You'd be surprised what a standard machinist level can do for you. I have a
Starrett master precision level as well as a ~6 inch Lufkin basic machinist
level without any graduations except the center. Honestly, I can get about the
same level out of both of them, if you have a good eye for symmetry (dividing
the bubble) you can too. OTOH, forget the Chinese knock-offs of the Starret
Master Precision. The vials in those are useless for anything other than
woodwork maybe.
> From: [email protected]
> Subject: Emc-users Digest, Vol 97, Issue 19
> To: [email protected]
> Date: Tue, 6 May 2014 15:22:32 +0000
>
> Send Emc-users mailing list submissions to
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> Today's Topics:
>
> 1. Re: Question re crooked headstock (Gene Heskett)
> 2. Re: Question re crooked headstock (Gregg Eshelman)
> 3. Re: Question re crooked headstock (Gene Heskett)
> 4. Re: Question re crooked headstock (andy pugh)
> 5. Re: Question re crooked headstock (Eric Keller)
> 6. Re: Question re crooked headstock (andy pugh)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 5 May 2014 22:33:09 -0400
> From: Gene Heskett <[email protected]>
> Subject: Re: [Emc-users] Question re crooked headstock
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: Text/Plain; charset="windows-1256"
>
> On Monday 05 May 2014 22:13:12 Steve Blackmore did opine:
>
> > On Mon, 5 May 2014 04:48:55 -0400, you wrote:
> > >I suggested that a heavy steel bar, a 1x6 wide, nominally 24" long, to
> > >help stiffen it up, and was told its a never mind. By someone on this
> > >list about 2 coons ages ago. Whether I could find another at the
> > >scrap/recycle yard about 50 miles away, I haven't looked. As for
> > >added stiffness, I don't think a 1/4" plate would do anything but
> > >change the resonant frequency, probably down in pitch because its more
> > >mass than stiff at that thickness. (IMO)
> >
> > Steel plate stops the feet sinking in the wood/mdf and allows shimming
> > without it just sinking in.
> >
> > >But its certainly better advice now, having lived with it, sitting on
> > >that mdf in 2 locations now and never getting a straight turn out of
> > >it.
> >
> > MDF and just two bolts - no wonder it turns tapered :) Needs to be
> > bolted down to something rigid enough to enable you to pull the twist
> > out of the bed. It will have one - no doubt. The casting weren't
> > weathered before machining, It will have been clamped down to some
> > dubious surface, machined then ground, both releasing stresses and when
> > unclamped it twists and bends.
> >
> > My lathe came with it's own stand, it had a nice heavy cast top but it
> > was far too big for the available space, so I made my own. My stand is
> > 3" box section welded up, 10mm steel top with drip tray sandwiched
> > between lathe feet and top. I put a shelf in there and it has steel
> > panels bolted to sides and back.
> >
> > One of the best buys I made was a boxed Starrett Model 98 level, only
> > paid ?50 for it and some other tools from a Snooker table
> > repairers/installers that shut down :) Multiple graduations are 5 thou
> > per foot and you can get damned close with a good level alone.
> >
> > My method is use the level to get it even at headstock and tailstock
> > ends, then use taper turning test to get it spot on. My lathe/stand
> > isn't level, it tilts forward and towards the tailstock, otherwise
> > coolant doesn't drain - but it has no twist so turns true.
> >
> > Steve Blackmore
> > --
>
> I'll restart my search for a suitable piece of 1 by steel. The first place
> I'll look, after I get my GMC inspectable again (terminal rust of rocker
> panels, minor crack in windshield its had for a decade) has about 50
> kilotons of magnetic scrap. They surprised me several years ago when I was
> lamenting that what I really needed was a solid block of alu I could saw
> the makings from. He went behind the scales & came out lugging one piece,
> about 50 lbs, roughly 6" square cross-section and around 2 feet long,
> obviously band sawed from a much larger 6" thick sheet. $1 a lb, I still
> have perhaps 10 lbs of it left. Not very hard stuff, a bit gummy to
> machine, but hey, it works. No level that accurate though. Set it on 3"
> studs, nut and washer below, nut and washer above, using them for jacking
> screws I could pull it whichever way reduces the error. Or bolt it down on
> shimstock. That would be more rigid than 1/2" studs, but that stuff is
> hard to come by these days, as the only old chevy's with Christian Science
> oil are the ones you see at antique car shows. And the last mechanic that
> knew how to fit chevy's rods dies in the 70's. :)
>
> Thanks Steve.
>
> Cheers, Gene
> --
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 06 May 2014 00:38:40 -0600
> From: Gregg Eshelman <[email protected]>
> Subject: Re: [Emc-users] Question re crooked headstock
> To: "Enhanced Machine Controller \(EMC\)"
> <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> On 5/5/2014 2:48 AM, Gene Heskett wrote:
>
> > But its certainly better advice now, having lived with it, sitting on that
> > mdf in 2 locations now and never getting a straight turn out of it. I have
> > looked carefully at where the headstock is sitting on the bed, and can't
> > see any evidence of debris holding it apart anyplace. But that only says I
> > can't see it even if its there.
>
> I had two 7x lathes. One was an early Grizzly import, serial number 346
> IIRC. The thing was a cast iron turd. It had been abused (apparently
> with hammers etc.) by previous owners.
>
> I took it all apart, repaired the damage, did a few modifications, and
> made it into a usable lathe.
>
> Its largest problem was one corner of the headstock had been dinged some
> time after its bottom had been machined, leaving a raised edge. Another
> problem was the edges of the three bolt holes in the bed were raised. A
> file and a countersink took care of those and a rag wiped off the pieces
> of crud that were trapped between. After that that lathe cut very well.
>
> Didn't help the crude SCR chopper driver and its lack of torque at low
> RPM but it did the jobs I needed it to do.
>
> The other one was a Homier, one of their early imports, though much much
> later than when Grizzly started.
>
> There's a version of the 7x out there which is quite a bit higher
> quality than the usual version. It has a double ball bearing on the
> carriage wheel shaft, the apron is thicker to accommodate the bearings.
> The saddle is rectangular, heavier than the other version's H shape, and
> machined all over. It also has four headstock bolts VS three, way wipers
> on the saddle and an adjustable nut with a set screw in its end to take
> up any axial movement in the leadscrew.
>
> The original Homier 7x was that version and it was pretty much ready to
> go out of the box.
>
>
> ---
> This email is free from viruses and malware because avast! Antivirus
> protection is active.
> http://www.avast.com
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 6 May 2014 08:32:22 -0400
> From: Gene Heskett <[email protected]>
> Subject: Re: [Emc-users] Question re crooked headstock
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: Text/Plain; charset="windows-1256"
>
> On Tuesday 06 May 2014 08:00:29 Gregg Eshelman did opine:
>
> > On 5/5/2014 2:48 AM, Gene Heskett wrote:
> > > But its certainly better advice now, having lived with it, sitting on
> > > that mdf in 2 locations now and never getting a straight turn out of
> > > it. I have looked carefully at where the headstock is sitting on the
> > > bed, and can't see any evidence of debris holding it apart anyplace.
> > > But that only says I can't see it even if its there.
> >
> > I had two 7x lathes. One was an early Grizzly import, serial number 346
> > IIRC. The thing was a cast iron turd. It had been abused (apparently
> > with hammers etc.) by previous owners.
> >
> > I took it all apart, repaired the damage, did a few modifications, and
> > made it into a usable lathe.
> >
> > Its largest problem was one corner of the headstock had been dinged some
> > time after its bottom had been machined, leaving a raised edge. Another
> > problem was the edges of the three bolt holes in the bed were raised. A
> > file and a countersink took care of those and a rag wiped off the pieces
> > of crud that were trapped between. After that that lathe cut very well.
> >
> > Didn't help the crude SCR chopper driver and its lack of torque at low
> > RPM but it did the jobs I needed it to do.
> >
> > The other one was a Homier, one of their early imports, though much much
> > later than when Grizzly started.
> >
> > There's a version of the 7x out there which is quite a bit higher
> > quality than the usual version. It has a double ball bearing on the
> > carriage wheel shaft, the apron is thicker to accommodate the bearings.
> > The saddle is rectangular, heavier than the other version's H shape, and
> > machined all over. It also has four headstock bolts VS three, way wipers
> > on the saddle and an adjustable nut with a set screw in its end to take
> > up any axial movement in the leadscrew.
>
> I have none of that stuff. I have even contemplated making a new saddle,
> but there isn't enough bed width to make it worthwhile. But now that I
> have cut up part of that hat, I might consider bed wipers.
> >
> > The original Homier 7x was that version and it was pretty much ready to
> > go out of the box.
>
> Probably even Homier's is the junk model today. Not even listed on their
> site, I just checked. I see the Bolton 11x28 is on sale now, $2588+ship.
> They don't some with any "accessories" though, so first extra is a bigger 4
> jaw, and a decent tool post. $500. Or more. Nearly 500 lbs, should be
> stiffer. Site propaganda is amazingly devoid of real facts, mostly sales
> speak. 1.3 horse VS motor, 27" between centers, 1.5" spindle bore.
>
> Cheers, Gene
> --
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 6 May 2014 14:45:16 +0100
> From: andy pugh <[email protected]>
> Subject: Re: [Emc-users] Question re crooked headstock
> To: Steve Blackmore <[email protected]>, "Enhanced Machine
> Controller (EMC)" <[email protected]>
> Message-ID:
> <CAN1+YZUr=fp-b-bj-nhfi8iphxd639dfq4lbjjtc-uhd9bs...@mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On 5 May 2014 23:49, Steve Blackmore <[email protected]> wrote:
> > MDF and just two bolts - no wonder it turns tapered :) Needs to be
> > bolted down to something rigid enough to enable you to pull the twist
> > out of the bed.
>
> This does, of course, go against all the standard tenets of lathe
> design. Not unexpected for machines not manufactured with any
> consideration of lathe design, perhaps.
>
> My Rivett sits on two inset ball-bearings at the headstock end and a
> spherical washer at the tailstock end specifically to ensure that the
> support stand could have no influence on the shape of the bed.
>
> In the case of Gene's lathe it seems quite possible that the head
> simply isn't straight on the bed. It would be interesting to put a
> long bar in the chuck and see if it is possible to move the headstock
> about.
>
> --
> atp
> If you can't fix it, you don't own it.
> http://www.ifixit.com/Manifesto
>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 6 May 2014 10:57:32 -0400
> From: Eric Keller <[email protected]>
> Subject: Re: [Emc-users] Question re crooked headstock
> To: "Enhanced Machine Controller (EMC)"
> <[email protected]>
> Message-ID:
> <CANEU9UzAP=8d2opkar3mjn30rs7nwdffswmqjkh-mdo1+cg...@mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On Tue, May 6, 2014 at 9:45 AM, andy pugh <[email protected]> wrote:
>
> >
> > This does, of course, go against all the standard tenets of lathe
> > design. Not unexpected for machines not manufactured with any
> > consideration of lathe design, perhaps.
> >
> > My Rivett sits on two inset ball-bearings at the headstock end and a
> > spherical washer at the tailstock end specifically to ensure that the
> > support stand could have no influence on the shape of the bed.
> >
> >
> > I think the classical approach to machine design was to make the mounting
> to the base flat and provide for leveling. A lathe is a compliant
> structure, so a kinematic mount doesn't seem like it would be as effective
> as one might like. Then again, the small Chinese lathes have the lowest
> standards of construction of any of the Chinese machine tools. They don't
> take them seriously. Would be nice to be able to get a small lathe to use
> on a mill table, but those things are basically pointless.
>
>
> ------------------------------
>
> Message: 6
> Date: Tue, 6 May 2014 16:22:01 +0100
> From: andy pugh <[email protected]>
> Subject: Re: [Emc-users] Question re crooked headstock
> To: "Enhanced Machine Controller (EMC)"
> <[email protected]>
> Message-ID:
> <can1+yzvjm-o_6shgs-ffiax+dq5lxumwisa2bv6frenxbs6...@mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On 6 May 2014 15:57, Eric Keller <[email protected]> wrote:
> >> I think the classical approach to machine design was to make the mounting
> > to the base flat and provide for leveling. A lathe is a compliant
> > structure, so a kinematic mount doesn't seem like it would be as effective
> > as one might like
>
> Reading lathes.co.uk (and I have read all of it) seems to suggest that
> the traditional approach was three bolts. Rivett just took it to
> extremes. The Rivett bed is basically a solid rectangular bar.
> (There is a central slot, but it is half an inch wide, and only about
> 1/3 of the total bed length.)
>
> I think that my Chinese 9x (which, actually, might be an Indian
> knock-off of a cheap Chinese lathe) has only two bolts, one at each
> end.
>
> However, I have never noticed that it turned tapered, for all its other
> faults.
>
> --
> atp
> If you can't fix it, you don't own it.
> http://www.ifixit.com/Manifesto
>
>
>
> ------------------------------
>
> ------------------------------------------------------------------------------
> Is your legacy SCM system holding you back? Join Perforce May 7 to find out:
> • 3 signs your SCM is hindering your productivity
> • Requirements for releasing software faster
> • Expert tips and advice for migrating your SCM now
> http://p.sf.net/sfu/perforce
>
> ------------------------------
>
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>
> End of Emc-users Digest, Vol 97, Issue 19
> *****************************************
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