# On the Level: Further Adventures with the G0602



## RJSakowski (Aug 26, 2018)

When I built the stand for my G0602 lathe, I made leveling adjusters for the four legs.  They were simple in design; a 1/2-13 bolt  and jam nut threaded into a plate at the bottom of each leg.  However, in trying to precision level the lathe, I ran into some issues. 

When adjusting the height of each leg, there was a tendency of the bolt to walk across the floor.  Not a problem for a workbench but when you are leveling a lathe with a sensitive level (.0005"/10"), it can be a frustrating game of Whack a Mole.  The second issue deals with the fact that three points determine a a plane.  Four adjustment points inevitably result in one leg not touching.  Solving the second issue first, I made another leg for the tailstock end of the stand.  I now can adjust the front to back level with the two left-hand adjustments and the left to right level with the added tailstock adjustment.  The two original adjusters were left in place and after leveling, they were lowered to just shy of touching to act as stabilizers in the event the center of gravity would shift outside the triangle formed by the three leveling adjusters.

The issue of walking was solved by modifying the bolt head by cutting a shallow cone.  These mated with disks which had a conical depression.  A dab of grease was put in the depression on the disk and bolt was lowered into the cup.  This was repeated for the other two feet.  A quick check was made to make certain that the stand was positioned properly and the leveling process began. 






The headstock was leveled front to back first.  Two 1-2-3 blocks were placed on the headstock end of the bed and the precision level was placed across them.   The process went smoothly with few iterations.  The final adjustments in leveling involved just nudging the wrench slightly but the leveling was completed.  Next, the level was placed on the rear way and the tailstock foot adjusted to level the lathe left to right.

Two 1-2-3 blocks were placed on the tailstock end of the bed, the precision level was placed across them, and the level checked.  Shims were added under the tailstock to level  the tailstock end.  I noticed that adding shims would cause a slight shift headstock level so it was re-leveled and the tailstock leveling process repeated until both were level.

Next I mounted my faceplate with a dome headed bolt about 3.5" from the spindle axis.  I placed my .0001"/div. test indicator on the compound and adjusted it so it was at maximum deflection when the bolt head was horizontal to the spindle axis and the cross feed was retracted to about 1/4" from end of travel.  The carriage was locked and the indicator was zeroed.  The faceplate was rotated 180º and the maximum deflection of the indicator was noted.  The indicator read -.00013"  which meant that the cross feed would cut a slightly concave face.  I felt that this reading was close enough to not warrant any improvement.





Next, taper was checked using Rollie's Dad's  Method.  A 1"diameter by 12" bar was used.  The test indicator was adjusted to hit the bar at a point horizontal to the spindle axis and close to the chuck.  The cross slide was adjusted so the average of maximum and minimum reading was zero.  The carriage was moved out about 10" and the maximum and minimum readings were made.  The average was -.0075".  A .010" shim was placed under the front side of the tailstock and the headstock end was re-zeroed.  The average tailstock reading was reduced to  -.0035".  The .010 shim was removed and a .012" shim  added. and the process repeated.  This brought the tailstock reading to -.0017".  
Moving to a .015" shim, the reading was now +.0015".  Removing the .015" shim and replacing with  .012" and .0015" brought the reading to -.0001" which was deemed good enough.

The lathe adjustment process wouldn't be complete without a two collar test.  An aluminum bar 2.1`" in diameter and 7" long was mounted in the chick and the two collars turned, one about 1/4" from the chuck and the second 5.7" from the chuck.  The difference in turned diameters was less than .0001".


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## craptain (Aug 26, 2018)

Wow!! That's a lot of work for a home shop machine. I admire the precision but wonder if you will ever work to that standard. Personally I know that I won't. 
I still congratulate you on a job well done. 

Sent from my SM-G930T using Tapatalk


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## thomas s (Aug 26, 2018)

Nice job RJ. I need to do this to my mill stand.


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## TerryH (Aug 26, 2018)

Excellent work RJ!


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## GunsOfNavarone (May 6, 2020)

I guess I'm confused. Where these adjusters on the bench yo made or somehow attached to bottom of lathe? You are NOT using the 2 mounting bolts that are standard on the G0602? Rather, these (4) mounting bolt system you came up with?


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## FlyFishn (May 18, 2020)

Read through this thread. Interesting idea with the adjustable feet. I was thinking the same thing the other day for the ability to level.

This is an old thread, by the way (from 2018).

The way I read the OP's description of the leveling is that the stand is home-made. There are 2 leveling "feet" on the head stock end and 1 leveling "foot" on the tail stock end. That makes the triangle that was referred to - the 3 feet make up the points of the triangle. The same point was made for the 3 points describing a "plane" - and that is what the OP was leveling to, as opposed to using 4.



RJSakowski said:


> The second issue deals with the fact that three points determine a a plane. Four adjustment points inevitably result in one leg not touching. *Solving the second issue first, I made another leg for the tailstock end of the stand.* I now can adjust the front to back level with the two left-hand adjustments* and the left to right level with the added tailstock adjustment.*



I added the bold. The part about the "left to right level with the added tail stock adjustment" I am reading to mean that is a single leg/foot that took the place of the original 2 with the 4 post set up that was attempted earlier.

The domed bolt head and the depression cut in to the disks on the floor keep the bolts able to be tuned up/down with the weight of the lathe and stand resting on them without the "walking" mentioned. That makes perfect sense to me.

I had looked at some feet that were shock absorbing the other day and was thinking at least having the height adjustability would be good for leveling, shock absorbing would help dampen floor vibration (either from the lathe or another machine vibrating the floor transferring to the lathe). The home made bolt/cup disk idea would be excellent to start with though. For that matter, some hard rubber matting could be placed under the disks to dampen floor vibrations if that was ever an issue.


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## RJSakowski (May 19, 2020)

GunsOfNavarone said:


> I guess I'm confused. Where these adjusters on the bench yo made or somehow attached to bottom of lathe? You are NOT using the 2 mounting bolts that are standard on the G0602? Rather, these (4) mounting bolt system you came up with?


I just saw your post.  

The leveler disks are sitting free on the floor.  The adjustments screws have a slightly domed head to fit the depression in the disk.  The idea it to prevent the stand from walking when I adjust the level.   The stand is supported with two levelers under the headstock end and a single leveler at the tailstock end providing a stable 3 point mount.  To prevent tipping of the stand the two original leveler at the tailstock end are adjusted to just shy of touching.  This system prevents any twisting of the stand that can occur with a four point mount.

On addition, I put my lathe on 7/8" risers which are bolted to the lathe base with the single bolt  These in turn are drilled and tapped on the four corners of each plate for mounting to the stand.  This provides a rigid base to mount the lathe on which can be shimmed as required.  The three point suspension allows thelathe to be roughly leveled but will not introduce any twist.  Any final adjustments are made by shimming under the risers.


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## GunsOfNavarone (May 19, 2020)

@RJSakowski  I was going to look at your profile to see your thread on this mod... I don't have access. I'm gonna get some 2x1" steel tube and build a 3 point stand as with the fiasco of calibrating the machinist level taught me much about the value of that ability over 4 point. I though to use the 2 stock mounting points on g0602 but just snug, and under the stand, have the 4 points that thread into the stand pressing up from bottom on the 4 ends of the G's normal shimming points. AS the steel is going to cost around $150, I'd like to have the right approach jumping in.


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## RJSakowski (May 19, 2020)

GunsOfNavarone said:


> @RJSakowski  I was going to look at your profile to see your thread on this mod... I don't have access. I'm gonna get some 2x1" steel tube and build a 3 point stand as with the fiasco of calibrating the machinist level taught me much about the value of that ability over 4 point. I though to use the 2 stock mounting points on g0602 but just snug, and under the stand, have the 4 points that thread into the stand pressing up from bottom on the 4 ends of the G's normal shimming points. AS the steel is going to cost around $150, I'd like to have the right approach jumping in.



 Here is there earlier thread re: the risers.
https://www.hobby-machinist.com/threads/getting-a-rise.72180/


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## FlyFishn (May 19, 2020)

RJSakowski said:


> The leveler disks are sitting free on the floor.  The adjustments screws have a slightly domed head to fit the depression in the disk.  The idea it to prevent the stand from walking when I adjust the level.   The stand is supported with two levelers under the headstock end and a single leveler at the tailstock end providing a stable 3 point mount.  To prevent tipping of the stand the two original leveler at the tailstock end are adjusted to just shy of touching.  This system prevents any twisting of the stand that can occur with a four point mount.



Thank you for the added information.

Have you checked the run out on a long piece across the lathe to check the alignment of the ways down the bed?

With the 1 foot/leg on the tail stock end you don't have any ability to adjust for "twist" in the bed casting - only to level what there is with respect to the plane of the floor, but not calibrate the alignment of the ways on top of the casting.

For close-in work at the chuck this likely isn't a problem, but it could be noticeable with longer pieces even if you set a steady rest or center in the tail stock and have that dialed in. Slight twisting of the ways towards the tail stock will change the distance the tool is from the work = where you may find differences in the dimensions of your work at different distances from the chuck/head stock.


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## RJSakowski (Jul 9, 2020)

FlyFishn said:


> Thank you for the added information.
> 
> Have you checked the run out on a long piece across the lathe to check the alignment of the ways down the bed?
> 
> ...


Sorry for the late response.  I just read your post.  I have a 20" length of 1.250  316 round that I use with the RDM method.  

The tail end of the lathe is firmly bolted to the risers.  The assumption is that the lathe base can't twist relative to the rise.  The riser has a four bolt mount to the table so shims can be placed on each corner as necessary to correct twist of the lathe bed.

The lathe stand is fairly substantial and uses a three point suspension to avoid adding any stress to the stand. https://www.hobby-machinist.com/threads/on-the-level-further-adventures-with-the-g0602.72338/


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