How to get a program to accurately print circles of various diameters?

[dennis thompson]

I am making a birdhouse in the shape of a lighthouse which is circular. I don't have a lathe so I'm making 1" thick circles , reducing each one by 1/8" in diameter. I have to make about 15 of them. I can draw the circles with a compass but I'd like to draw the circles on a computer to increase the accuracy of the circles. I found a program to do this but when I print out the circle it's never the right size. Can anyone tell me how to draw and print out ,accurately,circles of varying diameters?
Thanks

[Bill Dufour]

can't be done. That is why blueprints have every dimension marked. paper expands and contracts with humidity. Many inks are water based. Toner fuser heat will also cause differential movement.
Bil lD.

[Frank Pratt]

Check the printer settings to make sure there is no scaling. I've used a number of different programs and printers to generate to-scale images and they were very accurate. Except for an old HP inkjet that always printed things a little small.

[Pat Barry]

Use compiter software to make a 4 inch circle (larger is better)
Print it out
Measure it
Develop scale factor, for example your 4 in circle is actually 3.5 inches. You need to scale up so 4/3.5 is your scale factor = 1.1428
Multiply your desired circle diameter by the calculated scale factor and use the computer software to make your x diameter circle scaled up by your scale factor, so, for example you want a 2.5 inch diameter, multiply this by your scale factor, and use the result for your scale corrected diameter, ex 2.5 times 1.1428 is 2.857 inches.

[dennis thompson]

Use compiter software to make a 4 inch circle (larger is better)
Print it out
Measure it
Develop scale factor, for example your 4 in circle is actually 3.5 inches. You need to scale up so 4/3.5 is your scale factor = 1.1428
Multiply your desired circle diameter by the calculated scale factor and use the computer software to make your x diameter circle scaled up by your scale factor, so, for example you want a 2.5 inch diameter, multiply this by your scale factor, and use the result for your scale corrected diameter, ex 2.5 times 1.1428 is 2.857 inches.

Pat
Thanks for the advice, I had tried that and after about 20 tries with no success , I went back to my compass

[Lee Schierer]

I use DoubleCad XT to draw circles. Make sure your print settings are set at 100% and hit the print button. The print out will be plenty accurate for woodworking. You can attach the paper to your wood with some spray adhesive. If you are making multiples of the same size you can glue your paper pattern to tablet backing.

[Alan Caro]

dennis thomspn,

The only method I use to print objects accurately to size is to use the PLT command- plot in AutoCad in which the drawing is done to size by selecting the circle tool, set the center point, type in the radius or diameter- accurate to the desired number of decimal points. To print, select 1:1 in the Plot dialog box and it will print on the plotter of printer quite accurately to size. Many times I've printed house plans on 11" X 17" sheets and the scale is accurate enough to scale dimensions to a useful accuracy. I think that versions of CorelDraw - which can be used to control a CNC, and possibly Adobe Illustrator have the ability to print accurately to scale.

Overall though I think a careful application of the compass is faster, directly on to the birdhouse facade, so there's not the additional step to transfer it. If you have a ground steel rule that has the marking engraved, set the compass point on the 0 groove and having a really good bevel point on the lead, set the radius.

I find making any hole smaller than I can get my hand into ends up really a mess as even very fine, narrow jig saw blades meander around a bit and have to be finished considerably. Consider a set of hole cutters 1/4" increments and, sand out to the compass line.I'm getting ready to make a music production /computer desk and the panel cutouts which are either triangles with the side connected by a radius or alternately simply circles. All the curved cuts are planned around standard-size hole cutters.

411760

411761

The alternative plain one:

411762

In any event- not fine woodworking!

Alan

"Measure twice, saw once, sand to fit"

[Grant Wilkinson]

I'm not sure why you believe that your compass in not accurate enough, nor why Bill says that it is impossible to use a computer application. I can draw circles and have them print to the size that I specify using Sketchup, Photoshop and Paint Shop Pro. I'm sure that there are many others available. I would stick to drawing them with a compass directly onto the wood - no paper template needed - and cutting them out.

You could use a router on a home made tremel to get them perfectly round. That way, you don't need t draw them before hand with anything.

[Stan Calow]

plastic template from Office Depot? Thats what I've used.

[Dave Cav]

https://www.amazon.com/Jasper-200J-Circle-Cutting-Plunge/dp/B00009K77A

[Kev Williams]

It's easy, really ;)

I do watchback refurbs using my fiber laser, my elcheapo Canon printer/scanner and Corel.

My customer sends me a resurfaced back and a pic of the watchback prior to refinishing. I put the watchback on the Canon flatbed scanner, and the scan goes into Corel. I then resize the photo best I can and superimpose it onto the scan of the watchback. Then using available lettering and hand digitizing I superimpose new lettering and artwork onto the scan and pic. When I'm finished the result is a near verbatim copy of the original...
411765411764
My point is, basic scanning with a cheap printer into Corel gives me accurate size results. On these jobs, I simply had to line up the new engraving to the backs, no resizing was necessary.

I just sent a 2" circle I drew in Corel to my Canon (inkjet) and my Samsung (black only laser)
411766411767
-- 2" in, 2" out, +/- .005", which is well within standard engineering tolerances for 2 decimal dims...

Doesn't need to be Corel to draw a good circle, plenty of free graphics programs to download :)

[Larry Frank]

I do this with PowerPoint and a Brother Laser Printer. It is very accurate.

[Larry Edgerton]

Make a sub-base for a router and space the holes in the sub-base to what you want, use a tilt base router if you want them angled. Once you have the setup perfected you can make them into perpetuity all sized exactly the same with no markings at all.

[Frederick Skelly]

I do this with PowerPoint and a Brother Laser Printer. It is very accurate.

That's what I was thinking too.

[roger wiegand]

For representational purposes I use the computer, adjusting as others have described to get the printout to correspond to the size I actually wanted. For actual accuracy in the shop I use either a compass or trammel points on a straightedge for bigger circles. I don't have any technology that would let me cut a wooden circle to greater than 10 thousandths in accuracy, so a knife line or sharp pencil is fine. (nor do I have any wood that would retain that level of accuracy for any period of time with changing temp and humidity).

[Jim Koepke]

I am making a birdhouse in the shape of a lighthouse which is circular. I don't have a lathe so I'm making 1" thick circles , reducing each one by 1/8" in diameter. I have to make about 15 of them. I can draw the circles with a compass but I'd like to draw the circles on a computer to increase the accuracy of the circles. I found a program to do this but when I print out the circle it's never the right size. Can anyone tell me how to draw and print out ,accurately,circles of varying diameters?
Thanks

It appears you may be over thinking this.

My suspect popped up in one line:


I found a program to do this but when I print out the circle it's never the right size.

Not knowing what program it can not be said for sure, but my guess is it might be the software.

Using a compass to draw ~15 circles increasing in size by 1/8" diameter (1/16" radius) would be quicker than reading this thread.

jtk

[dennis thompson]

It appears you may be over thinking this.

My suspect popped up in one line:



Not knowing what program it can not be said for sure, but my guess is it might be the software.

Using a compass to draw ~15 circles increasing in size by 1/8" diameter (1/16" radius) would be quicker than reading this thread.

jtk

Jim
You are absolutely right. I bought a good compass for $4 and made everything I needed, I certainly did over think it.😊

[Pat Barry]

Jim
You are absolutely right. I bought a good compass for $4 and made everything I needed, I certainly did over think it.😊

Ok, great, but the question in the thread was "how to get a program to accurately print circles of different dimensions?"

[Jim Koepke]

Originally Posted by dennis thompson
Jim
You are absolutely right. I bought a good compass for $4 and made everything I needed, I certainly did over think it.��


Ok, great, but the question in the thread was "how to get a program to accurately print circles of different dimensions?"

Yes, though sometimes it is simpler, and wiser, to stop trying to walk through a brick wall and instead choose a way to go around.

jtk