Vase Problems

[Michael E. Thompson]

I had a small log laying around the shop and decided to try my had at turning an end grain vase. Using a face plate, I turned it round and gave it a rough shape. Tail-stock was used up to this point. Then I moved the tail-stock out of the way and started hollowing the end.

Initially it was turning fine and I started getting a bad vibration. The vibration was so bad it loosened the faceplate from the spindle. I tried everything, big tools, little tools, gouges to scrapers to oland tools, cutting inside-out and outside-in. I even bored a 1-1/2" hole in the center. Nothing seemed to help.

The log is maple approx 4" diam, 6" tall with a crotch on the open end. Not dry, but not wet either.

What am I doing wrong?

Thanks
Mike

[Gary Conklin]

Did you turn a small cup in the end attached to the faceplate, or just mount it to a flush cut end?

[Steve Schlumpf]

Michael - without seeing your setup - my first thoughts are that you are using a faceplate to secure an end grain turning. Screws going into end grain just don't hold well and I am willing to bet that they have weakened their hold on the turning - that is why you are starting to get vibration. Just an opinion.

[Curt Fuller]

What Steve said!
But I've also had the vibration problem even when holding endgrain wood with a tenon in my talon chuck. You wouldn't think it possible for the chuck to start unscrewing from the spindle but it does. What I've done to prevent it is to use a nylon washer between the chuck and spindle. That serves two purposes. It lets you really tighten the chuck down against the spindle and still be able to get it back off when your done. And it absorbs some of the weird vibration that causes the chuck to unscrew.
I would be very wary of using a face plate in endgrain. I'm not saying it can't be done, I'm just saying I would advise against it. But if you feel like you've got enough grip with the screws to make it work, the nylon washer might help with the unscrewing of the faceplate from the vibration.

[Bernie Weishapl]

What Curt and Steve said. I agree that screws will not hold well in endgrain at all. I do the same as Curt does with the nylon washer to absorb the vibration and keep the chuck tight.

[Richard Madison]

It does indeed seem unlikely that a faceplate or chuck would unscrew from the spindle in conventional use. More likely, as Steve said, that the screws are losing their grip on the wood.

[Jeff Nicol]

When you put screws into end grain there is nothing holding them in place as the fibers of the wood go the same direction as the screws. So every time you cut into the wood the piece flexes and loosens the screws. You could try predrilling with a small bit and drenching each hole with CA and that might help, but it would be better to turn a tenon to be grabbed with a chuck to complete the hollowing. Or get a steady rest to support the end where you are holloing. Also the thing about end graind you have to be cutting it and not scraping it , as the scraping just adds more vibration. Spoken with experience and disaster first hand!

Jeff

[Michael E. Thompson]

The screws in the end grain. I should have guessed that, they did loosen up quite a bit. I tried longer/bigger screws and had the same results. I had considered using a chuck but thought a face plate would have been stronger. I never considered the screws pulling out.

Nylon washer is a great idea. I am going to pick up several of those tonight.

I will grab another log and try again tonight with all these suggestions.

Thanks
Mike

[Mike Minto]

michael, yeah, i've had the same prob from time to time; i now use the large jaws on my chuck to turn long hollow forms. i have also made a steady rest to help with this, because the force generated by your tools on a long piece of wood supported only at one end are great. sharp, sharp tools, a light touch and slower rpm than usual - for me, under 400.

[curtis rosche]

when using screws in the endgrain, leave alot of waste so that you can put in large screws, like 2 inche screws at least. also, put them in at anlges, some as angled as possible, some not as angled. and put them in different directions. i do that, and since i started that, i havent had a problem. also, if its wet wood, let it sit for a week with the screws in, the wood seems to tighten around the wood...

[Michael E. Thompson]

michael, yeah, i've had the same prob from time to time; i now use the large jaws on my chuck to turn long hollow forms. i have also made a steady rest to help with this, because the force generated by your tools on a long piece of wood supported only at one end are great. sharp, sharp tools, a light touch and slower rpm than usual - for me, under 400.


I have concidered building a steady rest but have not because I plan on upgrading my lathe in the near future and don't want to spend the effort or money on one just yet.

I am limited on my lathe to a mininum of 500 RPM due to the pully, wish I could turn slower on some things.

Thanks for the help.
Mike

[Gary Conklin]

I am rather confused by the screws in the end grain being an issue. I have never had issues with this. I have seen Lyle Jamieson screw directly into the end grain with 1.5" screws with no issues. He just turns the end mounted to the faceplate with a slight concave so that is doesn't "wobble."