G0602 Lathe Taper Questions....

cookj320

cookj320

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My lathe cuts about .006 taper in 5 inch cut.....
Questions
How do you know/tell head stock is aligned to bed?
How to diagnosis whats causing taper? head stock, bed, carriage or tail-stock. ?
I was reading the post on test bar storage so i do understand some taper is al;ways going to be there but i feel this is to much, what is acceptable taper?
 
To test my headstock I bought a 5C test bar on ebay for $100. Once the headstock was aligned I did the tailstock with a DI and the same bar on centers.
 
I doubt your headstock is adjustable.
Did you level it? Twist in the ways will cause you to cut a taper.
 
ddickey said:
I doubt your headstock is adjustable.
Did you level it? Twist in the ways will cause you to cut a taper.
Click to expand...
Assuming your post is directed to me;
I don't know if my headstock is adjustable but I didn't touch it. I leveled the lathe with a machinist level (.0002/10 inches) to get in the ballpark and then dialed in the headstock by adjusting the steel feet on the cabinet while sweeping the test bar with a DI on the carriage. It was only off a few thou but I got it within 001" on the length of the bar.
 
I worked today to get my lathe level and turned a 1" piece 12" long with out using tail stock and only got .001" difference in 9 inches.
I don't know if any adjustment can be made on the head stock of g0602.....was hoping someone here knew this answer.
 
No it was directed towards cookj320. I'm new at this also but from what I've learned is that once you get the tailstock and headstock ends level then you should only make tailstock feet adjustments. Leave the headstock. Nine inches is probably a little to far especially without tailstock support. I think southbend instructions say six inch peice.
 
cookj320 said:
I worked today to get my lathe level and turned a 1" piece 12" long with out using tail stock and only got .001" difference in 9 inches.
I don't know if any adjustment can be made on the head stock of g0602.....was hoping someone here knew this answer.
Click to expand...
I think .001 in 9 inches is great. I'm surprised a 1 inch bar 9 inches long didn't deflect more than that. I thought 1.5 inch diameter was minimum for something like that. You most have done a real good job on grinding that lathe tool.
 
The G0602 headstock is adjustable. There are four cap screws holding the headstock to the bed and two set screws at the back of the headstock to make controlled adjustments. The control panel has to be removed to access the two front screws and the two back screws are in rather tight quarters.

BUT do not make an adjustment to the headstock before determining that you do not have a twist in the ways. I had a taper of around .002"/" and corrected it by adjusting the headstock. That got rid of the taper but now facing a piece creates a domed surface. There is no way to correct this problem other than returning the headstock to its original position.

As I see it the order of alignment should be:
1. level the lathe
2. correct any twist in the ways as determined by the two collar test or Rollie's Dad's Method (hereafter called RDM)
3. check for headstock misalignment as indicated doming or dishing on a faced surface (a light skim cut on a face plate or disk mounted in the chuck)
4. recheck for twist in the ways
5. align tail stock using two collar test or RDM method
 
Google 'Rollies dad method. There are numerous directions and videos about checking head alignment. It does not require fancy high dollar test bars. The head is bolted to the bed with 4 bolts. You align the spindle to the bed with under the head.shims. Having to adjust the spindle alignment is fairly common with the Seig 7X series. I have not heard a lot of complaints about the G602.

Level the bed before you do anything more. The two pillar bed support is more friendly than a 4 corner system, but it is possible to pull the bed wopper-jaw if the mounting surfaces are not planer.

It is more likely that the tail stock is set over than anything else. Check the spindle alignment first. Clean the sockets and put centers in the head and tail. Dead is better than live for the tail. Make sure the points line up before going on. Turn test collars at both ends between centers. Adjust tail stock. It is most likely off horizontal. Vertical misalignment is possible.

Testing between centers tells you that the lathe is in alignment. Testing with a bar in a chuck, supported at one end may just be telling you the the chuck jaws are off, or the lathe is off, or you just have normal deflection.

------------------> Like RJ said. We crossed. Like minds and all that.
 
I've ordered some drill rod and will re-check an update with pic's. I really appreciate everyone's help!!
 
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