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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