--- In 7x12minilathe@..., "Neil" <cobra_neil@...> wrote:
Hi,
Just joined the list, and introducing myself. I'm an electronics hobbyist
that's looking into making a product that will need small enclosures and so
far I'm looking into buying the tools and doing this myself. One option is
to turn and thread alum rod/tube and hence I found this list. I know next
to nothing about metal machining, so the actual processes are undecided, and
hence so are the tools. Looking forward to learning a bunch.
Cheers,
-Neil.
google thelittlemachineshop.com This site will give you a vast amount of information on lathes and mills and a lot of your questions you may have. Doc Ferguson
[Non-text portions of this message have been removed]
|
Re: Gear reduction for real Bull lathe.
That is my experience, too.? In my mind, advancing the timing of the brushes is not logical, for what is happening inside an electric motor is essentially happening at the speed of light.? Advancing spark timing in a gas engine is logical, because it takes time for the flame front to propagate through the combustion chamber. ?But advancing timing in an electric motor? I can’t see it. ?However, I can’t say that it has never been done, either. ? Robert ? From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of Robert Francis
? I've heard time and time again, the motors being set to run in the"main" direction, but never have I seen it documented by the equipment manufacturer. I think it's an old wives tale!
toggle quoted message
Show quoted text
On 05/19/2013 08:19 PM, Roy wrote: ? Some of the controllers are set up to add a speed limiting resistor in reverse. That's supposedly because the brushes are advanced a few degrees to improve efficiency when the motor is running in the normal direction. In reverse, the benefit becomes a loss.
Roy
|
Re: Gear reduction for real Bull lathe.
That's why I weasel worded what I posted! The controllers are standard commercial units, they're presumably set up to work with any suitably sized motor without damaging either the motor or controller. Reducing reverse speed satisfies that requirement.
Roy
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--- In 7x12minilathe@..., "Robert Furmanak" <rfurmanak@...> wrote:
That may be true on some motors. However, my gear reducer lacks John's
idler, and I have been running my lathe motor in reverse for 3 years now
without any ill effect. My motor, which is a 350 watt motor off of a Sieg
Mini Mill, appears to run equally well in both directions.
Robert
From: 7x12minilathe@... [mailto:7x12minilathe@...]
On Behalf Of Roy
Sent: Sunday, May 19, 2013 9:19 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.
Some of the controllers are set up to add a speed limiting resistor in
reverse. That's supposedly because the brushes are advanced a few degrees to
improve efficiency when the motor is running in the normal direction. In
reverse, the benefit becomes a loss.
Roy
--- In 7x12minilathe@...
<mailto:7x12minilathe%40yahoogroups.com> , Jerry Durand <jdurand@> wrote:
On 05/19/2013 12:14 AM, John Lindo wrote:
My arrangement differs as an idler gear has to be incorporated into
the the assembly so as the spindle rotates in the normal anti clockwise
direction without having to have the machine set in reverse.For some
reason,Real Bull lathes have a common problem of slower RPM when in
reverse.
Why not just swap the + and - wires to the motor so it runs the other way?
--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
Threading Dial Turns and Doesn't Turn
Hello Again,
HF's shows to keep the dial disconnected until you need it. Is that correct to keep it backed off, disengaged while not threading?
Next, when I adjusted it to be engaged, it spins when I turn the crank as well as when the lathe running and the lead screw turned on but the half nut is disengaqed. When engaging the half nut, the dial stops spinning. Should the dial stop spinning when the half nut is engaged? I searched for videos and only 1 showed the dial but wasn't clear to see it for the 2 seconds it showed.
Thanks
|
Re: Tails from the newbies...
--- In 7x12minilathe@..., "cptwinderatgmaildotcom" <cptwinder@...> wrote:
As some of you may know, I purchased a 7x10 lathe a couple years ago and a G0704 mill just recently. Up until about 6 months ago my "shop" was a 7'x7' Rubbermaid shed. Not a lot of room so not a lot of time spent in it.
Six months ago I was able to move into a bigger house, with a bigger yard, and a bigger shed. My "shop" is now a 24'x12' wood and tin shed. I have been spending most of my free time running 150 amp circuit to the shed and running multiple 20 amp circuits to each wall, installing lights, etc.
What little machining I have been able to get in since the purchase of the lathe has been primarily aluminum. It took me a few tries, but I made a new front sling lug for my Bushmaster AR-15. I also used the mill to turn a piece of round bar stock square. I know, I'm a master machinist now ;)
So last night, I figured I would create a test bar for aligning the tail stock on the lathe. I sure hope future projects go smoother.
First I screwed my pawnshop-special grinder to the bench, found a box roughly big enough to use for a rest and set out to grind my first lathe cutter. I have come to the realization that 1/8" HSS cutters are going to be more frustration then they are worth, more on this later. After what seemed like an hour, I had a cutter with roughly the angles described all over the web. I say roughly because I had about a dozen additional facets; but the angles seemed correct at the cutting point. I then used a diamond file to remove burs and to round the tip.
I roughly centered the tail stock by visually lining up the points of the centers. Then re-installed my 3-jaw chuck. Luckily the bar I picked up at Home Depot fit not only through the spindle, but the chuck center hole as well. I say luckily because I just grabbed a piece out of the bin and was surprised that it barely fit; but fit. I didn't even think about it having to fit through these holes when I grabbed it.
While attempting to face off both ends, it became abundantly clear that the 1/8" tool holders I'm using stick out way to far for any rigidity. I'm using these, for those that want to avoid my mistakes. If I make a cut any deeper than .001 the tool digs in and about rip the compound off. Ok, that is a little dramatic! But there was visible rocking in the rigidity of the cross slide, compound, and tool holder.
Yes, it could have been my grinding job on the cutter. It could be I have the cross slide gibs too loose. It could be a lot of things, I just do not know for sure. If there is a machinist in Columbus, Georgia that wants a case of beer or a steak dinner in trade for a couple hours of looking over my shoulder, email me directly.
After facing both sides I moved on to center drilling them. This was equally as eventful. I believe the bar I used was 5/16". I can't verify the size, as I am not currently at the house. However, I attempted to use a #4 center drill; my thought being, more surface on the center the better. I have read/heard several times that the lathe will tell you when something is wrong. She does!! The scream she let out as I neared the end of the taper, you would have thought I had a small girl strapped to the bench and cutting off her fingers one at a time. Cutting oil didn't help either. On the second side, I discovered that as long as I kept pressure on the center drill it cut with no screaming. As soon as I would stop the pressure, screaming.
At this point, I'm dripping sweat as if I was in a sauna(shed isn't insulated yet and I'm 380 lbs and not use to with kind of physical labor). I'm waiting for the police to show up to investigate the screaming girl without fingers. I remove the drill and 3-jaw chucks, re-install the centers. Attempted to put my newly faces and center drilled test bar between them, and...
I do not know how many times I've read on these forums that the 7x10 is really a 7x8. But when I hacksawed the bar to the length I needed, I cut it 8" long figuring it would be 2" short and make it easy to flip the ends back and forth while taking measurements to center the tail stock. In order to get my bar between the centers, I have to loosen the tail stock and slide it almost off the ways. Ok, minor inconvenience, trudging on!
I get my bar setup between the centers, lock down the tail stock, give the tail stock wheel a turn to ensure the centers are well seated. Start the lathe going, start to advance the cutter, then "wait a minute, this isn't going to work" says one of the voices in my head. I forgot the faceplate and lathe dog.
Shutting down the lathe, loosening the tail stock, removing my test bar, I install the faceplate. Get everything set back up and was about to hit the power button... I forgot the lathe dog. It's getting late, I'm tired, sweaty, and just plain not thinking. If I was at work, I would be calling it a night before I did something really stupid, like "rm -rf *" in the root directory. For those none computer people, that would remove every file on the server.
I once again, loosened the tail stock, removed my test bar, grabbed the lathe dog... Ya, that dog won't hunt! It is too small!
At this point I gave up...
I'm not sure if I can drill out the dog I have to fit or if I'll have to make a new one. Either way, new project on the list of projects need for the projects need for the project.
Wow you are just scaring yourself. My suggestion is to google the " little machine shop.com run it altogether. There you will find on that page information and go to each of these sites. Read this material over. Download these to word and save it and print out a manual. Since you have a small machine and have not used it and just getting back into machine work you will notice that after checking out the sites that you could actually take that small lathe and turn it into a 7 x 14 at least by just buying the bottom unit. That way you will learn everything there is about your machine and how to do your turning without all that screaming. Doc Ferguson
|
Re: Spindle Lopes and Clicks when Rotating
Actually, after I took the back cover off, electronics cover off, rear gears off and lead screw off, just to adjust the belt, all I had left to do was to take out the 3 screws that hold the headstock off. I read those 3 screws are really tight and need a leverage bar so I decided to pass on that for now. That idea to spray some white grease in the holes sounds like a good idea to me.
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., "Roy" <roylowenthal@...> wrote:
Taking the headstock off looks like it would be harder than it actually is!
Roy
--- In 7x12minilathe@..., "newmachineshop" <dieselm@> wrote:
I just tried it and moved the hi-low lever all the way to lo while turning the spindle by hand so the teeth engaged. Ran it very low speed on the speed dial just to when I heard the clicking/thunking noise. When I hear the thunk, I can see the drive belt flex. Turned off the unit, changed the hi-lo lever to high and started it up again, and it's much louder. I don't think this will break in. I'm not looking forward to taking the entire headstock off.
Thanks
--- In 7x12minilathe@..., gerry waclawiak <gerrywac@> wrote:
There is no detent to hold the lever in position so when you change gear you need to make sure that the lever moves fully left or right.
You are right in not trying to change gear whilst the lathe is running, that could lead to breaking the gears.
The best way to change and ensure full movement is to rotate the chuck slowly by hand in the normal direction whilst changing the lever and it should move fully one way or the other
The noise is possibly that the gears are new and not run in. Most lathes have plastic gears but some have metal which are naturally noiser.
I would suggest that provided nothing is locking or grinding that you run the lathe for a while to give the gears a chance to mesh and run in and things should improve.
You might also like to check the positioning of the lever for the auto feed. Often the detent positions for that lever (dimples in the headstock casting) are poorly defined and the change gears might be rubbing slightly.
If there is something else in the speed change mechanism it is really a head off job.
Gerry W
Leeds UK
If this doesn't work it is realy
To: 7x12minilathe@...
From: dieselm@
Date: Sun, 19 May 2013 13:37:56 +0000
Subject: [7x12minilathe] Spindle Lopes and Clicks when Rotating
Hello,
First, I'd like to thank everyone that has answered my questions!!
I've run into my first problem with the HF 7x12 Mini-lathe. When I rotate the spindle/chuck it doesn't always rotate smooth. I can feel high spots or loping. After rotating it for awhile by hand, it seemed to get smooth. I took the cover off the threading/power feed gear area. I have the spindle direction lever in neutral so the gears aren't engaged. I tried running the unit for a couple seconds and I hear a clicking noise so shut it off. The HI-LOW lever seems to stop in different positions. NO, I didn't try to change it while running. Sometimes the lever moves all the way towards the tailstock and touches the housing and sometimes it stops an inch short of it. Moving it either way doesn't make the spindle rotate smooth.
Any ideas what I need to look at or do I need to take the entire headstock off to access the hi-low system? I don't see anyway to access that lever.
Thanks
|
Re: Lathe Cutter Starter Set
Part of it is the difficulty most folks have with visualizing 3 dimensional objects. There's a classic puzzle with 3 holes; a circle, a square & a triangle, all with the same major size. Very few people can visualize or describe the object that fits all 3 holes. When I presented it to my engineering classmates, the only one who figured it out was a female who'd been a successful draftsman (draftsperson?) before she got the chance to go to college.
Roy
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--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...> wrote:
And I, who started running metal cutting engine lathes at age 18 in 1947, use carbide tooling, even the el cheapo brazed on stuff, after I've sharpened it, even on my little Unimat DB, but only on occasion, when it seems the best choice. I mostly use HSS toolbits because I can buy a couple of pounds of used ones for a dollar. This makes a lot of HSS available for grinding special form tools as well as ordinary cutters. The first job given to me back there in 1947, was grinding a HSS toolbit to proper shape from a blank. In the time when I taught machine tool class, that was the second job my kids got before they were allowed to use a lathe. The first one was to sand a proper shape on a wooden blank. I was surprised to learn that most kids could not read English nor understand an isometric drawing. 90% of 'em had to be shown. Seems that it is still true of a lot of first time lathe owners. Full disclosure: I started on wood turning lathes before I was a teenager. 11, if I remember.
Mert
-----Original Message-----
From: 7x12minilathe@... [mailto:7x12minilathe@...]On Behalf Of michael kolchins
Sent: Saturday, May 18, 2013 8:34 PM
To: 7x12minilathe@...
Subject: Re: [7x12minilathe] Re: Lathe Cutter Starter Set
I am a home shop machinist like most of us. I printed out the post from the fella that claims HSS doesn't compare to carbide inserts. I stopped at my nephews shop, he and several other family members are machinists,have been for 3 generations now.
They actually laughed at the post.They use both HSS and carbide inserts depending on the job at hand.
Tom said he uses HSS probably 90% of the time.I won't say what they actually said of the post as Mom used to say "If you can't say something nice ,keep your mouth shut"
Personally I have a set of insert tooling that I used a couple of times,not carbide but HSS. I was taught how to grind HSS and for me it is the first choice. I also have a 10x22 lathe that I have only used HSS.
Mike
----------------------------------------------------------------------------
From: gerry waclawiak <gerrywac@...>
To: "7x12minilathe@..." <7x12minilathe@...>
Sent: Saturday, May 18, 2013 12:37 PM
Subject: RE: [7x12minilathe] Re: Lathe Cutter Starter Set
I was thinking exactly the same thing Tony
The relevance of professional machinists and their precision production machinery and is a long way from the world of hobby machinists and Chinese low cost, relatively low precision and fit Hobby Machines making one off projects for their own enjoyment..
Most of my work is fairly low precision and on everyday materials normal steel, cast iron, bronze, brass, various plastics and HSS is perfectly satisfactory and a couple of dollars of tool will last years of sharpening.
The techno babble doesn't impress me much either but I'm just a hobby machinist doing it for the fun so maybe my opinion doesn't matter
Gerry W
Leeds UK
----------------------------------------------------------------------------
To: 7x12minilathe@...
From: ajsmith1968@...
Date: Sun, 19 May 2013 01:15:07 +1000
Subject: RE: [7x12minilathe] Re: Lathe Cutter Starter Set
> I dont see any benefit in using HSS UNLESS -special thread forms -very
high
> end finishing at high rpm and very low cut depth
>
> Inserts require a good lathe fit - no slop. Thats all. So does ANY level
of
>
> Just my opinion, shared by just about 100% of professional turners and
> workshops today.
> Of the 19.998 workshops (my industrial contacts database, fwiw) and
>
> I am making custom (high resolution high accuracy) dies now.
> 20 mm D, 0.25 mm rise (about 100 tpi), trapezoidal thread. Lapped. For
sub-
> micron linear stage adjusters, and optronics control gear.
> --
> -hanermo
Have you ever read the name (or purpose) of this group?
Tony
|
Re: Spindle Lopes and Clicks when Rotating
There's a design for an improved motor mount, based on a gate hinge, in the "files" section.
Roy
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Show quoted text
--- In 7x12minilathe@..., "newmachineshop" <dieselm@...> wrote:
Solved!!! Belt was loose and was skipping a tooth. Couldn't see it until I removed the gears on the back then the back housing. Adjusting it is a chore as when I tighten the 2 nuts, the motor shifts up and puts the slack back into the belt. There's some type of gib screw between the screws I'll have to see if it affects the adjustment.
Thanks
P.S. From what I've read, taking of the headstock to grease the gears wouldn't be a bad idea and may be necessary in the future unless they're greasing that properly these days since that doc was written about several years ago.
--- In 7x12minilathe@..., gerry waclawiak <gerrywac@> wrote:
There is no detent to hold the lever in position so when you change gear you need to make sure that the lever moves fully left or right.
You are right in not trying to change gear whilst the lathe is running, that could lead to breaking the gears.
The best way to change and ensure full movement is to rotate the chuck slowly by hand in the normal direction whilst changing the lever and it should move fully one way or the other
The noise is possibly that the gears are new and not run in. Most lathes have plastic gears but some have metal which are naturally noiser.
I would suggest that provided nothing is locking or grinding that you run the lathe for a while to give the gears a chance to mesh and run in and things should improve.
You might also like to check the positioning of the lever for the auto feed. Often the detent positions for that lever (dimples in the headstock casting) are poorly defined and the change gears might be rubbing slightly.
If there is something else in the speed change mechanism it is really a head off job.
Gerry W
Leeds UK
If this doesn't work it is realy
To: 7x12minilathe@...
From: dieselm@
Date: Sun, 19 May 2013 13:37:56 +0000
Subject: [7x12minilathe] Spindle Lopes and Clicks when Rotating
Hello,
First, I'd like to thank everyone that has answered my questions!!
I've run into my first problem with the HF 7x12 Mini-lathe. When I rotate the spindle/chuck it doesn't always rotate smooth. I can feel high spots or loping. After rotating it for awhile by hand, it seemed to get smooth. I took the cover off the threading/power feed gear area. I have the spindle direction lever in neutral so the gears aren't engaged. I tried running the unit for a couple seconds and I hear a clicking noise so shut it off. The HI-LOW lever seems to stop in different positions. NO, I didn't try to change it while running. Sometimes the lever moves all the way towards the tailstock and touches the housing and sometimes it stops an inch short of it. Moving it either way doesn't make the spindle rotate smooth.
Any ideas what I need to look at or do I need to take the entire headstock off to access the hi-low system? I don't see anyway to access that lever.
Thanks
|
Re: Gear reduction for real Bull lathe.
I've heard time and time again, the motors being set to run in
the"main" direction, but never have I seen it documented by the
equipment manufacturer. I think it's an old wives tale!
On 05/19/2013 08:19 PM, Roy wrote:
toggle quoted message
Show quoted text
?
Some of the controllers are set up to add a speed
limiting resistor in reverse. That's supposedly because
the brushes are advanced a few degrees to improve
efficiency when the motor is running in the normal
direction. In reverse, the benefit becomes a loss.
Roy
--- In 7x12minilathe@...,
Jerry Durand wrote:
>
> On 05/19/2013 12:14 AM, John Lindo wrote:
> > My arrangement differs as an idler gear has to
be incorporated into
> > the the assembly so as the spindle rotates in
the normal anti clockwise
> > direction without having to have the machine set
in reverse.For some
> > reason,Real Bull lathes have a common problem of
slower RPM when in
> > reverse.
> >
>
> Why not just swap the + and - wires to the motor so
it runs the other way?
>
> --
> Jerry Durand, Durand Interstellar, Inc.
> tel: +1 408 356-3886, USA toll free: 1 866 356-3886
> Skype: jerrydurand
>
|
Re: Gear reduction for real Bull lathe.
That may be true on some motors.? However, my gear reducer lacks John’s idler, and I have been running my lathe motor in reverse for 3 years now without any ill effect.? My motor, which is a 350 watt motor off of a Sieg Mini Mill, appears to run equally well in both directions. ? Robert ? ?
toggle quoted message
Show quoted text
From: 7x12minilathe@... [mailto:7x12minilathe@...] On Behalf Of Roy
Sent: Sunday, May 19, 2013 9:19 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Gear reduction for real Bull lathe.? ? Some of the controllers are set up to add a speed limiting resistor in reverse. That's supposedly because the brushes are advanced a few degrees to improve efficiency when the motor is running in the normal direction. In reverse, the benefit becomes a loss.
Roy
--- In 7x12minilathe@..., Jerry Durand <jdurand@...> wrote:
>
> On 05/19/2013 12:14 AM, John Lindo wrote:
> > My arrangement differs as an idler gear has to be incorporated into
> > the the assembly so as the spindle rotates in the normal anti clockwise
> > direction without having to have the machine set in reverse.For some
> > reason,Real Bull lathes have a common problem of slower RPM when in
> > reverse.
> >
>
> Why not just swap the + and - wires to the motor so it runs the other way?
>
> --
> Jerry Durand, Durand Interstellar, Inc.
> tel: +1 408 356-3886, USA toll free: 1 866 356-3886
> Skype: jerrydurand
>
|
Re: Gear reduction for real Bull lathe.
Some of the controllers are set up to add a speed limiting resistor in reverse. That's supposedly because the brushes are advanced a few degrees to improve efficiency when the motor is running in the normal direction. In reverse, the benefit becomes a loss.
Roy
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., Jerry Durand <jdurand@...> wrote:
On 05/19/2013 12:14 AM, John Lindo wrote:
My arrangement differs as an idler gear has to be incorporated into
the the assembly so as the spindle rotates in the normal anti clockwise
direction without having to have the machine set in reverse.For some
reason,Real Bull lathes have a common problem of slower RPM when in
reverse.
Why not just swap the + and - wires to the motor so it runs the other way?
--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
|
Re: Spindle Lopes and Clicks when Rotating
Taking the headstock off looks like it would be harder than it actually is!
Roy
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., "newmachineshop" <dieselm@...> wrote:
I just tried it and moved the hi-low lever all the way to lo while turning the spindle by hand so the teeth engaged. Ran it very low speed on the speed dial just to when I heard the clicking/thunking noise. When I hear the thunk, I can see the drive belt flex. Turned off the unit, changed the hi-lo lever to high and started it up again, and it's much louder. I don't think this will break in. I'm not looking forward to taking the entire headstock off.
Thanks
--- In 7x12minilathe@..., gerry waclawiak <gerrywac@> wrote:
There is no detent to hold the lever in position so when you change gear you need to make sure that the lever moves fully left or right.
You are right in not trying to change gear whilst the lathe is running, that could lead to breaking the gears.
The best way to change and ensure full movement is to rotate the chuck slowly by hand in the normal direction whilst changing the lever and it should move fully one way or the other
The noise is possibly that the gears are new and not run in. Most lathes have plastic gears but some have metal which are naturally noiser.
I would suggest that provided nothing is locking or grinding that you run the lathe for a while to give the gears a chance to mesh and run in and things should improve.
You might also like to check the positioning of the lever for the auto feed. Often the detent positions for that lever (dimples in the headstock casting) are poorly defined and the change gears might be rubbing slightly.
If there is something else in the speed change mechanism it is really a head off job.
Gerry W
Leeds UK
If this doesn't work it is realy
To: 7x12minilathe@...
From: dieselm@
Date: Sun, 19 May 2013 13:37:56 +0000
Subject: [7x12minilathe] Spindle Lopes and Clicks when Rotating
Hello,
First, I'd like to thank everyone that has answered my questions!!
I've run into my first problem with the HF 7x12 Mini-lathe. When I rotate the spindle/chuck it doesn't always rotate smooth. I can feel high spots or loping. After rotating it for awhile by hand, it seemed to get smooth. I took the cover off the threading/power feed gear area. I have the spindle direction lever in neutral so the gears aren't engaged. I tried running the unit for a couple seconds and I hear a clicking noise so shut it off. The HI-LOW lever seems to stop in different positions. NO, I didn't try to change it while running. Sometimes the lever moves all the way towards the tailstock and touches the housing and sometimes it stops an inch short of it. Moving it either way doesn't make the spindle rotate smooth.
Any ideas what I need to look at or do I need to take the entire headstock off to access the hi-low system? I don't see anyway to access that lever.
Thanks
|
Re: Spindle Lopes and Clicks when Rotating
You need to remove the headstock to access the speed change gearing. On mine, the shift linkage needed some fiddling to get it give full gear engagement in both speeds. Since the shifter works by sliding straight toothed gears, it sometimes needs a little spindle rotation to get them aligned for full engagement.
Roy
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., "newmachineshop" <dieselm@...> wrote:
Hello,
First, I'd like to thank everyone that has answered my questions!!
I've run into my first problem with the HF 7x12 Mini-lathe. When I rotate the spindle/chuck it doesn't always rotate smooth. I can feel high spots or loping. After rotating it for awhile by hand, it seemed to get smooth. I took the cover off the threading/power feed gear area. I have the spindle direction lever in neutral so the gears aren't engaged. I tried running the unit for a couple seconds and I hear a clicking noise so shut it off. The HI-LOW lever seems to stop in different positions. NO, I didn't try to change it while running. Sometimes the lever moves all the way towards the tailstock and touches the housing and sometimes it stops an inch short of it. Moving it either way doesn't make the spindle rotate smooth.
Any ideas what I need to look at or do I need to take the entire headstock off to access the hi-low system? I don't see anyway to access that lever.
Thanks
|
Re: Why does the finish look like this?
Thanks to everyone who replied!
The piece is about 2.375"x4" and I was not using the tailstock (I still need to cut down my drill chuck arbor to fit into the tailstock.)
I am going to try using the tailstock and making a pass to see how it turns out. If this solves it i'll be ordering the 4" 4-jaw along with a QCTP from LMS.
Thanks again!
toggle quoted message
Show quoted text
--- In 7x12minilathe@..., "Robert Furmanak" <rfurmanak@...> wrote:
My interpretation of your pictures is that the work piece is flexing and vibrating. The reason I say that is that your surface may be rough, but it is also quite shiny, as opposed to the dull finish I get on some hard to machine alloys. There also seems to be a repeating pattern in your finish, another sign of the work piece flexing. It appears that your work piece is relatively long, because I can see one of the lathe bed ribs in the background. I am guessing it is the second rib, which makes your piece about 6 inches long? That is too long without using the tailstock or a steady rest. Also, it appears your diameter is maybe 2 inches? In any event, it is too large to fit inside the chuck?�?s center hole, which means that your work piece is supported only by the small gripping area of the jaws in front of the chuck. That is especially true if you are using the outside chuck jaws. The little staircase portions of the outside jaws are very small for holding a piece this big and long. If you plan on doing a lot of work with pieces this size, perhaps you should buy a 4 inch 4 jaw chuck like this one:
<> &category=
Regards,
Robert
_____
From: joeelmendorf <josepilove@...>
To: 7x12minilathe@...
Sent: Sunday, May 19, 2013 1:56 AM
Subject: [7x12minilathe] Why does the finish look like this?
I am very new to turning (got my lathe last week) and I am curious why the aluminum is looking like it does.
I ground my own HSS tool (but also got the same from an indexible carbide tool) by hand. I tried it on some steel after and it looked normal.
I used the power feed with the stock gearing and tried a bunch of different RPMs (from 70-700). I also tried without power feed and there wasn't any difference.
I bought this piece of stock from a local metal shop and it was advertised as 7075, but since it was usable drop/scrap there are no markings on it.
Also worth noting, the chips are VERY jagged.
photo16CFB264-EA3B-4537-B8AE-653805281A4E.jpg <>
FYI: the finish on the left is what I am taking about (it should be smooth). The right is my attempt at threading.
Any help in identifying what I am doing wrong would be greatly appreciated!
Thanks!!
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Re: Why does the finish look like this?
Nope. Ann Arbor, MI.
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--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...> wrote:
Are you anywhere near central MA, Joe?
Mert
-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of joeelmendorf
Sent: Saturday, May 18, 2013 7:56 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] Why does the finish look like this?
I am very new to turning (got my lathe last week) and I am curious why the
aluminum is looking like it does.
I ground my own HSS tool (but also got the same from an indexible carbide
tool) by hand. I tried it on some steel after and it looked normal.
I used the power feed with the stock gearing and tried a bunch of
different RPMs (from 70-700). I also tried without power feed and there
wasn't any difference.
I bought this piece of stock from a local metal shop and it was advertised
as 7075, but since it was usable drop/scrap there are no markings on it.
Also worth noting, the chips are VERY jagged.
FYI: the finish on the left is what I am taking about (it should be
smooth). The right is my attempt at threading.
Any help in identifying what I am doing wrong would be greatly
appreciated!
Thanks!!
|
Re: Gear reduction for real Bull lathe.
I don't know this product, but I do know that if the motor has
either lead strapped to ground or common, swapping the red and black
wire blindly may well release the "magic blue smoke".....
....magic blue smoke is essential for the motor speed controller
operation.....
....replacement magic blue smoke is NOT available from Little
Machine Shop....only replacement motor controllers.....
One would certainly need to check the schematics, service manual,
and even using an ohmmeter, check and see that neither terminal is
commoned to the ground, chassis, or one side of the power supply.
I would strongly suggest checking with an expert on that machine or
proceed with extreme caution if blindly moving forward....
If it is a true DC motor, and there is no ground path, only the
motor load, it is certainly possible that this will work without
damage.
Warren
On 5/19/2013 2:10 PM, John Lindo wrote:
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?
Jerry
I have something?lodged?in the back of my brain, that?I have read
somewhere not to
swap the wires.
I am no electronics boff,and tend to leave
PCB's etc well alone.If I don't see it move,I tend
to leave it to experts in?their?field.
Maybe you or other members can spread more
light on this.
Also I never really got from the forum many
months ago,a reasonable answer as to why when the
switch on the control box is turned to reverse,?
the Real Bull lathes run slower.
Siegs I believe do
not seem to have that problem.
The idler set up is no show stopper at the
moment,and fits into the total package nicely.
John L
Spain.
From:
Jerry Durand
To:
7x12minilathe@...
Sent:
Sunday, May 19, 2013 5:22 PM
Subject:
Re: [7x12minilathe] Gear reduction for real
Bull lathe.
?
On 05/19/2013 12:14 AM, John Lindo
wrote:
My
arrangement differs as an idler gear
has to be incorporated into the the
assembly so as the spindle rotates in
the normal anti clockwise
direction
without having to have the
machine set in reverse.For
some reason,Real Bull lathes
have a common problem of
slower RPM when in reverse.
Why not just swap the + and - wires to the
motor so it runs the other way?
--
Jerry Durand, Durand Interstellar, Inc.
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand
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IMO, high speed, VERY shallow cuts. Concentrics expose the cutting tool to alternating shock forces rather than constant pressure and any play in the tool holding/driving mechanisms will show up on the work, looking something like a chatter trail.
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--- In 7x12minilathe@..., "imadgets" <shasabolton@...> wrote:
OK I admit I've always been eccentric.
But I would like some advice on turning eccentric. (On the mini Lathe)
I am turning the outside of an off centered brass cylinder in the 4 jaw chuck such that only half of the revolution is making a cut. This is for my beginner small elmers wobbler engine project.
I am getting heaps of chatter. I got it down to size eventually but the process did not feel ideal.
I have adjusted the cross slide nut to remove pretty much all backlash.
Any advice?
Fast or slow speed?
Face or turn the bulk of the cut?
Cutting depth?
etc
Thanks alot
Shasa
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Re: Standard Carriage Lock used with Milling attachment
I don't have the LMS milling attachment, but a Palmgren milling attachment, which is bigger and has more capacity (and I got used for about the price of the LMS milling attachment). ?The LMS design looks pretty good, and it also has a built-in angle block attachment to use it on the cross slide, which I had to make for the Palmgren.
However, a minilathe is so small that it's going to have problems with any milling attachment. ?The reason they hang off the left side of the cross slide is that if they didn't, they wouldn't be able to move down BELOW the level of the cross slide, so their range would be very restricted. ?But putting anything heavy in the the milling attachment's vise unbalances the cross slide's weight so much that it leans to one side, is very unsteady, etc.
I solved that problem by adding a second threaded shaft that goes from the vise of the milling attachment itself down to a flat steel surface (a piece of key stock) on the lathe bed. ?I made the threaded shaft on the device 20-tpi, because that's the thread of the Palmgren's vertical adjustment, so I could ?adjust the height of the vise by turning both shafts the same amount. ?For the LMS unit, you'd want a 1.5mm thread to match the vertical-adjustment thread of that unit. ?
Having both the milling attachment and the vise supported separately improves the performance of the milling attachment tremendously, because the cross slide only has to move the milling attachment and doesn't have to also support its weight. ? You could easily make something similar for the LMS milling attachment.
Thinking it over now, I spent a lot of the time MAKING a long 20-tpi shaft, and there was no need for it. ?I could have just used suitable threaded rod, and you can too. ? Also, I graduated the top of the shaft I made so I could reliably turn the shaft to the vise the same amount I raised the vertical adjustment of the milling attachment. ?Another (and perhaps better) way to do this would be to put an indicator on the right of the cross slide measuring the distance to the bed, and looking at this to raise the vise and the milling attachment the same amount.
Here's a photo of the device I made. ?There are several more in the photo section in the folder "Mike T's stuff."
Mike Taglieri
On Sun, May 12, 2013 at 6:50 PM, Michael Jablonski <michaeljab@...> wrote:
?
I
finally took my milling attachment out of the box and cleaned it up today.
Removed the compound slide and the lower dovetail swivel from the
cross slide.
Mounted the milling attachment.
?
My
first impressions confirmed my original thoughts. That being that I should have
put the money I spent on the lathe's milling attachment towards a new mini
mill.
?
I'm
not sure why they hang the milling attachment so far over the left side of the
cross slide. This just gives it more leverage to flex. There are three mounting
holes in the base on my milling attachment, but only two screws, and two
threaded screw holes to thread into on the cross slide swivel. Maybe the third
hole comes into play on a lathe other than the 7X.
?
The
standard carriage lock that is available for purchase which mounts on the left
side of the saddle interferes with the milling attachment. You cannot move the
cross slide in. The milling attachment hits the handle of the lock, preventing
it from being usable.
?
The
milling attachment's vertical slide lock is so long that even when the slide is
locked, there is maybe 3/8 - 1/2 inch of thread left. I'll probably take some
measurements and cut this down to size. Not a big deal, but just one more reason
not to bother with the milling attachment in the first
place.
?
The
three screws they use to hold a work piece in the so called vise leave about
5/8" opening when tightened down as far as they will go. So if you want to mill
something less than 5/8" you will need to use a spacer block. Also the threaded
holes for these screws seemed a bit sloppy. The screws have a pretty good wobble
in these threaded holes. Maybe I'll make the holes larger and thread them to a
larger size.
?
I'll
need to remove the standard carriage lock and ?temporarily use it on the right side of the saddle. This will
mean removing the milling attachment first. Not easy for me with my limited
strength. The milling attachment is pretty heavy. LMS shows it having a 12 pound
shipping weight. No problem for most people, but a big deal for
me.
?
Anyway, that's how I spent my Mother's Day afternoon.
?
Footnote: all dimensions are estimates. I didn't measure anything
once I realized it wasn't going to be used today.
Michael - USA
Micro-Mark MicroLux
7x16
?
?
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OK I admit I've always been eccentric.
But I would like some advice on turning eccentric. (On the mini Lathe)
I am turning the outside of an off centered brass cylinder in the 4 jaw chuck such that only half of the revolution is making a cut. This is for my beginner small elmers wobbler engine project.
I am getting heaps of chatter. I got it down to size eventually but the process did not feel ideal.
I have adjusted the cross slide nut to remove pretty much all backlash.
Any advice?
Fast or slow speed?
Face or turn the bulk of the cut?
Cutting depth?
etc
Thanks alot
Shasa
|
Re: Lathe Cutter Starter Set
i bought lms's starter kit and it came with the carbide set. not sure why it comes with the carbide but i'm now wishing it had the hss set.
i guess i will have to get a hss set so any recommendations ?
i got this?
=
?
thanks,
george
?
From: MERTON B BAKER
To: 7x12minilathe@...
Sent: Sun, May 19, 2013 3:24:14 PM
Subject: RE: [7x12minilathe] Re: Lathe Cutter Starter Set
?
???
And I, who started running metal cutting engine lathes at age 18 in 1947, use carbide tooling, even the el cheapo brazed on stuff, after I've sharpened it, even on my little Unimat DB, but only on occasion, when it seems the best choice.? I mostly use HSS toolbits because I can buy a couple of pounds of used ones for a dollar.? This makes a lot of HSS available for grinding special form tools as well as ordinary cutters.? The first job given to me back there in 1947, was grinding a HSS toolbit to proper shape from a blank.? In the time when I taught machine tool class, that was the second job my kids got before they were allowed to use a lathe.? The first one was to sand a proper shape on a wooden blank.? I was surprised to learn that most kids could not read English nor understand an isometric drawing.? 90% of 'em had to be
shown.? Seems that it is still true of a lot of first time lathe owners.? Full disclosure: I started on wood turning lathes before I was a teenager.? 11, if I remember.
?
Mert
?
I am a home shop machinist ?like most of us. I printed out the post from the fella that claims HSS doesn't compare to carbide inserts. I stopped at my nephews shop, he and several other family members are machinists,have been for 3 generations now.
They actually laughed at the post.They use both HSS and carbide inserts depending on the job at hand.?
Tom said he uses HSS probably 90% of the time.I won't say what they actually said of the post as Mom used to say "If you can't say something nice ,keep your mouth shut"
Personally I have a set of insert tooling that I used a couple of times,not carbide but HSS. I was taught how to grind HSS and for me it is the first choice. I also have a 10x22 lathe that I have only used HSS.
Mike
From: gerry waclawiak
To: "7x12minilathe@..." 7x12minilathe@...>
Sent: Saturday, May 18, 2013 12:37 PM
Subject: RE: [7x12minilathe] Re: Lathe Cutter Starter Set
?
I was thinking exactly the same thing Tony
The relevance of professional machinists and their precision production machinery and? is a long way from the world of hobby machinists and Chinese low cost, relatively low precision and fit Hobby Machines making one off projects for their own enjoyment..
Most of my work is fairly low precision and on everyday materials normal steel, cast iron, bronze, brass, various plastics and HSS is perfectly satisfactory and a couple of dollars of tool will last years of sharpening.
The techno babble doesn't impress me much either but
I'm just a hobby machinist doing it for the fun so maybe my opinion doesn't matter
Gerry W
Leeds UK
To: 7x12minilathe@... From: ajsmith1968@... Date: Sun, 19 May 2013 01:15:07 +1000 Subject: RE: [7x12minilathe] Re: Lathe Cutter Starter Set ?
> I dont see any benefit in using HSS UNLESS -special thread forms -very
high
> end finishing at high rpm and very low cut depth
>
> Inserts require a good lathe fit - no slop. Thats all. So does ANY level
of
>
> Just my opinion, shared by just about 100% of professional turners and
> workshops today.
> Of the 19.998 workshops (my industrial contacts database, fwiw) and
>
> I am making custom (high resolution high accuracy) dies now.
> 20 mm D, 0.25 mm rise (about 100 tpi), trapezoidal thread. Lapped. For
sub-
> micron linear stage adjusters, and optronics control gear.
> --
> -hanermo
Have you ever read the name (or purpose) of this group?
Tony
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Warren LeMay