tiltable head is probably the easiest way to do it.
I've watched the process, but have never done it myself. It can also
be done with a lathe. I don't know if a drill press will work,
probably not. Forget about using a tubing notcher. If the metal is
soft enough for a notcher to work, then it's not strong enough to
ride.

>I'm sure the Luna is a good choice for
>"doing it" only the person who has to pay for
>it might disagree :)

I don't know anything about Luna mills. Mitering bicycle tubes does
not require fabulous precision. A Chinese benchtop mill could be used
if you're cheap or desperate. The accuracy is mostly in the jigs and
fixtures.

[AMuzi]

The expression for that is 'beyond parody'[1]. Example:

http://wordpress.rideapart.com/2018/03/motorcycle-helmet-study-spinal-injury-reduction/

[1] this woman coined the phrase:
http://www.1490wlfn.com/vicki_mckenna.html

She's one of your people, Frank, but doesn't use her Polish
name professionally.

[AMuzi]

On 3/19/2018 1:47 PM, Emanuel Berg wrote:
> Jeff Liebermann wrote:
>
>>> What do you think guys, maybe this one is
>>> a good choice?
>>>
>>> https://www.youtube.com/watch?v=jML8nVSntuE
>>
>> A good choice for doing what?
>
> In another thread was the question, how do they
> cut aluminium tubes so that they fit together
> before welding, e.g. the top and down tube to
> the head tube? And the answer is a
> milling machine (and not a press drill).
>
> I'm sure the Luna is a good choice for
> "doing it" only the person who has to pay for
> it might disagree :)
>

An easier question. Just ring up Andy Newlands:

http://www.strawberrybicycle.com/gallery/view_photo.php?set_albumName=Marchetti&id=ML314

http://www.strawberrybicycle.com/gallery/view_photo.php?set_albumName=Marchetti&id=ML317

[John B.]

On Mon, 19 Mar 2018 12:43:45 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

A file is accurate enough :-)

--
Cheers,

John B.

[John B.]

On Mon, 19 Mar 2018 12:21:41 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

I thought that you "knife guys" hand forged the blades. At least that
was what Jesse Clift did when he made what was probably the original
Bowie knife :-)

--
Cheers,

John B.

[AMuzi]

+1

Since I'm in the 'no two alike' frame repair business, I can
miter a top tube at both ends to length with a file faster
than the setup on a general purpose mill.

http://www.yellowjersey.org/gth8.jpg

If you're making a lot of frames to the same geometry, a
Marchetti & Lange machine is what you want, but that is not
Mr Berg.

[John B.]

Back when I was working at it I wore USAF supplied corrective glasses
that were also classified as "safety glasses".

When I was in High School I worked one summer in a shop that had
machines similar to the photo in your UMass reference. The shop
belonged to two old brothers and apparently was originally built by
either their father or grandfather - my father remembered it being
there when he was a boy.

The first job that they gave me was making nuts... on a lathe that the
cross slide was calibrated in 128ths of an inch.

As an aside, one of the brothers had a Henderson four cylinder
motorcycle that probably dated to the 1930's sometime that was in
perfect like new condition. He would occasionally ride it to work if
it didn't look like rain :-)

--
Cheers,

John B.

[Jeff Liebermann]

On Tue, 20 Mar 2018 08:23:50 +0700, John B. <sloc...@gmail.com>
wrote:

>On Mon, 19 Mar 2018 12:21:41 -0700, Jeff Liebermann <je...@cruzio.com>
>wrote:

>>My payment for doing the computers, electrical and motors is that I
>>get to use the mill to make custom knives. Something like this:
>><https://www.youtube.com/watch?v=98ly5-1bhHU> (0:00 to 4:30)

>I thought that you "knife guys" hand forged the blades. At least that
>was what Jesse Clift did when he made what was probably the original
>Bowie knife :-)

Some do, but I don't. If you skim through the YouTube videos on knife
making, there are different ways to make the blades:
Blacksmith forging (heat it up and beat it into shape).
Grind, belt sand, or file into shape.
Grinding auto leaf springs, used saw blades, or other steel shapes
into something resembling a blade.
CNC mill or grind to shape.
Cheat and buy a kit.
I'm currently in the last category and sending my blades to a heat
treating shop.

The overwhelming majority of the YouTube videos I've watched deal with
forging, grinding, or sanding the blade. That's great for making one
unique knife, but not suitable for production volume, which is what
I'm thinking of doing.

Blade Steels:
http://sharpeningmadeeasy.com/steels.htm
http://www.osograndeknives.com/catalog/blade-steels.html
https://www.bladehq.com/cat--Steel-Types--332

Heat Treating:
https://evenheat-kiln.com/?p=heat-treating-information

Kits and supplies:
Woodcraft Kits - https://www.woodcraft.com/categories/knife-kits
Knife Kits - http://knifekits.com
Texas Knifemakers Supply - http://texasknife.com
USA Knife Maker - http://usaknifemaker.com
Crazy Crow Trading Post - http://crazycrow.com
K&G - http://knifeandgun.com
Jantz Supply - http://knifemaking.com
Atlanta Cutlery - http://atlantacutlery.com

Incidentally, sharpening all my kitchen knives to an edge sharp enough
for shaving was NOT a good idea. I'm cutting myself quite often and
am slowly destroying my cutting boards and dishes. Paper plates no
longer work as my knives cut through the paper.

[John B.]

On Mon, 19 Mar 2018 19:48:03 -0700, Jeff Liebermann <je...@cruzio.com>

I don't do kitchen work but periodically my wife hands me a bunch of
kitchen knives and says "Sharpen them". Generally these are cheap
stainless knives and I've found that simply making a pass across a
grinding wheel on each side works pretty well. It produces a sharp
edge which is not perfectly smooth, more like a very fine tooth saw
which seems to cut better then a perfectly smooth blade.
--
Cheers,

John B.

[John B.]

Way back when machinists did a lot of filing to fit. While it was
probably slower then a modern CNC machine it was sure cheaper and you
could keep everything in your toolbox :-)

--
Cheers,

John B.

[Jeff Liebermann]

On Tue, 20 Mar 2018 10:59:44 +0700, John B. <sloc...@gmail.com>
wrote:

>On Mon, 19 Mar 2018 19:48:03 -0700, Jeff Liebermann <je...@cruzio.com>
>wrote:

>>Incidentally, sharpening all my kitchen knives to an edge sharp enough
>>for shaving was NOT a good idea. I'm cutting myself quite often and
>>am slowly destroying my cutting boards and dishes. Paper plates no
>>longer work as my knives cut through the paper.

>I don't do kitchen work but periodically my wife hands me a bunch of
>kitchen knives and says "Sharpen them". Generally these are cheap
>stainless knives and I've found that simply making a pass across a
>grinding wheel on each side works pretty well. It produces a sharp
>edge which is not perfectly smooth, more like a very fine tooth saw
>which seems to cut better then a perfectly smooth blade.

Disclaimer: I am a beginner on knife making but am learning fast.

It depends one what and how you're using the knife to cut. If you
draw the knife as if you were sawing through the food, a rough edge is
quite superior to a razor sharp edge. However, if you're pushing your
way through the food with the knife, the razor edge works better.

What I did was buy about 15 assorted knives at a local outdoor flea
market and 10 more at a local thrift shop. I used these for practice
to learn how to sharpen them and how to modify the shape of the blade.
Most were stainless but I also found a few 1095 high carbon steel "Old
Hickory" knives.
<https://www.knivesplus.com/OLD-HICKORY-KNIVES.HTML>

I bought a Harbor Freight 1x30 belt sander and belt assortment from 80
grit to 800 grit:
<https://www.harborfreight.com/power-tools/sanders/1-in-x-30-in-belt-sander-60543.html>
an angle guide:
<https://www.amazon.com/Knife-Sharpening-Angle-Guide-Sharpen/dp/B01HVXFP80>
and a collection of whetstones:
<https://www.ebay.com/itm/Japanese-Whetstone-Knife-Grit-1000-8000-Sharpener-Sharpening-Water-Stone-Stand/222660726466>
I also setup a binocular microscope so I could see what I was doing to
the edge:
<http://www.learnbydestroying.com/jeffl/pics/microscopes/Olympus%20SZ30/slides/SZ30-01.html>
After a few frustrating failures, I determined that I could produce a
usable but rough edge with the belt sander, and then refine it to a
razor sharp edge with the water stones. The sanding might only take a
few minutes on the belt sander, but the water stone polishing can
easily take hours. I can easily see the difference with the
microscope.

I have 6" grinder, but I would not use it to sharpen knives. It takes
off too much metal too quickly to maintain control. When I tried it,
the result was a rather "wavy" edge. Even a belt sander takes off too
much metal if you use a rough (80 or 120 grit) belt. If you have a
belt sander, try starting with 120 grit to remove the dings and chips.
Then use increasingly finer belts until you get to 400 or 800 grit.
You can probably just quit there, or if you want a smooth edge, use a
succession of water stones (1000 to 3000) to improve on the edge.

[John B.]

On Mon, 19 Mar 2018 22:43:37 -0700, Jeff Liebermann <je...@cruzio.com>

Somewhere around the Net is a site that talks about super sharp, or
deadly sharp, or some other fancy name. That guy used plain old emery
paper on a flat block to sharpen a knife.

I've tried it and it works pretty well except that if you move the
blade forward - leading with the sharp edge - it scrapes the abrasive
off the paper :-) But it does work pretty well if you pull the blade
"backward" with the sharp edge trailing. I usually have a couple pf
wood blocks with emery paper glued to one side laying around the
bench. If you are cutting something like glass cloth a couple of
swipes across the blocks every cut or so keeps a pretty good edge on
the knife.

I made several "work knives" - sort of a substitute for a folding
pocket knife, after I broke mine - out of "All Hard" power hacksaw
blades. The edge holds up pretty well to abuse but doesn't "take an
edge" as well as say old files.

There is a Usenet group "rec.knives" that used to be pretty active but
I haven't been there for quite a while.

--
Cheers,

John B.

[Emanuel Berg]

Jeff Liebermann wrote:

> I don't read every thread.

Who does? :)

> It's called "mitering":
> <https://www.google.com/search?q=mitering+bicycle+tubes>
> A mill with an tiltable head is probably the
> easiest way to do it. I've watched the
> process, but have never done it myself.
> It can also be done with a lathe.

I do have a lathe, only I don't know if it
works. Maybe I can repair it. Getting the pipes
in place are probably easier with
a mill, right?

> I don't know if a drill press will work,
> probably not. Forget about using a tubing
> notcher. If the metal is soft enough for
> a notcher to work, then it's not strong
> enough to ride.

OK.

> Mitering bicycle tubes does not require
> fabulous precision. A Chinese benchtop mill
> could be used

OK, what brands are they?

[Emanuel Berg]

AMuzi wrote:

> http://www.yellowjersey.org/gth8.jpg

Right, but are the tubes typically that thin?
If so I see the point.

[Emanuel Berg]

AMuzi wrote:

> http://www.yellowjersey.org/gth8.jpg

Also, how does one know how much to file away?
Like if you have one tube that has diameter A,
and another has diameter B, and A > B, and you
want the second tube to be at an angle X from
the first?

If we return to the lathe guys they have
a small thing with rods that can be pushed back
and forth to form a pattern, perhaps something
like that can be used to do a template if it is
difficult to compute?

[Emanuel Berg]

Jeff Liebermann wrote:

> I don't know if a drill press will work,
> probably not.

What's the problem with a drill press? If the
tubes are as thin as in AMuzi's photo, I don't
see power being a problem assuming the tubes
can be fixed robustly which one has to do
anyway with a milling machine?

[Emanuel Berg]

AMuzi wrote:

>> I'm sure the Luna is a good choice for
>> "doing it" only the person who has to pay for
>> it might disagree :)
>>
>
> An easier question. Just ring up Andy Newlands:
>
> http://www.strawberrybicycle.com/gallery/view_photo.php?set_albumName=Marchetti&id=ML314
>
> http://www.strawberrybicycle.com/gallery/view_photo.php?set_albumName=Marchetti&id=ML317

If you are saying those machines are
inexpensive, they don't look like that, if you
are saying buy pipes from someone else, one
might as well buy a buycycle... a bicycle, and
be done with it. And perhaps one should!

[AMuzi]

On 3/20/2018 9:09 AM, Emanuel Berg wrote:
> AMuzi wrote:
>
>> http://www.yellowjersey.org/gth8.jpg
>
> Also, how does one know how much to file away?
> Like if you have one tube that has diameter A,
> and another has diameter B, and A > B, and you
> want the second tube to be at an angle X from
> the first?
>
> If we return to the lathe guys they have
> a small thing with rods that can be pushed back
> and forth to form a pattern, perhaps something
> like that can be used to do a template if it is
> difficult to compute?
>

I made a frame plate:
http://www.yellowjersey.org/photosfromthepast/wat9b.jpg
http://www.yellowjersey.org/peg13h.jpg
http://www.yellowjersey.org/peg13i.jpg

but Joe Bringheli or Andy Newlands will sell you a premade
fixture:
http://www.yellowjersey.org/jk30.html

[AMuzi]

On 3/20/2018 9:36 AM, Emanuel Berg wrote:
> Jeff Liebermann wrote:
>
>> I don't know if a drill press will work,
>> probably not.
>
> What's the problem with a drill press? If the
> tubes are as thin as in AMuzi's photo, I don't
> see power being a problem assuming the tubes
> can be fixed robustly which one has to do
> anyway with a milling machine?
>

1.0mm for heavy touring tube, mostly 0.9 and 0.8 tube in my
repair photos. The latest air hardening tubes are drawn as
thin as 0.3mm.

[Emanuel Berg]

AMuzi wrote:

> 1.0mm for heavy touring tube, mostly 0.9 and
> 0.8 tube in my repair photos. The latest air
> hardening tubes are drawn as thin as 0.3mm.

?

I have an aluminium frame here which is 2.065kg
and the head tube is 3.7mm and the saddle tube
is 2.35mm!

[Jeff Liebermann]

On Tue, 20 Mar 2018 14:52:52 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>Jeff Liebermann wrote:
>> Mitering bicycle tubes does not require
>> fabulous precision. A Chinese benchtop mill
>> could be used

>OK, what brands are they?

I think I'll pass on recommending a particular brand or mill. I don't
have much experience with frame building or cheap Chinese mills. Find
a frame builder and ask them what they prefer for mitering.

Otherwise, if you want to go online window shopping:
<https://littlemachineshop.com/info/minimill_compare.php>
<https://www.harborfreight.com/two-speed-variable-bench-mill-drill-machine-44991.html>
<http://www.grizzly.com/products/Mini-Milling-Machine/G8689>
<https://www.micromark.com/Milling-Machine-R8-500W>
Plan on spending about as much as the mill costs on a vise, clamps,
fixture parts, tools, end mills, dial indicators, safety equipment,
etc. Add more money if you want to do major modifications on the
mill, such as a Z axis feed, bigger motor, or electronic speed
control.

CNC conversion kits are available:
<https://makezine.com/projects/cnc-mini-mill-conversion-kit-hardware/>
<http://www.cncfusion.com>
<https://www.grizzly.com/products/Mini-Mill-Retrofit-Kit-Compact-Series-Microstepper-for-G0704/T25436>
etc...

Hints: Start with a decent mill, not a piece of junk. If you can't
afford a decent mill, be prepared to rebuild a used mill. If you
don't have any experience with machine tools, take classes. If you
don't have the tools to get started, borrow someone else's mill. If
you're about to spend $4,000 for tools to make a single $500 frame,
you might want to reconsider the economics involved. Do your
prototyping on someone else's machine until you know what you need to
make a frame. Everything costs twice as much and takes twice as long
as planned.

[Frank Krygowski]

After trying many techniques over the decades, my favorite tool for
sharpening knives is a steel block whose top surface is impregnated with
industrial diamond abrasive. It seems to last forever, which for
practical purposes means it stays flat. I have other whetstones that
have gradually gotten concave, which makes it tough to maintain the
proper edge angles.

I use the classic technique, which is sharpen the main bevel at
something like 20 degrees, then lightly sharpen a smaller bevel at 45
degrees, and touch up or polish the edge with a hone or other piece of
hard steel. I use the hone far more often than the abrasive. Lots of
times, the edge just needs touching up, not actual grinding.

--
- Frank Krygowski

[Jeff Liebermann]

On Tue, 20 Mar 2018 15:36:07 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>Jeff Liebermann wrote:
>
>> I don't know if a drill press will work,
>> probably not.
>
>What's the problem with a drill press? If the
>tubes are as thin as in AMuzi's photo, I don't
>see power being a problem assuming the tubes
>can be fixed robustly which one has to do
>anyway with a milling machine?

1. Most use bushings, not bearings, which can't tolerate much side
loading. Getting rid of the wobble is not easy.
2. Lack of power. The typical 1/2 HP motor drive does not have the
power to drive large diameter tools. If you try, the belt will slip
or the Morse taper holding the drill will spin. If you succeed, the
motor won't tolerate continuous running.
3. End mills might fit in a drill chuck but without a locking
mechanism will slip and spin.
4. No cutter lube system.
5. Drill table tilt is difficult to adjust to perpendicular to the
cutter.
6. Setup and fixturing is not easily repeatable.
7. E-bay X-Y tables are junk.

Don't Mill With a Drill Press
<https://www.youtube.com/watch?v=h-8ddRE7iWM>

"IMPOSSIBLE!" Milling Machine from a Drill Press
<https://www.youtube.com/watch?v=xY-wXcFhx5w>

SUCCESS!! Drill to Mill Conversion.
<https://www.youtube.com/watch?v=gXvaZImOTbc>

There are numerous YouTube videos showing various ways to convert a
drill press into a mill. Learn by Destroying(tm).

[Frank Krygowski]

On 3/20/2018 12:22 PM, Jeff Liebermann wrote:
> Everything costs twice as much and takes twice as long
> as planned.

Here, I must disagree. For many years, I did my plans, then multiplied
by three instead of multiplying by two. I found multiplying by three
produced cost and time estimates that were much more accurate.

But then, when I was doing some work for a small local company, the
owner pointed out multiplying by three was really not very scientific.
He said it's much more scientific to multiply by pi.

So 3.14159 is what I've used ever since.
--
- Frank Krygowski

[AMuzi]

Your 'don't mill with a drill press' link mentions lower
receivers. Ouch. That's a spectacularly bad idea in a drill
press:

http://personal.linkline.com/rlockyer/XD9/PLOWER2.JPG

The Inter Webs are full of bad examples after which the guy
had to start with a new blank. It's a relatively fast simple
setup in a vertical mill.

[Jeff Liebermann]

On Tue, 20 Mar 2018 12:49:36 -0400, Frank Krygowski
<frkr...@sbcglobal.net> wrote:

>On 3/20/2018 12:22 PM, Jeff Liebermann wrote:
>> Everything costs twice as much and takes twice as long
>> as planned.

>Here, I must disagree.

Does that mean you agree with everything else that I wrote?

>For many years, I did my plans, then multiplied
>by three instead of multiplying by two. I found multiplying by three
>produced cost and time estimates that were much more accurate.
>
>But then, when I was doing some work for a small local company, the
>owner pointed out multiplying by three was really not very scientific.
>He said it's much more scientific to multiply by pi.
>
>So 3.14159 is what I've used ever since.

Instead of Pi, I suggest a more optimistic Euler's number of
e=2.7182818...

It's actually worse than Pi. In a former life and job, the project
manager would ask me how long it would take for me to prototype,
build, and deliver some gizmo. He would then double my estimate. His
time estimate would then go to the engineering manager, who would
double it again. When it left the desk of the chief engineer, it was
again doubled. Knowing that it was now 8 times my original estimate,
marketing would optimistically give a delivery date slightly less than
my original estimate, and then double the scope of the project. The
resulting 16 times my original estimate would be a fairly good number
for the final 100% completed. Cost overruns are much the same, but
can be made to look acceptable by creative cost accounting.

[Radey Shouman]

Scary sharp.

> I've tried it and it works pretty well except that if you move the
> blade forward - leading with the sharp edge - it scrapes the abrasive
> off the paper :-) But it does work pretty well if you pull the blade
> "backward" with the sharp edge trailing. I usually have a couple pf
> wood blocks with emery paper glued to one side laying around the
> bench. If you are cutting something like glass cloth a couple of
> swipes across the blocks every cut or so keeps a pretty good edge on
> the knife.

I have not tried this with knives, but it works well on plane irons,
chisels, and such, moving forwards or backwards. The advantage is that
a wide variety of grits are easily available, and the surface stays as
flat as it started. I just use a granite floor "tile", which is flat
enough for my purposes.

The disadvantage is that abrasive paper costs considerably more than
sharpening stones if one sharpens a lot.

[Radey Shouman]

That diamond "stone", if it is wide enough, will flatten other
whetstones quite nicely. Although if you wait until the stones are
seriously dished it's not worth the effort.

[Frank Krygowski]

I had a nice Arkansas stone that broke before it went concave, sadly.

My next best stone was a large one (maybe 2" x 6") given to me by the
machinist who lived next door. But it was concave to begin with, and
it's very concave now. I suppose I should find a way to flatten it. It's
too big for my little diamond stone. Any advice?

--
- Frank Krygowski

[Radey Shouman]

I have seen a flat surface and sandpaper advised, but haven't tried it.
Diamond lapping plates up to 4" wide are easily available, albeit not
cheaply. Norton and others sell flattening stones intended for
waterstones, but I would bet they work fine with Arkansas or other
oilstones.


--

[Jeff Liebermann]

On Tue, 20 Mar 2018 12:25:58 -0400, Frank Krygowski
<frkr...@sbcglobal.net> wrote:

>After trying many techniques over the decades, my favorite tool for
>sharpening knives is a steel block whose top surface is impregnated with
>industrial diamond abrasive. It seems to last forever, which for
>practical purposes means it stays flat.

If it's this type, that has the diamonds imbedded in a sheet of
plastic, they are probably NOT flat.
<https://www.harborfreight.com/3-piece-2-inch-x-6-inch-diamond-hone-blocks-36799.html>
If it's a far more expensive diamond plate with mono crystalline
diamonds and where the diamonds are embedded in a more stable
substrate, they work very well:
<https://www.dmtsharp.com/sharpeners/bench-stones/dia-sharp/>
The problem is that the grain size of the diamonds is rather small. In
order for them to remain in place, about two thirds of the diameter
needs to be imbedded in the plastic, aluminum, or whatever. That
leaves very little sticking out to do the cutting. If the substrate
is bent a little less than the height of the diamonds, you'll be
sharpening on air, not diamonds.

This video covers the problems quite well:
"WATCH THIS before you buy diamond stones for tool/knife sharpening"
<https://www.youtube.com/watch?v=zBND6emsSE4>

>I have other whetstones that
>have gradually gotten concave, which makes it tough to maintain the
>proper edge angles.

Stones are easy to flatten. Take a soft pencil and mark a grid on the
stone surface. Find another stone with a rougher grit and rub the two
surfaces together. The pencil markings will disappear as you grind
from the high spots. Keep grinding until all of the penciled grid
disappears simultaneously.

>I use the classic technique, which is sharpen the main bevel at
>something like 20 degrees, then lightly sharpen a smaller bevel at 45
>degrees, and touch up or polish the edge with a hone or other piece of
>hard steel.

I use 15 to 20 degrees for kitchen knives depending on blade
thickness. Mostly, I try to duplicate the original angle from the
manufacturer. I haven't tried any compound angle grinds yet.
<http://blissknifeworks.com/wp-content/uploads/2016/10/Grind-Angle-Chart-copy.jpg>

>I use the hone far more often than the abrasive. Lots of
>times, the edge just needs touching up, not actual grinding.

I look at the edge with a magnifier or microscope to see what I'm
dealing with. If it's dings, gouges, or chips, I use the belt sander
to remove these before sharpening. If it's just a little rough, then
I use a finer stone.

[John B.]

On Tue, 20 Mar 2018 14:55:32 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>AMuzi wrote:
>
>> http://www.yellowjersey.org/gth8.jpg
>
>Right, but are the tubes typically that thin?
>If so I see the point.

High end tubes are typically less then 1mm wall thickness. A Columbus
"Spirit" top tube is 0.38mm ( wall thickness ) and is butted on each
end to 0.5mm.
--
Cheers,

John B.

[John B.]

On Tue, 20 Mar 2018 15:09:49 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>AMuzi wrote:
>
>> http://www.yellowjersey.org/gth8.jpg
>
>Also, how does one know how much to file away?
>Like if you have one tube that has diameter A,
>and another has diameter B, and A > B, and you
>want the second tube to be at an angle X from
>the first?

There are quite a number of simple computer programs that given the
diameter and wall thickness and the angles the tubes are joined will
print out a template that you can use to mark the tube.

I use Tubemiter.exe that dates back to DOS days :-)

>
>If we return to the lathe guys they have
>a small thing with rods that can be pushed back
>and forth to form a pattern, perhaps something
>like that can be used to do a template if it is
>difficult to compute?
--

Cheers,

John B.

[John B.]

On Tue, 20 Mar 2018 15:36:07 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>Jeff Liebermann wrote:
>
>> I don't know if a drill press will work,
>> probably not.
>
>What's the problem with a drill press? If the
>tubes are as thin as in AMuzi's photo, I don't
>see power being a problem assuming the tubes
>can be fixed robustly which one has to do
>anyway with a milling machine?

"Hole Saws" are often used to miter tubes and yes, you could use a
drill press assuming that you have some sort of fixture to hold the
tube.
--
Cheers,

John B.

[John B.]

On Tue, 20 Mar 2018 17:07:17 +0100, Emanuel Berg <moa...@zoho.com>
wrote:

>AMuzi wrote:
>
>> 1.0mm for heavy touring tube, mostly 0.9 and
>> 0.8 tube in my repair photos. The latest air
>> hardening tubes are drawn as thin as 0.3mm.
>
>?
>
>I have an aluminium frame here which is 2.065kg
>and the head tube is 3.7mm and the saddle tube
>is 2.35mm!

And Andrew was talking about steel frames...
--
Cheers,

John B.

[John B.]

On Tue, 20 Mar 2018 12:25:58 -0400, Frank Krygowski
<frkr...@sbcglobal.net> wrote:

But the emery paper and wooden block are so cheap :-)

The various angles required to arrive at a cutting edge are very
dependent on the use to which the cutting device is to be put.
--
Cheers,

John B.

[John B.]

Google "how to flatten a dished sharpening stone". (5 million hits :-)

My only hands on experience is with grinding machine wheels which were
dressed with a single point diamond dresser which wouldn't be very
practical for a flat stone :-)
--
Cheers,

John B.

[AMuzi]

But maybe possible with a diamond tool in a fly cutter such
as is used for engine heads. I just replace the stone which
is infrequent and cheap.