Extending cross slide travel -- what is the currently accepted best method?
I need to machine some wider material.
Googling I can find lots of approaches and I'm struggling with what is considered the best approach in 2022 (ideas tend to evolve).
Gordon Scotts:?
Gadget Builfers:???(extends on above but incorporates a handle extension)
Twinsquirrel:??(handle extension is frowned upon and there is mention of buying and cutting down a longer screw from LMS).
Mikesworkshop:??(referenced in the above madmodder,? made his own longer screw but at end mentions not lengthening slot in carriage [hindsight]).
Maybe if I take everything apart and pour over the above 4 threads in more detail the subtleties of the differences would become apparent,? but instead I thought I'd ask :-)
Thanks!
|
Hi Ades workshop
He is starting a mini lathe work over
A different take
Dennis
|
Re: Saddle/Carriage adjustments
After cleaning the metal chips out of the gears in the apron; I used
my scroll saw to make a plastic cover for the gears. To grease the
gears I used some Mobil synthetic grease. Now the carriage moves
easier and smoother. I've not turned anything yet to see what/if any
improvement was made. May try turning something tomorrow, maybe some
aluminum, to see if I made any improvement. Not exactly perfect, but
here's a pic of the cover I made before the grease was added.
Stan
On 2/2/22 10:31, John Mattis wrote:
toggle quoted message
Show quoted text
When I first got my mini-lathe, I fabricates a
plastic cover for the gears and dillie the cavity?behind?the
cover with some cup grease.
This was 20 years ago and I have had no problems with it.
Regards,
John Mattis
On Tue, Feb 1, 2022 at 4:32 PM
Bill Williams < BWMSBLDR1@...>
wrote:
Stan, a question that has been in the
back of my mind for a while is ¡°Is it possible to seal
the apron well enough to hold oil for lubrication of the
geartrain?¡± The oil level would need be only high enough
for the lowest gear to just dip into the oil. I would
follow up on this idea but my handwheel feed is working
so well unmodified that I hate to rock the boat!?? Bill
?
Sent from for
Windows 10
?
?
I decided
to take the apron off this afternoon and may have found
the problem or part of the problem.? When I turn the
carriage hand wheel with the apron off, there's a spot
that offers some resistance to turning. There are some
metal shavings inside the apron and gears too. Maybe a
good cleaning and making a cover for the gears is in
order. I have a piece of .05" thick plaskolite that I
could use for that purpose.? With the apron off, the
carriage moves back and forth pretty well. I don't have
the experience to know if it's too snug. I'll see how
easily the carriage moves once I get the apron cleaned
and put back on. I assume white lithium grease is what I
should use on the gears?
Stan
?
|
Re: Saddle slop -- source, solution(s)?
You make a good point, Mark!
As long as it is performing to your satisfaction all is well. Over time the saddle should settle into a comfortable spot on it¡¯s own.
|
Re: Saddle slop -- source, solution(s)?
Update.
I found some adjustment issues with my saddle's shimmed slide plates (say that 3 times fast!).? Their mounting screws had loosened up a bit over time, permitting the saddle to ride up a bit over the Vee as the saddle was twisted.? Tightening them up eliminated the indicator variation due to that, so I reinstalled my 3/4" test rod and performed RDM.? I saw about .0005" variation at the headstock end and zero to .004" as I rotated the spindle, so I believe that comes to misalignment a bit less than .002"? over a distance of about 10 inches.? The polished guide rod is very smooth so it's pretty good for this kind of test.? I didn't observe much evidence of bed twist as I moved the indicator along the bed.
I haven't performed RDM on the vertical axis yet.? I really need to switch over to using one of my DTI's for these measurements, now that I know the spindle is fairly well aligned.? I have a 15-0-15 and a 4-04 (.0005" and .0001") DTI I can use for this.
Visual examination of the saddle V revealed that about 25% of the V really is in contact with the bed V (based on the polish marks on the V).? Rather than scraping to improve the contact area, I'm thinking about using PSA-backed sanding paper strips attached to the bed to refine the saddle "V".? Pretty much as described by a document in the Files section.? The procedure doesn't alter the bed surface.? But as it stands the lathe does pretty well on steel so why fix something if it ain't broke??
|
Re: Saddle slop -- source, solution(s)?
John,
I was in the process of performing RDM when I found the issue described in my original post.? Since the saddle is unstable there was no point in continuing with RDM until I figure out what's going on.
Based on your and other similar comments I definitely will check the carriage V.? Since the problem could be related to differential wear along the bed I will examine it as well.?
Thanks,
Mark
|
Re: Saddle slop -- source, solution(s)?
Mark,
I ran into saddle slop and found it was caused by ridges in the carriage "V" on my lathe. It is worth checking for this since it is easy to detect and fix.? See:
Once the carriage slop is settled you might look at RDM as a method to check headstock alignment.? It is unclear from your description exactly how you made the measurements where the DTI reading was varying but it sounds much like the measurement used in RDM except that you weren't averaging to remove the effect of the test bar being held at a slight angle in the collet. The theory for this method of alignment is here:
If you poke around on that page you'll find more info on RDM and how it applies to use with your Thomsen guide rod.
John
|
Re: Saddle slop -- source, solution(s)?
I hand scraped all the sliding surfaces of the carriage and cross slide on my 7x16. I was also able to get the cross slide scraped square so I am able to face square with .0002¡± concavity over 1¡±. ?I did no filing or lapping. It has not needed any further attention in the ten years since. A scraped surface also holds oil well in all the minute little pockets. The underside surfacesof the ways were well within .001¡± of parallel from the factory. That was a great help right from the beginning.
|
Re: Saddle slop -- source, solution(s)?
I agree with Roy. The top surface of the bed is the only precision ground part of the machine, so don't lap or modify it. What you do is use the surface of the bed as your reference for modifying other areas.?
Get something greasy you can use to color a surface. Prussian Blue oil paint from an art supply store or online is the traditional choice, and a small tube will last you for years. I'm calling this "bluing" but you may use another color. (You can even use lipstick, if you have some handy that SWMBO doesn't want). You need something that won't dry out, so a Sharpie, etc., won't work.?
What you do is smear a very thin coating of the bluing onto the bed and rub the saddle lightly on it, then look to see what areas of the saddle got colored. You'll probably be appalled at how little contact you have. (If the fit were perfect the whole surface of the saddle would be colored).??
Then you scrape or file away the places that are colored and try it again.? That's removing the high spots. As you keep doing this over and over, more and more areas will be blue as you get better and better contact over the whole surface.
Mike Taglieri?
Some good comments!? ? ?Give me more homework :)
|
Re: Saddle slop -- source, solution(s)?
Some good comments!? ? ?Give me more homework :)
|
Re: Saddle slop -- source, solution(s)?
Mark,
I think .005¡± variation is a lot over 10¡±.
I think it sounds as if there is a issue with the fit of the saddle as you eluded to. Is the saddle pivoting or twisting on the ways? If so, do you think there is a possibility the saddle retainer plates are loose fitting and not holding the saddle down? It could also have something to do with the rack and pinion creating the twisting movement. You probably have to go through some process of elimination.
Dick
|
Re: Saddle slop -- source, solution(s)?
The top of the bed is surface ground at the factory - it's the? reference surface for everything on the lathe. The mating surfaces on the carriage & HS are NOT ground & may well be misaligned. Check the vertical alignment & see if also varies along the length of the bed. I had to clean up the underside of the HS & deburr things for stability & add a small shim to get decent alignment in both planes. Similarly, the underside of the carriage is worth refining. I did away with the jack & clamp screws by shimming the slide plates. I was able to get things close enough that I had to file off the raised ridges from the serial no. being stamped on the bed.
Roy
|
Saddle slop -- source, solution(s)?
For various reasons today I decided to check the spindle alignment on my 7x12.? I have a 12 inch 3/4" diameter polished Thomson guide rod I bought awhile back just for this purpose.? I removed my headstock, installed a 3/4" MT3 collet and secured the rod in the collet.? I measured the runout at the headstock and it was less than .001", using a QCTP-installed dial indicator.? The DI was in contact with the side of the rod.? Running the carriage to the left I noticed something interesting.? The dial indicator reading started bouncing up and down and near the end of carriage travel I was seeing about a 0/.005" variation on the indicator.? Twisting the saddle would cause the same magnitude of variation.? At the halfway point the variation was around .0025" when I messed with the saddle so it seems to be sort of linear.
This variation can't be related to the spindle, it has to be the saddle.? Since saddle twist should be constrained by the bed vee, it looks to me like the issue is a gradual change in the match between the bed and saddle vees..? Since this variation is?least in the region where the bed sees the most wear, I'm wondering if the bed and saddle have sort of been use-lapped to better match each other near the headstock.
Deliberately lapping the less-used portion of the bed vee might work, but it's not clear to me that the vee is the issue.? Maybe it is the flat part of the bed that's worn down and thereby increased the contact area in the vee?? What sort of measurements would provide more insight into the problem?
One thing:? I have not measured the height variation along my test rod.? That will a good thing to do, based on my theory that bed wear is the issue.
The other thing to note is that if my theory is true, a new lathe should exhibit this kind of sensitivity to twist, but all along the bed.
Comments?? Suggestions?? Should I just be happy that I'm only seeing .005" variation over about 10 inches?? If this was just taper, maybe; but, due to this effect I will see a periodic variation down the length of a work piece, not a uniform taper.? I had noticed periodic variations in the cutting sound produced as I travel down a longer workpiece, and now I think I know why.
I'm also curious if others have observed the same thing.
-Mark
|
Re: Free Machining pdfs Available Online
pdfdrive.com?? , don't get discouraged the book titles when the
page loads , you have to search for the book or tye of book your looking
for .
animal
toggle quoted message
Show quoted text
On 2/2/2022 5:52 AM, fxkl47BF via groups.io wrote: On Tue, 1 Feb 2022, Miket_NYC wrote:
Saw this on the Metal-Shapers-and-Planers group. At first?glance it looked like the usual fluff for bored housewives and New Age kooks.??
BUT it has Volumes 1 and 2 of the Machinist's Bedside Reader, which has been out of print for years. It also has (an old) Machinery's Handbook.
These are probably illegal pdfs and I try to be a good boy, but when a book is in high demand and the publisher seems to have no interest in reprinting it, that seems
like a justifiable reason.
Mike Taglieri? Do you have the url for these books?
|
Re: Saddle/Carriage adjustments
When I first got my mini-lathe, I fabricates a plastic cover for the gears and dillie the cavity?behind?the cover with some cup grease. This was 20 years ago and I have had no problems with it. Regards, John Mattis
On Tue, Feb 1, 2022 at 4:32 PM Bill Williams < BWMSBLDR1@...> wrote: Stan, a question that has been in the back of my mind for a while is ¡°Is it possible to seal the apron well enough to hold oil for lubrication of the geartrain?¡± The oil level would need be only high enough for the lowest gear to just dip into the oil. I would follow up on this idea but my handwheel feed is working so well unmodified that I hate to rock the boat!?? Bill ? Sent from for Windows 10 ? ? I decided to take the apron off this afternoon and may have found the problem or part of the problem.? When I turn the carriage hand wheel with the apron off, there's a spot that offers some resistance to turning. There are some metal shavings inside the apron and gears too. Maybe a good cleaning and making a cover for the gears is in order. I have a piece of .05" thick plaskolite that I could use for that purpose.? With the apron off, the carriage moves back and forth pretty well. I don't have the experience to know if it's too snug. I'll see how easily the carriage moves once I get the apron cleaned and put back on. I assume white lithium grease is what I should use on the gears?
Stan
?
|
Re: Free Machining pdfs Available Online
Kevin Just took a look at your website list. Lots of info/links. Thank you for all your research/work.
On Wed, Feb 2, 2022 at 6:25 AM, kaje7777 <kevin.quiggle@...> wrote: Some time ago I put together a list of free books online of interest to machinists; go to the link below and scroll down to "Books and Manuals - Free" : A couple of related notes:
- I haven't checked this list in some time, so some of the links may be broken
- A while ago Google "improved" google Sites and forced a migration to the new version, which lacks many functions of the old version, such as internal linking. Unfortunately this greatly reduced the usability of my Sites based website.
|
Re: Free Machining pdfs Available Online
On Tue, 1 Feb 2022, Miket_NYC wrote: Saw this on the Metal-Shapers-and-Planers group. At first?glance it looked like the usual fluff for bored housewives and New Age kooks.??
BUT it has Volumes 1 and 2 of the Machinist's Bedside Reader, which has been out of print for years. It also has (an old) Machinery's Handbook.
These are probably illegal pdfs and I try to be a good boy, but when a book is in high demand and the publisher seems to have no interest in reprinting it, that seems
like a justifiable reason.
Mike Taglieri? Do you have the url for these books?
|
Re: Free Machining pdfs Available Online
Some time ago I put together a list of free books online of interest to machinists; go to the link below and scroll down to "Books and Manuals - Free" : A couple of related notes:
- I haven't checked this list in some time, so some of the links may be broken
- A while ago Google "improved" google Sites and forced a migration to the new version, which lacks many functions of the old version, such as internal linking. Unfortunately this greatly reduced the usability of my Sites based website.
|
Re: MSC Free Shipping Codes ??
On Tue, 1 Feb 2022, BuffaloJohn wrote: MSC has a OneStop program, where you get free ground shipping on orders over $49 (looks like small items, no big hunks of iron, etc.) and no promo code pricing on items.
I don't recall how I got on the proram, but you can check out
I read you don't have any program fees and no renewal is required, I think you just become a regular customer.
On Tue, Feb 1, 2022 at 11:55 AM Michael Jablonski <michaeljab@...> wrote:
Haven?t seen any codes in a while, but Free shipping kicks in automatically when you buy $199 or more.
?
Yeah? my feelings exactly.
?
Michael - California, USA
Micro-Mark MicroLux 7x16
LMS 3990 Hi-Torque Mill with power feed
?
?
?
From: [email protected] <[email protected]> On Behalf Of Kevin Jones
Sent: Tuesday, February 1, 2022 5:35 AM
To: [email protected]
Subject: [7x12MiniLathe] MSC Free Shipping Codes ??
?
Does MSC send out free shipping codes anymore???
They used to send out a free shipping code for a $99 order, and very rarely a $50 order. But I have not seen a code in quite a while.
Regards,
Kevin Jones Terms and Conditions Fees In exchange for your acceptance as a member in the Membership Program and/or for your receipt of any Benefits for one (1) year, MSC may charge an annual membership fee. MSC may, from time to time, offer different membership terms to you or to other customers, including different Fees, and may offer waived or discounted Fees. MSC will notify you in writing of any such offers, which will control over any terms herein. You will always have the option to cancel your membership (see "Cancellation" below).
|
Free Machining pdfs Available Online
Saw this on the Metal-Shapers-and-Planers group. At first?glance it looked like the usual fluff for bored housewives and New Age kooks.??
BUT it has Volumes 1 and 2 of the Machinist's Bedside Reader, which has been out of print for years. It also has (an old) Machinery's Handbook.
These are probably illegal pdfs and I try to be a good boy, but when a book is in high demand and the publisher seems to have no interest in reprinting it, that seems like a justifiable reason.
Mike Taglieri?
On Tue, Feb 1, 2022, 7:15 PM mike allen < animal@...> wrote: ???? ?? has tons of books on their site
? ? ? ? ?animal?
|
OldToolmaker
GadgetBuilder
John Mattis