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Working on my South Bend 9C

Pretty sure I even remember the simple math! My questions are more about how to account for the work holding aspects. I'll try to draw it up later.
 
Golem Pens said:
I really need a phone holder, but if I'm reading this right I'm under .0005" TIR?
Click to expand...

Wonderful! I bet you are happy!

If you don't mind, I'd like to convey a few thoughts about how to use a DTI. It prolly won't make your numbers worse - and actually it might even make them better! It's a recommended process thing.

The needle of a DTI should not be dragged sideways. The best way to use them is to drag the needle away from the indicator as closely as possible.

Turn the indicator body sideways and tilt it inwards so that the needle drags lengthwise along the circumference on the inside of the taper. On inside tapers like that it can't be perfect, but you should try to make it as perfect as possible.

The needle shaft itself should be as close to tangent to the point of contact as possible and the surface friction of the taper on the needle should be trying to pull the shaft out of the indicator body.

Also, remember that DTI's are relative measurement devices. They don't give absolutely accurate readings. Only approximate readings. Less runout is always better than more.

Try it! And post a photo so we can see it!
 
I am very happy with the state of things! Lots of pieces have fallen together this week, including some not here. I feel like I may be close to production ready again.

Thank you for the info on using a DTI properly, I shall adjust accordingly!

Hopefully tomorrow I'll get going on the next iteration.
 
Susquatch, thanks for the primer on the DTI.
This old machinist has always used a dial indicator (i have 3) for all my setups.
The DTI, also the offset boring head are pretty new tools to me.
Even in old age, i continue to learn.
 
Model Citizen said:
jcdammeyer, was the hole you were boring that wasn’t accurate in delrin?
Click to expand...
No it was Bambu PA-CF which is a PLA laced with carbon fibre. Both holes at each end had tree support and support filament so the support came off easily enough but instead of nicely round it wasn't Not sure why.

Currently printing this in PLA. Has 3 degree taper and was resized by 3% to handle shrinkage. Is a pattern for a metal version of the plastic one.

1774325973402.png
 
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