woodbowlsandthings

November 11, 2017

Video Hollowing

Filed under: Wood Lathe — Tags: , , , , , , , , , , — peteblair @ 4:03 pm

I know that there are lots of turners who are either already hollowing using video of are thinking about trying this technique. This Blog is meant to be a jumping off spot for those who are still contemplating the process. It’s only the way I do it and not by any means a difinitive way to proceed. I do not plan to share the details of the equipment I use because there are so many choices and I purchased so many years ago the items may no longer be available.

As far as I can remember, the use of video in hollowing became known about 5 years ago when a world renown turner began demo’ing and selling his system.

For those of you how have been living in a cave or on another planet for the past 5 years the technique involves positioning a camera above the cutter and then drawing it’s outline on a sheet of mylar which then appears on the video screen when the cutter is actually in the form. I hope I have explained it well enough but please feel free to contact me should I be able to add anything or help you better understand the technique.

So about 5 years ago and being the cheap SOB that I am, I thought I could hack together my own system. I had an old MS laptop laying around and I had WIFI phones and cameras with the ability to connect to it, but, of course that wasn’t enough for me. I soon was scouring Amazon for cameras etc. I found a very cheap, new I was told, Colonoscope camera. I sure hope it was new!! It had it’s own light but the picture was a problem.
Anyway, to cut a long story a little shorter, I found that the Lap top was a pain to set up and take down and by the time I ran the software to get everything working I could have hollowed several vessels using my laser. In addition, the web WIFI cams all had a short ‘lag’ which drove me nuts!!  This led me to stop trying the process and continue my old ways using a laser.

I hadn’t totally given up though as I discovered that several turners were using Back-Up Automobile camera set-ups which included a small monitor and camera. Yep, a few were even shown with the lines to back between which I apparently were pretty easy to ignore when hollowing.
So of course, I had to try those as well and also found a really cheap video surveillance camera without the monitor and bought that too.

When the part arrived I took a quick look and with all the wires etc. it all seemed way too involved. I’d just rather be turning than messing with all those wires!!

It might be my age or ?? but I have a great deal of trouble remembering peoples names and the turner who demonstrated his video techniques at the last meeting of the Vancouver and District Wood Turners Guild has fallen into that category.
It’s too bad because it was his demo that got me thinking a little more about utilizing this technique.

So the next day I hunted around my shop, it took me about 2 hours to remember that I had stashed all the parts in an old sewing box.

The only easy to hook up was the surveillance camera because it came with a 12 volt brick power supply. The back-up-system was designed to wire directly to the 12 volt of a vehicle. Lucky for me I have ‘bricks’ of all voltages and designs in boxes and drawers. I found a 12 volt one, cut the cord and wired it to the back-up system and hooked up the surveillance camera and quickly discovered that the distortion was way too much at close range to be usable.

So with wires going every which way I connected the complete back up system. Dragged it over to my lathe and with a few minor modification had it up and running in no time. It worked great but the back up monitor is only about a 7″ screen. I need something bigger.

I remember that we moved a cable box from a 17″ tv in our kitchen to a room where one of our grandsons ‘hangs’ so he could use it on a large tv that his dad has left for us to store. My wife was quite happy to have it out of the cabinet that it was in now she has more shelf space to display her ‘stuff’.

Ok, so now I am really on to something. I quickly disassembled the foot that the tv stood on and made an aluminum plate from which I could hang it on my exhaust fan box right at the end of my lathe. With a few quick changes it was up and running perfectly.

As you can see from the photos I hold mylar film on the tv with magnets and draw the outline of my tool on it with a sharpie. One cool thing about using the magnets as opposed to tape or ?? is that I can easily reposition it  should I change the angle of the cutter. In addition I can keep all the old sheets to reuse anytime I am using this system and thus don’t need to keep redrawing the cutter. If I like I could actually leave the TV in place but I need to come up with some sort of cover to keep the dust out so for now I stash it on a shelf. The camera and arm it is attached to simply hang on the wall behind my lathe. The camera does have a small lens cover. I’m not totally convinced that the camera is totally suitable and I continue to search for a cheap replacement. What I believe would work even better is what is termed a ‘closed circuit’ camera.

A couple of ideas that were shared at our last meeting that are exceptionally helpful are to place a white or black piece under the turning to provide contrast at the edge which helps to see where the cutter is. Another is if a round magnet is placed on the screen over the cutter and extending outward it provides a means to ensure the finished thickness is easily delineated.

 

 

 

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November 10, 2017

Negative Rake Scraper

Just a quick note to let anyone who might be interested, know that I now use a negative rake scraper with my hollowing rig. Up till recently I was using a tear drop shaped scraper sharpened in the standard manner but found that on occasion it was just a little grabby.
I thought why not make it into a neg rake scraper so I ground it to about a 60 degree included angle.
After changing the angle the center of the scraper was no longer on the center line and to make up for that I just added a small brass shim under the scraper. I think it is still slightly below center but it seems to work just fine for me.
Seems to work just fine for me.

 

March 15, 2017

Drying Wood

Like many if not all wood turners I often get lucky and am able to turn green wood. Of course this means that we need to find a way to get it dry after we either rough turn it or turn it to finish. Sometimes I turn hollow forms so thin that they are almost dry when I finish but more often there is still some moisture that needs to be removed without the piece cracking.
Some turners let it dry by gradually allowing exposure to the air by many means such as bagging, boiling, putting in shavings, setting on the floor and gradually moving them higher in the shop. Most of the methods take a while and we really want to hurry the process.
Most turners agree that if the inside of a piece dries faster than the outside the wood tends to sort of compress and limit cracking. Some people wrap with the outside with plastic wrap, some coat with paint or a wax in emulsion. This lead me to my new method.
This winter has been pretty damp with lots of snow and rain and we were often drying boots and runners etc with a relatively cheap ‘Boot Dryer”.

The one I have is adjustable as to time it runs and has the option of using heat or not.
By adding hollow sections of plastic pipe etc to allow the air to get into and circulate inside the bowl or hollow form the drying process is sped up.


I am not a scientist and have a very limited knowledge of it’s principals and as a result I am unable to actually quantify the results of my method. All I know is that pieces treated like this tend to dry in about half the time of pieces left on their own.
I have only been trying this with fairly thin hollow forms and bowls that I will return to the lathe to sand and finish.
I have no experience with twice turned pieces dryed with this method.

By using the weight of the item I now am confident that the pieces I dry this way dry twice as fast as they do if just left to dry on their own.

I now have a little more information. The week before last I used my boot dryer to dry some small fairly thin bowls made from Gravenstein Apple wood and again the wood dried about twice as fast as a piece I left on its own and I had no cracking. At the same time I dried a small cup shape, it can be seen on the other blog (https://woodbowlsandthings.wordpress.com/2017/04/17/gravenstein-apple-wood/ ‎) about Apple it was dyed and then sanded. I sort of messed up as I didn’t manage to get the bottom as thin as the rest and after about 12 hours on the dryer I noticed some small cracks on the inside. I stopped using the boot dryer and the cracks mostly closed up and never made it to the outside. d

February 16, 2016

Pro-forme Hollowing tool

Last week while I was hollowing an 8″ tall cup form I decided it was past time that I tried the Pro-Forme Hollowing tool that I bought about 5 years ago.

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It has been sitting mixed in with the rest of my hollowing tools and every once in a while I would take the plastic cover off of it and then put it back. I had read that it was especially nice in end grain and even better if the wood is green. Today was the day for a trial. I put it in my Kobra Hollower, but before I started to hollow I drilled a hole with one of my modified spade bits to the depth I wanted to go. The Pro-Forme was set at the factory and worked like a charm. With practice I’m certain I could get as good or better finish inside than is possible with a scraper. I did notice that as I got beyond about 6″ the 1/2″ bar I experienced a little vibration but I was able to go the full 8″.
Thinking about how much I liked the way the tool worked and seeing that I had a spare cutter I felt I should do something to help with deeper hollowing. My first thought was to ask a friend of mine if he could make me a 1″ bar with the end modified to fit the Pro-Forme but this of course required me to buy a 1″ polished steel bar and seemed like it might be more work than it was worth.
I realized I already had a 1″ bar for my Kobra and all I needed was a short extension that could be installed in that bar to which I could attach the Proforma.
Luckily I have a few pieces of drill rod hanging around my shop and was able to find a 2 1/2″ long piece of 1/2″.

I clamped it in a vise and proceeded to notch it out with a zip cut blade my cordless grinder.

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After some grinding, polishing and filing I completed the adaptor and hopefully can now go up to about 14″ deep.

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February 8, 2016

Which came first?

This question has been asked about the chicken and the egg for a long, long time. I think I finally have the solution.

If you have followed my blog at all, you will know that I really appreciate the art and turning skill of Betty Scarpino. I sat in on a wonderful all day Demo of hers and the next day was lucky enough to spend the day in a workshop with her as well.

Betty informed us that during the workshop we would be making and egg which would be finished with Liming wax, a pod and a candlestick holder.

After watching her demo I had a hard time sleeping that night as I was determined to use some or all of her ideas but bring my own slant to them. After all, I sure didn’t want to do a Scarpino, because no one could do one as good as she.

Sometime during the night I came up with a plan.

I would make an egg as per her suggestions and make a pod but my pod would be turned with more than two centres and would house the egg.

A little head scratching during the work shop but in the end I came up with this piece.

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The pod is maple, turned and hollowed wet. I finished it with a light coat of yellow glue and wood filler to give it some texture. Usually we texture by taking material away but a fantastic turner by the name of John Keeton suggested that I should try adding texture instead. The feel of the pod is really interesting, what a great idea John. Then with acrylics I painted the inside, added the branch from my driftwood collection and put the egg inside.

My solution to the age old problem is, the egg came first, it came from a pod . . .

 

Thanks Betty!

October 29, 2014

The best wood lathe drill . . .

I’ve been away for a while and am very pleased to see that I am continue to get a few hits on this site.
As a wood turner who generally uses a drill to set the final dept of many of my turnings I have always struggled with the center hole and the square sides that most drills leave at the bottom of a hole. Another problem I was always dealing with was the heat build up from friction and the difficulty in removing bits once the hole was complete.

I have now developed a way to make a nice round bottomed hole by repurposing a wood drilling “Speed Bit”.

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These reshaped bits drill really well and easily with very little heat,to just about any dept a person could want to drill. There are lots of extension available which allow holes as deep as one would want to go.

The cutting action is smooth and clean in hard and soft woods when these bits are held in a chuck in the lathe tail stock. They cut beautifully in end and side grain.

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I currently make them in three sizes 1/2″ – 3/4″ – 1″.

If you ever use a drill bit to set the depth of a bowl, box or hollow form you must try this bit!

Should you wish to try one, please email me for pricing and shipping costs.

June 28, 2014

Re-cobbled

The continuing saga of my path to discover an ‘easy’ way to sand the inside of hollow forms.
If you read the previous post and are following along then here is the next edition.

I previously purchased a rock tumbler at a garage sale this is a much faster turning devise than either of the BBQ motors I was trying earlier.

With the increase in speed I can in two days get the same revolutions I was getting in 2 weeks. I do realize that at some point if it spins too fast the glass will just cling to the outer walls and not tumble or grind the inside of the hollow form as I intend to.

The rock tumbler uses a 1725 rpm motor connected to a 1.5″ dia pulley which is then connected with a vee belt to a 9″ pulley. Please feel free to correct me if I’m wrong but by my calculations this devise now spins my hollow forms at  287.5 RPM. I wondered if it might be too fast but I can hear the glass and marbles (yes I have included marbles this time around) sliding and grinding as it spins. I am certainly not a machinest and the part that is in between my chuck and the shaft of the pillow block is not a tight fit and as a result the chuck ‘wobbles’ a little which i believe may add to it’s ability to sand.

Here’s a shot of my ‘re-cobbled’ devise.

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I tip it slightly toward the bottom and alternately the top in an attempt to get the glass and the marbles working more on the ends where the torn grain is. I try to tip it about about 2″ and run about half time with it tipped each way.

Here is a comparison shot of one piece before sanding and after about 300,000 rotations.

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And a closeup of the one on the right.

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I think you can see quite an improvement as far as sanding and removal of ridges goes but as you can see it hasn’t cleaned up the torn end grain.

If I was to do a finished Hollow form I would spend a little more time with my tools to try to minimize the torn grain prior to using my sanding devise.

Please feel free to email me if you have any comments or questions.

June 16, 2014

Sanding the inside of a Hollow Form

Occasionally I really want a really good finish on the inside of a Hollow Form no matter how big the opening is. An example would be when I want to pierce the form with some sort of art that would allow people to get a good look at the inside. Another might be when I make a Hollow Form influenced by harvey Fein. His work frequently has openings in the shape of slits or slots that go all the way through the piece.
To this end I read somewhere that if pieces of broken tempered glass are put inside and slowly rotated they will eventually finely finish the inside.
I am presently experimenting with this process and have rough turned the inside of a couple of blocks of Birch. I used my Kobra hollowing system and made no attempt to get a smooth interior. I did perform a final light cut with a freshly sharpened cuter. The intention was to leave some roughness and some ridges.

The blocks are about 3″ square and 5 1/2 long.
Here is a photo of the devise I cobbled together with parts I had laying around.

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It enables me to angle the turning if I want more finishing done towards either end. The original BBQ rotisserie motor turned twice as fast as my current one. I had planned to turn a week with it slanting towards the top and a week towards the bottom but during the process I decided I needed to keep track of revolutions rather than days/weeks.
Here is a picture of one of them prior to beginning the process.

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Here is a photo comparing the one on the left (unsanded) and on the right the sanded one.

This was accomplished in about 8600 Revolutions.

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As you can see the section on the left does have a much nicer finish and actually feels as if it has been sanded quite well. It did not however remove much of the ridges. I think I will devise a faster turning model and give it a try again. Sanding with more revolutions this time.

On another thread someone suggested the addition of marbles along with the glass and this I will try next.

May 26, 2014

More of Molly’s Influence

I continue to enjoy making miniature and smaller size hollow forms adorned with some of the pyrography techniques which I learned in a all day workshop with Molly Winton. This series includes Orca Whales.

Thinking about Molly’s influence I am not too sure how she feels about the work I am producing in her shadow. Sometimes I wonder if the artist(s) whom influence my work would really rather I didn’t mention their names or if they might be embarrassed by my attempts to incorporate some of the details which they use. At any rate, until I learn differently, I shall continue to list those whom have influenced my techniques and design features in the pieces I show here.

I have apparently started a series, not planned but because there are some similarities I will also post a series on this blog.

of  related Blogs.

This piece is the first in the Orca Series. It includes a four ‘lip’ opening influenced by Molly(she does a 3 point) as well as the sort of basket weave that she uses on the lower part of the piece.

On this piece I used a small round “writing point’ burning point to detail at the dark parts of the Orcas. I then stained the maple around them. This left the whiter parts of the Orcas the natural maple color although not as white as they are in nature.

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I have completed a few others in this series but will post them individually.

My work can all be seen on my Web Site woodbowlsandthings.com

Please feel free to comment or send me a note if you wish to discuss my work or would like any more details.

April 28, 2014

Molly Winton’s Influence

Filed under: Art, Wood Lathe — Tags: , , , , , , , , , — peteblair @ 2:30 pm

I have become enamoured with turning miniature hollow vessels after the full day Workshop I took with Molly Winton, see earlier post. These very light, small turnings are textured with a burning pen similarly to how Molly does hers. I would be flattered if her influence can be seen in my work I just adore what she does.

I am not totally pleased with this piece but I do believe it is a good beginning. I plan to incorporate a more West Coast theme in my future work.

These are turned from green Cherry, about 2″ tall and 2″ wide with my rendition of Peace Doves flying around the top.

To view more of my work please visit my website woodbowlsandthings.com.

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