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Re: Max workpiece diameter for fixed steady?

 

Hi Chris,
I have never tried this but perhaps you could make a loose plug
attached to a spindle. Insert the spindle into the tailstoch chuck.
Lubricate the plug with silicone or washing up liquid ( for plastic) or
oil (for metal) and insert this in the tube so that it is sitting
inside but close to the end of the tube. Now you can clean up and true
the end of the tube using a lathe tool. Then withdraw the plug turn the
tube around and trim the other end.
I hope this is useful.
Kind regards
Mike
Kingsley, UK

--- In 7x12minilathe@..., "Chris Eilbeck" <chris@...> wrote:

What's the maximum diameter of material I could fit in a fixed steady?
I need to true the ends of a piece of 2.125" tube but it's way to
long to just run in the chuck without any additional support. I'll
have to mail order a steady but I can't get any scale from the on-line
pictures of the device. Are there any other ways of doing this if I
can't just use a fixed steady?

Cheers

Chris
Re: Max workpiece diameter for fixed steady?

 

--- In 7x12minilathe@..., "gerry waclawiak" <gerrywac@...>
wrote:

It is surprisingly difficult to get any info on the capacity of
steadies but
according to littlemachineshop.com the one for the min-lathe is only
good
for 1" so not a lot of good for you.
Just for reference, I've maxed out my SIEG steady (courtesy of LMS) at
just over 1.5". I had to put the fingers in backwards, trim the prism
until the steady was well leveled, and even file a bit of the body
away for this to happen!
Re: Max workpiece diameter for fixed steady?

 

Engineman has a nice steadyrest that looks like it could be built to
handle quite large diameters, see(near the bottom of the page):



John

--- In 7x12minilathe@..., "Chris Eilbeck" <chris@...> wrote:

What's the maximum diameter of material I could fit in a fixed steady?
I need to true the ends of a piece of 2.125" tube but it's way to
long to just run in the chuck without any additional support. I'll
have to mail order a steady but I can't get any scale from the on-line
pictures of the device. Are there any other ways of doing this if I
can't just use a fixed steady?

Cheers

Chris
OT: Re: 1st microwave to tear apart

Jim RabidWolf
 

THEORETICALLY if the microwave hasn't been used for a while, the capacitor
MIGHT not have a charge on it as many units have a bleeder resistor across
them. BUT, capacitors will charge up from static in the air around them,
just sitting naked on a shelf.

ANY capacitor over a hundred volts or so should be stored with a shorting
wire across the leads which should remain there until after the unit is
attached to its circuit. (and if a cap is a really large value, anything
over 40 volts should be shorted - the skin resistance can be broken by just
a little more that forty or so volts, depending on moisture, etc. If the
leads break thru the skin, ANY voltage can be lethal - once you're past the
epidermis, as little as a few milliamps can kill.

I learned the lesson long ago with CRT's from televisions - they'd build up
a charge just sitting by themselves. Later, in college, we were working with
fractional farad capacitors of the multi-thousand to megavolt range - those
were built in 30 and 55 gallon drums (some even larger) and we used to take
great fun in loosening the nut on one side, swinging the shorting bar out
for a minute or so, and then flipping it back into place (with a wooden
broom handle) - just to hear the snap. Sometimes you'd get a bit of a tickle
even through the broom handle...We had to quit since we were burning the
bolts away - monel nuts and bolts in the 1 1/4 size were quite expensive,
even 35+ years ago <G>

Rabid
Uncle Rabid ( )
We Repair Electronic Speed Controllers
For Asian Mini Lathes and Mini Mills
"Just Crazy Enough To Get the Job Done"
(Join Rabid's Lathe/Mill Controller/Mod's List!)
(Also visit BarStockEngines - join us in building without Castings!)

----- Original Message -----
From: "Malcolm Parker-Lisberg" <mparkerlisberg@...>
To: <7x12minilathe@...>
Sent: Thursday, March 08, 2007 3:46 AM
Subject: Re: [7x12minilathe] 1st microwave to tear apart


There is a large capacitor connected to the magnetron
circuit (usually thick red wire) short across its
termials with a well insulated screwdriver and hold
for a couple of seconds. If the microwave has not been
used for some time then their should not be any charge
on the capacitor anyway. The magnets around the
magnetron are usefull. After unscrewing the mounting
screws and cutting the wires you need to remove the
screening lid on the base to allow access to cut the
heater wires so that when you leaver off the end
plates (first prize opent the 'C' slot that holds the
plates in place) you can extract the magnetron tube
from the assembly and remove the magnets. The
magentron is glass and under vacuum so wear protection
so that if it should break you are well protected.
After removing the couple of turns for the heater
winding I found the best way to remove the secondary
windings was to use a slitting saw in a dremmel clone
cutting close to the laminations. You can then punch
out the cut stack. Protect the primary windings (and
your fingers) as the slitting saw does have a mind of
its own. And then just
The relay that is mounted on the PCB can also be
usefull as it has a high current rating for its
contacts.




--- rick201m <rick201m@...> wrote:

I got a free microwave and want to take it apart but
need to be sure i do it safely. Have heard about
the
residual build up of voltage in the capacitor.

Can someone give me a procedure to properly
discharge
it so I can begin?

Any other things to watch out for?

Thanks very mcuh,
Rick in CO



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Re: Max workpiece diameter for fixed steady?

 

It is surprisingly difficult to get any info on the capacity of steadies but according to littlemachineshop.com the one for the min-lathe is only good for 1" so not a lot of good for you.

I honestly don't know how I would tackle this problem but hopefully someone will suggest something.

Sorry!

Gerry
leeds UK


From: "Chris Eilbeck" <chris@...>
Reply-To: 7x12minilathe@...
To: 7x12minilathe@...
Subject: [7x12minilathe] Max workpiece diameter for fixed steady?
Date: Thu, 08 Mar 2007 14:11:30 -0000

What's the maximum diameter of material I could fit in a fixed steady?
I need to true the ends of a piece of 2.125" tube but it's way to
long to just run in the chuck without any additional support. I'll
have to mail order a steady but I can't get any scale from the on-line
pictures of the device. Are there any other ways of doing this if I
can't just use a fixed steady?

Cheers

Chris

_________________________________________________________________
Exclusive Ed Byrne daily comedy clips on MSN Video

Re: 1st Timer Accessories-Which 4-Jaw chuck?

 

The standard minilathe chuck is an 80mm (just over 3") three jaw and I suspect that your 8x14 will come equipped with a 3 jaw of similar or slightly bigger size as standard, maybe a 4". Some of the 8 and 9" hobbty lathes come bundled with a 3 jaw and four jaw independant so you may not need to do anything.

If you do have to buy one I would suggest that you start off with a budget 4" 3 jaw to get a bit of practice in as these are very versatile, easy to use and are generally accurate enough for most work, especially if you are turning parts that do not need re-chucking.

Four jaw independants are for more accurate work, holding irregular parts, boring and turning off centre etc but they involve a lot more setting up with dial test indicators so are best left until you build up some lathe time.

Many people think it is a good idea to get the biggest chuck they can get to fit and this is a common mistake as they forget that the jaws extend past the chuck body as the workpiece size increases and the jaws will then hit the bed or saddle long before the chuck capacity is reached so you can have the bizzare situation that when fitted to the lathe your physically bigger chuck has less usable chuck capacity than its smaller brother!

There was an interesting article either on www.mini-lathe.com or one of the links about selecting chucks generally as well as fitting larger chucks to the 7x minilathes and as an 8x is not that much larger it may be of interest to you.

Gerry
Leeds UK


From: "rancerupp" <rupps@...>
Reply-To: 7x12minilathe@...
To: 7x12minilathe@...
Subject: [7x12minilathe] 1st Timer Accessories-Which 4-Jaw chuck?
Date: Thu, 08 Mar 2007 13:48:15 -0000

I'm looking for accessories in anticipation of my 8x12 HF purchase.

There are so many chucks to choose from. 3", 4", 5", self centering or
independetent jaws. In my limited knowledge, I expect that independent
jaws is what I want. Should I get the biggest that my lathe & pocket
book can handle? Price IS a consideration to me. Any recommendations
for a 5" (specific part #'s please)? Thanks. :)

Rance

_________________________________________________________________
Exclusive Ed Byrne daily comedy clips on MSN Video

Re: Max workpiece diameter for fixed steady?

Arnie Minear
 

Chris,

Yea, about 1" is right. I had the same problem, I had to bite the
bullet and make a steadyrest. I will post a picture in the photos
section under steadrest. It is a fairly easy project if you can
access a mill. Works much better than the original one. I use mine
for making underwater dive light canisters.

Arnie
Re: Buying & Using a Knurler

 

Hi,

Based on an article in Model Engineers Workshop I created this spread
sheet which figures out the correct OD of what you want to knurl so that
the knurl works out.

www.pacificsun.ca/~john/ELS/photos/Knurling.xls

Just enter in the Knurl dimensions and tooth count. Then the diameter
of what you want to knurl. It then calculates what the closest diameter
is that will result in a nice finish. Turn your work to that diameter
and knurl away.

John Dammeyer


Automation Artisans Inc.

Ph. 1 250 544 4950


There is nothing particularly hard about knurling just align
throught the
centre of your work, tighten the knob, select slow speed and
apply plenty of
cutting oil and just tighten up and keep applying oil as you
go until you
get the knurl depth you need. If you are knurling a shaft just slowly
traverse the carriage from end to end as you go tightening
form time to time
at either of the ends.
Re: Best Plastic to use

[email protected]
 

I machine UHMW with no issues, a bit stringy though

----- Original Message ----
From: "ckinzer@..." <ckinzer@...>
To: 7x12minilathe@...
Sent: Thursday, March 8, 2007 9:18:03 AM
Subject: Re: [7x12minilathe] Re: Best Plastic to use

About PVC: Yes, I used to make oodles of parts from it and it wore
tools worse than anything. Even to the point that when making a high
quantity of parts I could easily learn how much extra to turn the
handwheel with each part so I got the same finished size to make up
for the tool wear part to part. Of course, until the tool got so dull
it needed overall resharpening. This is also the time I became very
fond of using a diamond hone to touch up tool bits.

I also machined a lot of molybdenum-disulfid e impregnated nylon.
(Sort of a plastic moral equivalent to "Leadloy".)

Chuck K.

Quoting John <John@GadgetBuilder. com>:

I doubt there is a "best" plastic for turning. Most of the less heat
sensitive plastics turn nicely if you use very sharp bits with low
rake and modest rpm -- plastic will self-feed like brass so zero or
negative rake helps if you take deep cuts. Regular bits work OK for
shallow cuts.

I've had good luck with: Delrin, nylon, HDPE, and polysulfone. These
are not too sensitive to heat but they do make long, stringy swarf.
Tufnol is less temperature sensitive and turns to dust rather than
strings - excellent for pulleys and gears.

Lucite is very temperature sensitive so it is much more difficult but
with care it can be used for lenses.

PVC turns OK, is a bit temperature sensitive and often has impurities
that produce surprising tool wear.

John
Re: Tailstock chuck - Groz vs. LFA

 

--- In 7x12minilathe@..., "trevor_rymell" <sacentre@...>
wrote:

Check out the chucks on sale at LMS. I bought this $9.00 one and am
very happy with the quality.


Trevor
Trevor,

Thank you for your reply. Unfortunately, the Get-It-To-My-Door price
of that chuck works out to be a little over $30, plus at least a week
in transit. (I have to commend LMS for their outstanding work here:
they get my packages here faster and cheaper than any other US
business I've dealt with.)

You have helped me with the idea that good chucks don't necessarily
have to come from LFA or Jacobs. I had half expected to hear that
there were only two classes, cheapys and $100 ones.

- Paul Moir
Re: Best Plastic to use

[email protected]
 

About PVC: Yes, I used to make oodles of parts from it and it wore
tools worse than anything. Even to the point that when making a high
quantity of parts I could easily learn how much extra to turn the
handwheel with each part so I got the same finished size to make up
for the tool wear part to part. Of course, until the tool got so dull
it needed overall resharpening. This is also the time I became very
fond of using a diamond hone to touch up tool bits.

I also machined a lot of molybdenum-disulfide impregnated nylon.
(Sort of a plastic moral equivalent to "Leadloy".)

Chuck K.

Quoting John <John@...>:

I doubt there is a "best" plastic for turning. Most of the less heat
sensitive plastics turn nicely if you use very sharp bits with low
rake and modest rpm -- plastic will self-feed like brass so zero or
negative rake helps if you take deep cuts. Regular bits work OK for
shallow cuts.

I've had good luck with: Delrin, nylon, HDPE, and polysulfone. These
are not too sensitive to heat but they do make long, stringy swarf.
Tufnol is less temperature sensitive and turns to dust rather than
strings - excellent for pulleys and gears.

Lucite is very temperature sensitive so it is much more difficult but
with care it can be used for lenses.

PVC turns OK, is a bit temperature sensitive and often has impurities
that produce surprising tool wear.

John
Re: 1st Timer Accessories-Tool Bits (HSS vs Carbide)

 

I'm not clear on what exactly you're comparing with HSS and Carbide
tools. A say 3/8" HSS blank costs about $2.00 and can be finished on
both sides, effectively making it two tools. A cheapy brazed carbide
tool set costs say $17 for 5 tools, or about $3 per tool. But then
there are both HSS and carbide indexable inserts, pre-ground HSS bits,
and there is a great range of qualities of brazed carbide tools.

For most of the metals you're working, you won't get much advantage
from carbide. In fact, it can be substantially worse as material like
aluminum tend to stick to "normal" carbide, while HSS will provide a
superior finish. Carbide works better on steel and other hard metals
though.

The difficulty with working with HSS blanks is the need to learn how
to grind them yourself. This can be alleviated somewhat by purchasing
pre-ground HSS tools so you can see what they're supposed to look
like. There are also some good tutorials online. Fortunately, it is
possible to grind HSS on a bench grinder equipped with common
aluminium-oxide stones.

Sharpening or shaping your carbide tools will require the use of a
silicon-dioxide "Green" stone.

With HSS blanks you can grind a tool to whatever shape would best suit
a job. This is perhaps their greatest advantage: you can make
exactly what you need on the spot. Their great disadvantage though is
that you have to turn half as fast as you can with carbide to keep the
tool from wearing out too fast.

So the choice really depends on how you wish to use the lathe. If you
want to get turning straight away or at high speeds, pick up some
half-decent brazed carbide bits and a green stone for the grinder. If
you need flexibility, don't mind first learning how to grind tool
bits, and can cut at a more leisurely speed pick up some HSS blanks.
If you want to get cutting straight away and want but want HSS (and an
education), pick up some pre-ground HSS tools. If you want to go
immediately into heavy production, use throw-away indexable carbide
inserts and forget about grinding or sharpening anything.

Personally I think there's room for both tools in the home shop. I
hope this helps you with your decision!

--- In 7x12minilathe@..., "rancerupp" <rupps@...> wrote:

I'm looking for accessories in anticipation of my 8x12 HF purchase.

I thought Carbide would be better but HSS seems to cost more. Why? And
which one should I opt for? To tell you the truth, I'm thinking that
the inserts would be the best route. But picking the right ones out
seems to be a nightmare.

I expect I'll be turning mostly alum. but also brass, copper, and a
little bit of steel.

Rance
Re: Best Plastic to use

 

--- In 7x12minilathe@..., "John" <John@...> wrote:

I doubt there is a "best" plastic for turning. Most of the less heat
sensitive plastics turn nicely if you use very sharp bits with low
rake and modest rpm -- plastic will self-feed like brass so zero or
negative rake helps if you take deep cuts. Regular bits work OK for
shallow cuts.

I've had good luck with: Delrin, nylon, HDPE, and polysulfone. These
are not too sensitive to heat but they do make long, stringy swarf.
Tufnol is less temperature sensitive and turns to dust rather than
strings - excellent for pulleys and gears.

Lucite is very temperature sensitive so it is much more difficult but
with care it can be used for lenses.

PVC turns OK, is a bit temperature sensitive and often has impurities
that produce surprising tool wear.

John



--- In 7x12minilathe@..., "wireless_paul" <paul@> wrote:

Wondered what the best plastic was for turning?
Paul
Thanks for information John.
Someone made me a couple of feet for a vintage communications receiver
out of black plastic. Better than the original (which were lost)
ones. Now I have my lathe (just one week old!) fancied having a go for
some of my other receivers.
Had a look at your Web site, most impressed, will have to study it in
more detail.
Paul
Cross slide gibs

[email protected]
 

Hi guys,



last night I've spent some hours trying to improve the cross table gibs of
my mini mill. Dismounting the x-axis I've notice that gib was bent, so using
the drill press I have straightened it. Then, using the belt sander, I've
smoothed the dovetail-side surface of the gib taking care to keep it
parallel to the other one as was at the beginning. I've spent about half an
hour, using as small pressure as I can on the gib and changing often the
orientation in respect of the belt movement. At last I've used a special
rubber abrasive disk on my dremel to mirror-lap the contact surface of the
gib.

Then

I've mounted it on, registered the screws and tried the table movement. It
is smoother than before. I've then measured the movement of the table in
tightening the locking screw. My quality digital comparator reports 0.035 mm
(about 0.0015"). In the past it was much more, I don't know how much. No
matter, it could be acceptable since I'm going to install a digital scale on
the x axis.

So

I've done a careful look at the gib in place and. surprise. the gib surface
do not adheres completely to the dovetail surface. I've done a look to all
other gibs, in the mill and in the lathe. No other one was perfectly plane
aligned. To be more precise either gib surface and dovetail one are good
flat plane, the problem is the alignment between the top side and bottom
one. When I tight the set screws the gib adheres only in the bottom part of
its plane with the bottom part of the dovetail plane (in some gibs the
planes are the upper ones). Practically I've discovered that the pressure
between gibs and dovetail is not over the entire planes but only on a thin
line, all gib / dovetail long, of contact between them.

Now my questions are:

Is it normal? I've expected a complete planes contact.

There is someone has noticed the same thing on his machine?

If it is an abnormal situation, which could be the cause and which the
solution?



Gianni










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[Non-text portions of this message have been removed]
Re: Motor Temp Rise on the HF 8x12-14

Ed Boysun
 

That really doesn't seem all that far out of line, to me. When being run
continously, most motors will be nearly hot to the touch. Generally, if
you can place your hand on them and count to 2, without being burned,
nothing will be hurt in the motor. I guess I should really check some of
my larger ones with an IR temp gun after they have run for a couple
hours, but I'd be surprised if they didn't run at least that warm.

Just looked at the plate on one of my water pump motors. That one is
thermally protected for 40C above ambient.

Ed B
--- In 7x12minilathe@..., "druid_noibn" <druid_noibn@...>
wrote:

Hi All,

For those who might find it "interesting" 鈥� I noticed the motor of
the HF 8x12-14 was a tad warm and thought a check was in order.

With a motor and ambient temp of 65F the lathe was turned on 鈥� no
metal turning. The probe was located on the upper part of the motor
housing, between the motor body and the junction box.

Without noting all of the readings, in the course of:
13 minutes 鈥� temp rise 39.3F;
30 minutes 鈥� 49.7F;
46 minutes 鈥� 58.1F;
63 minutes 鈥� 63F 鈥� shut-down motor
66 minutes 鈥� 65.7F

I didn't run the motor unloaded yet.

So the motor runs hot - an auxiliary fan might be in order.

Take care,
DBN
Re: Best Plastic to use

 

I doubt there is a "best" plastic for turning. Most of the less heat
sensitive plastics turn nicely if you use very sharp bits with low
rake and modest rpm -- plastic will self-feed like brass so zero or
negative rake helps if you take deep cuts. Regular bits work OK for
shallow cuts.

I've had good luck with: Delrin, nylon, HDPE, and polysulfone. These
are not too sensitive to heat but they do make long, stringy swarf.
Tufnol is less temperature sensitive and turns to dust rather than
strings - excellent for pulleys and gears.

Lucite is very temperature sensitive so it is much more difficult but
with care it can be used for lenses.

PVC turns OK, is a bit temperature sensitive and often has impurities
that produce surprising tool wear.

John

--- In 7x12minilathe@..., "wireless_paul" <paul@...> wrote:

Wondered what the best plastic was for turning?
Paul
Re: Best Plastic to use

 

Delrin (also called acetal) is a good one...just be sure to turn any
plastic slowly...

-------

--- In 7x12minilathe@..., "wireless_paul" <paul@...> wrote:

Wondered what the best plastic was for turning?
Paul
Re: Max workpiece diameter for fixed steady?

andrew franks
 

Chris, the C-shaped hole in my Warco one is 2.25" diameter, approx, and the "fingers" can be withdrawn sufficiently to make full use of that space. So, theoretically it would just do it, (though I haven't checked to see if the hole is concentric to the lathe's centre line). My travelling steady is the same.
Could you make up a plug which is a running fit inside the tube, with a mandrel to be gripped in a tailstock chuck, or is your tube too long to allow room for the chuck? Maybe a similar plug, bored to fit over the tailstock sleeve? If all else fails, could you knock something up out of wood with brass fingers, if it's a one-off job?
Andy

Chris Eilbeck <chris@...> wrote:
What's the maximum diameter of material I could fit in a fixed steady?
I need to true the ends of a piece of 2.125" tube but it's way to
long to just run in the chuck without any additional support. I'll
have to mail order a steady but I can't get any scale from the on-line
pictures of the device. Are there any other ways of doing this if I
can't just use a fixed steady?

Cheers

Chris






---------------------------------
All New Yahoo! Mail 鈥� Tired of unwanted email come-ons? Let our SpamGuard protect you.

[Non-text portions of this message have been removed]
Best Plastic to use

 

Wondered what the best plastic was for turning?
Paul
Re: Max workpiece diameter for fixed steady?

 

If I remember correctly, the fixed steady will handle stock slightly
over 1" in diameter. An expanding mandrel is what you want for this
application. Somebody here pointed me to an automotive tailpipe
expander as an inexpensive alternative. I bought one at Harbor
Freight, and it works like a charm for this application. HF sells them
in three sizes, here's a link to the small one...



Alternatively, you can probably find one of these at your local auto
supply store, if needed immediately...

Mark

--- In 7x12minilathe@..., "Chris Eilbeck" <chris@...> wrote:

What's the maximum diameter of material I could fit in a fixed steady?
I need to true the ends of a piece of 2.125" tube but it's way to
long to just run in the chuck without any additional support. I'll
have to mail order a steady but I can't get any scale from the on-line
pictures of the device. Are there any other ways of doing this if I
can't just use a fixed steady?

Cheers

Chris
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