Optimizing Head and Tailstock of lathe so they point straight at each other?

[Jon Rista]

just a thought. the drill bit might not be true. especially if it's been sharpened at home. if the point isn't exactly center it will drift in tge cut. same is true if one of the wings is duller than the other one.

It wasn't just a single bit. Happened with all my bits and forstners.

Wanting to get the same precision in a cheap low cost $400. China lathe as in a N.American $4000 lathe is just not going to happen.
Sell that problem lathe and get a better lathe might make you happy.

I understand that. Never expected the Wen to be as good as the Powermatic. Just that I think it could be dialed in better. It WAS better at one point, before I had to deal with the damaged spindle. Its also not a problem lathe, not like people responding in this thread seem to think. 🤷‍♂️

 

[Jon Rista]

A set of center bits are cheap, made for metal turning without live centers.
If possible, I choose one whose outer diameter is a bit larger than the drill bit.
I keep one in a spare Jacob's chuck at all times.
View attachment 69067

I actually do use center bits. I bought a set about three years ago just for this purpose. I don't think I have wander or drift when the bit first hits the wood. What was definitely happening before I adjusted the headstock, was the bit was simply contacting off-center. As such, the hole on the contact end was too large. Still is, to a slight degree. Granted, some of your points are valid, and it may be that the blank is not strait, even if the headstock and tailstock are perfectly aligned. But I get the exact same problem across both blanks and bits/forstners. So I don't think its a blank problem, or at least, not primarily a blank problem (probably is partly due to the blank in some cases.) I do usually round blanks before drilling.

The current, remnant problem is far smaller of a problem than it was when I started the thread. It is also not just about drilling, the drilling was really a test to see if the adjustment worked to resolve or reduce the problem. I was having some trouble turning some of the small things I am turning these days. Those problems seem to have been resolved. For example, I turned several sets of acorns out of a 1.5" diameter maple dowel. The first few sets were problematic when turning the outer tips of the acorn-seed shape (which was tailstock side), especially near the beginning of a given rod (which were about 8" long I'd say?) I started with tailstock support, but ultimately had to turn off that little button of wood in order to part each acorn off. Once the tailstock was no longer holding things in place, the wood would shift, and I'd have problems with the acorns turning true, and then of course all the problems that come from that. These problems lessened a bit as I got closer to the headstock, but even for the last acorn, were not eliminated.

FWIW, I no longer have this problem at all. I'm just picky, and I think the alignment of the Wen could still be improved. If I need more perfect drilling, I'll use the Powermatic (which is where most drilling happens anyway.)

Two ways to prevent bits and Jacob's chuck from rotating in the tailstock:

1) I use a rod that perfectly fits the chuck key hole in the chuck.
A good strap wrench also could work.
View attachment 69068

2) Keep taper shank bits from rotating with small channel lock pliers, or vise grips.
View attachment 69069

If without one, this is great for clean 2MT sockets. There are other methods.
View attachment 69071

JKJ

This is interesting. I'd never heard of a taper shank bit. Are those only viable for larger bits? For a lot of the stuff I turn, its either a forstner (i.e. I'm drilling a short hole to accommodate say candles of various sizes, or whatnot), or a smaller drill bit (i.e. 12.5mm/10.5mm for a lot of pens, and similar in inches.) I think all the normal or bradpoint bits I use are smaller in diameter than the MT2 hole.

Also, the last photo there... That looks like a ream...but, is it metal? Or something else?? Curious where you got that... I have a metal ream, which I use occasionally to clean out both morse tapers on this lathe. I'm always a bit afraid that I'll add a little ridge at the point where the ream ends. It fits quite a ways into both the spindle and quill, but still. A resin reamer would be nice, just for cleaning them out.

 

[Vincent Vogel]

That's a good point, no pun intended. And the bit needs to be sharp! It took me a long time to learn to sharpen, especially large diameter bits.

Some things that cause drifting are, (in my opinion) and experience:

• Sharp bits, as mentioned. Sometimes not mentioned - spiral flutes should be sharp, not dull or damaged.
• Slightly bent drill bit, maybe too slight to notice. Examine by rolling on a flat surface (surface plate is ideal)
• No or improper starting hole (I always use center bits or a starter bit). Starting the hole is more than half the battle.
• For larger bits, drilling a starter hole with a smaller bit can sometimes help.
• Wood grain - if not straight, the bit can follow the grain if other things aren't right.
• Too long a bit might flex. If drilling a a deep hole, I start the hole with a short stub (screw machine) bit, drill as deep as it will go, then switch to the longer bit.
• Vibration, wobbling of wood and/or bit. For a deep hole, it's helpful to turn at least the end of the blank round then steady with the hand.
• Speed too slow. If very slow, the bit can wobble more. I find a higher speed can help (for several reasons).
• Sloppy hardware. High quality Jacob's chuck. Clean 2MT on both chuck and tailstock.
• Sloppy hardware 2 - even better, eliminate the Jacob's chuck completely and use taper shank bits for both small and large dia holes.
• Sloppy hardware 3 - low precision lathe construction (as mentioned elsewhere)
• Along with that, the MT surfaces should not be damaged. A MT on the Jacob's chuck can twist if the bit catches and cause galling. A reamer can repair bad galling.
• Clean, round drill bit shank with no problems. Some develop burrs or galling. Use a file to repair or grab a different bit.
• High quality bits. Expensive, but can make a huge difference in the Big Picture.

​

That's all I can think of at the moment. I can say I haven't had a wandering drill bit for a long time.

A set of center bits are cheap, made for metal turning without live centers.
If possible, I choose one whose outer diameter is a bit larger than the drill bit.
I keep one in a spare Jacob's chuck at all times.
View attachment 69067

Two ways to prevent bits and Jacob's chuck from rotating in the tailstock:

1) I use a rod that perfectly fits the chuck key hole in the chuck.
A good strap wrench also could work.
View attachment 69068

2) Keep taper shank bits from rotating with small channel lock pliers, or vise grips.
View attachment 69069

If without one, this is great for clean 2MT sockets. There are other methods.
View attachment 69071

JKJ

Where did you find the green morse taper cleaner? I've been looking for one and can't seem to find one. Thanks.