Metric or Imperial

[ZiggarParticipant @ziggar]

try this

http://www.cgtk.co.uk/metalwork/linear

a few other neat tools on there too

Z

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 17/11/2013 12:27:56

can set to do 50mm radius but where do you set 100 units ?

John,

Sorry; I should have clarified … These are designed as "Setting Circles" [primarily for telescopes, etc.] and, by default, they are calibrated in degrees, from 0-360.

Unfortunately the free version doesn't allow much manipulation … but you can get 0-100 markings by cheating a bit.

There isn't room on an A4 page to do 50mm radius, but this works OK for 40mm.

40 x 3.6 = 144 so tell it to use 144mm radius; set the paper size to A4 portrait; and the Y-origin at 25mm [to just clear the footer text] … The print will effectively spill off the top of the page, leaving 100 available to wrap round a 40mm drum.

Nice clean pdf … without registering on the site.

Probably not much use if Graham needs 50mm radius; but at least it demonstrates the concept.

MichaelG.

[Oompa LumpaParticipant @oompalumpa34302]

Actually Michael, the diameter of the graduated wheels is 38mm so 19mm radius. How would that work?

Thanks again,

graham.

[Michael GilliganParticipant @michaelgilligan61133]

Hi Graham,

Hadn't realised they were titchy scales !

Go to the Linear Scales page, and have a look at the drop-downs for:

• Basic Options
• Paper Options
• Formatting Options

All the items that have not got a "Gold" mark are freely useable.

Put 68.4 mm [ i.e. 19 x 3.6 ] for the radius, and whatever scale width you want

Maybe change the Font size to about 8 point.

The first 100 should wrap neatly round your dial.

MichaelG.

[John Stevenson 1Participant @johnstevenson1]

Where does the 3.6 come from ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 18/11/2013 00:06:55:

Where does the 3.6 come from ?

.

360 degrees in a circle

Default scale shows 360

We want 100

360 / 100 = 3.6

Make the scale for a "bigger dial" and use just the first 100.

MichaelG.

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Michael Gilligan on 18/11/2013 00:00:50:

Hi Graham,

Hadn't realised they were titchy scales !

Go to the Linear Scales page, and have a look at the drop-downs for:

• Basic Options
• Paper Options
• Formatting Options

All the items that have not got a "Gold" mark are freely useable.

Put 68.4 mm [ i.e. 19 x 3.6 ] for the radius, and whatever scale width you want

Maybe change the Font size to about 8 point.

The first 100 should wrap neatly round your dial.

MichaelG.

And that Michael, has worked perfectly. Thank you for that. I will laminate them and stick them on tomorrow.

You never know, my headaches may stop!

graham.

[Michael GilliganParticipant @michaelgilligan61133]

Graham

Glad it worked for you …

Just one thing: I suddenly realised that 100 divisions is based on what John said

… I don't remember you mentioning the actual pitch of the screws !

100 divisions will be right for 10tpi … but for anything else we will need a different calculation.

 

Off to bed now.

MichaelG.

 

 

Edited By Michael Gilligan on 18/11/2013 00:33:35

[Oompa LumpaParticipant @oompalumpa34302]

Yes, I see that. It is actually 16 tpi I believe but to be honest, anything to get away from the fractions!

Thanks again.

[Michael GilliganParticipant @michaelgilligan61133]

16 tpi … I guessed it probably would be.

So; If you want to read directly in thousandths of an inch …

You will need 62.5 divisions on the dial. [*]

360 ÷ 62.5 = 5.76 and 5.76 x 19 = 109.44

So try making the "Setting Circle" scale for a radius of 109.44 mm.

The first 62.5 should wrap neatly round your dial.

MichaelG.

[*] Unfortunately, there is no easy way of "tidying-up" the fact that one full turn moves the slide 1/16"

[Oompa LumpaParticipant @oompalumpa34302]

[*] Unfortunately, there is no easy way of "tidying-up" the fact that one full turn moves the slide 1/16"

Michael, thank you very much for that.

Yes – it is messy but I will put up with it until Santa brings me a DRO

[Author]

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