Made myself a cone thingy today.

[JDarvall]

To quickly set the calipers. Got the idea from a book I'm reading at the moment. I turned it from scrap and have attached it to the side of the lathe. Spose all you blokes have already got cone thingys

[funkychicken]

Good thinking 99:2tsup:


An improvement would be to make it stepped

[artme]

Spose all you blokes have already got cone thingys
Nope.
Will have one soon.:D:D:D

[BobL]

To quickly set the calipers. Got the idea from a book I'm reading at the moment. I turned it from scrap and have attached it to the side of the lathe. Spose all you blokes have already got cone thingys

Nuh . .. might make 2 one for imperial and one for metric :wink:

Somewhere I have also seen an thingo for inside measurements, It was actually just a set of holes in a board drilled out with forstner bits.

[weisyboy]

it going on the list.

might get to it by next christmas:roll:

[JDarvall]

:D.

I like your idea funkychicken. Will put it back on the lathe and step it all before the pencil marks smudge out. and do it again in pen.

[TTIT]

I'd leave it as it is Jake - how else will you get a half size (a tad bigger etc!) between your markings :shrug:

[Lignum]

Jake... What are you doing on a lathe? Have you decided to give up woodworking for a while?

[JDarvall]

I'd leave it as it is Jake - how else will you get a half size (a tad bigger etc!) between your markings :shrug:

I spose. your right. Its not really something that needs to be that accurate anyway eh. Just for sizing in, for between profiles.

[JDarvall]

Jake... What are you doing on a lathe? Have you decided to give up woodworking for a while?

well I should. There's no money in it. I'm going to make a few chairs Lignum with lots of spindles.

[BobL]

I spose. your right. Its not really something that needs to be that accurate anyway eh. Just for sizing in, for between profiles.

That poofteenth above actual size is a very useful one when turning. Say I'm turning to 25 mm - I would set my calipers for 26 mm and take bigger cuts till the calipers fit then I creep up to the right size using smaller cuts.

The cone thingy could also be useful other way - say you want to turn to 25 mm mm so you turn for a while and you drop the calipers set at 25 mm on the turned wood and it sort of sits on the wood but its hard to envisage whether you have 1 or 2 mm to go. Set the calipers to the size of the wood being turned and then drop the calipers on the cone and see how much there is to go.

Of course a digital vernier calipers are pretty handy in these situations.

[orraloon]

Good idea. Will save some time as I always have to rummage in the shavings to find the ruler.
Regards
John

[Frank&Earnest]

That poofteenth above actual size is a very useful one when turning.


I wouldn't have thought that there were many big poofteenths among turners.:D

[JDarvall]

The cone thingy could also be useful other way - say you want to turn to 25 mm mm so you turn for a while and you drop the calipers set at 25 mm on the turned wood and it sort of sits on the wood but its hard to envisage whether you have 1 or 2 mm to go. Set the calipers to the size of the wood being turned and then drop the calipers on the cone and see how much there is to go.



I can see how that may help. One thing that I haven't mastered yet,, that gets me nervious,, is sizing tenons to fit some hole. I like the fits to be just right, but I feel that its not going to be accurate enough with calipers.....either because the calipers flex a bit, or because I'm accually cutting at the wood a little with them so that I've really sized bigger overall...etc..

Can only relax when I can test the fit, but to do that I have to dock the end off. point of no return sort of thing.

[rsser]

Not sure I get you with the tenon size query AT.

How would this work?

Turn it down to a bit over size, then turn the tip down to your best guess and fit it into the hole. Twist the tenon to and fro a bit and remove. The mark left on it tells you what size it should be and then you can take a light cut on part of the remainder and retest. And repeat.

Make sense?

[weisyboy]

i jst use a scrap of wood and when i drill the hole for teh mortise i drill a hole in the scrap at the same time and use that ot test the fit.:2tsup:

[joe greiner]

Can only relax when I can test the fit, but to do that I have to dock the end off. point of no return sort of thing.

Not necessarily, Jake. If you cut your spindle blanks to exact length, the centre divots will enable re-mounting without drama. Save the tenon cuts until last, and you should be able to flip the piece so that the spur centre has enough to bite into for turning the opposite end. Unless you need very small tenons; then you might need off-lathe "turning" with the 60-grit gouge.

Joe

[tameriska]

Glad to hear that you finally got yourself a cone, Apricotripper :U

It must be a sheila thing, but when I first saw the pic, my immediate thought was "ring sizing gauge"

[JDarvall]

Ta. Sorry I wasn't very clear.

The problem sometimes is ......that both ends need tenons. These tenons are under the dimeter of the spur drive ( but I didnt think I could just flip it of course and size only at the tail :rolleyes:) and also their through tenons, whose ends will be seen......so I've got to dock both ends to length after turning to remove the spindle marks in the end grain.

And I was also worried that since the tenons are smaller than the head spur drive, the spurs wouldn't have enough grip on such a small diameter and rip itself out of the kerfs and spin...

I suppose I was just looking for confidence in being able to size them perfectly with calipers only. Keep the process fast without having to remove the spindle from the lathe and make an actual test fit. So that I can mark off everything to length on the lathe, size everything, and take straight to saw to dock off both ends with a stop and know the tenons will fit without test. Something to improve on in my sizing technique.

What do you think of those sizing jigs you can get that attach to parting tools ? ......I was thinking they maybe more accurate with one of them than sizing with normal calipers in one hand, and parting tool in other.

[JDarvall]

It must be a sheila thing, but when I first saw the pic, my immediate thought was "ring sizing gauge"
:)does look a bit like one of those eh.

[RETIRED]

Use a spanner of the correct size for tenons.

[JDarvall]

Ta . Have used them. But often I don't have the right sized spanner.

Have you ever tried those jigs you attach to your parting tool for sizing in ?

[RETIRED]

Yep. Can get pretty close with one but is acquired "feel" .

[rsser]

Made by Sorby I think.

Parting tool attachment.

[JDarvall]

Ta. I was thinking I could make my own.

Being searching the net and found this...(just copied it here)

Quick & easy home-made tenon turning gauge
Using the drill bit you plan to use to bore the holes for your tenons, drill a hole near one end of an 8" long by 2" wide piece of 3/8" to 1" thick (depending on your tenon size) scrap stock. Mark the centerline of your hole (across the narrow, 2" wide direction) before you start drilling.
Once the hole is drilled, use your table saw or bandsaw to saw your hole in half, leaving an open arc at the edge of your gauge. Then, simply check your turning progress by placing this open arc over your tenon.

I'm liking this for a direct check. A half circle of the actual mortise hole the tenon will fit. In my hand, so I can check for tight fit all along the tenon, without having to stop lathe and check or oversize the the length for docking off latter.