SX2p mill taper extraction

With the SX2p mill to extract the taper the drawbar needs a tap with a copper mallet, over time I know the exact tightening required to hold the taper.

Over time this must do the bearing some damage with the knocking required for extraction.

I made a tool which works well but gives such a crack I am wondering if I will be doing more harm than hitting the drawbar.

Any advice please, Bob.

I have an SX2P, which is now nearly three years old, and always strike the drawbar with a hammer, and sometimes not too lightly. Original ball bearings are still in place and no sign of wear or damage to the raceways. The tool you have made will split the tapers but since both are soft some damage may be done to the end faces were you contact. these face don't come in contact so it will only be cosmetic. I have always struck tapers to separate nd will contuse to do so.

A couple of wedges would provide pressure all across the faces of spindle and holder. Easy to make or Arc supply them at reasonable cost. You could drive them in with a G clamp...

Edited By not done it yet on 03/01/2019 14:26:29

I reckon concern about bearing damage due to striking the drawbar is overstated. There are plenty of examples on the web and in old magazines written by chaps concerned this might do damage, but I've not seen anyone confirm anything bad really happens. If it did the world would be full of people mending their mills!

I think that - done properly - most of the energy from a hammer tap is consumed breaking the taper friction rather than hammering on the bearing. And any excess when the taper gives ends up in the chuck or tool, not the spindle. I imagine a shock-wave travelling down the drawbar looking for the path of least resistance. This is most likely to be the taper joint. The speed of the tap is important - if the taper isn't dislodged a lot of slow pounding on the drawbar could damage the bearing.

Hitting the drawbar doesn't worry me at all, but I take care not to overtighten it. On my mill hand-tight plus about a quarter turn with a spanner seems enough to stop the tool spinning in the spindle even under heavy loads, and it releases with no trouble. A drawbar tightened by an angry gorilla or locked by corrosion would be more dangerous to the bearings.

Dave

I've been hitting my X3 for about 11yrs now and my balls seem fine, infact apart from when it first arrived I've never had to adjust them and it gets a fair amount of use.

What is the top cap made from on the SX2P? The one on the SX2.7 is metal and it was not releasing the R8 tooling until right at the end of the drawbar thread, a very simple mod and it will now release after about 1.5 turns of the drawbar.

The Wedges that ARC do won't fit a MT or R8 spindle they are made for smaller B and jacobs tapers so you can get chucks off arbours

Edited By JasonB on 03/01/2019 15:30:25

I have no problems with mine at all, just a turn of the drawbar and a light tap with a hard rubber mallet and it releases.