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Nai84
22nd October 2010, 06:03 PM
Hey Everyone

I have been honing my skill with green wood I decidced to rough out a blank to it dry out a natural edge bowl is what I went with and this is how it turned out. I didnt have many problems with it this time except when I try to speed up the lathe it vibrated like mad am I still doing something wrong or what:? I turned the whole thing a slow speed just to be safe as last night it flew off at me :oo:

Cheers Nai

wheelinround
22nd October 2010, 06:28 PM
Nope nothing wrong the balance should only be due to the shape of the bowl. looks good from here. :2tsup::2tsup:

artme
22nd October 2010, 07:37 PM
Looks good from here too!!:2tsup::2tsup::2tsup:

As Ray says the shape causes vibration.

How are you chucking the bowl for it to fly off??

wheelinround
22nd October 2010, 08:49 PM
Ian when your creating the tenon are you making the sides straight or doing it with a dovetail for both internal and external. If you look at the jaws of the chuck you'll see what I mean.

Nai84
22nd October 2010, 08:51 PM
Hey wheelinround

Thanks, Well that sound kind of simple eough reason why it would vibrate thanks again:2tsup:

Hey artme

Well I had another look today when I finished turning it out for it to dry, I think I cut the tennon to short and with the vibration from the lathe when I went to speed it up to get a better cut it flew off the lathe and scared the hell out of me:oo: but let me say lesson learnt when turning odd shaped bowls make sure tennon is correct size and do not try to speed it up if it vibrates:). Ok question time how deep should the tennon be :?

Cheers Nai

Sawdust Maker
22nd October 2010, 08:53 PM
Looks like a badly "out of kilter" bit of wood
it should have been disposed of rather then put on a lathe. It can harm the environment and the neighbourhood it is kept in or adjacent to!
I'm happy for you to send it over here along with any other timber cut from the same tree for safe and hygienic and nuclear free disposal.
It's the least I can do for a mate, really

wheelinround
22nd October 2010, 08:59 PM
Hey wheelinround

Thanks, Well that sound kind of simple eough reason why it would vibrate thanks again:2tsup:

Hey artme

Well I had another look today when I finished turning it out for it to dry, I think I cut the tennon to short and with the vibration from the lathe when I went to speed it up to get a better cut it flew off the lathe and scared the hell out of me:oo: but let me say lesson learnt when turning odd shaped bowls make sure tennon is correct size and do not try to speed it up if it vibrates:). Ok question time how deep should the tennon be :?

Cheers Nai

Nai I was once told 1/8th :~:no: do what you feel comfortable with look at the piece your turning if its like what you have above your going to need a good solid grip.

Look at your Jaws use a depth gauge or ruler and measure, youll pick it up and soon be doing it with your eye's shut almost.

Nai84
22nd October 2010, 09:10 PM
Looks like a badly "out of kilter" bit of wood
it should have been disposed of rather then put on a lathe. It can harm the environment and the neighbourhood it is kept in or adjacent to!
I'm happy for you to send it over here along with any other timber cut from the same tree for safe and hygienic and nuclear free disposal.
It's the least I can do for a mate, really

Hey Sawdust Maker

Sorry mate but I plan on keeping the wood and turning plenty more bowls like this but if you would like a peice to turn then I might be able to help :D

Hey Wheelinround

Thanks again mate I will try it out at least I have learnt my lesson now and I am never gonna let it happen again, So if I make tennon so it almost touches the bottom of the chuck it should be all good then :2tsup: or is that no good

Cheers Nai

Pat
22nd October 2010, 09:25 PM
Neil, my tenons range from about 4mm for smaller blanks (>150mm) that are in balance thru to about 12mm for 400mm + platters or out of balance blanks.

wheelinround
22nd October 2010, 09:25 PM
Ian I have a new set of Nova Powergrip (http://www.teknatool.com/products/Chuck_Accessories/PowerGrip.htm) jaws and was turning a piece last week on my Nova lathe and it spat off :o Lucky no damage. These jaws are much deeper and have bite. The green softwood I am turning wasn't the problem I was. I have in the past been used to straight sided powergrip jaws the new ones are dovetailed to suit the USA market. I assumed so made a straight tenon.:doh:

Wood will crush and move even in the best of jaws.:~

Nick you want a piece of similar wood give me a buzz ....how big :U

Nai84
22nd October 2010, 09:38 PM
Hey Wheelinround

Well my jaws are virmarc 100 and I think the main problem was me not cutting the tennon long enough and I am thinking about getting a bigger set of jaws to do bigger peices any seggestions

Cheers Nai

Sawdust Maker
22nd October 2010, 09:42 PM
...

Nick you want a piece of similar wood give me a buzz ....how big :U

About [ ....................................... ] that big :rolleyes:
Bring it over for the turnfest

Just to compleatly highjack this thread - we've got to sort out the Tuesday turn/comealongs, I reckon every second Tues or 1st and 3rd Tues of every month

Nai84
22nd October 2010, 09:47 PM
Hey Sawdust Maker

Sounds like fun wish I could come along and play to :( :( :(

Nai:(

Sawdust Maker
22nd October 2010, 09:50 PM
I dunno
jetstar trip every 2nd week :p

Nai84
23rd October 2010, 02:26 AM
I dunno
jetstar trip every 2nd week :p

Hey Sawdust Maker

I wish that could happen maybe if i win lotto :p

Cheers Nai

Paul39
23rd October 2010, 08:23 AM
Ian,

Quote: (I turned the whole thing a slow speed just to be safe as last night it flew off at me.)

The above is why I like slow speed and tailstock , especially for roughing.

Last Friday I bought a set of #3 jaws for my Oneway Chuck. I have been using #2 jaws with the tailstock to keep the bowl on the lathe.

With the bigger grip of the #3 I was comfortable using just the chuck after hacking the bigger chunks off the outside while using the tailstock.

For bigger bowls the bigger grip is much better. I also like a deep recess or a long spigot to grip. With a bigger bowl the larger & deeper is not out of proportion.

wheelinround
23rd October 2010, 08:31 AM
Neil, my tenons range from about 4mm for smaller blanks (>150mm) that are in balance thru to about 12mm for 400mm + platters or out of balance blanks.

:? who's Neil??

Been a long week Pat:q


Ian I dont have Virmarc jaws but as Pat has said above should do well size wise.

Other wise securing to a face plate is the way to go :2tsup:

Pat
23rd October 2010, 08:45 AM
:? who's Neil??

Been a long week Pat:q

Yes! Looks like I'll be working solo from the end of next week as well, should make it a bit easier to know where the job is up to, but the volume of work will be enormous:~

I use a face plate, with the appropriate length screws (Sachy Robinsons 14g) to rough the outside of the bowl and to turn a trued spigot. My face plates range from 75mm to 200mm.

turnerted
23rd October 2010, 04:36 PM
When you're turning green wood,it pays to check the tightening of your chuck after a few minutes turning. It's supprising how much the tennon will crush .
Ted

Nai84
24th October 2010, 12:16 AM
Hey Guys

Thanks for all the info again guys it will be used wisely :2tsup: does anyone have any pics of how they mount bowl into the lathe with or without the chuck :2tsup:

Cheers Nai

Paul39
26th October 2010, 04:56 AM
Ian,

Put "mounting a bowl blank" in search above. Lots of Ideas. You have been turning enough that you should be able to visualize what to do by the comments there.

dr4g0nfly
26th October 2010, 05:12 AM
I've got the same problem with a green Ash blank I've roughed out - I tracked it down to the additional density and wetness of the heartwood being off the centre-line of the chuck.
It should come better when it's drier - could you have the same off-centre problem?

Nai84
26th October 2010, 01:46 PM
Ian,

Put "mounting a bowl blank" in search above. Lots of Ideas. You have been turning enough that you should be able to visualize what to do by the comments there.


Hey Paul39

I have been turning for a while and I can visualize all the comments but I am the short of presons that loves to get as much info as possible and if that inclueds pics great if not oh well thats why I love this forum so much yous guys have have helped me so much with info and pics alike and I am greatfull off all the help you and the guys have given on this matter and many others:2tsup:

Cheers Nai

PS
Once again THANKS TO ALL FOR YOUR HELP:2tsup:

Paul39
27th October 2010, 10:15 AM
Ian,

Here are 3 pics of a method I described earlier. I hack the blank more or less round and put a reasonably flat part against the face plate. In this case I used two 1 1/4 X 8 drywall screws to keep it on the face plate. I run the live center against the other side and tighten, turn the blank over a few times by hand, tighten some more,

I then cut the end against the tail stock flat, leaving a little spigot with the hole made by the live center point in it.

I then turn it around and using the spigot, center it on the faceplate and run the live center up against the right side, tighten, spin, retighten, As the side against the face plate is flat, the friction of bowl against the face plate drives the blank. The pressure of the live center and the spigot left on the side towards the face plate keeps it centered.

Then I flatten the side against the live center and make the bowl round, tightening the tail stock center as we go, as the blank is loosened by the banging of the interrupted cut.

I then decide which is the bottom of the bowl and make a recess or spigot to fit the chuck. This partly dry walnut piece was started on the 20 inch Woodfast and further refined and hollowed on the 350mm Hegner.

I got # 3 jaws for my chuck a couple weeks ago and will get the 1 1/4 X 8 insert for the chuck so I can mount it on the Woodfast.

In due course I will get a bigger chuck and 5 inch jaws for the Woodfast.

P. S. For those who noticed the rust. The photos are within an hour after I got the lathe home from the seller and dragged it into the back yard in pieces. I have since polished all the bare metal and disassembled, cleaned, and greased everything but the spindle, which runs like a silk scarf running through an ivory napkin ring.

A very sweet lathe.

Paul39
27th October 2010, 11:04 AM
A few more pics:

After I split this blank I noticed the crack and used a couple turns of electrical tape to keep things together.

Why a lathe stand is better than a bench. Stand in progress.

Fast and dirty depth gauge, stick tool to bottom of bowl, sight along rim, put thumb in line with rim. Align thumb with rim, bottom is at tip - more or less.

Three ways of holding a blank or bowl on a faceplate or chuck. A broken lid to a water filter, I held it against the faceplate and trimmed off the handle and sharp edges. A wheel hub for a riding toy. A knob from a computer printer.

I see on preview the photos have arranged themselves in the order taken. I expect you folks can figure which is which.

Paul39
27th October 2010, 12:00 PM
More pics:

Selection of medium density fiberboard faceplate covers from discarded furniture. The grooved one on the left is from finishing several bowl bottoms. I cut the groove just a bit bigger than the bowl, lay a piece of soft cloth over the face plate, fit the bowl, bring up the live center to gently hold the bowl in place, do the finishing as much as possible, remove the bowl and hand finish where the live center was.

The cup in the center top is for holding wooden eggs for finishing. Second photo shows the spigot for the chuck to grab.

Three and four show a sanding disk made from an off cut of 5/4 6 inch decking. Recess in back for chuck to grab, I cover the front with double sided carpet tape and stick on a 6 inch disk. If I make a flat bottom turning, I clean up the bottom with this, making it slightly concave by rotating the piece and running it off the edge of the sanding disk. I finish by hand sanding.

The last is part of a cherry log a friend brought me from his place in Ohio. I started it between centers on the Woodfast, As someone commented, a drive center on a big blank acts like a forstner bit.

As things progressed I had the bottoms of two bowls with a hunk of wood between. I cut a spigot on the right side, and a recess on the left. I used a diamond shaped cut off tool, then a thinner one made from a bread knife, then stopped the lathe and used a hand saw for the rest.

As you can see I have retained a center point on both sides. The wood was quite wet and has been moving a lot. The center points will help me remount, as I can put the top against a face plate, stick the point of the live center into the hole in the center, and recut the recess or spigot.

The last photo of the inside of the left bowl shows how much wall thickness I leave on a damp bowl. I leave more with fresh cut wood as I have to cut off more to make it round after it has dried oval.

Nai84
28th October 2010, 02:25 AM
Hey Paul 39 Once again thanks for the abundence of info and the pics you have given me a few ideas that i gonna try out and see how i go i will let you know what the outcomes are and with pics aswell. I would like to know what the wood is that you were using it look cool once again thanks for the info and pics :2tsup: Ian

Paul39
28th October 2010, 08:14 AM
The smart answer to what wood is it. Tiswood, as opposed to tain'twood.

I think maple, as the bark and even color of the wood through the log seem to indicate. Also the burled area looks like maple burl I have cut.

My across the street neighbor had a dead maple tree fall, so now I have two crotches and a base with about 20 feet of straight, tapering from 14 inches to 10 inches. The base has mushrooms growing on it so it should have some spalting.

I took a few pics of the pile on my sidewalk.

wheelinround
28th October 2010, 08:41 AM
Nice neighbourly gesture FREE wood :U

Nai84
28th October 2010, 09:43 PM
Hey Paul39

Awsome what a nice neighbour free wood :D, Cool maple well it lokks like you had fun turning it, The piece with mushrooms on it will be nice when its turned I wish I had a neighbour like that :2tsup:

Ian