Re: Why I Do Single-Point Threading
I have done a lot of single point threading but because I did not have a tap or die in that size.
I never had a choice.?
If doing blind R/H threading use reverse and start the thread inside so tool bit is outside when finished?
A36 steel use high rake for better finish?
Dave?
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Why I Do Single-Point Threading
I think I do more single-point threading than tap or die threading.? ? Certainly in larger thread sizes (1/2" and up), and certainly not in small thread sizes (less than 1/4").? ? Projects I do with large fine threads generally require single-point threading, especially if fine fitting is desired.? ?I have a project to do with 7/8"x32tpi threads. The images are of 1/2x20tpi threads - with no discernable play and smooth turning.? ?The male threads are on 3/4" brass rod and the nut is gold iridite (yellow chromate?) finish grade 8. It's the beginning of a drain spud for a furnace humidifier.? ?It is since drilled through 0.280" and has a 3/4" male 45 degree taper seat on the left side.? ?Does it need to be that good?? ?No, but I want it that good.? ?After all, it's a hobby!   -- Lone Tree, Colorado? ?USA
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Re: Lightening darkened steel
Roy
5:22pm? ?
There are some Ni based rods that do a reasonable job of color matching cast iron. Success is helped with experience - find a welder who's done it repeatedly.
Us mere mortals are more likely to be successful with brazing. All the caveats about slow temperature changes & doing small areas at a time still apply
I found someone interested a color match is a real pain. It is surprising of different colors in cast iron.? I like brazing too it does great job and can done with almost sun glasses and a torch. I still have 100 pounds of rod for cast iron work.? Dave?
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Re: Lightening darkened steel
There are some Ni based rods that do a reasonable job of color matching cast iron. Success is helped with experience - find a welder who's done it repeatedly.
Us mere mortals are more likely to be successful with brazing. All the caveats about slow temperature changes & doing small areas at a time still apply.
Roy
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This is project I plan to do for a long time A flame eater engine aka candle eater engine. See file section for complete set of drawings? Dave? 
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davesmith1800 <davesmith1@...> added folder /1) Projects to make
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Re: Lightening darkened steel
After I sold my business I work as Repair Machinist.? You see a lot of attempts at cast iron repair.? JB weld was one best to see , you had take time to remove all JB from casting. This same for bad welds and brazing.? Mainly it add hours to job.?
This includes strip tap holes everthing they try fail.?
That would include welding , brazing and plug {drill and tap for crank cases not thread inserts} and must be done right the first time.
Dave?
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Re: Lightening darkened steel
This Old Tony has a video about this??
It¡¯s not easy. In the past when I¡±ve had to repair a cast iron piece (treadle on an old sewing machine) I went with brazing which worked well, but your application may vary. On Jan 18, 2024, at 1:20 PM, mike allen < animal@...> wrote:
??? ??? YA need to use a nickel rod & pre heat but not too
hot & go slow & let cool often is the way I was taught way
way back . I've always bee luck enough to be around some real good
wenders when I have needed CI welded . animal
On 1/18/24 12:16 PM, Jacques Savard
wrote:
help
if you know casting iron
how can we weld it?
?
I have an old tool, a type of miter saw for wood that is
broken, the parts seem impossible to weld or repair with a screw
Can cast iron be welded?
jack 47 71
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: Lightening darkened steel
As a life long mechanic and also a shop owner, I never ever messed with welding or brazing cast iron. If it needed to be done I took it to a pro. Mickey moused work will always fail. If it's basically nothing of importance then fine, braze it. But dont expect such a job to take any stress. Also, if you try brazing it and you mess it up or it breaks and you take it to a pro to properly get repaired, you will get charged extra because now it takes more to clean things up to be able to properly repair it. My life long experiance.
george
On Thursday, January 18, 2024 at 12:20:43 PM PST, mike allen <animal@...> wrote:
??? ??? YA need to use a nickel rod & pre heat but not too
hot & go slow & let cool often is the way I was taught way
way back . I've always bee luck enough to be around some real good
wenders when I have needed CI welded .
animal
On 1/18/24 12:16 PM, Jacques Savard
wrote:
help
if you know casting iron
how can we weld it?
?
I have an old tool, a type of miter saw for wood that is
broken, the parts seem impossible to weld or repair with a screw
Can cast iron be welded?
jack 47 71
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Re: Lightening darkened steel
I use both?
I like brazing over using cast iron rod?
But cast iron rod is closer match.?
Dave?
toggle quoted message
Show quoted text
Gordon
12:54pm? ?
Look into brazing. Usually quite successful in bonding cast iron. Surface prep is the key for either welding or brazing.
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Re: Lightening darkened steel
Look into brazing. Usually quite successful in bonding cast iron. Surface prep is the key for either welding or brazing.
Gordon On Jan 18, 2024, at 12:16, Jacques Savard <jacquessavard@...> wrote:
help
if you know casting iron
how can we weld it?
?
I have an old tool, a type of miter saw for wood that is broken, the parts seem impossible to weld or repair with a screw
Can cast iron be welded?
jack 47 71
Gordon Taylor
gptaylor98363@...
Those that say a job?cannot be done should?not interrupt those that?are doing it.?¨D?George?Bernard Shaw
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Re: Lightening darkened steel
??? ??? YA need to use a nickel rod & pre heat but not too
hot & go slow & let cool often is the way I was taught way
way back . I've always bee luck enough to be around some real good
wenders when I have needed CI welded .
animal
On 1/18/24 12:16 PM, Jacques Savard
wrote:
toggle quoted message
Show quoted text
help
if you know casting iron
how can we weld it?
?
I have an old tool, a type of miter saw for wood that is
broken, the parts seem impossible to weld or repair with a screw
Can cast iron be welded?
jack 47 71
|
Re: Lightening darkened steel
help
if you know casting iron
how can we weld it?
?
I have an old tool, a type of miter saw for wood that is broken, the parts seem impossible to weld or repair with a screw
Can cast iron be welded?
jack 47 71
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Re: is this an original minilathe
Yes, that's fine.? ?The "this" I commented on is the separate spacer, which the 8x's I mentioned do not have.
--
Lone Tree, Colorado? ?USA
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Re: Lightening darkened steel
I have machine a lot of cast iron most a high quality class 45 .
It has dill look just machining.?
The Chinese cast iron has a brighter can not till you why.
Dave?
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Re: $1000 Budget: Which 7 x 14 to buy?
??? ??? well that gives then the extra inch or some .
??? animal
On 1/18/24 2:18 AM, Charles Devore via
groups.io wrote:
toggle quoted message
Show quoted text
In the
70's? I worked at a shop that purchased a new lathe made in
Romania. The Romanian who came out for some warranty repair
said they measured turning length distance from a spindle
faceplate(not chuck) to tailstock..In
a message dated 1/17/2024 8:44:26 PM Pacific Standard Time,
mctaglieri@... writes:
?
Actually, I did that myself on my own lathe. Might as
well get as much capacity as you can on such a small
lathe.
?
Mike Taglieri?
An unscrupulous
marketing person might grind the centers so they sit
less proud in the tapers to generate a more generous
distance between...
?
On Wednesday, January 17th, 2024 at 8:37 AM,
Aaron Woods < awoods550@...>
wrote:
On Wed, Jan 17, 2024 at 04:56 AM, Paul
Fox wrote:Can someone explain how the length
measurement is usually done, and how HF fudges
that measurement to make 8 == 10 ?? ?I'm
convinced that I don't want one -- just trying
to understand.paul
The 7x10" measurement probably came about through
incorrect measurement and / or very poor rounding
up of the metric conversion and has stuck. It is
not just HF, pretty much all of the sellers that
market these in inches use that term for the Sieg
C2 Model 200. Sieg itself lists these lathes with
a swing of 180mm (7.08") and between centers
distance of 200mm (ie Model 200). Properly
converted 200mm = 7.87".
The between centers distance is the length of a
part that can be held on the lathe between
centers. You can find some variation on identical
lathes based on the centers used. For example the
very common 9x20 lathe (aka Grizzly G4000 / Jet
BD920) is listed by different vendors as either a
9x19 or a 9x20 lathe. This difference is based on
whether they supply the lathe with a live or dead
center for the tail stock. A live center is about
1" longer giving lathes that ship with a live
center a slightly shorter 19" between centers.
I suspect as the first of the Chinese mini lathes
to arrive, the person tasked with measuring and
converting to inches, measured the distance
between the spindle and tail stock without centers
in place giving a number closer to 10". When the
Model 300 (300mm aka 11.8") arrived, the person
given the task of measuring was more competent and
measured correctly with centers in place.
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Re: Lightening darkened steel
That¡¯s not necessarily something you want to remove.?
If it¡¯s not rust, it¡¯s likely oil, bluing (which doesn¡¯t have to be blue) or some other rust preventative, some might be the finish left by case hardening, or some combination.?
If it¡¯s rust, use something like Evaporust, but be prepared to treat it with something ?immediately after de-rusting it.
I¡¯d simply clean them with a de-greaser if it¡¯s just gunk accumulation, followed by an oil application.
Basically you don¡¯t want to rush in to produce a shiny finish in case you destroy the protective layer you¡¯re mistaking for rust.
Also if it¡¯s just old and darker but that isn¡¯t affcting the use¡why worry about it?
This is peripheral to lathes I guess, hope it's OK to ask.? Have a couple of items from another lathe that I'm cleaning up and repurposing for my 7x.
I'm guessing you all have seen older bare metal steel tools.? They get darker over time with use if not protected.? I'm guessing some of it is oil, some is dirt and other contaminates, and some is probably a chemical reaction, possibly rust or rust-related.
I know you can brighten most things up by abrasion - sanding/polishing/etc but that removes at least some of the metal.
Are there any chemical treatments that can brighten steel that has darkened over time, or is it a permanent change in the metal?
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: is this an original minilathe
Most lathe use a casting for head stock and bolted to bed.
Most turret lathes and screw machines have the head stock and bed cat together.?
Dave?
toggle quoted message
Show quoted text
Craig Hopewell
5:06am? ?
I've not seen this. Looking at Grizzly and Vevor (amazon), they appear to be a single piece headstock in the images.
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Re: Lightening darkened steel
In plating they use acid.??
Dave?
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Lightening darkened steel
This is peripheral to lathes I guess, hope it's OK to ask.? Have a couple of items from another lathe that I'm cleaning up and repurposing for my 7x.
I'm guessing you all have seen older bare metal steel tools.? They get darker over time with use if not protected.? I'm guessing some of it is oil, some is dirt and other contaminates, and some is probably a chemical reaction, possibly rust or rust-related.
I know you can brighten most things up by abrasion - sanding/polishing/etc but that removes at least some of the metal.
Are there any chemical treatments that can brighten steel that has darkened over time, or is it a permanent change in the metal?
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davesmith1800
chrisser