# Finial featurette



## Rich L (Sep 4, 2012)

Details matter

This little exercise is one I've been wanting to do for a long time. It's a curious little application of ornamental turning using an engine turning machine adapted for the extra decoration ability. I'll go through the whole process so excuse me if I get a bit elementary for some.

First of all, the goal is eventually to do this in solid silver although this will work on just about any pen material, including wood (especially wood) but the differences would mostly be in threading the part and the end game of polishing (don't polish the wood).

I started off with a very good substitute for silver to get this off the ground - nickel silver. For those that don't know, this stuff is also called German silver and it has absolutely no silver in it. This stuff is also sometimes confused with cupro-nickel but that series of alloys has a different scheme of composites. The nickel silver I used is a common alloy referred to in the industry as 752 nickel silver or 65-18 nickel silver. The 65-18 refers to ~65% copper and the 18 is ~18% nickel. The rest is zinc and some trace metals for strength, workability, etc. In many cases it is not a particularly fun metal to work with because of the copper and nickel. Copper and nickel are a pain to machine and when mixed in this alloy you get mixed pain. But, ordinary turning with sharp tools is easy as long as you take a resonable cut. Surface finish, especially with coolant (WD40, etc.) is remarkable. When done it shines up just like silver - well, almost. So, enough about the material.

Here's the drawing of the part (which gets some changes 'cause there are a couple mistakes on it) - a barrel finial - and some 5/8" stock chucked up in a 5C arrangement. For those that care, the insert is a DCGT type. For exterior turning I used about 800 RPM and generally about .025 DOC. I think you can see the nice finish I'm getting.

Next is boring the hole and since my drawing dimension (which isn't on the drawing!) just happened to match a 5/16 end mill, I used that to get the flat hole bottom. RPM drops to ~400 for that operation and feed is really slow because of the large surface area encountered by the plunge operation. Coolant was necessary for cutting and to cool - this stuff gets hot.

Next steps are turning down an area for threading and turning the thread relief groove. Back up to 800 RPM for that.

Now for threading - the pitch will be .5mm and the major diameter is .440 inches (sorry for the mix in units). Radial DOC will be .015 inches and I'll have to lightly sand off the thread crests as this material always produces burs. The threading tool is a full ISO form laydown type and I'm just doing a straight plunge. For these tiny threads I don't feel the need to do flank cutting.

Next step is to cut the angle (5º) so I just set the compound at 5º - nothing really critical.

Cutoff follows, RPM back to ~400 using a standard carbide insert cutter with a .087 width. Again, this material needs coolant for cutting ease and heat dissipation. Heat management is critical here as this stuff creates hot chips that will weld themselves back on to the sides of the groove - and that's bad. The lube lets them slide out and cools them off. So, with copious squirting of WD40 I get the nice round curlies from this operation.

Here it is - all turned. Next I have to sand off the little tit left from cutoff and I'm doing this carefully with 600 grit paper and WD40 so that I retain the flat and perpendicular surface on the end that I want to play with.

Tit gone and nice flat surface.

OK, this is the engine turning machine that has an ornamental turning overhead cutting frame drive system (this is a whole 'nother subject in itself so I apologize if I'm leaving some of you behind. Just post questions and I'll be happy to answer). The machine is a 96 year-old Lienhard Chaux de Fond rose engine. The nature of this machine, the rocking action it does, is key to this whole thing.

The business end of this machine has an ER40 collet chuck adapted to a centering apparatus for critical workpiece leveling and setting concentricity. The finial I just turned is held in the chuck- hand tight. The other little nose thing coming in from the left is the business end of the cutting frame. The overhead DC motor drive pulley system makes a little tiny carbide bit spin around and cut things.

The close-up of the brass "rosettes" (by the way, that's where "rose" engine came from) shows a little wheel in the center that is fixed to the machine casting. The whole spindle that holds the rosettes and the ER collet rocks back and forth against that little wheel as the spindle turns. So, if you can imagine, a spinning bit and a rocking spindle might make an interesting design in the finial - and it does!!

The final step is to polish it all up. I used 1500 grit paper all around before the polishing wheel and then did the polishing "cut" with ordinary white rouge and then followed by the "color" with ordinary red rouge. Put it on the end of a silve pen and as they say in France - Voilà! (Actually, the only not voilà is taking pictures of shiny objects … )

Cheers,
Rich


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## Wright (Sep 4, 2012)

That is beautiful, how did you get the design on the top?


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## BRobbins629 (Sep 4, 2012)

Think we need a far advanced penturning section.  Always enjoy your stuff Rich.


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## MarkD (Sep 4, 2012)

Looks like a very successful experiment. That's pretty cool!


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## Robert111 (Sep 4, 2012)

Amazing! What gorgeous work you do, Rich!


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## IPD_Mr (Sep 4, 2012)

Rich -  That is slick.  Well beyond my capabilities, but I just may have to order some of the nickel silver on my next material purchase.  That really polished up nice.


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## skiprat (Sep 4, 2012)

Yikes, I almost missed this thread!!!. :biggrin:

I was searching the web a few days ago, trying to find a source of a tool to do the basic engine turned swirling pattern and of course using all the usual search words your site pops up. So like I often do, I dropped in and drooled for a while:biggrin:

I eventually found the damascening tool and the hard rubber inserts from Brownells in USA. They have shipped already and I hope they get here real soon. 

Anyway, this thread and seeing your site again has re-ignited my goal to finish my own rose engine project. 

You know I think your craftsmanship is wonderful already, so I won't bother saying NFGJ :biggrin:


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## IPD_Mr (Sep 4, 2012)

skiprat said:


> Yi
> 
> You know I think your craftsmanship is wonderful already, so I won't bother saying NFGJ :biggrin:


 
Well put Steven.  Now I hope you are not making something that you just push a button and out pops your part.  Anyone can do that, there is no craftsmanship in that, well at least that was what I was told over and over again.  :biggrin:


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## longbeard (Sep 4, 2012)

Thats pretty awesome stuff, sure would like to see a video 
love the finial


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## skiprat (Sep 4, 2012)

LOL, Hiya Tam:tongue: You know me well enough to know that If I can't cobble something together from bits of old washing machines and gaffer tape, then I'm not happy. :biggrin:

I agree to certain extent about 'just pressing a button' but I think that it takes a different type of skill and craftsmanship to do the *first* one. Anyone can press the button for the *second* one, but the first one requires special mental knowledge which is just as important as good hand skills. :biggrin::wink:


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## Dustygoose (Sep 4, 2012)

WOW


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## PenMan1 (Sep 4, 2012)

Rich:
Each new piece of your work seems to eclipse your last piece of sensational work!
Skip WON'T say it (because it is WORTHY of so much more).....BUT I WILL!

B.L.F.I.E.S.....Best looking finial I've ever seen! You should be proud!


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## PenMan1 (Sep 4, 2012)

longbeard said:


> Thats pretty awesome stuff, sure would like to see a video
> love the finial


 
Well, Rich. You have certainly RAISED the bar! In the old days, they were happy with just a tutorial:biggrin::biggrin::biggrin::biggrin::biggrin::biggrin:


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## Curly (Sep 4, 2012)

That would be a Rosette with 12 bumps on it to make that pattern with the cutter above or below the centerline, correct? Looks great. 
Pete

Sent from my iPhone using Forum Runner because I can't reach my desktop!


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## Kalai (Sep 4, 2012)

That is one great job you did, I have always wanted to get a rose engine.  Was it hard to get yours?  Are they easy to find?  Aloha.

Kalai


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## Rich L (Sep 5, 2012)

Thank you all for your kind comments - they are very much appreciated and motivating and some of them are pretty funny.

So, to try to answer "wright's" question - what happened between the picture of the rose engine and the final finial. It is clear and not too awfully surprising that there is still mystery there especially for those that don't know how these engines work or have never seen one in action. I was there once and it took a while to get my head around the concept of a rocking lathe spindle never mind that the spindle can "pump" axially as well. Not all rose engines can "pump." I've attached a graphic that might help explain a little more. The basic things are:
1) the contact wheel, or rubber, as it is called, is stationary
2) the spindle has radial spring pressure on it that keeps the rosette in contact with the rubber
3) the spindle rocks on a pivot that is underneath the spindle
4) as the spindle turns at a very slow rate (~1 (one) RPM in this case) the lobes on the rosette cause the spindle to shift, or rock, on the pivot.
5) the cutting apparatus is stationary - if it is a single engraving cutter then the point of that tool stays where it is and cuts lines in the face of the workpiece - if it is a rotating fly cutter (which is what is going on here) then the frame of that spinning cutter is stationary.

Stationary cutting tool or frame, stationary rubber, moving spindle in two dimensions.

So, the workpiece is turning and it's also moving back and forth (rocking) at the same time. If you apply some cutting tool against the face of the workpiece that is turning and moving, a pattern will emerge on the face of that workpiece. That's how the design magically appeared.

I hope that helps and even more so I hope I got the question right! I'll try to make a video of the next one but it's really close quarters in there with misting WD40 coming off that fly cutter. Maybe I'll do it dry up until the last pass.

Not to forget - "Curly" is the winner of the 4-week, all expenses paid, trip to the bustling, metropolitan, and cultural get-away of Flin Flon, Manitoba starting December 21, 2012. 

Attached depiction of the rosette used. Flycutter was below centerline. What happens is that the cutter follows an outline that resembles the shape of the rosette, _but_ one important thing happens when the cutter is positioned closer to center than the actual radius of the rosette: the amplitude of the rocking movement is invariant - defined by the rosette - but the circumference is diminished. That's why there are the apparent wide radial variations in the undulating design. Those undulations in their amplitude match exactly the amplitude of the waves in the rosette. Probably making things more fuzzy. Oh well...I'm tryin'

Cheers,
Rich


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## Rich L (Sep 5, 2012)

Kalai said:


> That is one great job you did, I have always wanted to get a rose engine.  Was it hard to get yours?  Are they easy to find?  Aloha.
> 
> Kalai



They are easy to find - just look up Gold Machinery and look at the prices. You will almost always need to do some restoration. There are a couple folks that are making new ones of the old style ($35-40K and they are gorgeous!) and there is Lindow White that make a newer, much less expensive, style. You can also build your own. Depends on what you want to cut, metal or wood, or both that will define the style that's suitable and the price. Just start joining the ornamental turning forums and googling for them. They're out there. I got mine by falling into the right company at the right time. I was very lucky.

Don't hesitate to PM me if you need some further help.

Cheers,
Rich


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## Curly (Sep 5, 2012)

Darn I won't be able to go to Flin Flon.  I only get 2 weeks off for the holidays. I guess Marla will just have to make do with a short trip to Spuzzum. 

I realized after posting the rosette couldn't have 12 equal bumps. There wouldn't be the 4 loops I'd it did. So I knew them that it had to have a pattern of some kind repeated 4 times. 

Like Skippy I need to get to making my rose engine. It's why I bought my metal lathe and mill. Ornamental lathes around here are as elusive as the Sasquatch. 

Pete

Sent from my iPhone using Forum Runner because I can't reach my desktop!


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## bluwolf (Sep 5, 2012)

Beautiful work Rich!

Mike


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## OKLAHOMAN (Sep 5, 2012)

Having one and then knowing how to use it are two different things. But for those that just have to have one:
Mills Rose Rotary Engine Turning Machine - Exceptional | eBay or 
Lienhard "Swiss Made Antique Rose Engine Turning Machine" Guilloche..Rare Find ! | eBay


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