How to divide an inch in one thousand


#1

I would like to print a ruler to put around a wheel and divide that wheel in exactly 1000 unit. It’s for the knob on a lathe. My knob is actually 2 inches diam. I would like to make a new one bigger say 3.5 inches.
I would like to print this rule 3.5 x 3.1416 x 1/2" wide
Each thousand line should be higher than the thousand. And I would like to print the 5 and 10 thousand by there relative number i.g. 5 10, 15 etc.

Is this is possible to be done accurately

thanks

Robert


#2

Sure. It’s possible to draw that. It’ll be tedious putting in the numbers. You’ll have to settle on the knob diameter and divide the circumference into 1000 parts. Basic math. After you figure out the spacing, draw a set of lines with larger marks for the major divisions. I would draw the lines between two major divisions and then just copy that in a linear array.

Doing it accurately in SketchUp won’t be a problem but printing it accurately might be an issue. Depends on the printer.




#3

Just use 9 lines and 10 spaces between intermediate marks. :smile:

Shep


#4

Shep, what are you on about?


#5

With sketchup there is almost always more than one way to do something. Here’s a knob 3.5" in diameter with 1000 lines then I added the 5/1000 line. It’s a start! If this approach interest you I’ explain how.


#6

Greg, now flatten that out so it can be printed on paper and wrapped around the knob. :wink:


#7

Give me a minute while I work on it


#8

I think getting a fine enough printer will be more difficult than making the drawing.
Not sure I would bother in SU though when a 2d program would probably give a better result and perhaps even automate the numbering.


#9

I think Box might be right. But here’s the JPEG anyway


#10

I assumed from the start that the @Patoine was talking about 3D printing a new, larger nob…

If attempting to print a simple 2D scale acutely you will need to account for printer stretch and drift…

A vector image printed across the page will have less discrepancy then one printed length wise…

john


#11

So how did you do that? Did you flatten the cylinder or did you just take the easy way and draw it flat from the git go as I suggested?

And Box and John have reiterated better what I was trying to say about printing it.


#12

I calculated the circumference and drew it out flat in SU.


#14

BTW: I often attach a magnifying glass when a lath’s scale is to small for my eye sight…
you can even get them with led illumination built in…

john


#15

John, you might look into a digital read out for your lath I just looked and found one for $23.00 on Ebay. under DRO. In the mean time your question is good because finding the solution helps us learn more about SU


#16

Thanks to all of you for your answers.
First I must apologise even if my question return some funny answer. I deserve them.

In fact, I don’t need to divide an inch in thousand line. A normal knob is divided into 200 lines representing 1 thousand of an inch, It take 5 turns to move a table a complete inch.

here is what I try with no big success

With Parallell camara and top view I first trace one vertical line and copy it 3 inch apart and use the command 200s
The final count is not 200 lines exactly. its something like 210.

The length is not three inch it’s more six or seven inches.

I won’t be able to warp it arond my three inch knob,

But I was able to print the numbers
it look like this

How should I Proceed ?

Thanks


#17

Figure out the circumference of the knob. Divide that number by 200. That’s the interval spacing you need between the lines. Draw a line for the first index mark, select it and Move/Copy it by the interval you calculated and then hit Enter. Immediately type x199 to get a total of 200 marks.

Or try this. Draw a line the length of the circumference of the knob. Right click on the line and select Divide. Type 20 and hit Enter. This will give you the spacing for the index lines.

Then draw the first 10 index lines off those points. I turned on Endpoints in the style setting and set them to 3 so they can be seen. Then copy the nine index marks shown selected with Move/Copy making enough to reach the opposite end.


#18

Thanks,
what about the print length. Is there a way to print exactly three inches?

Regards


#19

As for printing to scale, it can be done if the paper is long enough. To go around a knob the size you were referring to in your first post, you’ll need about 11" of marks.

You’ll have to set up a standard view and parallel projection. Then you should be able to set up in Print or Print Preview for the 1:1 scale.

This shows the setup on my computer. I don’t have a printer attached and can’t set it up for paper to handle the length on one sheet so it shows 2 sheets. It would be easiest to do this in LayOut, though, but you need SketchUp Pro for that.


#20

The circumference of a 3-1/2" knob is 3.5 * PI ~= 10.995574. In order to avoid cumulative error, start with a line of this length and divide it into 200 segments. There are 41 of the long tick marks and 40 groups of four shorter ones:


#21

Super but I will try it. I don’t understand the first part of choosing the arc too and divide it i 7 segment. I have to learn that. Is it because we are in 2D mode that ti shows that recti line I will try that.

Thanks