Generating division plates from scratch

[John McNamaraParticipant @johnmcnamara74883]

If you want to mark a certain number of divisions along a specified length The old tilt the ruler method works. I have used it but it is not very accurate, finding the exact intersection of two lines not at right angles creates a fuzzy intersection. You often see it in woodworking books.

You could make a tape to match a certain diameter then wrap it round. >**LINK**
Not for me, too many measurement transfers and possible errors, but doable.

Regards
John

[BazyleParticipant @bazyle]

I thought the OP had either left out a whole paragraph by mistake and would fill in in due course, or more likely, as with so many engineers, is just not the most proficient at expressing himself.

I have 3 methods to meet Jason's challenge, but am stuck on how to actually mark the plate without using any marking implement. I'm wondering if allowing birds to 'paint' it white initially and then scratching the marks with a twig is permitted, owing to the similarity of a twig to a pencil.

[JasonBModerator @jasonb]

My method may work at least for 12divs but will need an extra step.

Well my thoughts were that we would not be making dividing plates without a dividing head or rotary table to put them on, not allowed to use div head  so why not use rotary table. Now I'm sure that if I suggested using the scale on the side of my rotary table you would all say that is not accurate enough as there is backlash, thickness of the engraved lines and it's far eastern origin to throw things out. So how about this method.

1. Take a blank dividing plate and poke a hole in it anywhere you want.

2. Mount this plate inplace of the handle, fit the detent and quadrants if you like.

3. Fit a second blank plate onto the table of the rotary table (no mention we were limited to number of plates)and with the detent in the hole of the first plate spot drill and then drill through.

4. Give the detent 45 full turns and drill another hole. This gives us a 2 hole division plate

5. Take off the one hole plate and replace with the newly made 2 hole one and fit a third blank plate to the table

6. So with detent in a hole drill your first hole in the third plate.

7. Now 12 divisions equals 30degrees per division. So give the detent 7 full turns and a half turn so it ends up in the opposite hole (7×4) = (1×2) = 30

8. Repeat for the remaining holes.

 

No measurements, no marking out, no use of a calculator, DRO, CNC and NO RULER

 

I too would like to hear the OP's method and see it applied to other divisions, not just the easy ones, what about 47 divisions for example?

 

 

Edited By JasonB on 16/06/2016 15:27:30

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Alan Johnson 7 on 16/06/2016 11:13:30:

As was said along time ago by very wise men: "there is nothing new under the sun." Look at Roy Smalley's article in MEW 157 "Dividing on the Lathe." No pencil or rule used!

Alan

.

… or you could even refer back to Michael Gilligan's 1993 article in Model Engineer 😇

But of course, I defer to Euclid.

MichaelG.

[duncan webster 1Participant @duncanwebster1]

Engineers only solve problems when they need to. If the OP had a dividing head or rotary table he'd use them, so we must assume he hasn't. In which case he doesn't need any division plates.

Edited By duncan webster on 16/06/2016 16:17:53

[Michael GilliganParticipant @michaelgilligan61133]

Posted by duncan webster on 16/06/2016 16:17:30:

Engineers only solve problems when they need to. If the OP had a dividing head or rotary table he'd use them, so we must assume he hasn't. In which case he doesn't need any division plates.

.

Clockmakers, Woodturners, and many more I'm sure, often do 'dividing' on their plain lathes.

MichaelG.

[duncan webster 1Participant @duncanwebster1]

Yeah but they are using the lathe as a dividing head, so use it to make plates via one of the many excellent methods detailed elsewhere

[Michael GilliganParticipant @michaelgilligan61133]

I think we're getting rather 'Chicken & Egg' now, Duncan

MichaelG.

[still waiting for John Fielding to show his hand]

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