making an ID lapping tool

In the process of building a spindle for an ID grinder the bearing seats in the housing had to be lapped. This video shows the fabrication of a lapping tool from cast iron (GG25 / EN-GJL-250) .

- intro 00:01
- turning and facing on Torsa lathe 01:16
- drilling 02:22
- boring internal cone 2:38
- test fit 04:20
- setup with dividing head on Thiel Duplex 158 milling machine 04:37
- drilling 05:49
- shaping with parting insert using the quill of Thiel milling machine 07:06
- purpose ground cutting tool 07:42
- shaping internal slots 08:00
- shaping external slots 11:00
- semi finished lapping tool 17:39
- setup for lapping bearing seats in spindle housing on Emco Compact 8 lathe 18:06
- lapping 18:06
- adjusting the lap 18:38

[mesuthan]

I would love to watch a video on lapping itself. Keep it up!

[Topsworkshop]

Harald, 5 stars on this one! you should definitely do more of these, I think a lot of us are more interested in "how" you do stuff, than just watching them go, I love watching machines work but your setup and process is so much more valuable, thank you!

[Machine_NZ]

Hi Harald, thanks for making this video and showng the process of how it was made. Cheers Kevin

[doncarr]

Thank you Harald for the information which you provided on the taper of the taper arbor. This information is very difficult to find as most people do not include any information on this aspect of the lapping tool.

[LeoNordin-cb]

This design is one of the few that actually works reliably for straightness i believe.
Designs that are not hinge or taper based will flex easily and the tensioning will not be perfectly straight.
Precision hinges feels expensive and worse for roundness/Precision overall. While the tapered design can be very accurate and stiff.

[marcostavares]

5 start english, Very nice work, Thank´s for sharing.

[bambukouk]

There is absolutely nothing wrong with your English and I prefer real human voice - thank you!

[HaraldFinster]

This is my first attempt to use spoken comments instead of subtitles.
I appreciate your feedback: do you prefer my bad simple English or should I stick with the captions?

[James-fsrn]

👍 looks like some fine German engineering.

[doncarr]

Harald: Can you tell us what degree of taper are you using on the taper arbor?

[deanfranks]

American English speaker you're more than capable.

[pablodiablo]

Amazing, have you ever made any in smaller diameters? Say 12mm? I`m considering it but no idea how to do the internal slots 🤔

[sto]

What is the difference between lapping and honing? Thanks.