Lathe chuck backing plate woes

[Nubble]

So I recently bought a backing plate from a company called Shars and I started the machine it the way it the directions said which resulted in a good fit on the front face of the backing plate with no run out but when I flip it around to machine the back the entire backing plate has quite a bit of run out... And I have no idea how to fix it... This link takes you to a video of the problem because it's too big to upload on the website...

https://imgur.com/a/NFI6TQH

 

[Jimsehr]

If the plate runs true on the front side that is all that matters.
You should not worry about the back .The back will Not run true if you just screw it on the spindle. So if the front has no runout you are good to go.

 

[Batmanacw]

Screw it on, turn it, run it....the back is irrelevant.

 

[Nubble]

If the plate runs true on the front side that is all that matters.
You should not worry about the back .The back will Not run true if you just screw it on the spindle. So if the front has no runout you are good to go.

All right thank you I'm still very new to this so I wasn't sure.

 

[markba633csi]

Also, since I also have a Shars chuck: they give you a lot of extra length on the backing plate hub. I actually cut about a 5/8" piece off
mine with a hacksaw before doing the final machining to help tuck the chuck in closer to the headstock. It's optional of course.
You can flip it around and install it backwards to machine it but you need to make a spacer first- I made one out of 1/8" aluminum

 

[Nubble]

Also, since I also have a Shars chuck: they give you a lot of extra length on the backing plate hub. I actually cut about a 5/8" piece off
mine with a hacksaw before doing the final machining to help tuck the chuck in closer to the headstock. It's optional of course.
You can flip it around and install it backwards to machine it but you need to make a spacer first- I made one out of 1/8" aluminum

Well that's something I certainly could do. Using a spacer didn't even cross my mind.

 

[Jimsehr]

OWell that's something I certainly could do. Using a spacer didn't even cross my mind.

If it runs true I would not mess with it. Wait till you have more experience.