Metal to Wood !

[gawdelpus]

Recently Neil (dai sensei) and I put our heads together to create a ball turning attachment for our wood turning :) , Mine will most likely be only used for the balls on top of my pepper grinders :) but can turn up to 150 mm dia balls. Neil made his to to suit both his woodfast and larger jet so needed a few extras added , I did a quick test on some scrap to make a 60mm ball ,to test the theory ,might need a bit more tweeking ,but nothing major ,this was also a good excuse for Neil to give his new metal lathe a workout hehe, hw will add pictures of his after its finished painting :) cheers ~ John

[Willy Nelson]

I suppose you had a ball making it, once you got around to it

Sorry, now seriously
If the stand had a groove instead of the holes (where the two allen bolts are, this would give an infinite choice of ball sizes only limited to the length of the groove, and mounting plate
Willy
Jarrahland

[dai sensei]

Finished mine today, except for the paint job, tomorrow's exercise.


...If the stand had a groove instead of the holes (where the two allen bolts are, this would give an infinite choice of ball sizes only limited to the length of the groove, and mounting plate
Willy
Jarrahland

The limit of ball size is normally the height between the top of the bearing housing and the centre of the lathe, the mounting/rotating plate has more capacity (although John chopped his off short). John's like mine has holes at 20mm c/c, but the tool has >30mm movement so we still get a continuous ball size availability, my plate is longer to ensure limit is the height availability. The advantage of 2 bolts, in lieu of a single bolt in a slide slot, is that the tool is always presented at 90 degrees to the ball.

[KBs PensNmore]

Gentlemen VERY nicely made, when does production start :U LOL. Seriously though an excellent execution of a difficult problem.
Kryn

[gawdelpus]

I suppose you had a ball making it, once you got around to it

Sorry, now seriously
If the stand had a groove instead of the holes (where the two allen bolts are, this would give an infinite choice of ball sizes only limited to the length of the groove, and mounting plate
Willy
Jarrahland

Willy we had a lathe and drill available , no milling machine ,so in place of a slot we have a series of holes at 20mm c/distance and abour 30mm tool travel so the ball diameter capabilites is in my case from "0" size ball to about "150" mm dia, and anything in between :) Neils is designed for his woodfast like mine and his larger Jet,so he can have even larger balls hehe ! cheers ~ John

[bench1holio]

looks like it does the job john :2tsup: should be spot on for doin s&p mill balls, well done!

[dr4g0nfly]

I've no idea if this guy will post to Aus, but he makes a 100mm & a 150mm ball turning tool, I've seen them in operation and they work extreamly well.

150mm ball turning tool (http://www.ebay.co.uk/itm/WOODTURNING-LATHE-150mm-LARGE-BALL-TURNING-TOOL-JIG-/290689488478)

He also makes a thread forming tool as well - not seen it working though so no comment to make on it.

He makes them himself - not a company and the prices are almost give-away.

[artme]

That cutter looks like it gives a pretty good finish fellas.

A job well done!!:2tsup::2tsup::2tsup:

[Big Shed]

Looks pretty handy, did you get your inspiration from Vermecs' Sphere Cutting Jig?

Vermec's Tools (http://www.vermec.com/id1.html)

Looks fairly similar.

[gawdelpus]

Fred ! yes that Vermec was the inspiration :) , our model is less sophisticated ,no cam locks hehe. Cheers ~ John

[dai sensei]

The Vermec version is a well made unit, and unless you have time on your hands with little worth, is actually a cheap way to go let me tell you. There are many hours work in these if you are making them yourself. The biggest problem I had with the Vermec is the amount of room the actual bearing housing takes away from the available radius. The cam lock however is a nice feature.

[Tim the Timber Turner]

The advantage of 2 bolts, in lieu of a single bolt in a slide slot, is that the tool is always presented at 90 degrees to the ball.

Square to the work is not always the best way to go.

If the tool is canted to the left and a small round cutter used, the ball can be cut much further around towards the headstock.

This means a much smaller diameter stub and less work to finish the ball.

In a 60mm ball a stub of about 10mm is achievable.

Cheers

Tim:)

[dai sensei]

Good point, I hadn't thought of that. Mine does have a small round cutter

[gawdelpus]

Hi Tim:) I am probably missing something here, the mechanics of turning a ball dictates that the pivot point is at the centre of the ball and the cutting tool is square to that pivot ,so when pivoted backwards and forwards it arcs across the centre point of the ball. to form the size required . Any tool advancement has to remain in this geometry. If the tool is placed at an angle ,then a different means of advancing the tool needs to be accommodated ,eg the tool remains fixed relative to the centre of the ball, and the tool holder has to advance as a unit , As any adjustment of the tool inwards to reduce diameter would shift the tool away from the centre line ? Keen to see any sketch or pictures of what you are saying as I just don't quite get it :? . Cheers ~ John

[RETIRED]

John. The cutter still works on the centre line but because you are only cutting half the ball you can have the cutter advanced a little on the headstock side and go past the centre on the free end. The "swinging" arm still moves in the same arc.

More confused now? :D

[gawdelpus]

Thanks :) I am sending my technical assistant to Melbourne in a couple of weeks , I will sick him onto you for a full rundown hehe, He might even bring his model for advanced tips :) cheers ~ John :D

[dai sensei]

This may help. The blue ball is with the tool at right angles, the green ball is at ~45 degrees (I have shown all quadrant positions). With the same circle, the ball is larger, but still a ball

Might drill some more holes in mine at the base, so I can use 45 degrees

Cheers

[Tim the Timber Turner]

Hi Tim:) I am probably missing something here, the mechanics of turning a ball dictates that the pivot point is at the centre of the ball and the cutting tool is square to that pivot ,so when pivoted backwards and forwards it arcs across the centre point of the ball. to form the size required . Any tool advancement has to remain in this geometry. If the tool is placed at an angle ,then a different means of advancing the tool needs to be accommodated ,eg the tool remains fixed relative to the centre of the ball, and the tool holder has to advance as a unit , As any adjustment of the tool inwards to reduce diameter would shift the tool away from the centre line ? Keen to see any sketch or pictures of what you are saying as I just don't quite get it :? . Cheers ~ John

G'day John

I've no idea about the maths involved in this.

I'll let someone much smarter than me explain that.

I have made many balls with my Vermec Ball Cutter and only found out about using an offset by trial and error.

" quote"
John. The cutter still works on the centre line but because you are only cutting half the ball you can have the cutter advanced a little on the headstock side and go past the centre on the free end. The "swinging" arm still moves in the same arc.



please!! there you go again agreeing with me!! Please stop!!! keep it up and I'll start thinking I'm an expert.

Cheers

Tim:U

[Tim the Timber Turner]

Might drill some more holes in mine at the base, so I can use 45 degrees

Cheers

Neil

I think from memory, 45 degrees will be too much.

I would suggest one bolt in the centre of the post will allow you to experiment with the amount of offset.

Cheers

Tim:)

[dai sensei]

You could be right Tim. I'll think a bit more about it, only using a M8 HT bolts at present, a larger bolt will have insufficient edge distance to the existing holes. I could always fill the existing holes I guess.

[gawdelpus]

Bugger ! should have grabbed one of Neils round carbide tools while I had a chance lol. Now I will have to redesign my turning tool to allow for an offset hehe , ah well no biggie :)
thanks for the feedback gents~ Cheers ~ John :D

[dai sensei]

still got one spare, I'll add it to your bill :U:U

[David Pride]

I found when designing the sphere attachment for my lathe it was better to have all the contact surfaces inline with the pivot.Introducing offsets can cause chatter if the structure is not rigid enough. The large spheres I make are roughed with a scraper and then sometimes finished with carbide tips made for aluminum. I also found that if the cutter is able to be rotated, it can be pulled across the surface with the tip (triangular cutter) trailing (cutting with the side) so to cause a slicing cut that is very smooth as a finish. The cutters for aluim have a deeper groove for chip breaking so are much smoother for wood. The round cutters are also good. I use the highest speed I can for the finish cut.

[Tim the Timber Turner]

I found when designing the sphere attachment for my lathe it was better to have all the contact surfaces inline with the pivot.Introducing offsets can cause chatter if the structure is not rigid enough. The large spheres I make are roughed with a scraper and then sometimes finished with carbide tips made for aluminum. I also found that if the cutter is able to be rotated, it can be pulled across the surface with the tip (triangular cutter) trailing (cutting with the side) so to cause a slicing cut that is very smooth as a finish. The cutters for aluim have a deeper groove for chip breaking so are much smoother for wood. The round cutters are also good. I use the highest speed I can for the finish cut.

I agree with David about the chip breaker.
In softer timbers, it will cut much cleaner than a flat top cutter.
A 16mm round flat top cutter will expose more cutting edge to the wood. This can load up the cutting edge and lead to chatter when working around towards the stub.
A 10 mm round tip with a chip breaker is the way go.
David, I was interested in your use of a triangular cutter.
Good thinking an your part.
Cheers

Tim:)

[TEEJAY]

Hi Neil,

Yep I will definitely get one of those Vermec models when I get the lathe up and running again - got a new 3hp motor for it this week.

I would like to try it with the oval turner too - should make for some interesting pepper and salt grinders.

Cheers mate

[dai sensei]

Ok here is mine, still with a double bolt system to attach the main tool post to the swivel plate, painted with hammer-tone blue. The top tool clamp has a brass insert to ensure the SS tool is not damaged when clamped. I will drill and tap a central hole in the tool post to have the option of a single bolt in the middle. It will raise the cutter edge slightly, but if a problem, I have a plastic slide under the tool post that can be removed lowering the post.

I made mine so it would fit both the smaller WoodFast, plus my larger JET. When I use the JET, there is a spacer block for the tool post plus a ring plate to attach to the bearing housing base, to allow for the larger ball capacity and ensure the jig remains central to the lathe respectively.

The main cutter is a 8mm round timber cutter from the WoodCut systems I had spare. I have slanted the cutter at 15 degrees similar to the Vermec system as I have found this to give a better finish. The ball shown is a dry old piece of Blackwood, with literally no tear-out, so I'm pretty happy. I too rough out the ball with my normal chisels.

Cheers

[BobL]

Slicko!

[TTIT]

Ok here is mine, ............What have you got in the corners of the base plate that sits on the bed Neil? Can't figure it from the pic :?

[gawdelpus]

The way this locks onto the bed is with a 16 mm stainless stud locked into the bottom of the bearing housing , the 4 corners have a hole drilled to take an 8 mm shaft to lock the housing onto the bed ,less sophisticated than a camlock ,but very effective , the plate underneath is tapped to take the 16mm stud :) cheers ~ John

[dai sensei]

What have you got in the corners of the base plate that sits on the bed Neil? Can't figure it from the pic :?

There is an 8mm hole in each corner for a rod I use to tighten the bearing housing down to the lathe. The bottom plate (under the lathe top plate) is threaded and the bearing housing has a threaded rod, so I twist the housing to tighten by hand, then the rod to fully tighten. This is in lieu of a cam lock, which would be better, but takes up more room out of the available height.

[dai sensei]

You beat me John :U:U

[Metalman]

Hi,
can these devices be set up to cut a concave shape in the end of a blank, that is, hollow out a bowl to a set radius? It should be possible by moving the main pivot towards the tail stock and reversing the tool holder on the arm. Any thoughts?
Mm. (visiting from the metal work forum.)

[dai sensei]

Hi,
can these devices be set up to cut a concave shape in the end of a blank, that is, hollow out a bowl to a set radius? It should be possible by moving the main pivot towards the tail stock and reversing the tool holder on the arm. Any thoughts?
Mm. (visiting from the metal work forum.)

Yep :2tsup:

[gawdelpus]

Ok Been a while since I played with this,taking advice from wiser heads I made a rounded tool holder and offset the tool from its original inline to 25 degrees offset ,this will allow me to part off the ball if necessary ,just have to make another tool to do that now ,not difficult :)
here's some pictures of the changes :) the ball is about 60mm dia , cheers ~ John