Chuck Recess

[Richard Findley]

Do you worry about the underside of your tv set, sofa, car or fridge when you buy it? Probably not. So why should you worry about the undersides of you bowls as long as it is neat and tidy. Whether it has screw holes or a recess is not liklely to put the customers off. In fact if you leave the recess on the customer can bring it back that beautiful cherry fruit bowl a few years to be polished up or if it has got damaged it can be remounted and skimmed.

I've been thinking about this statement. The underside of my sofa is neatly upholstered with piece of fabric across the base, just so it is nicely finished off. The underside of a TV has 4 little rubber feet, positioned so it sits level and safely, it may also have some vents to allow air flow. I can go on if you like....

The point is, everything has a bottom and you can leave it rough but all that does is show low standards and a lack of design. A well finished bottom raises your bowl above the rest and is so easy and cheap to do, I see no reason not to.

Just my opinion.

Richard

 

[pete honeyman]

As robert chapman says in his book,' a bpwl is only as good as its worst feature' - a recess isnt necessarily a bad thing, but you need to think about it in the context of the piece and design/finish itb suit.

iMHO that is.

Pete

 

[Bodrighy]

On the occasions when I have done craft fairs etc you come across turners with felted bottoms hiding screw holes, recess that aren't cleaned up inside let alone decorated, Tenons poorly removed leaving tool or sanding marks. In my opinion any turner who takes a pride in the quality of his work finishes it off completely. I have been know to leave a tenon on as a foot but I reverse the bowl and clean it up not leave chuck marks on it. If I use a recess I usually decorate inside it and then round it off afterwards. The only time I have used felt was where I made some vases out of some gorgeous spalted sycamore and could not in any way get the bottom cleaned up properly as the grain was just too soft so I did the best I could and put flt on it. Even then I felt guilty :lol:
If I was buying furniture, the place I would look to see what the quality was like would be inside or underneath. I f a job is worth doing it's worth doing well as the old craftsmen used to say

Pete

 

[CHJ]

I use a socket mounting on nine out of ten of my turnings, just a routine and method I feel comfortable with.

I personally would not let an item leave my shed with any more trace of the mounting socket than shown above, in fact it is one of the things I get complimentary remarks for when recipients compare the pieces with items they have seen at local craft fairs and 'local art' outlets.
It takes a matter of 1-2 minutes at most to blend away the dovetail if you plan your working method.

 

[George Foweraker]

Hi lee.
The trouble with a recess is that as you tighten the jaws in expansion mode they are putting stress on the wood.
A spigot is much safer in my opinion as it does not weaken the wood.
I leave a very shallow foot on nearly all of my bowls as it gives them a bit of lift.

Regards George

 

[robo hippy]

It gets argued about a lot, but as far as I am concerned, there is no mechanical strength advantage to either a spigot or recess. When PROPERLY MADE both work well. The emphasis is the 'properly made' part. When either method fails, it is either bad (punky, cracked, or bark included) wood or a poorly made spigot or tenon. If the spigot or tenon is properly made, and it fails, then there is too much or too little tension (over or under tightening) of the chuck. The biggest difference in the chucks that I can see other than jaw design is the keyed chuck vs the tommy barred chuck which uses levers to tighten. Lower gear ratio on the keyed chucks, so it is a bit easier to get the tension up. Both work, and you have to learn what to do to make it work properly.

robo hippy

 

[myturn]

I would disagree.

In expansion us8ing a recess there is nothing to support the wood outside of the recess other than the small amount of wood around it.

In compression using a spigot it will take a lot more force and the spigot is self-supporting as it is a solid. The only thing that will break a spigot is crushing what is weak wood and if you used a recess with the same wood it would break far sooner.

I've had far more failures using a recess than using a spigot.

 

[George Foweraker]

Exactly right

 

[guyandzoe]

I dont have an opinion either way. I have very very few failures either with a spigot or with a recess. Much less than one per year of either. BUT you do need to have a good understanding of your wood and your chuck and not put too much chuck pressure on any recess one makes. The success of a recess is not dependent on the sideways jaw pressure.

I find a good set of jaws will hold tenaciously to a well made recess - which includes both the angle of the undercut and the flat surface for the face of the jaws to sit upon - something that is shared with a spigot. Most failures, i think, are down to the turner making a mistake and not to the method of holding.

As others have said ones final design often dictates which method to use and a spigot gives one more options than does a recess., which rather fixes the size of a foot if one is not to lose too much wood.

Should one remove evidence of chucking? Well, again I dont have any firm opinion. I have sold hundreds and hundreds of bowls with recess in place. Only other turners ever have anything to say on the matter and I have not noted any adverse reaction from my buying public. I think it is just the difference between the practical and the theory and I blame the show circuit/judges for placing too much emphasis on the removal of any evidence of mounting and that emphasis has unfortunately moved into practical turning when it possibly has no relevance there. Having said that I remove the evidence on bowls which are either very highly priced or which are destined for Galleries.

It is a personal matter. If you are into showing and competitions then you need to get rid. If not dont worry too much about it, ignore the pressure and do what you think is best for your market/conscience.

 

[SVB]

This spigot / recess strength issue is an interesting, debate if slightly academic!

Given wood is a compressible medium, in the interests of debate and to put the opposite case I could argue I am not so sure the spigot will always be stronger.

At the limit, to hold a piece of timber one needs to balance the force trying to remove it.

A recess will spread a given force over a larger area of timber than a spigot for any given set of jaws. Therefore, it could be possible to apply a larger holding force (as the load applied by the jaws will be spread over a larger area) with a recess PROVIDED sufficient material is left to support the timber around the recess.

The above comes back to where I started, as timber is compressible, the amount required to support the recess is not necessarily that large and only needs to be enough to be greater than the compressibility of the timber which of cause will vary from species to species and even piece to piece.

Just a thought! (hammer)

Simon

 

[guyandzoe]

Well said that man!