Fixing Manual Mill Spindle - No Contact Between The Taper of Tool and Spindle

[GBWM]

Hello. Recently I've had problems with a cheap manual mill I bought for my workshop. I wasn't able to fit MT4 tools - these didn't want go deep enough so the taper fits properly. Check out how I solved the problem. What do you think of this solution? Maybe it will give someone an idea how to deal with such issue.

[tonyfoale]

I did something similar to covert an R8 mill spindle to an ISO 30 taper. I rotated the head to half the included angle and bored the spindle using the vertical table/knee feed. It would not work using the quill feed, that would just bore a parallel hole regardless of the angle.
It is important that the tool edge is set on the centreline, the equivalent of setting tool height on a lathe.

This method ensures good concentricity, better than removing the spindle and cutting the taper in a lathe where there will always be some runout.

The same technique can also be used to repair a damaged R8 taper.

[DIYer]

Thanks GBWM! We've added your Mill Spindle Modification to our Milling category,
as well as to your builder page: GBWM's Homemade Tools. Your receipt:

Mill Spindle Modification by GBWM

tags: mill, spindle, modification

[GBWM]

I did something similar to covert an R8 mill spindle to an ISO 30 taper. I rotated the head to half the included angle and bored the spindle using the vertical table/knee feed. It would not work using the quill feed, that would just bore a parallel hole regardless of the angle.
It is important that the tool edge is set on the centreline, the equivalent of setting tool height on a lathe.

This method ensures good concentricity, better than removing the spindle and cutting the taper in a lathe where there will always be some runout.

The same technique can also be used to repair a damaged R8 taper.

That had to be an interesting operation. Do you have any video of the process?

[tonyfoale]

That had to be an interesting operation. Do you have any video of the process?

No video nor photos and I do not even have that mill now.

[GBWM]

No video nor photos and I do not even have that mill now.

That's unlucky. But thanks for sharing the idea!

[TrickieDickie]

Use WD40 or kerosene when cutting aluminum

[GBWM]

Use WD40 or kerosene when cutting aluminum

Sometimes I use WD40. Is kerosense any better than WD40 or the effect is similar?

[tonyfoale]

Sometimes I use WD40. Is kerosense any better than WD40 or the effect is similar?

TapMagic is great on Aluminium. WD40 also have a dedicated fluid for machining in addition to their traditional (W)ater (D)ispersant 40.

[MasterMaker]

Sometimes I use WD40. Is kerosense any better than WD40 or the effect is similar?

Would stay away from WD40 for anything with enough cutting-force to create smoke...

When I started out I used it and fairly frequently I would get these crazy heart-palpitations with my heart beating at a mile-a-minute and so hard I could properly feel it when I put my hand on my chest, stopped using WD40 and it went completely away...............

So it would appear that once you heat WD40 past it's smoke-point some kind of CNS active compound is created............