Drawing Ellipses

[IndyTom]

I am about to pull out the very little hair I have left. I am trying to get my walls ready to cut out and tried drawing my first elliptical arcs tonight. I was using screws at the loci, and some steel wire to make my loop. I could not get it to come out right.

Can anyone shed some light on this for me?

Tom

[Miriam C.]

Tom, Andrew has a how to on his website.

http://www.angib.pwp.blueyonder.co.uk/t ... tear80.htm

Enjoy

[bdosborn]

Here you go:
clicky to Andrews Site

I used the info to make an ellipse on the rear of my trailer and it worked great.
Bruce

[bdosborn]

Doh! 4 minutes too slow!

Bruce

[Sonetpro]

Tom,
When I did mine I bought these little pulleys from the hardware store. I ground the pin off and had 2 nice roller bearings. I just screwed the wheel to the loci and used 12 ga stranded wire it was more flexible than the steel wire. It rode in the wheel concaves perfectly and made a smooth elipse.

[bdosborn]

I am about to pull out the very little hair I have left. I am trying to get my walls ready to cut out and tried drawing my first elliptical arcs tonight. I was using screws at the loci, and some steel wire to make my loop. I could not get it to come out right.

Can anyone shed some light on this for me?

Tom

I just used a piece of string instead of wire. It took me awhile to get the ellipse in the right spot but drawing wasn't a problem.
Bruce

[Dean in Eureka, CA]

Tom,
Definately use Andrew's guide and be sure you are doing your calcs correct to get the loci points and have them on the correct axis. (Major I think)
A piece of plumb bob string worked fine for me, although keeping the correct tension on the string line when swinging the big rear elipse was a bit dicey.
After you get your arcs drawn, it might be a good idea to check them and fair them, if neccesay, with a batten and some small brads.
Cut out just proud of the line with a jig saw and belt sand them into shape, but use care that the edge is at a 90 degree angle to the surface when using the belt sander. I made a hand sanding jig to do fine touch ups here and there after using the belt sander...
BTW- That was for the template.... Once I had that, I used it as a router guide and a router to to trim my walls into shape.
We wanna see pics by the weekend.

[angib]

Yup, biggest problem with drawing ellipses is stretchy string. Using metal wire seems an extreme reaction, but then I've never tried it.

Andrew

[IndyTom]

OK, I feel sheepish. I knew I had seen a tutorial on drawing ellipses but had completely forgotten that it was on Andrew's site. And to think, it was discovering Andrew's site by accident that started this insanity.

Sonnet Pro, I new I had seen some sort of roller, so thank you for reminding me.

Andrew, The steel wire was left over from the electified fence I had to put up to contain my overly enthusiastic beagle, and was what I had handy in the garage.

I will pick up a couple of the pullies and some stranded wire later today.

Tom

[Mark72]

Tom, your not the only one that was sucked in by Andrew's wonderful website! It sure takes all the hard figuring out of it! Thanks Andrew!

Mark

P.S. I used twine to draw my eliptical arc, It dosn't have the strechy properties that nylon string has.

[IndyTom]

[quote="Mark72"]Tom, your not the only one that was sucked in by Andrew's wonderful website! It sure takes all the hard figuring out of it! Thanks Andrew!

Mark

The strange thing about it Mark, is that I was looking for sailboat plans when I came across Andrew's site. Building a camper was something that I had never thought of.

Tom