MT4 Adapter spun in spindle, how do I clean up the spindle taper?

[WobblyHand]

I was using an MT4 to MT2 adapter in the spindle of my G0752Z/G0602 lathe to machine an MT2 soft arbor. It appears the MT4 adapter spun in my spindle. Not only was the adapter gouged, but the very nose of the taper appears to be all roughed up. I'd bet that the taper adapter is wrong, I'll blue it and check. Obviously, I'm more concerned about the spindle. The damage appears to be confined to the very edge of the spindle. What is the best way to clean it up?

Those dark areas in the spindle are rough and sharp. As I said, the damage is at the very edge. Is this just a round stone job to flare it out? Or? Not even sure I want to try inserting the adapter again, even after stoning them, but I guess that's the only way to know if the taper adapter is off spec. Of course the Grizzly could be off spec, but I would think the adapter is the more likely culprit. There is no other evidence of any other contact scarring on the adapter or deeper in the spindle.

 

[mikey]

Just grind or sand the defects off. It should not affect the fit in the taper. I would toss that adapter, though.

 

[WobblyHand]

Just grind or sand the defects off. It should not affect the fit in the taper. I would toss that adapter, though.

Yes, this adapter is making me unhappy. I had this go while I was parting a soft arbor, contributing to my woes. Wasn't a happy time.
The MT2 taper held, but not the MT4. Know of a place to get an adapter that is a reasonable value?

 

[Dabbler]

You have spin marks in your taper. You *could* buy a MT4 finish reamer and using your tailstock, ream the headstock very lightly to remove the gouges visible in the photograph. It looks like someone previously has spun an adapter in the headstock, or that there was a few pieces of swarf in the headstock when machining your taper. The face is only cosmetic - that would take completely different operations to do properly.

This adapter needs stoning to remove the swarf and the gouge. You still have a lot of very good finish in it and should be usable for many years.

 

[WobblyHand]

You have spin marks in your taper. You *could* buy a MT4 finish reamer and using your tailstock, ream the headstock very lightly to remove the gouges visible in the photograph. It looks like someone previously has spun an adapter in the headstock, or that there was a few pieces of swarf in the headstock when machining your taper. The face is only cosmetic - that would take completely different operations to do properly.

This adapter needs stoning to remove the swarf and the gouge. You still have a lot of very good finish in it and should be usable for many years.

When I inserted the taper, I cleaned both the spindle inside and the taper by wiping them with a paper towel, deep into the bore. The taper prior to this looked very clean, because it was brand new and unused. I know I haven't spun a taper before in this lathe as this is the only taper I have ever inserted into the spindle. I am pretty sure the damage was not there prior to this, because I do remember inserting my finger in the taper bore and not feeling any rough spots anywhere, including on the edge. I think this is new damage caused by me using this adapter. If you look carefully, there are tiny pieces missing in the spindle, they fractured at the edge. I will end up stoning the inner edge by the taper to smooth out the sharp burrs. There were NO burrs before.

As for the adapter, I may clean up the surface and blue it to check for fit. I wouldn't be surprised if there's practically no contact, save for near where the damage occured. If this is the case, this adapter will find some other use, perhaps as ballast. If by some chance there's some reasonable contact, maybe I will use it again. Kind of hard for me to trust it at this point.

 

[SLK001]

Use your fingers and find high spots, then use a stone to remove them. I'm assuming her that the spindle is very hard. This type of spinning is usually done when the taper is not properly seated (it was coming out during operation).

You might also want to check that your spindle is really an MT4 and that the adapter is also.

 

[tq60]

Grab a handy permanent marker and paint the taper fully.

Slide in gently until it stops.

Smack it in with a 2x4.

Remove and inspect.

Where no ink it mating, ink left not.

Sent from my SM-G781V using Tapatalk

 

[RJSakowski]

You can check the spindle taper with the MT4 center that came with the lathe. I would blue the taper to check. If it checks OK, repeat with the adapter after it is cleaned up. That should tell you where the problem lies.

 

[mmcmdl]

Your spindle has no way of locking the tang hence it spun . Clean up the damage on both and keep the reducer for use in a MT4 lathe tailstock . Not a big issue .

 

[mikey]

Yes, this adapter is making me unhappy. I had this go while I was parting a soft arbor, contributing to my woes. Wasn't a happy time.
The MT2 taper held, but not the MT4. Know of a place to get an adapter that is a reasonable value?

Personally, when I need to put something inside my spindle I am looking for quality, not cost. I don't use adapters but if I did I would maybe opt for something from a known good maker, like this one.