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suspected headstock alignment with bed problem

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Forum topic by socrbent posted 12-12-2013 02:58 AM 1177 views 0 times favorited 12 replies Add to Favorites Watch
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socrbent

419 posts in 1737 days


12-12-2013 02:58 AM

Advise please – When I turn between centers there seems to be some misalignment between the headstock and bed rails. The headstock has been aligned with Recently as I turned 16 cherry 8” spindles 3/4” stock, first marked marked the center on one end then mounted the spindle on the lathe with other end in a chuck and the marked center of the spindle in a live center in the tailstock. after turning the spindle when I backed off the tailstock quill the piece would move off center about 1/16”. I don’t see anything in the manual for this Nove DVR XP to align the headstock. This may not be a major problem.

-- socrbent Ohio


12 replies so far

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Grandpa

3256 posts in 2143 days


#1 posted 12-12-2013 03:38 AM

When you move the tailstock to the headstock, do the points touch point to point? I would start there. Make those align. I have a Jet lathe and the headstock rotates on this machine. It is moveable and has a locking lever. If you can’t do that then you need to look at some way to move the tail stock. Since there is no misalignment until you move the quill in the tailstock it sounds like you have something that is bent on that end. Center isn’t true or the quill moves. Can it be loose in the housing?

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socrbent

419 posts in 1737 days


#2 posted 12-12-2013 03:57 AM

Grandpa – when tailstock is moved to headstock the points match. Headstock is movable to turn inboard or out board and seems to be locked in correct position. Live center and quill seem to work correctly.

-- socrbent Ohio

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Wildwood

1887 posts in 1602 days


#3 posted 12-12-2013 12:46 PM

How square is the end of the blank? I like to use a parting tool to square up end of spindle blank before mounting in chuck.

You can always try mounting a blank off the lathe, and see if blank moves as you tighten the chuck. Just set chuck on flat surface or in bench vise and look for movement when you tighten the chuck. Will soon find out if your blank is not square, base of jaws not square, or you are over tightening.

Have you tried placing wood in chuck loose bring up tailstock lock down tailstock, use hand wheel to move blank in or out then tighten chuck? Using this method blank should remain centered once tail stock taken away.

-- Bill

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socrbent

419 posts in 1737 days


#4 posted 12-12-2013 04:36 PM

Bill – Each spindle was mounted loosely in chuck and then the tailstock was brought up and placed in the center on the other end that was located by my center finder then the chuck was tightened, the quill advanced to create moderate pressure on spindle, the piece turned and then the quill in the tailstock was backed off. at that point the spindle wold move aft about 1/16”. Your suggestion to check the chuck is something I will test. Can you tell me more about over tightening. I was cranking the chuck until it would not turn more without what I felt was excessive force.

-- socrbent Ohio

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Jimbo4

1432 posts in 2231 days


#5 posted 12-12-2013 05:19 PM

scorbent – Are you using one of those plastic washers between the headstock and the chuck, as this will cause an alignment issue. Also, when attaching the chuck, screw it down on the spindle until it reaches the headstock, then tighten it down with just enough to hold it in position. Might also want to check the allen screw that holds the adapter into the chuck, as it sometimes comes loose and will cause a centering problem.

-- BOVILEXIA: The urge to moo at cows from a moving vehicle.

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SCOTSMAN

5839 posts in 3053 days


#6 posted 12-12-2013 07:11 PM

Please make sure everything is super clean and you don’t have crud-dust interfering with the internal spindles of the points as they meet.It is also worth checking is if the bedbars are tight enough assuming you have bedbars on your lathe.Alistair good luck my dear friend I am sure you will sort it out eventually..

-- excuse my typing as I have a form of parkinsons disease

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Wildwood

1887 posts in 1602 days


#7 posted 12-12-2013 08:22 PM

I zeroed in on chuck because sounded like over tighten jaws crushing fibers, tenon not long enough, blank not square, or blank canted in jaws because spindle too long for jaw set, more than lathe alignment problem. That is why recommend installing spindle in chuck off lathe

Of course have no idea on your chuck or jaw set you are using!

For very thin spindles I use these jaws in my chuck.
http://www.oneway.ca/chucks/accessories/spigot_jaws.htm

I prefer spigot jaw above because they tend to hold a longer a tenon little better than step jaws.

http://www.oneway.ca/chucks/accessories/step_jaws.htm

I sometimes will leave a little shoulder on a tenon to insure spindle blank runs true even without tailstock support. That shoulder helps keep spindle blank centered while tighten my chuck around my tenon. I could also use that same procedure if using step jaws, just that spigot jaws allow for longer tenon.

Using step style jaws, over tightening and spindles too long a definite no-no. Crushing wood fibers or spindle too long can cant one way or the other once tailstock support removed. Turning a tenon and leaving a shoulder might help some, but would use tail stock support until final last light cuts.

-- Bill

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socrbent

419 posts in 1737 days


#8 posted 12-12-2013 08:38 PM

Thanks for everyone’s help!
Jimbo4 – no plastic washer in place between chuck and head stock. I’m going to recheck, but chuck seems to be firmly attached to the head stock and adapter allen screw is tight.
Scotsman – Lathe and chuck are only a couple of months old so I don’t believe I have used it long enough to accumulate crud inside chuck.
Wildwood – I’ve not yet had time to test chuck off lathe. I should have time later today. When turning the 16 spindles I used spigot jaws from Nova (http://www.teknatool.com/products/Chuck_Accessories/Pin.htm) very similar to those from Oneway.

-- socrbent Ohio

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Jimbo4

1432 posts in 2231 days


#9 posted 12-12-2013 10:00 PM

socrbent – I also have a DVR XP, and after swiveling the head I always check the live and dead center alignment by sliding the tail stock center up to within a fraction of an inch of the head stock center, then nudging the head until it aligns with the tail center, and then lock the head down. I know this sounds like a pain in the patootie each time, but at least everything will be in alignment.

-- BOVILEXIA: The urge to moo at cows from a moving vehicle.

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REO

889 posts in 1542 days


#10 posted 12-12-2013 11:09 PM

sounds like the bed could be out of line. just because the points line up when they are together doesn’t mean that they will be in line when they are apart. the headstock may be out of square with the bed. put a piece of metal rod or tube in the chuck and check with a square across the bed with the leg up and against the rod or tube. measure from the bed way to the corner of the square. take measurements at the chuck and then again a foot from the chuck. even out of square the centers can line up when they are at the right point for convergence

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socrbent

419 posts in 1737 days


#11 posted 12-12-2013 11:11 PM

Jimbo4 and Reo – That may have been the problem. I released the head for the first time since I bought the lathe earlier today. Then swiveled the head and returned it to being over the rails. Centered the headstock with the tailstock and locked it down. There was some play that allowed the headstock to change alignment. I now know the detentes to align headstock are not very positive. Making some more turnings will tell if this was the cause of the alignment problem.

-- socrbent Ohio

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Jimbo4

1432 posts in 2231 days


#12 posted 12-12-2013 11:21 PM

The detents, I have found, have a slight amount of play. That’s why I align the centers and then tighten the head stock, then “nudge” it to make sure it’s tight. But – just to let you know – I find this the ONLY annoyance of my XP, and wouldn’t trade it for anything. Except maybe, perhaps, by chance, a 2024 XP.

-- BOVILEXIA: The urge to moo at cows from a moving vehicle.

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