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Discussion Starter · #1 · (Edited)
Posting this thread for my fellow woodworker friend DaveTTC. Hoping to save both of us some large emails with pictures.

I mentioned to DaveTTC that I was going to work on this project and he asked to see the build pictures.

This project was part of a one day demonstration Mark Gardner gave to my local Woodturning club back in March. A very informative day.

Marks web site for those who are interested. He makes some really nice pieces.

http://markgardnerstudio.com/home.html

He demonstrated how to make a multi-axis bowl.

This is one of Mark's bowls. Mahogany with white paint embellishment. I may replace with my own picture later.



FYI, in order to make this project, you will need a special jig for the eventual step of turning the inside of the bowl.

The jig inside diameter will dictate the maximum size of the bowl, and especially the max size of the initial cube.

The jig can be made with construction lumber and plywood.

One of the legs goes from side to side. The other leg has a cut-out in the middle to match the first leg.



The inside radius of this jig is 6in, so this is the maximum size of cube which can be made to start the project.

The bottom of the picture has a tenon for mounting in a scroll chuck.

Glue on the tenon, true up the plywood, then find the centre as close as possible for attaching the legs to be centred which will help in the accuracy of the final turning of the inside of the bowl.



Continued in another post.
 

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Discussion Starter · #2 ·
Initial step - make a blank

The initial step for the bowl is to make a blank which will be of dimension so that when turned it will fit in the jig.

In my case 6in max.

The blank must be an accurate cube. If the blank is not an accurate cube, it will show in the turning of the outside.

Mark Gardner used 2 @ 3in thick pieces of wood, single species.

I do not have 3in thick stock on hand, so I am making my bowl from a piece of Peruvian walnut and 2 pieces of cherry. I like the combination of walnut and cherry and had boards which were 6in wide, so efficient use of the board.

I cut off pieces of the walnut and cherry a little longer than 12in, so I had room for a little sideways movement while gluing up the slab.

I glued the three pieces together.

I had a bit of work to get the pieces flat. They had been planed, but were not flat. It is worthwhile to spend the time to get the pieces flat and not assume you can clamp them flat.

I started out with the blank being 3in thick, dry fit. After working on flattening the pieces I ended up just over 2 7/8in thick. This meant I needed to trim the width of the blank to a dimension = 2 @ blank width + thickness of the plywood which for this project is now 5 15/16in.



I will later be cutting this slab in half and gluing the two halves together. Mark Gardner glued the surfaces together then had to use a bandsaw to cut them apart.

I decided to use a paper joint with a piece of plywood in between. I am hoping the plywood makes it easier to mount the blank and be sacrificial from some of the mounting marks.

While I had the table saw fence positioned to trim the sides of the blank, I cut the plywood to be a square. I recommend if using a plywood sacrificial layer, you cut this at the same time as trimming the blank.

My piece of plywood posed on top of the blank.



Next step is to trim one end of the blank on the table saw.



Next I used the piece of plywood to set the correct width on the mitre gauge.



Flip the blank so the trimmed end is now at the right and next to the mitre gauge stop. Then make the first cut.



Then make the final cut.



In addition to the piece of plywood, I am also using a paper joint which will allow me to take the bowl halves apart later after turning the outside.

Paper is glued to the blank halves. Pay attention to the grain orientation. I recommend having grain run the same way for both halves.

I normally use Titebond III for gluing but for this temporary joint I am consuming my small bottle of Titebond I.

For small paper joints I like to use CA glue, but that would be expensive for this area.



Glue applied ready for the plywood.



The assembly is now clamped while the glue sets.

I like to clamp side-to-side and front-to-back to keep the cube as close as possible to the desired dimensions, then a couple of clamps on the top for the main pressure.

The blank is now being left for the glue to cure. I will continue in another post later.

Thanks for looking.
 

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Turning Wood Into Art
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G'day Dave,

Interesting read, I have not seen anyone demonstrate anything like this before. I follow with interest. Good read.
 

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Discussion Starter · #4 · (Edited)
Turning the outside of the blank

The glueup was left to cure over night.

Since I have a bandsaw, I decided I would cut off the end grain corners to minimize tearout issues.

I marked a circle on both sides. Only needed one for the bandsaw, but wanted to ensure I had a good centre marked on each side.



A short time on the bandsaw and the corners are removed.



I did not take a picture of the blank mounted in the lathe. Obvious for DaveTTC.

I am using a spur drive in the headstock. The Oneway Live Centre has a pin and a ring for suport. Turning the end grain orientation first. You are really just turning this round.

At the end of turning this is what the joint should look like. You can make out the circle I marked.



This is what the future bottom side of the bowl should look like.



I was too eager to continue turning. I should have sanded this cylinder since it is the only time I will not have "air" when turning. I forgot so now I will be power sanding the entire outside.

The flat ends are now marked with as good a centre as possible.

The blank is now re-mounted to turn the face grain.

REMEMBER TO TURN DOWN THE SPEED OF THE LATHE.


For folks just starting in turning, this part of the project will have a spinning object with lots of "air" between the contact of the wood and turning tool, in this case a bowl gouge. Start slow, increase as you get confidence and watch the "ghost" at the top. Having a back or top light helps a lot to see the "ghost".

Take light cuts to minimize tearout.



After a short time, this orientation will be turned round.

If you had an accurate cube and good centres you should end up with a bottom square.

This is one side.



This is the other side.



Considering this is my first attempt at making this project since I saw the demo in March, I am happy with how this looks at this stage.

Now to sand the outside before I split the piece and then mount on the jig to turn the inside. If it was not obvious before, this project will make two bowls.

The blank has been turned on two axis. After we mount in the jig we will be turning in a third axis. Hence the name of the project - a multi-axis bowl.

Stay tuned for the next update.

Thanks for looking.
 

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Discussion Starter · #5 ·
Initial sanding

Before sanding, it is a good idea to confirm that both sides of the now-turned blank will fit in the jig.

If they fit, good to go. If they do not fit, then either you will need to turn a little more, or modify the jig.

Mine fit easily. Do not worry about a gap. The halves will be mounted in the jig using hot glue.

This picture was taken after sanding.



I found it was easy to use my Random Orbit Sander (ROS) to power sand th the outside.

I was able to hold the ROS in place and rotate the blank with my other hand. It did not take long. Only sanded to 100 grit at this point. I may get dings or scratches in later steps so I thought I would only sand to a coarse grit. I wanted to ensure there were no deep tool marks which needed to be turned to remove.

I sanded one axis, then remounted in the original holes for the first axis.

One side.


The other side.



That is the progress today. Stay tuned for another update tomorrow.

Thanks for looking.
 

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Turning Wood Into Art
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Good stuff Dave ... Looks like I'm the only one along for the ride.

Great tutorial, love your use of pics and explanations when you do these builds
 

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Good stuff Dave ... Looks like I'm the only one along for the ride.

Great tutorial, love your use of pics and explanations when you do these builds
Not true, nice demo so far, I will have to give this a go.
Thanks for the nice details.
Syd.
 

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Discussion Starter · #9 ·
The last phase - the hollowing

This phase starts with splitting the blank. A paper joint normally is easily split. This is the largest surface area paper joint I have used, so I was surprised at the effort to break the joint.

I needed to use my drawknife and a rubber mallet, and a lot more force than I expected, but it did come apart, thankfully.



Next step is to plan for how deep to drill a hole in the bowl. I recommend drawing this out full scale, and if you use a glue-up assembly, to show the layers. I did not include the layers in this picture, and I will eventually regret this.



My local woodworker friend had made this project about a month ago. He warned me that when I needed to glue the bowl to the jig, I needed to be careful to plan how to place the bowl centred in the jig, and also how to try and get the bowl to be orthogonal to the lathe bed.

My build on this good advise, was also to determine how to ensure the bowl was centred in the jig. I did not recall how Mark Gardner did this back in March, so came up with my own solution.

I had a plan to use my Oneway live centre, with a special adapter and a special tapped piece of lumber. I later felt I needed to show DaveTTC how this could be done with the equipment he is likely to have on hand.

So I changed plans to use a drill chuck. If DaveTTC does not have this piece of equipment, he should purchase, since it is so useful for many projects.

Assuming a drill chuck is available, as well as a dowel, these are the steps I used.

First I placed the jig on my drill press table, and the bowl half in the jig. If a drill press is not available, use some method to support the jig to be level.

Getting the jig and especially the bowl in the jig to be level is important. I got this close, but not exact.

I drilled a 5/16in hole (8mm) for a 5/16in dowel. It seems the vibration of the bowl caused the hole to be slightly larger, so the dowel was more loose than I wanted. Next time I will drill an undersize hole.

I used the drill chuck to attempt to get the bowl half to be level to the mouth of the chuck. This worked, until the bowl vibrated during the drilling step. Not a lot, but enough to make the hole slightly larger than desired.



I checked the fit of the dowel in the hole.



Next I tightened the dowel into the drill chuck.



Next step is to mask the area where the hot glue will be applied. I normally do not use the normal cream coloured masking tape. It is too sticky and pulls the wood fibres when removed. Mark Gardner commented he tried various masking tapes, and the plain cream coloured worked best in his view, so I am using this type even though I hate using this tape. I hope it works.



Time for a dry fit of the bowl and the jig. I recommend locking the headstock to make the following steps easier to apply.



Review all sides so you know how well the bowl fits in the jig and where the gaps will be located.



My friend said I should only apply a single bead of the hot glue, since he applied too much and had a difficult time removing the bowl.

Due to the gaps I observed, I felt I may need additional glue. Perhaps my bowl was not as good a fit as his bowl. This was his jig.

I did a second round of hot glue to fill some gaps. I will find out later how difficult the bowl will be to remove from the jig, but I wanted to be confident the bowl was stable in the jig for hollowing.



First test was to drill a hole to aid in the hollowing. I like to have a centre hole drilled. I used a 1in (25mm) Forstner bit. I also felt this would be an easy test of how well the hot glue was holding the bowl. All went well.



I then marked out the area I would hollow out of the bowl.



Light cuts, and lots of light cuts to minimize the forces on the hot glue. Happy to report the hollowing went without incident.



Next step is to remove the paper from the surface. A combination of bowl gouge followed by sanding to get the last paper and remove any tool marks.




DaveTTC should now be smiling. At this point I realised I had blown through to the bottom layer of the cherry. When I drew out the circle for the depth, that drawing did not show the layers, so I forgot that I would be close to the bottom layer. Crap. I may be able to feather this, but lesson learned.

This is my first attempt to make this project, so I am learning my own lessons as I go along.

This is the extent of my progress today.

Next step will be to sand the inside before I remove from the jig.

Stay tuned for later updates.

Thanks for looking.
 

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Turning Wood Into Art
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Yeah I was smiling by that stage ....


Laughers through my nose while laying on the bed, so glad I don't have a cold lol

Looking good Dave. Shame about the cherry, feathering off - that kind of rings a bell

All tuned here.
 

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Discussion Starter · #11 ·
Sanding and remove from jig

Sanding the bowl on the inside was a challenge. Small diameter and parts of the walnut end grain had tearout, despite my attempts to cleanup with turning tools including my round nose scraper.

I ended up using the scalloped discs on a flexible sanding pad with the cordless drill.

This is the bowl after sanding to 320 grit.



Time to see how difficult this will be to remove from the jig. I locked the headstock with the jig side which had the biggest gap. Using my gasket scraper to pry this loose.



It did not take much effort which reinforces the need to be careful when hollowing. A catch during hollowing and the bowl may break the glue. Not a lot of glue, which was recommended by Mark Gardner and my friend.



The masking tape came off easily and left no residue. I was happy at how well this came off.



I then mounted by Beall buffing wheels to buff this to allow me to see where I still need to sand before applying any finish.

Side view.



Bottom view. The opposite side to this one has a line of small dings. Not sure when this happened, but will need to be sanded out.



Top view, and as expected the small area in the middle stands out due to being the lower layer.



That is the end of this programme. For a first attempt, this went well. I learned a lot. I will update when I have applied finish to this bowl.

For the other half, I am thinking about trying to make a jig to use with my vacuum chuck. One of the local turning club members said he made such a a jig. After seeing how easy the bowl popped off the glued jig, I would like to have a little more confidence with the vacuum chuck holding the bowl. I know DaveTTC does not have a vacuum chuck so I did not want to try this for the first bowl.

An interesting project. Takes a lot longer to take the pictures, edit, upload to WWT and then post the thread than it takes to make the project.

Now its your turn DaveTTC. :laughing:
 

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Turning Wood Into Art
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You're on !!!

Great build, I enjoyed it. I still think you should submit some of your work to be published
 

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Beautifully Done :thumbsup::thumbsup::thumbsup:
 

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Discussion Starter · #16 ·
Awesome tutorial. Once I get a little bit better I'll give it a try. Thanks!
Thanks. The turning part is not difficult. The outer turning is just rounding the cylinder. The inner turning is just hollowing to be somewhat round.

I found I spent more time on creating the blank, the jig, than the actual turning.
 

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Good stuff Dave ... Looks like I'm the only one along for the ride.

Great tutorial, love your use of pics and explanations when you do these builds
Huh :eek: .
I'm paying attention :icon_smile:
but here in the back of the classroom , the internet has been a tad slow of late .
 

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Discussion Starter · #20 ·
Making the jig

I was not going to show a build on making the jig. It seemed easy enough, but as I got to the detail on the support arms, I found a wrinkle, so providing the details so any readers can avoid some headaches.

The jig will dictate the max bowl size. I am going with the 6in max size. If you are purchasing bowl blanks, a 6in size is available in a number of wood species.

Based on my size, I looked around for some scraps. I prefer to make jigs out of scraps if possible.

I found a round cut-out from making a feeding station for one of my dogs in 2004. The dog has long since passed, but the feeding station is used by the latest dog. The cut out was about 8 1/2in dia (216mm) which is a good size for the jig. The pack rat wins again.

For the arms I found a couple of pieces of 2x4 construction lumber I had been using to support items being painted. Good for a better use in the jig.

I need to mark the cut out which is 3in dia (108mm) so I lay the pieces side by side so I can place the centre of the compass on the one side while I draw the arc on the other side.



Next is to decide how the jig will be mounted in the lathe.

I am hoping this jig can be used with my vacuum chuck, so I decide to recycle one of my attempts to make a vacuum chuck. This was not running true at the time.

I cut off the plastic sewer drain fitting, and retrue the wood base. I am using a base which has been threaded to fit on the lathe headstock. This will allow me to seal the base for potential use with the vacuum system. If that does not work, I can still use the jig and free up my scroll chuck.

There is already a hole in this base, from the original desire to use this with the vacuum system.


If you have never seen a spindle tap, the Beall Tool Company makes a few of these. Not expensive, and very useful for making jigs for the lathe.

http://www.leevalley.com/US/wood/page.aspx?p=57074&cat=1,330,49238

I mounted the base on the lathe, and tested the cut-off disc to see if it ran true. A bit of sanding of the base and the disc, then running as close as I can get these to true.

Marking out the disc for gluing. I drill a 1/4in dia (6mm) hole in the centre. This will be used for getting the disc and later arm centred.



Since the disc is painted and I did not want to spend the time to remove, I did not use yellow glue. Instead I mixed up some two part epoxy.

Epoxy applied, then the disc is mounted on the lathe and the tailstock pushed in place to centre the disc.



Checking the base side to ensure the epoxy does not run.



I cut out the arcs from the two arms with a bandsaw close to the line. I then smoothed out the curves on a drum sander. I wanted the curve to have a consistent gap with the future bowl blanks, if possible.

Note the solid arm has a 1/4in dia hole drilled in the centre. This will be used later, and also allow potential use of the vacuum system.




The two arms were the same. One is mounted intact. The other has a cut-out the width of the first arm.

Next step was to check the fit with the present turned bowl. This is when I spotted the wrinkle. I did not take pictures.

This picture was taken after fixing the winkle. Close gap and consistent.



The problem was that the two short pieces had a greater gap than the solid arm. I was scratching my head. I had measured the amount to cut out carefully. I am not sure what is happening but I needed to fix.

I trimmed about 1/16in off the two piece and re-checked. Now the bowl was a good fit at the top, but still a gap at the bottom. I needed to raise the two piece slightly. Rather than gluing e.g., 1/16in strips, I used a hand plane to shave the solid arm to remove the depth needed to get a consistent gap.

It is worth paying attention to the jig.

You are likely pondering how to use a bowl to check the jig when you need a jig to make the bowl - Catch 22. You will not have a bowl - but you can easily make a cut-out of the shape on paper, as I did in an earlier post.

This paper cut out is slightly larger than my bowl. One side.



The other side.



Next step is to glue the arms to the disc. I am taking advantage of the 1/4in dia hole to centre the arm on the disc using a 1/4in dia bolt.



I mixed more 2 part epoxy, applied to the solid arm, mounted on the bolt, then tightened a nut and clamped. Then glued on the two side arms and clamped.

A good example of needing lots of clamps.



This is where I stopped to allow the glue to cure and edit the pictures and prepare this post.

Stay tuned for updates. Thanks for looking.
 
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