Bushings causing a burr

[Kebo]

I am experiencing a problem while turning slimline pen blanks. I'm using a mandrel saver. The problem I'm having is, on the tailstock end of the mandrel, the bushing is cutting into the mandrel causing a significant burr...to the extent I'm having trouble getting the bushing off the mandrel. Is anyone else having this issue and does anyone have a reason why or a solution for this problem. Thanks in advance.

 

[tomtedesco]

I am guessing here, but I would check. Mis-alignment with head stock and tail stock, too much tailstock pressure, bad bearings in saver, bent mandrel?

 

[egnald]

I used to have a lot of galling on the mandrel because of my bushings.
I think the following is what helped me:

Make sure your mandrel isn't already bent.

Use only enough tailstock pressure to keep the blank from spinning.

Make sure your tools are sharp.

Trim the corners (round the blank) using a sander or bandsaw before starting to turn, or make very light cuts when turning the corners off to reduce the tailstock pressure needed and to prevent the blank from spinning on the mandrel.

Of course, clean/polish your mandrel to eliminate any burrs or existing galling to start with.

Regards,
Dave

 

[Paul in OKC]

Are you having any issue with things spinning on the mandrel? Is the face of that bushing or the face of the saver rough? Could be coming from that.

 

[Charlie_W]

Do you square the ends of your blanks before turning ? If the blank ends are not square, it can cant the bushing and thus possibly cause your issue.

 

[Kebo]

I am guessing here, but I would check. Mis-alignment with head stock and tail stock, too much tailstock pressure, bad bearings in saver, bent mandrel?

Thanks for the reply. Alignment is perfect, bearings are good and mandrel is straight. I'll be conscious of the tailstock pressure and see if this helps.

 

[Kebo]

Do you square the ends of your blanks before turning ? If the blank ends are not square, it can cant the bushing and thus possibly cause your issue.

Yes.

 

[Kebo]

Are you having any issue with things spinning on the mandrel? Is the face of that bushing or the face of the saver rough? Could be coming from that.

The blanks have spun, but not excessively. I will check for roughness on the faces of the bushings and saver. Thanks for the reply.

 

[Kebo]

I used to have a lot of galling on the mandrel because of my bushings.
I think the following is what helped me:

Make sure your mandrel isn't already bent.

Use only enough tailstock pressure to keep the blank from spinning.

Make sure your tools are sharp.

Trim the corners (round the blank) using a sander or bandsaw before starting to turn, or make very light cuts when turning the corners off to reduce the tailstock pressure needed and to prevent the blank from spinning on the mandrel.

Of course, clean/polish your mandrel to eliminate any burrs or existing galling to start with.

Regards,
Dave

Thanks.