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Rose-EngineTurning

Journey into ornamental turning

Ornamental turningOTamong its fansisadmired by many but

practiced by few. One of theobstacles that holds turners back isthat this intriguing work requiresa rare specialty lathe.

At least it was rare until now.All the projects shown on thefollowing pages were turned on ahomemade rose-engine lathe. Notonly is it easy to build, its capableof doing precision OT work.

The four projects that follow

provide an introduction tothe rose-engine lathe and itscapabilities plus an overview ofsome basic techniques.

Of course, youll first have to build your lathe, described on page52. A dozen AAW members havealready made these lathes, and youcan do this too!

Much of what is described inthese pages will be obvious the firsttime you turn the crank on your

rose engine. But until you actuallysee it happen, text descriptionscannot do it justice. The magic ofhow a rose engine works and whatit does is something that has to beexperienced.

A rose engine differs fromother lathes in many ways, butthe biggest difference is that

the headstock is not stationary.Instead, the headstock is hinged,allowing it to pivot back and forth,called rocking. By controlling thisrocking motion with a rubber riding against a rosette acam-like diskyou can cutcountless patterns.

Another distinction is that,unlike regular turning, rose-engine turning is usually donewith a motor-driven fly cutter,

known as a cutting frame . Byhand-cranking the lathe, the turnerrotates the piece slowly past thecutter. The most common cuttingframe, a horizontal cutting frame,is a tool supported on some sort ofslide rest , which has a fly cutterrotating in a horizontal plane. Thecutter is spinning at high speeds

similar to router speedsandtaking light cuts on each pass.

For more help with terminology, seethe photos opposite and on page 52.To see a video clip of a rose engine inaction and for more OT history, visitthe AAW website at woodturner.org.

Get startedWhen first becoming familiar withyour rose engine, you may wantto devise some sort of a paperchuck, as shown in Photo 1 , whichis useful for drawing the patternsand helping understand what therosette, shown in Photo 2 , will

By Jon Magill

Instead of admiringornamental turning,its time you give it atry. Here is an easyand inexpensive wayto start, includingdetails on how tobuild your own rose-engine lathe.

Reprinted with permission. American Association of Woodturners

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Two basic cutsThere are two basic cuts whenturning with a rose engine, andthe effects are markedly different.Cuts are either made on the faceor the side of a workpiece. Thedifferences will come into playwhen you begin designing yourown OT projects.

Face cuts are made with anarcing movement of the headstock.

In general, they tend to be shallowwith interesting effects at theirnear and far edges. The arcingmovement of the headstock tendsto wash away details at the centerof most cuts. Face cuts are oftendone as a series of concentric cutswith some space between them,allowing the edge features to meet

at the ridges between each cut in aseries. This will make more senseonce you actually try it.

In contrast, side cuts areplunging cuts. The rosette allowsthe cutter to plunge into thework and then pull it back out.The depth and effects are quitedifferent from those of cuts onthe face. Two techniques are usedto progress the side cuts alonga piece: Simply move the cutteralong, creating straight flutes orgrooves, or you can phase therosette while making a series ofcuts. This second technique ofphasing can produce effects likespirals and chicken wire, as shownin Photos 3 and 4.

Last but not least is thesurprising effect of where thecutter is actually positioned. If thecutter is located on the operator-side of center, the pattern producedwill mimic the shape of the rosette.By simply moving the cutter to theother side of center, the rose enginewill invert the pattern of therosette, often with surprising and

pleasing results. Youll read moreabout this effect on page 50 in thesquare-knob details that follow.

Wood selectionBecause OT is less forgivingthan plain turning, choosingyour turning stock is key. Selecthardwoods that are as denseand as close-grained as possible.Sanding is generally not possibleafter cutting; the finish cut your

tool produces is critical.A wood that is dense enoughto show the pattern is important.That said, while you are learningand discovering the endless arrayof possible patterns, almost anyhardwood will work. Easternmaple is a relatively inexpensivewood good for experimentation.

KnobsTurning knobs for cabinets ordrawers is a simple, repetitiveproject that will require you tokeep track of your rose-enginesettings to get matching results onduplicate parts.

Start by making the blanks and

3

4

A simple spiral pattern emerges by phasingthe rosette with each subsequent cut.

This chicken wire pattern is created byalternating the phasing forward and backwith each cut. Each row of diamondsrepresents one revolution of cutting.

Purse mirrorA purse mirror is a good firstproject that you can accomplishusing mostly face cuts. Mirrorscome in various sizes (2" and 3"diameters are popular) and requireabout a "-deep recess.

Mount a round blank 2" to 4"in diameter (depending on yourmirror) onto your regular latheand turn a recess to accommodateyour mirror. The mirror at right was turned with European plum.

Mount a wasteblock slightlylarger in diameter than the recessyou just turned. Make a jam chuckand reverse the mirror blank ontothe jam chuck.

If you havent already done so,try some sample cuts to get an ideaof the basic patterns you like.

Now, move the blank over tothe rose engine and cut a pattern based on your plan, as shown in

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work with an interchangeable-tip screwdriver holder (Rockleris one mail-order source). Mostinterchangeable-tip screwdriverholders have 1/ 4" hex shanks, whichcan be driven into a 1/ 4" diameterhole. Eastern maple is a goodchoice of wood; it is hard enoughto stand up to use and it takes theornamentation well.

Mount a blank between centersand turn a tenon and shoulder tomount in your chuck. Mount the blank into your chuck and put it back between centers.

Cut a tenon on the tailstock endof the blank to accommodate theinterior dimensions of the 3/ 8" brasscompression nut, as shown in

Photo 12 . Thread on the nut tightlyagainst the shoulder, then trimany excess wood. Match a bit forthe tool-holder shank, then drill asdeep as the length of the shank, asshown in Photo 13 .

Drive the screwdriver shankpartially into the blank and adda dab of thick CA glue to theshanks groove. Finish drivingthe shank until it bottoms out onthe compression nut, as shown inPhoto 14 .

Secure the screwdriver holder ina chuck and mount it on the roseengine. To prevent the chuck jawsfrom marring the surface, wrap theholder with a layer of aluminumfoil. Start cutting your pattern at theheadstock end, as shown in Photo15. Cut to your desired diameter.

With your slide rest set at anangle you like, work your way outalong the handle at an appropriatetaper, as shown in Photo 16 .Unlike plain turning, the roseengine takes such light cuts thatyou can usually get away withcutting techniques like cutting

away from an already thinnedsection, which wouldnt work ona regular lathe. (For longer work,some of the antique rose enginesincluded a rocking tailstock to helpsupport the piece.)

Continue to work your way outslowly to avoid leaving visibleridges between your successivecuts. The fading stop creates ribsinstead of the sine wave that therosette would have created if left

unaltered. Work your way aroundthe butt end of the handle and cuta decorative pattern on the end.

Check the diameter of each compressionnut, then cut the tenon to t the interior.

With a belt-driven y cutter, make yourornamental cuts at the headstock end.

You can design and turn the entire handle

on the rose-engine lathe.

Insert the tool-holder shank and adherewith CA glue.

Drill the handle to the depth of the tool-

holder shank; most shanks are about 1".

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T-track holds the rubber, whichrides against the rosette; anotherholds the block that adjusts the bungee cord that supplies tensionto the headstock.

Once you have all theparts, it should take abouttwo days to cut, glue,

and assemble the entirelathe. If you or a friend has

a metal lathe and mill, youshould be able to easily make

the seven machined parts forthe rose engine. Or, use our kitsource (supplied with website

plans). Consider this lathe anaffordable platform to begin

exploring ornamental turning. Ifthere is sufficient interest fromAAW members, follow-up articlescan describe advanced capabilities

already designed to be added ontothis rose-engine lathe.

There are few critical dimensionsin the design of this homemadeversion. However, before youstart experimenting, you shouldconsider building one as closeto these plans as possible: Manysubtle aspects are not obviousuntil you have used a rose engine.Once you have used the lathe andunderstand how it works, modifythe design to suit your needs.

The plans for the lathe (see below) include details to allowphasing of each rosette, as well asthe adjustable fading stop for therosettes. These two simple featuresopen up the pattern options thatyou can produce on your rose-engine lathe.

In addition to building the basic lathe, you will need to buildor buy some type of slide restto manipulate the cutting toolsaround your work. And finally,you will also need at least onecutting frame to do the work. Theplans include some options for both of these.

Jon Magill

Rose-Engine LatheRocking headstock

Spindle (1"-8 tpi)

Used compound from metal lathe

Tool post to hold cutting frames

Plywood base for compound

Rosette mounted on main pulley

Rubber on T-track

Holes and pin for phasing rosette

Spindle end and main ange

Rosette-mounting thumbscrews

Hand-crank pulley

5 / 16" round V-belt

Step-up pulley

End of headstock pivot with shaft collar

AAWWEBFree plans on AAW website The complete

step-by-step plans, construction drawings, parts list, sources, and details about a parts kit forthe rose-engine lathe are available free to AAW

members at woodturner.org