# 7 X 12/14/16 inch mini lathe carriage lock LMS 2977 Review



## addertooth (Sep 26, 2020)

The small 7 by 10/12/14/16 lathes have a very light carriage.  Often when facing or parting they want to shift.  This can result in facing and parting operations which are not entirely flat.  I had resorted to stiffly holding the carriage wheel while cranking in the crossfeed; this was less than ideal.  Certainly you can put the feed in neutral, and then lock your half nuts to hold the position, but for a precise cut, you would have to rotate the feed thread first to get it in exactly the right position first.

LMS sells a pre-made carriage lock (for those who have not yet purchased a mill to make your own).  It bolts onto the lathe via the two screw holes which exist (in most of the current mini-lathes) for bolting on the follower rest.  It locks VERY securely, no complaints in that department.

When in the unlocked position the lever is entirely out of the way of everything.  It creates no limitations on what can reasonably be machined.  The lever rotates clockwise to lock.  As such, depending on the thickness of your way stock, it may be in full lock at a position which is not entirely clockwise. You can pop out and rotate the hex nut on the bottom, and the put it back in slightly rotated to get a more ideal "locked" position. If not done, then there is the risk the handle, in the lock position, could strike your outside jaws on a 4 inch or larger chuck.

With the lever in the least favorable position, (facing straight toward the chuck), there is roughly 2 inches of clearance. Once again, not a problem with a 3 inch chuck or 3 inch part being machined. It becomes questionable with a 4 inch part or chuck, and should be measured first.  It could become dramatic with a larger chuck or part. 
*******Edit update: HMan and WobblyHand pointed out the locking handle is spring loaded and can be lifted up and rotated out of the way of the chuck/work, and dropped back in to a different position on a spline.  This move the handle to a nicely tucked away position.  ******

In the case of the sample on hand, it locks well past the center line, and gives a more generous clearance (between the end of the lever and the centerline of the chuck) of about 2.5 inches.  It would "likely" clear a 5 inch chuck body, but not the jaws if they are extended past the edge of the chuck body.  This is assuming you are working VERY close to the chuck.

I considered popping out the hex nut on the bottom, and rotating it one face, but realized it would not be in full-lock when rotated full clockwise; so I lived with the fact it sticks out towards the chuck a bit in the locked position.

Now to state something obvious. The lever and bolt can be replaced with a washer and cap screw; this will eliminate all of the above risks, but it will not be as quick and easy to use.  It would have the merit of never creating a potential clearance issue (when locked, or when spinning swarf potentially snags the handle).

The pictures:
1. Bolted in place, red box defining the carriage lock.  It is in the Unlocked position.
2. Carriage lock in the Locked position
3. Lever shown in worst-case position for clearance.  There is about 2 inches of space between the chuck center line and the top of the lever.
4. Lever shown in the locking position on my lathe.  There is roughly 2.5 inches of space between the chuck center line and the top of the lever.


----------



## benmychree (Sep 26, 2020)

The easy answer would be to remove the handle when it gets in the way.


----------



## addertooth (Sep 26, 2020)

Benmychree,
Agreed.  That is why in my posting I said:

" Now to state something obvious. The lever and bolt can be replaced with a washer and cap screw; this will eliminate all of the above risks, but it will not be as quick and easy to use. It would have the merit of never creating a potential clearance issue (when locked, or when spinning swarf potentially snags the handle). "


----------



## Ken from ontario (Sep 26, 2020)

The lever on my (home made) carriage stop is straight , not angled, almost parallel to the ways and it's a rod about 1.5" long, I find it easy to just slide my hand to lock/unlock it, my point is, it is not necessary to have the handle on an angle like shown in the picture, in my opinion it just doesn't serve a purpose being that way. 
I would remove it and upgrade it with a hex bolt,  drill and tap a hole on one of the sides , then thread  a 2" SS rod/or tool steel to fit that hole,  this small change will make your carriage stop much easier and safer to use and you won't have to worry about bangging your knocles against the chuck.
 similar to the knobs in these pics:


----------



## addertooth (Sep 26, 2020)

Ken,

Yep, I don't have a mill *yet*.  Many of the nice doodads which I need to make will wait until then.  For now I am bound by what is available off the shelf.  I got tired of the lathe not having a carriage lock, and LMS sold a direct bolt-on part.   I felt it might be beneficial for others to know it exists commercially, and, what reasonable limitations it might have so they could make an informed decision on the purchase.

Don't get me wrong, I would repeat the purchase, but some other people out there might consider some of the limitations a deal breaker. Almost everything I machine is very small (under 3 inches of O.D.).  I know that lathes can do shapes other than "round", heck, I just go finished "shaping" a 4mm keyway in a spacer collar a few minutes ago.  But let us be frank, making many tools are much easier with a mill on hand.


----------



## Ken from ontario (Sep 26, 2020)

addertooth, I can clearly see a nice mill in your future.


----------



## addertooth (Sep 26, 2020)

I am in the middle of negotiations with the terrorist DRRNO (Deluxe Refrigerator Right Now Organization).  SWMBO (She Who Must Be Obeyed) is tired of how her working fridge looks, and wants a large stainless fridge with all the feel-good features.  She has made it clear that whatever the Mill costs, the fridge must be at least $500 more... and of course, I must pay for both.  It all started with "hey baby, do you mind if I take out a loan to buy a mill?".  The Lathe was not a struggle, as the combination of the Stimulus check and a nice (but not amazing) Powerball win provided the funds for it. 

But yes... a Mill is in my future, let us pray it is not the long-distant future.


----------



## hman (Sep 29, 2020)

Hmmmm ... Most levers of this type that I've seen have a spline arrangement between the lever and the "business end," that allows repositioning (clocking) the handle by lifting, rotating, and lowering it into one of the other splines.  There are probably at least 12 teeth on the spline, so you have 12 or more position choices.  No need to mess with the hex nut below.

Hope this helps!


----------



## WobblyHand (Sep 29, 2020)

@hman is right.  I have that carriage lock.  All you do is lift up the handle and re-clock it.


----------



## addertooth (Sep 30, 2020)

Hot darn!  I just tried that and it worked.   It arrived without instructions, and I failed to fiddle with it.


----------



## ChazzC (Jan 4, 2021)

addertooth said:


> Hot darn!  I just tried that and it worked.   It arrived without instructions, and I failed to fiddle with it.



I replaced the stock lever knob with a smaller Aluminum one (eBay):







I had to add a spacer to keep the lever easily accessible, and placed a spring between top bracket and the locking plate so the locking plate would always drop clear when released.

I also added "extra" tapped holes on the Cross-Slide & Compound gibs so I could lock them, too:






I put small ball bearings in the holes before inserting the locking levers rather than rounding the ends of screws to achieve point contact on the gibs.


----------



## addertooth (Jan 4, 2021)

Do my eyes deceive me, or is that an LMS 7350 on your bench.  I really like mine.


----------



## ChazzC (Jan 8, 2021)

addertooth said:


> Do my eyes deceive me, or is that an LMS 7350 on your bench.  I really like mine.


MicroMark 84631, 7 x 16, with a lot of modifications/additions. They are pretty much the same machine, but quality control on the LMS may be better. I'm happy with it since I don't have space for an 8.5 x 20. I also have an LMS 3990, but would love one of their bench mills (again, space - and cost - are a factor).


----------



## theradioshop (Jan 10, 2021)

Thanks for the review of this.  I have just been putting the machine in neutral and locking the half nut. Not the best but does work. After looking at several options I think I will make my own lock and put it on the tail stock side of the lathe.


----------



## ChazzC (Feb 10, 2021)

Since posting the above, I've been looking into alternatives to the LMS Carriage Lock as I have never liked the location of the locking handle. All of the ideas I could find for the tailstock side of the saddle blocked access to the cross-slide gib screws or my cross-slide lock:







However, I realized I had a third option for the location of a carriage lock: if you look closely at the photo above, you will see that I modified the saddle retainer setup. Combining ideas from Frank Hoose, Steve Jordan, LMS and David Fenner, I replaced the stock cap screws & set screws with M6-1.0 x 30mm set screws & Nylock nuts at the four corners:







This leaves the center hole in the back retainer empty, an the M6-1.0 hole in the saddle looking for something to do. The gap between the back retainer and bottom of the saddle is only about 0.005", so I tried using a cap screw to lock the carriage - it worked perfectly. I then made a locking bolt (tried one of my little blue adjustable lever wing nuts, but it was awkward):

















The body is made from 3/4” 12L14 round bar, the handle is 1/4” drill rod and the rest are hardware. The M6-1.0 x 25 setscrew and M4-0.7 cap nut are secured with red threadlocker, and the “working end” of the setscrew is coated with Vibra-Tite to prevent the lock from accidentally engaging. The cap nut finishes the handle nicely, and also provides a means of unscrewing the handle without having to mill flats on the shaft. The location of the cross hole for the handle was determined after everything else was assembled so it goes from unlock to lock with good access and room for wear without having to make a custom washer:












Since the lock is out of sight, I added a reminder label on the backslash:







I've attached a drawing; anyone may use the concept for their personal use, but I would appreciate acknowledgement.


----------

