Wood Turning

Really like your work, stig! I do all bowls and platters now as I'm just starting. But really nice to see creative pieces like that lamp! Good to see some things that I might want to attempt in the future.
 
Hey all, need some advise.

I'm having a lot of tool chatter when I turn. I have been researching to find the causes and haven't been able to nail it down yet. Here's what I do know:

My lathe is weighted down with sand bags, weights, etc.
My tools are sharp
I am getting the tool rest as close to the piece as possible

It's been a frustrating problem, as I can't get a clean cut. I'll rough shape something without a problem but light shear scrapes to get rid of tear out are all but impossible because of the chatter. When I put my hand against the piece you can feel that it is just a bit wobbly. I have taken very light normal scraping cuts to get it back into line, but it will go straight back to being wobbly within no time.

It is green-ish wood. Been drying for maybe 6 months. I don't think the wood would move that quickly (as in drying while I turn). It is doing this to me so quickly, and it does it before I start to hollow out too. (When hollowing I hear that is when the green wood starts to dry out and warp as the wood gets thinner).

So I am left with tear out that is really hard to sand away...and a piece that is fairly hard to shape in the first place.

I read it could be the spindle bearings? Or that the belts haven't been greased lately? (I do need to get on that).

What do you guys think?
 
Check your bearings first.
Then tell me what it is you are trying to turn and which tool you are using.

Pictures would be excellent, diagnosing a problem with so little info as you have given is fairly impossible.

It makes a hell of a difference whether you are truning a spindle with a skew or the inside of a deep bowl with a U-gouge.
 
Alright

I was turning the outside of a bowl. It was about 10 inches in diameter. It was mounted to a faceplate. The wood was tulip poplar. I was turning with both a large sorby 1 1/2 inch scraper and a deep fluted bowl gouge. Both tools were giving me the same issue.

I'll check the bearings first. Also had someone suggest making sure the pulleys on the motor and spindle to see if they were tight. These are some good places to start. I'll check back when I've done some more poking around
 
Could be, but I don't really see that some off centre with the head and tail stock causing serious chatter. What about your turning rpm? Certainly some woods are more prone to tear out than others.
 
If you are doing it right, a scraper should be unable to chatter.
Doing it right means having only edge contact to the wood, no bevel.

How many RPMs are you running it at?

Check that yor screws mounting it to the faceplate are tight.
 
I had trouble with this too. My faceplate has I think eight screw holes four of which are chamferred and I was using only those. I put four more screws in the other holes and it quit chattering.
 
Alright I'll check my screw tightness. I also have a similar problem when using my chuck though. (as a screw chuck and then when I have it mounted in the recess or tenon)

I tried a few simple fixes. I lowered my rpms to 650, and raised the tool rest a bit. (read that might help a little) Still giving me chatter.

I apologize I still need to figure out how to check the bearings. Hopefully I'll do that soon. But I did put my hand up to the headstock spindle wheel (not sure exactly what it's called) but the wheel where you insert the knockout bar, and I could feel a very similar slight wobble to that. Would that point towards bearing issues?

Thanks so much for the help
 
Took it to an industrial supply store that specializes in wood working equipment and is also a JET dealer. They found that the spindle pulley assembly was shot, and they replaced a few of the bearings for good measure. This process took almost 2 months because the spindle pulley was on backorder from JET.

So I can't turn for a few months, not too serious as I don't make my living off it, but you know, I missed it.

Then I get it back and...One, it takes me forever to get it back on the bed ways. They didn't remount the assembly on the bottom that tightens/loosens and lets it slide properly. I tinkered with it for about an hour before I got it to even remount onto the bed of the lathe.

And I got to turning a couple things a few days later and I am having the same wobble issues. Even after making the finest possible cuts on the piece it still has a nice wobble to it. You can feel it in the wheel on the back of the powerhead that you can spin the spindle with manually. It doesn't spin true.

All this after a couple months of the lathe in the shop and a 250 dollar bill.

So I've been pretty angry about it and am going to call them tomorrow. I don't know what's going on. They seemed like a reputable company and dealer. So...WTF?
 
Yeah, I called them and now we're thinking it might be the spindle shaft.
I'm taking it back to them so we'll see. Hope this works :/:
 
Easy fix, knurle it...or peen it with a center punch...shhhh... electric motor shop trade secret. Use with bearing locktite and it'll never be loose again.
 
An old machinest showed me that peening trick. Used it a few times. I think JET brand is Chinese or Taiwanese, and known to be inexpensive. That could be the problem.
 
More than likely bearings were electric motor bearings (C3 fit) and a bit 'loose' to compensate for the heat inside a motor, couple that with a shaft 'undersized' for a cooler running tighter fit bearing you'll get some play. On woodworking direct drive applications, routers and such it's standard shop policy to use bearing retainer locktite... ok my policy since it's just me in the shop.
 
Just went back and read the entire thread, good stuff! I'm going to get set up this winter. Found an expert wood worker, gave him some logs and he'll teach me the basics. Pretty stoked but I have a tool list a grand long to pick up!
 
stig said:
Willie, those burls are some of the best turning wood there is!
Make sure you get them off the log as whole as you can.
Each holds a wonderful bowl!




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sotc said:
If no one is opposed, please expound. I have a guy that will teach me lathe work and sharpening. I'm looking into purchasing a laguna 1836 and he gave me a huge list of things to buy. Probably be a month before I start pulling the trigger
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stig said:
Madrone is really hard to rough turn and dry without it cracking.
Trick is to rough turn, then boil them.

Lets take it the the Wood Turning thread.
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Please explain the proper way to dissect a burl from a log Stig.
 
Locust burls start out at one point and grow from there.
So they end up shaped a bit like an onion, with the pointed end towards the tree.
Best way to get them off is either, when there are far between the burls, to simply visualize where they satrt and try to make a cut under the "tip of the onion"
If they are close togeteher, I usually try to plunge cut with the bar tip from 3-4 sides in order to get them out as whole as possible without damaging the burls next to them.

Nice to tell this to someone who can use a saw.
Most woodturners, when I tell them to plunge cut, I worry that they'll not survive using the information.

When you get them off, store them out of direct sun.
They are WAY easier to rough turn wet, then dry afterwards.

Once you get a lathe, I can do a " how to" series for you with pictures.

I hope a good chuck is on that to buy list?
 
Yes sir, chuck, grinder, sharpening guides, special grinding wheel, list of chisels and more I think
 
Just adding to Stig's advice, there doesn't seem to be any need to be skimpy with the wood when cutting out a Burl, unless you risk cutting into other wood that you want to save as well. You can always trim down to your turning material with more precision using a bandsaw. You do have a bandsaw, eh Willie? No shop should be without one, an invaluable tool for anyone that does anything with wood, but care is needed when cutting material that isn't flat on the side facing down on the table. Lots of books out on bandsaw use. When considering a bandsaw purchase, the bigger the better if you have the space for it and three phase power. A good running bandsaw where the blade tracks well without vibration or jumping around, is a sweet thing. They usually can be trued up by adjusting the wheels, if you find a used one worth purchasing with decent condition rubber on it and proper blade guides.
 
I have a metal band saw :/: I don't foresee me buying a wood band saw for many years.... But I value the input and any more
 
If you have sufficient cutting height clearance to make it purposeful, probably you can put a wood cutting blade on a metal band saw. Purchase blades that have more teeth per inch than less. Course blades are generally for resawing, which is different from trimming around burls and such, a finer tooth blade would be fine. Metal cutting saws run slower than wood cutting, but it shouldn't be a problem. I happen to like a slower rpm saw, geared down my hulking saw from the original pulley to do that.
 
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