An Ellipsograph I and my apprentice made

george wilson

Global Moderator
H-M Supporter Gold Member
Joined
Jul 26, 2011
Messages
4,142
This MAY have been posted here. I can't remember. I was the Toolmaker at Colonial Williamsburg. In 2006,or 7,my long standing journeyman,Jon,retired. I got a new apprentice,and this was our first project together.The new apprentice was not inexperienced. He was a custom silversmith at Tiffany's for 5 years,and had been working in the Silversmith Shop for 3 years or so.

This ellipsograph was subsequently seen on The Woodwright's Shop (Roy Underhill).

The Cabinet shop was in the process of duplicating an 18th. C. tool chest,which had large,elliptical inlays inside the lid. They wanted to demonstrate this device during one of the seminars on woodworking that Col. Williamsburg holds every year.

It is about 6" square,made of mahogany and brass. The knurling on the knobs was done with knurls that I showed the apprentice how to make by using ordinary taps to mill out their edges to generate convex,old fashioned style knurls.

We also made a little swivel knife that would be useful in cutting out paper patterns if needed. Normally,a pencil goes into the hole in the hole in one of the arms. They did have pencils in the 18th.C.,except the little leads were square,sawn out of natural graphite,which,at the time was apparently only found in England. Europeans struggled to come up with a synthetic,clay based graphite. Cont'e,whose name is still well known today in pencils,finally suceeded in the late 18th. or early 19th.C.(I can't recall,getting old).

This device works the same as those little "smoke grinders",or B.S. grinders you may have seen as toys. However,this one is more accurately made and adjustable to change the shape of the ellipse,or the size of it.

DSC_0001.jpg DSC_0005.jpg DSC_0006.jpg DSC_0004.jpg
 
Very nice work!
Looks like you will have an excellent apprentice!!

Andrew
 
He had skill,just no experience with lathes and milling machines.
 
hi george! was just wondering if you ever had time and wouldnt mind sharing id love to see a demo on how the knurling was done with taps,very nice work!
 
If you do a search in the Practical Machinist's forum,I did a complete(with several bad pictures!) posting on "making Knurls".add my name and I'm sure it will come up. I need to do it here,but that post took some time. I'll try to post it here when I'm able.

I don't mean to be advising viewers to go to other fora,I just realized.
 
Last edited:
Back
Top