Group Project: Dividing Head - The Build

[rwm]

I am working on the trunnion index marks. I have calculated the location of marks for a .032 thick piece of brass screwed to the trunnion. There is .396" between markings at 15 deg of rotation. I can scribe the lines on my mill but I can't engrave numbers. Stamping will deform it. Does anybody have engraving capability to add the deg numbers? (0, 15, 30, 45, 60, 75, 90) It would be on a flat sheet of brass about 3" long.

You know, in playing with my device, I can see that the index marks on the trunnion will be hidden by the spindle index when in the vertical 90 deg position. Placement of markings is limited by the slot for the gear. I am wondering if putting the index marks on the end cap for the aux base would be a better way to go? This end cap could be thicker than .250 to accommodate engraving. This would be much more visible in use and you could put the marks anywhere on the circumference. This cap could be keyed with a 1/8 dowel pin to assure correct alignment. This would be a lot like making a graduated dial.

 

[Flyinfool]

You could put the markings on the end cap. You would need 2 dowels for proper registration.
As designed the one end was for locking the trunion and the other end was just along for the ride, that is why it is .255 wide. When I was designing all this one of the options that I had thought about was to use a dowel pin on the end cap with a single bolt in the center that had a lever for a quick and easy release and tighten, but the parts count was getting pretty high so I just went with the screws. Besides like you said it not like you are continuously changing that, it is just part of the initial setup.
I was also playing with the idea of a veneer on the base to be able to split degrees.

Way back the person that signed up for the indexing plates did have CNC ability. I do not remember who that was. Have to go searching to see if he is still around and willing to do things.

Oh Oh!!!!!
I just had a thought........ Always dangerous.
It just popped into my poor little brain of an easy way to make the veneer plate.
There is a place that have used for making prototype printed circuit boards for pretty inexpensive. The vernier plate with its 9° line spacing, could be a printed circuit board. The lines could be etched in the copper, then paint it black to fill in the lines and then lightly sand off the paint to expose the copper but leave the paint in the lines and then clear finish so the copper does not oxidize and get ugly. It would have 2 mounting slots so that it can be precisely adjusted to Zero.
The lines on the end cap should not be to hard to engrave and the numbers could be stamped on the face of the cap so bending should not be an issue.

Oh yea I did change the marking that was on the trunion, I made it go from -10° up to 100°. Not so much for the added range but for use with the vernier.

 

[Flyinfool]

Oh No, another thought.
Would someplace like a trophy shop be able to engrave the numbers. They engrave plaques and trophies everyday.

 

[rwm]

Probably yes. I was thinking about that. Think they might struggle with the curved surface. I also don't think they could get the graduated marks at precise distances. But the marks could be made on my machines and then they could just engrave the numbers.

 

[Flyinfool]

That is what I was thinking, You machine the marks and have them engrave the numbers.
If you moved the scale to the end cap then they could engrave on the flat surface.
The end cap could even be made bigger diameter to get the markings spaced further apart (I am old and blind so I think of things like this.).

 

[rwm]

I think I'm gonna just do a few basic marks. I don't see me selecting angles other than 15,30,45,60,75,90. I can't see fitting 1 deg markings. 5 deg is probably possible but overkill for me. It might actually be helpful to inscribe the direct index plate. Its a shame we don't have access to a laser!

 

[rwm]

I made an adapter for ER32 to a small 3 jaw chuck. This has more stick out than I prefer so I will try to mount directly in the collet when possible. You can also see the coarse index marks I put on the end cap. I still need to pin it.



I also ordered those index plates from eBay. I hope the quality is OK.

 

[extropic]

Looking good.

 

[Weldingrod1]

You might put a ER tapered back shaft on the Chuck and pull it in with a draw bar to get shorter...

Sent from my SM-S911U using Tapatalk

 

[rwm]

Drawbar threads are in use. That would maybe get me 1/4" at most?